CALIFORNIA AGRICULTURAL EXTENSION SERVICE CIRCULAR 42 March, 1930 PEACH CULTURE IN CALIFORNIA E. L. OVERHOLSER and W. P. DURUZ Cooperative Extension work in Agriculture and Home Economics, College of Agriculture, University of California, and United States Department of Agriculture cooperating. Dis- tributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. B. H. Crocheron, Director, California Agricultural Extension Service. COLLEGE OF AGRICULTURE UNIVERSITY OF CALIFORNIA BERKELEY, CALIFORNIA 1930 Digitized by the Internet Archive in 2011 with funding from University of California, Davis Libraries http://www.archive.org/details/peachcultureinca42over PEACH CULTURE IN CALIFORNIA E. L. OVERHOLSEEi and W. P. DURUZ2 CONDITIONS AND PROSPECTS OF THE PEACH INDUSTRYs California produces all of the dried peaches and practically all of the canning- peaches in the United States. Only a small part of the nation's supply of fresh peaches, however, is produced in this state. The clingstone varieties are used primarily for canning, while the free- stone varieties are used primarily for drying and fresh consumption. Clingstones. — During the past several years there has been a pro- nounced downward trend in the prices paid to growers for clingstone peaches. The average price in 1927 and 1928 was $21 a ton as against an average of $46 a ton in 1921 and 1922. The chief reason for this decline in price was the enormous increase in the canned pack which has doubled in the last eight years. Evidently, consumers would not buy as many canned peaches except at lower prices. Because of the very short crop of peaches, as well as of competing fruits in 1929, the price rose to $70 a ton. It should not be assumed, however, that similar short crops or high prices will prevail on the average during the coming years. Unless many trees are removed or the orchards are much neglected the peak of production is not likely to be reached until 1931 or 1932. At that time it is probable that the trend of production will be about 15 per cent higher than in 1928. Until the present time, the increase in the total pack of canned peaches has been retarded by the steady decline in the quantity of freestones canned. An average of 1,714,000 cases of freestones were canned in the years 1919-1921, but only 321,000 cases in 1927, and only 164,000 in 1928. Evidently only a small further decline in the freestone pack can be expected, and in some years, as in 1929, it may even be expanded. Exports of canned peaches have kept pace with the increase in the pack. On the average, about 15 per cent of our pack is exported. Our most important markets for canned peaches are the United King- dom, Canada, Cuba, and France. Freestones. — As contrasted with the rapid increase in the produc- tion of clingstone peaches during the past seven years our production 1 E. L. Overholser, Associate Professor of Pomology and Associate Pomologist in the Experiment Station, resigned. 2 W. P. Duruz, Assistant Pomologist in the Experiment Station, resigned. 3 The discussion on economic aspects is taken largely from : Wellman, H. R, The 1930 agricultural outlook for California. California Agr. Ext. Cir. 39:12-15. 1930. 4 California Agricultural Extension Service [Circ. 42 of freestone peaches has actually declined. The production of free- stones during the three years of 1926 to 1928 averaged only 196,000 tons a year as against an a,verage of 227,000 tons during the three years 1920 to 1922, a decrease of 14 per cent. AH of this decline has been in canning freestone peaches. The output of dried peaches and the interstate shipments of fresh peaches have remained at approximately the same levels. If the downward trend in the pro- duction of freestones continues, however, and present indications are that it will, the production of both dried and fresh peaches in this state will tend downward. The available figures on the acreage of freestones in California indicate that a substantial decline is in prospect during the coming years. Of the 67,436 acres of freestones in 1929, 60,692 acres, or 91 per cent, were in bearing and only 6,744 acres, or 9 per cent, were non-bearing. Furthermore, 64 per cent of the present bearing acreage is 11 years of age and older. Since the average commercial life of a peach tree is only about 20 years it is evident that some decrease in acreage, due to old age, may be expected. From 1921 to 1928 the production of dried peaches has fluctuated around 23,000 tons. There has been no upward or downward trend in production during this period. Likewise there has been no upward or downward trend in the average prices paid to growers. Prices have fluctuated around 7 cents a pound, which was also the average price received in both 1927 and 1928. Exports of dried peaches during the past two years were larger than in any year since 1919 with the single exception of 1923. The propor- tion of our total dried pack exported has also increased, particularly during the past five years. Approximately 22 per cent of the 19*28 crop was exported, as compared with 19 per cent of the 1927 crop, 12.4 per cent of the 1926 crop, 10.3 per cent of the 1925 crop, and 9.5 per cent of the 1924 crop. At the present time Germany, Canada, and the United Kingdom are the most important foreign markets for our dried peaches. Production of fresh peaches in the United States is now at about the peak and present indications are that there will be a decline in the trend of production during the next few years. This decline, how- ever, is not expected to be rapid ; and whenever conditions are favor- able to high yields, heavy production and low prices are likely to prevail. 1930] Peach Culture in California 5 In the five states of Georgia, North Carolina, South Carolina, Ten- nessee and Arkansas commercial plantings in recent years have not been sufficient to maintain the present bearing average. The propor- tion of young trees in these five states is now much less than four years ago. In 1929 only 25 per cent of the trees were less than six years of age as again 67 per cent in 1925. In Georgia about 30 per cent of the trees that were in commercial orchards in 1925 have been taken out or abandoned, and plantings have only been sufficient to replace one- third of them. More than 80 per cent of the decrease in the number of trees, however, has occurred in the southern district from which the earliest shipments are made. The peach acreage for the United States in 1919 is shown in figure 1. CALIFORNIA PEACH DISTRICTS Sacramento Valley Bisirici. — Nearly every count}^ in the Sacra- mento Valley grows peaches. The soil and water conditions are such that the peach tree thrives, making a remarkably quick and vigorous growth and producing fruit of large size. It is not uncommon for orchards to begin commercial bearing at three or four years of age, and at five years to produce 15 tons of fruit per acre (see figure 7). Sutter County in 1929 had the largest bearing acreage in this district, with Placer second, and Butte third (Table 1). In Butte, Sacramento, Sutter and Yuba counties mostly canning varieties are grown. In Solano, Yolo, and Tehama counties, the varieties are mostly freestone, used either for drying or shipping. Placer County, located in the Sierra foothills, where the elevation and soil are favor- able for shipping varieties, has specialized in growing these kinds. During the past few years however, new plantings have been curtailed because of unfavorable returns to the grower. The principal pests in the valley sections are peach leaf curl, peach blight, powdery mildew, peach rust and the peach twig-borer. The foothill sections contend with fewer of these troubles having prin- cipally peach blight and peach twig-borer. 8an Joaquin Valley District. — The San Joaquin Valley is the greatest peach district in California, having about 45 per cent of all the bearing acres and about 40 per cent of the non-bearing acres. In 1929 Fresno County had the largest bearing acreage in this district followed in acreage by Stanislaus, Merced, and Tulare. On the other hand, Tulare County had the largest number of non-bearing acres, followed by Stanislaus and San Joaquin counties. 6 California Agricultural Extension Service [Giro. 42 Most of these sections are growing the drying and canning varieties, although a few produce shipping varieties. Atwater, Livingston and Denair, and sections in Fresno and Tulare counties grow peaches for eastern shipment. The bulk of the dried peaches of California are produced in the San Joaquin Valley; namely, in Fresno, Tulare, Merced, Stanislaus, San Joaquin and Kings counties, where climatic conditions are particularly favorable for the production of an excellent sun-dried product. In 1927 and 1928 comparatively few additional trees were planted. In addition to the necessity of controlling leaf curl, twig-borer, and powdery mildew, peach blight must be taken into consideration in the spraying program. Certain plantings have been found unprofit- able because of nematodes or alkali in the soil, or because of little-leaf. TABLE 1 Estimated Acreage of Peaches in Leading Counties of California Clingstone Freestone Total District and county Bearing acres Non- bearing acres Bearing acres Non- bearing acres Bearing acres Non- bearing acres Sacramento Valley District : Butte 3,773 2,188 3,235 22 17,741 181 734 3,764 2,168 884 1,314 5,972 3,876 8,770 5,488 2,100 3,716 5,931 80 4,075 609 69 163 3,586 100 52 579 156 162 63 59 983 1,176 1,774 156 259 251 18 350 1,569 6,217 600 2,539 439 1,481 1,869 29 12,688 3,585 1,965 3,486 2,430 3,209 3,278 2,211 1,030 3,101 1,285 7,681 138 280 94 333 131 514 77 3 200 300 20 516 268 347 1,212 225 150 616 128 1,192 5.342 8,405 3,835 2,561 18,180 1,662 2,603 3,793 14,856 4,469 3,279 9,458 6,306 11,979 8,766 4,311 4,746 9,032 1,365 11,756 747 Placer 349 Sacramento . 257 333 Sutter 3,717 Tehama 614 Yolo 129 Yuba 582 San Joaquin Valley District: 356 Kings 462 Madera 83 575 1,251 Stanislaus 1,523 Tulare 2,986 Southern California District : Los Angeles. 381 409 San Bernardino. . 867 San Diego 146 Other counties 1,542 Total 76,012 10,565 60,692 6,744 136,704 17,309 Source of data: California Cooperative Crop Reporting Service, Annual Crop Report, 1928. 1930 Peach Culture in California 8 California Agricultural Extension Service [Circ 42 Very few new plantings have been made during the last two or three years in any of the counties in southern California. In fact, a considerable acreage of mature trees has been pulled out. This is due in part to the fact that the available water supply can be used more profitably for other crops such as oranges, and in part to rather low average yields of peaches. In these southern counties, except in foothill sections, the winters are frequently too warm to break the rest. Blooming, and the beginning of growth following such winters are greatly delayed, and only small crops are set. The growing of a limited acreage of freestone peaches for the fresh fruit market of Los Angeles and other nearby cities may be profitable in sections where there is not a great tendency for delayed foliation to be troublesome. The J. H. Hale has been planted to some extent for this purpose. CHOOSING A LOCATION FOR PEACHES A factor to be considered in choosing a site is that of initial or developmental costs. The land may produce good peaches but if the costs are excessive the returns may never pay a fair rate of interest on the money invested. In choosing a location for a peach orchard the more important factors to be considered are: (1) climate; (2) water supply; and (3) soil. Climate Most Favorable to Peaches. — Most of the best California peach orchards are grown below an elevation of 1500 feet. The larger peach districts in the state are found in the Sacramento and San Joa- quin valleys at an elevation up to 300 feet. The peach tree and fruit withstand satisfactorily rather high summer temperatures. There are a few orchards in the foothill districts, but the elevation of the profit- able ones rarely exceeds 2000 feet. In California the only loss from freezing in peach orchards is near blooming time or later. In a few sections the winters are frequently too warm to break the rest. In the spring after such a winter, bloom- ing, and the beginning of growth may be greatly delayed, and the crop set may be very small. Coast sections having heavy fogs and cool damp atmosphere are not well suited to peach growing. Such climatic conditions favor the development of brown rot, and other fungus diseases ; tend to lessen the color of the fruit ; and possibly tend to increase the acidity. Water Supply. — The mean annual rainfall in leading California peach districts varies from about 10 to 30 inches per year. For profit- able production, however, it is recommended that peaches be planted 1^^^] Peach Culture in California 9 only where the annual rainfall can be ■adequately supplemented with irrigation water. Soil for Peaches. — The best soil for the peach is a deep fertile loam, easily worked, and well drained. Large sections of land in parts of the state are totally unsuited to peach growing because of too shallow soil. It is unwise to buy land without determining the nature of the subsoil. A soil auger is an excellent means of determining the physical conditions of the subsoil, as regards texture and moisture, to a depth of six or eight feet. A peach soil must be free from excess of alkali salts, as the peach is sensitive to alkali. Excessive irrigation has sometimes resulted in the rise of the water table causing injury to the orchards. A high water table not only seriously limits the root development of the peach, but it may become a factor in the rise and accumulation of alkali in the upper soil layers, where most of the roots are found. The water table should not be within six or eight feet of the surface. Drainage to remove excess water may be feasible in some cases, although expensive. Land that requires drainage may be more satisfactorily utilized for the growing of other crops that withstand more moisture and alkali than does the peach. VARIETIES OF PEACHES FOR THE ORCHARD Choice of Varieties. — There are three important considerations in choosing varieties of peaches for the orchard; namely, (1) adaptabil- ity to the local conditions; (2) suitability for the purpose for which they are grown; and (3) time and sequence of ripening. The value of a variety in a particular locality can be best determined by the experience of growers. Groups of Peach Varieties. — Some authors divide the peaches into five groups — (1) Peen-to or Saucer; (2) Honey; (3) Spanish; (4) Chinese Cling; and (5) Persian. The varieties in the Peen-to (Saucer) group are jflat, usually with juicy, white flesh, mottled with red. The pit is small and round without pronounced corrugations. The tree frequently holds its leaves throughout the winter. While not of general commercial value, varieties of this race can be planted for home use in the very mild sections because they are not troubled with delayed foliation. The fruit of the Honey group has a deep suture and a pronounced beak. It has a sweet honey-like flavor, but does not keep well. The tree tends to hold its leaves over winter. The typical varieties are : Ploney, Florida, Gem and Pallas. These varieties like those of the Peen-to group do not appear to be troubled by delayed foliation. 10 California Agricultural Extension Service [CIro. 42 The flesh of the Spanish group is red in color and hard, and the skin is noticeably pubescent. The tree is large, vigorous, and adapted to the warmer localities. The typical varieties are : Blood Cling and Indian. The fruit of the Chinese Cling group is dull in color, with a thin skin, and flesh that is white or yellow, juicy, fine-grained, and of good quality. The leaves are large. Most of the commercial varieties are found in this or in the Persian group. Typical varieties are : Chinese Cling, Carman, and Greensboro. The Elberta is probably a cross between Chinese Cling, and Early Crawford. These varieties tend to have a long rest period. The Persian group includes all varieties originating from the importations out of Persia by way of Italy, Great Britain or the Colonies. The typical varieties are : Alexander, Early Crawford, Late Crawford, Hale's Early, St. John, Susquehanna, Tuscan, Phillips,* Heath, Foster, Lemon Cling, Salwey, and the somewhat newer midsummer varieties; Paloro, Hauss, Gaume, Johnson, Walton, and Sims. As with the North China group the varieties of this group also drop their leaves early and have a rather long rest period. Suitahility of the Variety for a Purpose. — Since peaches are raised for drying, shipping, canning, or for home consumption, it is necessary to select varieties that are best suited for these special purposes. The condition of the market has much to do with the way the fruit is sold or used. Some orchardists, therefore, prefer to raise freestone varieties that may be dried, or sold fresh. Clingstone varieties are used mostly for canning, although a very few are shipped as fresh fruit. Canneries use yellow-fleshed clingstone peaches. The canners' standard calls for a firm peach with a golden color, of good symmetri- cal size, without red at the pit, and the pit should be small. Among the yellow clingstone varieties, the Tuscan and Phillips were formerly preferred because they interfered less with the canning of pears, plums and cherries in July, and because desirable midsummer varieties were not then available. The midsummer varieties such as the Hauss, Paloro, Peak, Johnson, Gaume and Sims, however, are increasing in popularity. The Tuscan and Phillips appear to be losing favor with the canners at present, due to defects such as splitting of the pit and gumming of the fruit. The Tuscan is also objectionable because of the red color of the flesh near the pit, which causes a colored syrup. 4 The varieties, Phillips, Paloro, Hauss, Gaume, Johnson, and Walton originated in Sutter County, California. ^^2^] Peach Culture in California 11 A good dryino; peach should preferably be a freestone with a small pit. The flesh should be of a clear yellow with no red color at the pit, of firm texture, and sweet in taste. A peach like the Muir requires about five pounds of fresh fruit to make one pound of dried, while more juicy varieties, such as the Elberta require about seven pounds. In order of preference, the three leading drying varieties are : Muir, Lovell and Elberta. Characteristics desired in shipping varieties are color, size, taste, quality, capacity to withstand shipment without bruising and to keep well on the market. Most early dessert peaches have white flesh and many are clingstone varieties. The market prefers a yellow-fleshed freestone peach, having a skin relatively free from fuzz. A variety of peach that will meet these demands and also be satisfactory for canning or drying has distinct advantages. The Elberta and the J. H. Hale more nearly meet these requirements than do other var- ieties. Other shipping varieties include Mayflower, Alexander, Triumph, Hale's Early, St. John, Early Crawford, Strawberry, Sal- wey, Foster, and Levi. Time and Sequence of Ripening. — Canneries prefer varieties that supplement the canning of other fruits. For example, the Tuscan ripens early and is available when few other fruits are being canned. Hauss, Paloro, Libbee, Peak, and Sims mature between the ripening of the Tuscan and Phillips and, therefore, make the canning season continuous. For drying varieties less stress is placed on the sequence than on the time of ripening. The variety should ripen so as to be dried before the early fall rains and enable delivery to the packing house by the end of October. When the acreage is large and labor scarce, sequence in ripening, however, also becomes important. It may be advisable in such cases to choose more than one variety in order to distribute harvesting and drying over a longer period of time. In the case of fresh fruit, the time of ripening is especially impor- tant. The shipping fruit must be on the market when the demand is good. There must not only be a good demand for peaches as compared with other fruits, but there must be a satisfactory demand for the particular variety. New commercial plantings of shipping peaches should not ordinarily include a variety that must compete with a more popular one sold on the same market, although local preferences and fruit for home use may warrant a limited planting of the less popular varieties. 12 California Agricultural Extension Service [CIrc. 42 Approximate Ripening Dates for Canning Peaches. — The canning season for clingstone varieties normally extends from early July to the last of September. The approximate time of ripening of the prin- cipal California clingstone varieties is as follows : Variety Time of ripening Tuscan July 15-July 30 Hauss July 28-August 20 Paloro July 28-August 20 Johnson July 28-August 20 Peak July 28-August 20 Walton July 28-August 20 Orange August 10-September 1 Gaume August 10-September 1 Albright August lO-September 1 McDevitt August 10-September 1 Sims August 10-September 1 PhilHps August 25-September 10 Levi ■. September 5-September 25 These ripening dates vary from season to season, and between different districts there may be as much as ten days variation in any one season. Approximate Ripening Dates for Fresh and Drying Peaches. — The Elberta is now the most important of the shipping varieties but the J. H. Hale is gaining popularity. (3ther varieties in approximate order of their importance are Mayflower, St. John, Triumph, Lovell, Salwey, Early Crawford, Levi, Phillips, and Tuscan. The bulk of fresh peaches are shippend during July to early September. The approximate time of ripening of the principal shipping and drying varieties is as f oUow^s : Variety Time of ripening Triumph June 10-June 30 St. John June 28-July 15 Early Crawford July 5-July 25 Tuscan July 15-July 30 J. H. Hale July 18-July 30 Elberta July 21-August 6 Muir July 25-August 10 Lovell August 1-August 20 PhiUips August 25-September 10 Salwey August 30-September 15 Levi September 5-September 25 DESCRIPTION OF THE MOST IMPORTANT VARIETIES OF PEACHES Alexander. — The Alexander originated in Illinois soon after the Civil War. It has been one of the parents of several good early- ripening peaches. It is not grown extensively now anywhere except in California. It has been widely grown as one of the best early varieties. The fruit is greenish white, and is nearly covered w4th 1^^^] Peach Culture in California 13 deep red color. The flesh is firm, juicy, sweet, and, as grown in Cali- fornia, withstands transportation well. The trees appear to be some- what more resistant to leaf curl than many other varieties, and are hardy and vigorous. The fruit is inclined to be somewhat small, with a stone that is only partly free. The quality is fair for eating. The tree is often lacking in productiveness, and the fruits are relatively susceptible to brown rot. Early Craivford. — The Early Crawford originated in New Jersey in the forepart of the nineteenth century. The fruit has a very high quality, rich flavor, tender flesh, pleasing aroma, and abundant juice. It is very attractive, being large in size, with a deep red color on the sunny side, and is an excellent freestone variety for the home orchard. The trees are healthy and vigorous-growing but are rather late coming into full bearing. It was once the most extensively planted variety in California, but is now losing its popularity. In many sections the bearing has proved uncertain. Elherta. — The Elberta originated in Georgia about 1870 from a seed of the Chinese Cling which had supposedly been pollinated by Early Crawford. Claim has been made that several new strains or types of Elbertas have been discovered. June Elberta, Late Elberta, Early Elberta, and Fay Elberta are some of the names by which these strains have been called. The distinctive differences or merits of these, however, have not been definitely nor widely determined. Elberta is the predominating variety of peach in most of the producing centers in the United States. It is in demand as a fresh fruit and is perhaps the most popular variety on most of the markets. It is cosmopolitan, and succeeds on a variety of soils and under widely different climatic conditions. The fruits are large, attractive, freestone, ship and keep well. The variety is sometimes used for drying, six or seven pounds of fresh fruit giving one pound of dried product. It is not preferred by canners and the flesh is too red at pit to make a satisfactory dt-ying peach. The fruits are only medium in quality for eating, having a rather bitter taste even when ripe, and the stone is somewhat large. Gaume. — The Gaume is a variety of recent origin, having been discovered in Sutter County, California, as a chance seedling on the ranch of J. L. Ames near Live Oak. The flesh is yellow, firm, of desirable texture for canning and free from red color at the pit. It is a good producer and mid-season in time of ripening. The fruit with- stands handling well, but tends to drop prematurely. The variety is somewhat susceptible to peach rust. 14 California Agricultural Extension Service [Circ. 42 Hauss. — This variety originated in Sutter County and was named after the Hauss family who were early residents in the district. The skin is yellow, and striped with red. The fruit is elongate, oval in shape, and not of especially large size. The flesh is firm, yellow and free from red at the pit. It is one of the first mid-season peaches to ripen. The trees are productive and vigorous although the variety is somewhat susceptible to peach rust. Its adaptability has not been widely determined. J. H. Hale. — This variety was discovered as a chance seedling by J. H. Hale of South Glastonbury, Connecticut, about 1900. It is a popular, comparatively new shipping variety. The fruit is very large, round, yellow, blushed with red, and freestone. The skin has little fuzz ; the flesh is firm and of good quality but red at the pit and hence does not can satisfactorily. The variety is generally self -sterile, and tends, therefore, to be unproductive except when properly cross- pollinated. The trees are not so vigorous nor so widely adapted as Elberta. Johnson. — This variety originated in Sutter County, California. The fruit is large with fine-grained flesh which is free from red at the pit. The pit is small. The tree is very vigorous and productive. The variety appears to be somewhat less susceptible to peach rust than some of the other mid-summer varieties. The flesh tends to lack firmness. Its adaptability is not yet widely determined. Lovell. — The Lovell originated in California and was named about 1882. It is not extensively grown outside of this state. The fruit is uniformly large, nearly spherical and freestone. The flesh is firm and of a clear yellow color at the pit. It is a good general-purpose peach, satisfactory for canning and ships well. It is, however, most exten- sively dried, the drjdng ratio being about 5 to 1. The tree is vigorous and productive. The variety is not particularly attractive in color of skin for fresh fruit shipment. The tree appears susceptible to leaf curl as grown in some places. Muir. — The Muir originated as a chance seedling about half a century ago on the place of John Muir, in California. It is similar to the variety known as the Wager. Claims are made for several supposed variations of the Muir. It is the standard drying peach in California and is especially adapted for this purpose because of the following points: sweetness of flavor; density or firmness of flesh; uniform clear yellow color of flesh, but free from red about the pit; and ratio of green weight to dry weight, which is comparatively low — about 5 to 1. The fruit is large and freestone, with a relatively small pit. The trees are productive and vigorous, and little subject to leaf 1930] Peach Culture in California 15 curl. The fruit is also shipped satisfactorily and is a ^ood yellow- fleshed, freestone canning peach. It is not especially attractive externally and is not adapted for sale as a dessert fruit. Under certain conditions it splits at the pit and the halves tend to be unequal in size. Paloro. — The Paloro originated as a chance seedling in a dooryard at Gridley and was later named by Frank A. Dixon. The name is a contraction of two Spanish words: ''palo" meaning tree, and ''oro" meaning gold; therefore, Paloro means ''gold tree." It was first propagated in 1912. The fruit is large and round, yellow in color, with slight blush on the sunny side. The flesh is clear yellow in color to the pit, firm, and withstands handling well, and is an excellent mid-summer canning variety, in demand by the canners. The tree is vigorous and productive, but is subject to peach rust and mildew and tends to drop the fruit somewhat prematurely. The Peak closely resembles the Paloro and may be the same variety, or strain, with slightly later ripening characteristics. Phillips (Phillips Cling). — This variety orginated as a chance seedling in California in the orchard of Joseph Phillips of Sutter County, about 1885. It was discovered in a cannery by Mrs. E. Hail- stone and was first propagated by J. T. Bogue of Marysville, Cali- fornia. This is the most popular yellow clingstone variety in the state. The fruit is large, with excellent flavor, highly yellow-colored and with a firm flesh. The flesh has no red color at the pit, and the stone is small. It is one of the best canning peaches. It ripens progres- sively so that picking can be extended without loss due to dropping from the tree. The fruit is subject to gumming, which may result in serious losses. Salwey.—The Salwey was originated in England by Colonel Salwey who raised it about 1844. The fruit is very late in time of ripening and hence valuable in extending the freestone peach season. Its exceptional adaptability to many soils and climates make it widely grown in England, France and the United States. The trees are vigorous, hardy and productive. The fruit, however, is neither attrac- tive enough in appearance, nor high enough in quality to be a first class dessert variety. The flesh becomes dry with overmaturity and is red at the pit. St. John. — This variety originated in New Orleans over 100 years ago. It is fairly early in season of ripening, of good quality, yellow flesh, and freestone. It is satisfactory for shipping and for home use. The trees are hardy, but somewhat unproductive and lack in vigor under certain conditions. The fruits tend to be medium to small in size. 16 California Agricultural Extension Service [CIrc 42 Tuscan {Tuskena). — This variety originated in Mississippi. It received a place on the fruit list of the American Pomological Society in 1873. There appear to be several types, such as, for example, the Ontario. The fruit is large, of good quality, with yellow clingstone flesh. It has been rather extensively planted in the interior valleys and foothills of California. It is perhaps the best early cling variety for canning, although the flesh tends to be red about the pit. The fruit ripens rapidly, the skin is thin and the flesh bruises easily, hence this peach does not ship satisfactorily. There is much loss from so- called ' split-pit ' during certain seasons. PROPAGATION, SELECTION AND CARE OF NURSERY STOCK It is the common practice for peach growers to buy nursery grown trees. The reasons for this are that the grower ordinarily does not wish to wait a year or more and seldom has the time, facilities, or experience for the successful propagation of trees. When growers prefer trees propagated from buds taken from their own orchard and are willing to wait, it is often possible to contract with a nursery for their propagation. This may be warranted where there is difficulty in getting nursery trees of the desired type or strain. It will rarely be impossible, however, to buy good trees at reasonable prices. Home-grown trees may be economically produced when the grower is skilled in propagation methods, when he has the time and facilities to do the work, and requires sufficient trees to warrant this special work. Whether the peach grower buys nursery-grown or uses home-grown trees, certain essentials should be known in order to make a wise selection. The discussion pertaining to propagation is given with this idea in mind. Kinds of Roofstocks Used. — A survey made by M. J. Heppner, formerly of the University of California, indicated that for the season of 1927-28 the rootstocks used by the nurserymen for peaches were as follows: peach, 98.9 per cent; apricot, 0.8 per cent; and almond, 0.3 per cent. While popularity usually indicates which rootstock is best, the individual merits of the rootstock for conditions in the orchard should also be considered. The rootstock should make a good union with the peach, be adapted to the soil conditions, resistant to diseases and insects, and be uniformly true to type. The Peach Root. — The peach is the most important rootstock and makes an excellent union with the commercial varieties of peaches. The nurserymen are using seedlings grown from Lovell pits or from pits of some of the other varieties in California, such as Salwey, 1^30] Peach Culture in California 17 Elberta, Muir, and occasionally clingstone varieties. Pits are obtained either from canneries or dry-yards. The peach rootstock succeeds best on deep, light, well-drained soils, but it does not withstand heavy wet soils. The peach root is also susceptible to injury from alkali. In the foothill sections peaches are sometimes grown on soils not over three feet deep. Such trees, however, do not grow so large and do not appear to be so long lived and productive as those grown on deeper soils. The peach root is subject to attacks of the peach root-borer, crown gall, soil nematode, and oak root fungus. When free from pests and under favorable soil conditions the peach root is long lived. Under California conditions, while the peach top deteriorates after 25 to 30 years, the roots may live longer. The Apricot Roof.^The apricot root will grow on a wide range of soils, but does best on a moderately heavy, well-drained, fertile soil. The root is more subject to attacks by gophers than either the peach or almond. Crown gall, oak root fungus and the peach root-borer, also attack this root. The possible value of the apricot as a rootstock lies in the fact that it is resistant to the attacks of the soil nematode, which is a serious pest in certain soils of the San Joaquin Valley and of southern California. Attempts have been made, therefore, to propa- gate peaches on apricot root. The results, however, have not been entirely satisfactory. The union is sometimes uncongenial although there is no tendency to break. When the peach is budded six to eight inches high on the seedling or topworked upon the apricot it is claimed that it does better than when budded near the ground. It is reported that there are a few peach orchards in Riverside county, in Kern county, and elsewhere that are upon apricot roots. The use of the apricot as* a rootstock for the peach is still in an experimental stage. There is a possibility that a variety of peach may be found whose seedlings may be resistant to nematode attack. Prunus DavicUana as a Rootstock. — ^Seedlings of Prunus davidiana are considered promising as a rootstock for peaches for planting in spots of the orchard where the original trees on other stock have died because of alkali. This root is resistant to injury from alkali, and has been used as indicated above, in parts of Tulare and Sutter counties. The peach on this rootstock appears vigorous, with green foliage, under conditions where the trees on other rootstock have yellow foliage, stunted growth, and are gradually dying. According to F, W. Anderson of the Kirkman Nursery Co., however, this rootstock is not being used by nurserymen because it is extremely susceptible to crown gall. 18 California Agricultural Extension Service [Circ. 42 The Almond Root. — The almond roots deep and for this reason it has been nsed as a rootstock in the drier soils. This supposed advan- tage over the peach is probably over-emphasized and at present almost no almonds are used by nurserymen as a rootstock for the peach. The union with the peach is good but the almond root is very susceptible to crown gall, and also to the attacks of the peach root-borer and oak root fungus. Budding.^ — Seedling peaches are usually budded in July or August. In times of scarcity, the Mune bud' is also used but the resulting nursery trees are generally smaller. Buyers usually object to this small size and for this reason June budding is seldom practiced. Sometimes 'dormant buds' are planted in the orchard the winter or spring following budding, before the buds begin growth. This prac- tice, however, is expensive and the stand is seldom as good as with June buds or one-year-old trees. Grades of Nursery Trees. — When purchasing trees the grower should know something of the different sizes of trees offered for sale. Most nurseries grade trees according to diameter but list them in the catalogues as 4 to 6 feet ; 3 to 4 feet ; and 2 to 3 feet. Size, however, is not the only consideration. The tree should be healthy, must not have been stunted in its growth, should preferably be of medium size, from 3 to 5 feet high, calipering about l^ inch in diameter just above the bud, and should not be over one year old. When the order is large a visit to the nursery is desirable. Other things being equal, preference should be given to the nearest nurseries because the trees will be subject to the shortest shipment. Long ship- ments are expensive, and the trees may suffer from drying out. « Care of Nursery Trees. — Trees should be ordered early enough to insure delivery where possible by January. Unless they are to be planted at once they should be unpacked and carefully heeled-in, in moist but well-drained soil, until they are planted. Heeling-in is done by placing the trees in a shallow trench, side by side about the same depth as they stood in the nursery. Loose moist soil is then sifted between the roots and the trench filled. The soil should be firmly pressed about the roots, using care not to injure them. Topivorhing Old Trees. — In some cases the fruit grower may wish to topwork other fruit trees to peaches or to topwork his peach trees to more suitable varieties, rather than to plant nursery trees. This is rarely advisable if the trees are much over eight years of age, if they are too closely planted, or if they are not healthy. 5 Stahl, J. L. Propagation of deciduous fruits. California Agr. Exp. Sta. Cir. 294:1-24. 1925. ^^^^] Peach Culture in California 19 Since the peach does not heal over large wounds readily, it is unwise to use limbs much over two inches in diameter for topworking. The branches, however, may be cut back and the new variety budded into the shoots that grow from near the stubs. LAYING OUT AND PLANTING THE PEACH ORCHARD Preparation for planting the peach orchard may consist of clearing and leveling the land, establishing the irrigation and drainage systems, and properly tilling the soil. Leveling the Land and Estahlishing the Irrigation System. — Most peach trees in California require irrigation. Hence, the preparation of the land before planting becomes of importance. Poorly leveled land results in uneven irrigation, excessive use of water, greater labor costs, and frequently in too much water, resulting in a rise of the water table with possible consequent alkali injury. It is not generally practical to make marked changes in the original grade of the land, but advantage can be taken of the most desirable slope in laying out the irrigation system. If the trees are to be watered in basins or checks, flat grades or slopes can be utilized. At present, laying the checks according to contour seems to be the desirable practice.^ Local soil conditions must be taken into consideration. A contour or topographical survey will indicate the leveling neces- sary. The land should preferably not be scraped so deep as to result in infertile spots, which prevent the best growth of the trees. Some grain lands have been repeatedly plowed at the same depth and a hard layer of soil has resulted from the compacting of the soil particles by the plow. This plow-sole or plow-pan should be broken up before planting to allow water to penetrate freely. By changing the depth of plowing each year and by avoiding plowing when the soil is too wet, the trouble may be prevented. Irrigation Water. — In case the water comes from the outside, the grower should be assured of a regular supply when needed. The irrigation system and pumping plant, if the orchard is not in a gravity water district, should preferably be installed previous to planting. Before planting the grower ought to ascertain whether his acreage will warrant the expense of a pumping plant, or whether he can sell sufficient water to neighbors, after meeting the needs of his own orchard, to justify the investment.^ The water should be free from an excess of alkali salts. 6 Huberty, M. E. and J. B. Brown. Irrigation of orchards by contour furrows. California Agr. Ext. Cir. 16:1-16. 1928. 7 Johnston, C. N. Principles governing the choice, operation and care of small irrigation pumping plants. California Agr. Exp. Sta. Cir. 312:1-28. 1928. 20 California Agricultural Extension Service [Oirc. 42 Adding Organic Matter. — Much of the land in California that is used for peach growing is light in texture and located where summer temperatures are high. Under these conditions the humus in the soil is quickly exhausted. Lands that have been growing grain, or old orchard lands, are usually low in humus. When such conditions exist, the incorporation of barnj^ard manure or the plowing under of a green manure crop may be a part of the orchard preparation. Laying out the Orchard. — The first step in laying out the orchard is to establish the boundaries. If the field is square or rectangular and one side has been determined, the other sides may be established by laying them off at right angles to each other. The second step is staking out the orchard to the planting system to be used, and thus to establish the location of the trees. This frequently is done by use of a long planting wire with buttons at the planting interval. The usual planting system is where the trees are planted in squares, generally 22 to 24 feet apart. ^ To determine the number of trees to the acre in the 'square sys- tem,' multiply the distance between the trees in the row by the distance between the rows and divide this product into the number of square feet in an acre (43,560 square feet). The contour system of planting is adapted to land that is too steep and broken to use the square system. Orchard Filler's and InterpJanting. — Because of its early bearing habit the peach is sometimes used as a filler between other orchard trees, such as the walnut, which is slower to come into bearing. The fillers must be removed as soon as the permanent trees need the space. In a peach orchard it may be desirable to grow crops between the trees as a source of income before they begin bearing. Melons, beans, peas, cabbage, tomatoes, spinach, cauliflower, onions, beets, lettuce and other cultivated crops are used for interplanting. Some of these are grown during the winter months and others during the summer months. It is well to leave a cultivated strip of about five feet on each side of the trees to lessen competition with the trees. In sandy and sandy loam soils such intercropping may be dangerous because of the possible introduction of, or increase, in nematodes. Pollinators. — Commercial varieties of peaches are ordinarily self- fertile and set good crops without special provision for cross-pollina- tion. There is evidence, however, that the J. H. Hale is self -sterile bearing no viable pollen and hence should not be planted alone. Experience seems to indicate that any of the other commercial varieties will pollinate the J. H. Hale. 8 Allen, F. W. Planting and thinning distances for deciduous fruit trees. California Agr. Exp. Sta. Bui. 414:1-29. 1926. 1930] Peach Culture in California 21 Planting. — Usually the earlier the trees are planted in winter the better. Ordinarily they can not be obtained before December and perhaps not before January. If the trees have not opened their buds, plantino^ may be done as late as April. Early planting', however, is to be preferred, unless unfavorable soil or weather conditions prevail. A planting- board may be used to keep the trees in line. One form is a 1 X 4 inch board, 6 feet long, with notches or holes cut near each end and a notch cut in one side midway between the ends (fig. 2). The rig. 2. — Planting trees by use of a planting board. center notch is placed ag-aiust the stake where the tree is to be set and stakes are set in each of the end notches or holes. Then the planting' board and center stake are removed and the hole is dug:. The hole for the tree should be dug: shortly before planting* and should be suffi- ciently large to accommodate the root system. Digging the holes and planting the trees costs about $8.00 per acre under favorable soil and weather conditions. Experienced growers distribute only as many trees as can be planted before the roots dry out too much; keep the roots covered 22 California Agricultural Extension Service [Circ. 42 with burlap or canvas as they are hauled to the orchard ; cut off bruised, broken, interfering, dead, dried, or unhealthy roots ; discard trees with galls on the roots. The planting board is placed in its original position and the tree is set against the center notch. It is planted about the same depth that it stood in the nursery, with the roots in their natural position. Moist, fine, surface soil is then sifted about them and should be firmed care- fully. Unless the soil is moist, water is given by irrigation or from a tank wagon. Heading and Shaping. — The tree is cut back at planting time to restore the balance between top and root and to obtain the benefits of low heading. Most vigorous peach trees grow side branches in the nur- sery. Some trees, such as 'June buds' may form only a 'whip' with no side branches. When pruning the nursery tree, make use as far as possible of the satisfactory available side branches in forming the framework. The laterals selected should be vigorous and upright and not spindling and drooping. If it is necessary to remove all of the laterals they should be cut off not closer than one-half inch from the trunk. This is done to preserve the buds at the base which later may send out vigorous shoots. If the tree is a straight 'whip' it is cut back to a healthy bud about 24 inches above the ground. If, however, the tree has formed lateral branches, then three of the strongest of these, properly spaced on the trunk, are left to be developed into the main scaffold branches. The undesirable lateral branches are cut off. A desirable tree is one with three symmetrically directed branches selected to form the framework, spaced about six to eight inches apart on the trunk, with the lowest branch about eight inches above the ground. The three scaffold branches should be spaced as nearly equidistant around the trunk as possible. Whitewashing. — After planting and pruning, the trees, especially if large in diameter, may be whitewashed to prevent sunburn. Sun- burn may occur on hot bright days when the tree has inadequate leaves to protect it from the direct rays of the sun. Sunburn is not only a direct injury, but it also favors the entrance of borers and decay organisms. One formula for whitewash is as follows: Quicklime 5 pounds, salt 14 pound and sulfur ^^ pound. Stir in the salt and sulfur while the lime is slaking. Omit the salt when deer or rabbits may be troublesome. Tree Protectors. — Occasionally rabbits may 'bark' the young trees. In unusual cases it may be desirable to protect the trunks with small wire mesh, or commercial tree protectors, various sorts of which are on the market, selling for from $10.00 to $20.00 per thousand. 1930 Peach Culture in California 23 PRUNING AND SHAPING THE PEACH TREE9 The purposes of pruning may be enumerated as follows: (1) to produce a vigorous, mechanically strong, healthy tree, capable of bear- ing heavy crops over a long period of years; (2) to obtain a tree well shaped for convenience and economy in orchard management; (3) to mi '^W Fig. 3. — Fruit bud of the peach. iNote the two lateral fruit buds with a small leaf bud between. (From California Agr. Exp, Sta. Bui. 386.) distribute the fruiting area over the tree; (4) to favor early and regular bearing of profitable crops; and (5) to obtain desirable size and quality of fruit. Habit of Bearing. — The fruit buds of the peach are usually borne laterally upon one-year-old wood and on short spur-like twigs. If the 9 Tufts, W. P. Pruning young deciduous fruit trees. California Agr. Exp Sta Bui. 313:1-44. 1927. 24 California Agricultural Extension Service [Circ 42 tree is making a good growth, two fruit buds and a leaf bud at a node are likely to be common (fig. 3), while with trees making a weak growth fruit buds are generally single. Their position upon the twig is largely dependent upon the growth of the tree and the habit of the particular variety. A tree growing moderately, normally forms the fruit buds from the middle portion toward the tip of the season's growth. Trees making a rank growth are likely to produce few, and scattering fruit buds near the tip of the season 's growth. The forma- tion of fruit buds on the peach seems to be encouraged by a moderate growth of the twigs. Varietal Characteristics. — It is important to know the habits of the particular variety to be pruned. Generally, most varieties with a moderate growth have their flowers well distributed, such as, Alex- ander, Early Crawford, Elberta, Lemon Cling, Lovell, and Muir. A few, however, like the Phillips and Tuscan (Tuskena) tend to bear their fruit buds near the tips of the season's growth. Removal of the outer portion of the season's growth in varieties like the latter may, therefore, reduce the crop. Methods of Sh aping .—Msmj California growers use the open-center type of tree, modifying it according to their particular ideas. In this type of pruning the main branches arising from the trunk are allowed to grow more or less freely and the center of the tree is kept suffi- ciently open to admit light, but enough shade is left to avoid sunburn- ing of the branches. First Summer's Pruning. — In April or early May of the first grow- ing season unnecessary growth may be thinned out. If not already selected, three limbs for the framework as previouslj^ discussed may be chosen. Pinch off the tips of the undesirable shoots permitting a few leaves to remain to help shade the trunk and to contribute plant food to the tree. The trees may be gone over again in about six weeks to suppress subsequent undesirable growth. Unless this summer pruning is intelligently and carefully done early in the season, preferably by the grower himself, it will not generally accomplish the desired results and the purpose may be defeated. First Dormant Pruning. — The first dormant pruning will depend upon the previous pruning and the growth the tree has made. In most cases there will be some secondary branching on the main limbs. Each main branch should have two well placed secondary branches. The main limbs may be cut back lightly above the secondary branch- ing. Moderate rather than severe pruning will induce less excessive wood growth. 1930] Peach Culture in California 25 Second Summer's Pf^uning. — Usually the second summer's pruning consists in the removal of undesirable water sprouts early in the summer. If each main branch has not produced two secondary branches these may be selected and other competing shoots pinched back or removed. Second Dormant Pruning. — During the second winter thin out the growth made the previous summer, leaving six or eight selected secondary branches for the additional framework. These branches should generally not be cut except to balance the tree. In addition, thin out interfering, surplus branches or those in the way of cultiva- tion. By cutting forked branches unequally, weak crotches can be avoided, since the longer branch of a fork will gain the ascendency. Prune so- as to get a spread while the tree is young by making inside cuts; but after the tree comes into bearing make the cuts preferably on the outside to lessen decay at pruning wounds, to reduce sun-scald on the inside of main branches and to reduce possible breakage at point of cut under the weight of the crop. Third and Succeeding Summer's Pruning. — Summer pruning may be continued as long as it is necessary to obtain more branching or to remove watersprouts that are shading the lower parts of the tree. Severe pruning in the summer is weakening. The Third Dormant Pruning. — Continue thinning out interfering branches, or those in the way of cultivation. Remove watersprout growth. Seek to have the center of the tree somewhat open ; but there should be enough side branches and twigs to shade the main limbs and to bear fruit. In pruning permit the more stocky twigs to remain when possible, and remove the slender, spindly ones. Pruning the Bearing Tree.^^ — In the case of bearing trees, instead of cutting back to stubs, it is better to cut to vigorous lateral growth and thus judiciously thin out the tree. Start the thinning out process near the base of the tree. Leave the willowy, drooping branches or 'hangers' intact except when they are in the way of cultivation, or are unable to support a desirable amount of fruit. Continue the pruning by removing old or useless wood and the small dead twigs that can be removed without much trouble. The crop is largely carried by the one-year-old twigs borne on the two and three-year-old wood. Pruning should be sufficiently severe to cause the annual shoot growth to be from 10 to 24 inches long. Careful pruning of the fruit-bearing laterals above the second crotches is needed to properly distribute the fruiting wood along these 10 Tufts, W. P. — Pruning bearing deciduous fruit trees. California Agr. Exp. Sta, Bui. 386:1-47. 1925. 26 California Agricultural Extension Service [Circ 42 side branches. Neglect in this matter will result in an uneven dis- tribution of the crop and possibly a splitting of some of the main limbs. A good distribution of fruiting wood will lessen the need of props and bracing. The twigs on the secondary limbs are seldom shortened, except possibly to direct the growth. The longest branch of a crotch, where feasible, is left pointing toward the space that is to be filled. Branches near the end of the secondary growth are thinned to allow sufficient light into the center of the tree. When possible leave the twigs on the side of the secondary branches. Horizontal Fig. 4.- — Seven-year-old Elbcrta peach tree before pruning. Note vigorous new wood growth which, however, is not excessive. Compare with figure 5 after pruning by thinning. (From California Agr. Exp. Sta. Bui. 386.) growth is less likely to develop into rank shoots than the upright growth. Remove long interfering branches. The cutting of very large branches is likely to leave wounds which heel over slowly and this is to be avoided whenever possible. It is better to thin out regularly (figs. 4 and 5) so that the wounds made will heal over in one year's time. As a rough estimate, one man can prune about 20 full bearing trees of average size in a ten-hour day. Equipment for Pruning. — A list of some of the more important tools (fig. 6) for pruning include: (1) hand pruning shears with a 1930] Peach Culture in California 27 good spring: and a good cutting blade; (2) two-hand pruning shears for the larger branches; (3) tapered pruning saw with swivel blade which allows the removal of limbs without leaving stubs ; (4) hand saw with curved blade; and (5) tripod stepladder of desired length. For removal of the brush from the orchard, various tools and implements are in use, such as rakes, pitchforks, and brushburners.^^ Prunings should not be allowed to remain in the orchard long as they interfere with orchard operations and may harbor pests. Prompt burning of the brush is desirable. One man and a team can haul brush from about 1% acres of orchard per day. Fig-. 5. — A well pruned seven-year-old Elberta peach tree pruned by * thinning- out. ' Compare with figure 4 before pruning. Note large amount of growth removed. This tree has been pruned for four consecutive years by thinning — no cutting to stubs. (From California Agr. Exp. Sta. Bui. 386.) Treatment of Wounds. — The productive period of many peach trees is shortened because pruning wounds or other injuries have not been cared for. Wounds dry and check, and decay fungi gain entrance. In a few years decay may have developed in the larger limbs or in the trunk and the tree may split or break in a strong wind or under a heavy load of fruit. This trouble may generally be prevented by promptly dressing the wounds. 11 Zink, W. L. An orchard brush burner. California Agr. Exp. Sta Cir 269:1-12. 1923. 28 California Agricultural Extension Service [CIro. 42 Wounds which heal readily in one season do not need covering. Some protective dressing, however, should be applied to large wounds to keep out fungi. Bordeaux paste may be applied after the callus starts to form about the edges. One of the most common dressings is ''Grade D" asphaltum applied warm. Certain commercial prepara- tions, roofing paints, and asphaltum emulsions are widely used for covering pruning wounds, because they are cheap and can be applied cold, and are said to be very effective. Fig. 6. — Pruning tools most commonly used, including swivel blade saw, curved blade saw, one-hand and two-hand pruning shears. Wounds heal over much more readily when the original cut is close to the parent branch and smoothly made. A split limb can often be saved when the lower part is still well attached by raising the limb to its natural position and fastening it with bolts. Splinters on the edges should be removed and the wound smoothed to facilitate healing. CARE OF THE PEACH ORCHARD Tillage . — The soil in a peach orchard should be well tilled every year to incorporate organic matter, destroy weeds, and facilitate water penetration. It is desirable to obtain a heavy cover crop, either volunteer or planted, to turn under each spring. Plowing, however, should not be delayed until the soil becomes so dry that it will turn up lumpy or the growth of the trees be checked by competition with the cover crop for water. 1930] Peach Culture in California 29 An orchard should be plo'wed or disked to a depth of 6 to 9 inches. Plowing too deep near the trees may injure the roots. When feasible the direction of the plowing should be changed. Cultivation of some sort should follow plowing or disking. Irrigated ground should be stirred when it has sufficiently dried to work without packing. Culti- vation generally begins in March or April and is continued intermit- tently to keep down weeds until about September. Growers are find- ing, however, that the frequency of cultivation can be reduced with satisfactory results and lessened costs; by not cultivating, the expense of re-making the furrows is saved. Any growth during the fall and winter is plowed under the following March or April. The trees are irrigated with sufficient frequency to keep the soil moist. Tillage in the larger orchards is more cheaply done by use of a tractor. Many farms, however, require one or two horses in addition to the tractor to do odd jobs. Intercrops. — Many peach growers plant intercrops in the young orchard as a source of income. The possible danger of this practice in the young orchard is that the trees may be neglected or injured by too intensive interplanting, resulting from severe competition between the trees and the intercrop for moisture and soil nutrients. Among crops commonly grown are : berries, grapes, beans, lettuce, cabbage, onions, peppers, squashes, tomatoes, rhubarb or potatoes. It appears that cotton may be a good intercrop in the upper San Joaquin Valley. It is not difficult to grow these crops, but there may be difficulty in profitably marketing them. Furthermore, their care may conflict with the care of the peaches. Naturally, the crop should not injure the growth of the trees ; should not interfere with the work of irrigating and cultivating the trees and of harvesting the peaches, and should not demand special ability in harvesting and marketing. Leguminous crops are to be preferred where they are profitable. Sufficient culti- vated ground should be left betAveen the intercrop and the tree rows. The amount of space devoted to intercrops should be gradually reduced so that the trees will have the entire area when in bearing. Cover Crops. — The planting of some crop in the fall, to be turned under early in the spring, while green, is being increasingly practiced. This is to be recommended, where there is sufficient rainfall or irriga- tion water available in the fall, since the annual plowing under of a cover crop improves the tilth and helps to maintain the soil nitrogen supply. Among the cover crops most often used there are three that lead : sour clover (Meliloius indica), common vetch (Vicia sativa), and Canada field peas {Pisum arvense), A good growth of weeds will 30 California Agricultural Extension Service [Circ. 42 also supply considerable organic matter. The leguminous plants mentioned, however, not only supply humus but increase the nitrogen content of the soil, both of which are of value. Cover crops are usually planted in the fall, some about the middle of September in order to have the plants established before cold weather. In many sections when planted so early it is necessary to make provision for irrigation to start the cover crop. Melilottis indica is broadcasted at the rate of 20 to 25 pounds to the acre. If bur clover {Medicago hispida) is growing wild and contains nodules on the roots, then artificial inocula- tion for Melilotus may not be necessary. Unless the soil is already inoculated with the proper bacteria, artificial inoculation of the soil may be advisable with some legumes. Commercial Fertilizers. — The fertilizer element to which the peach is most likely to respond is nitrogen, since it, more than most fruit trees, requires a soil rich in available nitrogen. However, in Cali- fornia, there are many soils that seem to have enough nitrogen for the best yield of peach trees. Moreover, under some conditions, nitro- gen may reduce the size of peaches as a result of the increase in set, and reduce the color because of the shade from the increased foliage. With adequate water, and vigorous trees, excessive amounts of nitrogen may delay ripening several days. It is considered satisfactory to apply the fertilizers just before the spring plowing. The tree is in greatest need of nitrogen at this time. Nitrogen in the form of ammonium sulfate may be applied at the rate of one-half pound per tree for young orchards, up to as much as four or five pounds per tree, for mature orchards. Generally peach trees show little or no response from applications of either phosphorus or potassium. Frost Protection}^ — As the flower buds open they become more susceptible to low temperature. The blossoms are more tender the longer they have been open, and the young fruits are more tender than the newly opened flowers. The young fruits apparently become increas- ingly subject to frost until they are about one-half inch in diameter. It is usually the seed that is killed, the other part of the fruit requir- ing a lower temperature to kill it. It is possible to protect the blossoms and young fruit against frost injury by means of orchard heating. The cost of heating is con- siderable and the use of heaters for peaches would generally be so infrequent that their purchase would rarely be warranted. Initial cost of equipment for heating with *'lard pail" heaters is about $60 per acre and the annual overhead cost, to be prepared to heat, is about 12 Schoonover, W. E. and E. W. Hodgson. Orchard heating in California. Cali- fornia Agr. Exp. Sta. Bui. 398:1-69. 1925. 1930] Peach Culture in California 31 $15 per acre. Occasionally, however, frost protection may be profit- able. As for example, during the spring of 1929, when certain growers saved most of their crop by orchard heating, whereas certain others not equipped to heat, lost their entire crop. When the temperatures are near the danger point or slightly below for only very short periods of time, it is claimed by some growers that the possible injury may be appreciably lessened by the application of irrigation water, especially if all the growers in the neighborhood irrigate just previous to the drop in temperature. Water in basins or running in furrows liberates heat since it is generally at a tempera- ture higher than that of the air and thus may afford a small amount of protection. Fruit Thinning}^ — In general it is more profitable to thin peaches than any other deciduous fruit. Peaches are thinned primarily to increase the size of the fruit, inasmuch as it takes two 2-inch peach ;s to equal one 2%-inch peach in weight. With experience one man can thin by hand ten or twelve trees in a ten-hour day when from 1000 to 1500 peaches are removed from each tree. Thinning costs about 30 to 40 cents per tree. There is usually a dropping of young fruit about the first part of June from causes, such as insufficient moisture, inadequate pollination, and adverse climatic conditions. Thinning is generally postponed until after the fruit drop, when the prospect of the crop can be determined. It, however, is usually done previous to the hardening of the pit. On the other hand, increase in size may be eff'ected by later thinning. Peaches are thinned, four to six inches apart. The actual distance of spacing and number of fruits left on the tree varies with the variety, amount of crop set, character of twig and branch growth, soil, water supply, and other factors. Weldon^* suggests thinning so as to leave a given approximate number of peaches per tree. For example, if trees are planted 24 by 24 feet and a yield of 15 tons per acre of size two and three-fourths inch peaches is expected, each tree should average about 1155 peaches. The number of peaches per tree divided by three will give the approximate pounds of fruit, since it takes three normal-size peaches to weigh one pound. This multiplied by the number of trees per acre will give the total number of pounds, and when divided by 2000 gives the tons per acre. Growers are, therefore, advised to thin by count. It is 13 Tufts, W. P. Thinning deciduous fruits. California Agr. Exp. Sta Cir 258:1-13. 1923. 14 Weldon, George P. A new idea in peach thinning. Chaff ey Junior College, Dept. Agr. Bui. 5:1-4. 32 California Agricultural Extension Service [Circ 42 surprising" how quickly an individual can learn to closely estimate the number of peaches on a tree with a little practice. A thinning schedule adapted from Weldon is shown in table 2. Any desired yield can be computed from the figures given. TABLE 2 Thinning Schedule: of Peaches Number of peaches to be left on each tree to produce the tonnages indicated, of the 2J/2-inch or of the 2^-inch size Tons per acre desired Trees planted 20 feet by 20 feet (108 per acre) Trees planted 24 feet by 24 feet (75 per acre) 2H-inch size 2^-inch size 23i2-inch size 2^-inch size 1 5 10 15 70 350 700 1050 54 270 540 810 101 505 1010 1515 77 385 770 1155 Peaches are thinned by hand. All misshapen, blemished, or other- wise inferior fruits are removed, leaving one specimen to a cluster, and spacing the remainder to the desired distance. In connection with thinning, judicious dormant pruning to remove excess fruiting wood is helpful. Under some conditions, such as low prices or shortage of labor, thinning may be done by means of long poles. Bracing}^ — When the crop is heavy, propping or bracing is neces- sary to prevent the breakage of limbs (fig. 7). Young trees may be supported b}^ passing rope around the outer limbs. After the trees have attained sufficient height, a permanent system of wiring may be installed. There are various systems and kinds of equipment used ranging in cost from 25 to 35 cents per tree. Removal of Trees. — In the case of unprofitable orchards or of orchards too closely planted it is sometimes necessary to remove all or some of the trees. This may be accomplished best by pulling them when the ground is wet, or b}^ blasting when the ground is dry. One method of removal by pulling is by means of a team or tractor and a tackle with a chain around the trunk near the ground. Another method is by means of a portable derrick (fig. 8), which is set in place over the stump to be removed. Trees to be removed may previously be cut back to stumps and these left to die and the roots to partially 15 Barnard, L. C. Central wire bracing for fruit trees. California Agr. Exp. Sta. Cir. 244:1-10. 1922. 1930] Peach Culture in California 33 decay, in order to make pulling' easier. Axes, and dynamite may be used to cut roots to loosen those trees which are very difficut to remove. On the basis of removal of peach trees from ten acres, it is esti- mated that the cost per tree will average eight cents when a heavy tractor is used, or about fifteen cents when a stump puller is used.^^ Fig. 7. — Bracing by means of wooden pro])s. Tliis is a three-year-old Paloro peach tree which bore a crop at the rate of seven tons per acre at this age. Under some conditions the costs may be partially or wholly offset by the sale of wood for domestic purposes, three mature peach trees giving approximately one tier. Such a tier may cost from $2.25 to $3.00 for pulling and cutting combined, and has a sales value of from $2.00 to $3.50 16 Unpublished costs supplied by E. F. Serr, Assistant Farm Advisor of Sutter County. 34 California Agricultural Extension Service [Circ. 42 1930] Peach Culture in California 35 IRRIGATION The majority of the feeding roots of peach trees are probably within the upper six feet of soil. The moisture in this soil area is rapidly depleted dnring the growing season, bnt it appears possible for roots to take some moisture from greater depths. In most localities irrigation is necessary during the summer. It is impossible to store moisture in the upper six feet of soil in mature orchards for any long period of time during the growing season as the trees exhaust the supply rapidly. Hence, it is customary in many peach orchards to begin irrigation between April 15 and May 15, and follow with one or more irrigations before the crop is harvested. For normal growth of the tree and fruit it seems desirable for the soil to be adequately supplied during the growing season. There is little evidence that winter irrigation is necessary where winter rains are ample. In some districts, however, where irrigation water is available only during the winter months, and the rains are insufficient to fill the soil to the water holding capacity, winter irrigations may be given (fig. 9). Trees, however, should be ade- quately irrigated in the fall, and the soil should not be permitted to become dry after harvest and during the weeks preceding the winter rains. It is estimated that the peach should have an average annual minimum of 16 inches of rainfall, or its equivalent on soil having a high water holding capacity. Twelve to sixteen inches of rainfall in the winter insures enough water to fill six feet of average soil to the maximum field capacity. The excess water percolates to lower depths and may help to maintain the tree over dry summer months through its extraction by the deeper roots. It is necessary though to supple- ment the rainfall with irrigation. Where the soil depth is limited by bedrock and hardpan, water in excess of a limited amount which can be held in the soil or on the bedrock is lost as runoff. Experience shows that, even w4th abundant winter rainfall, summer irrigation will usually pay. A decision as to whether there is enough moisture in the soil is dependent upon the particular orchard. Young trees use less water than older trees, although it is usually advisable to irrigate to promote the growth of young trees. A soil sample taken to the depth of six feet by means of a soil auger or other tool is the best way to determine when to irrigate. A simple method is to take some of the soil sample and squeeze it in the hand ; if the soil crumbles easily upon releasing, irrigation is needed. 36 California Agricultural Extension Service [Circ. 42 An irrigation after the crop is harvested, generally in September or October, will benefit the trees and put the soil in condition to favor the germination and growth of the cover crop. This irrigation also aids fruit bud development and is, therefore, important from the uL Fig. 9. — Winter irrigation by means of tlie clicck or basin systerri. standpoint of the succeeding season's crop. It is desirable to keep an available supply of moisture in the soil throughout the year, since with sufficient moisture root growth may continue during late fall and winter months even though the top is dormant. 1930] Peach Culture in California 37 Methods of Irri(jatio7i. — There are three common methods of irri- f»ating' known as check (basin), furrow, and contour.^" With the basin or check system the soil is ridged into low levees by means of a disk or ridger forming basins, each having one or more trees. Water is allowed to flow from one check to the next, by cutting the levee when the upper check is filled. A nearly equal quantity of water is thus supplied to each tree (fig. 9). The furrow system is another means of irrigating. It is adapted to the use of small heads of water. Furrows may be used on gradual to somewhat steep slopes. The method works better if the land is graded before the trees are planted. Less labor is involved in irrigat- ing by furrows than with the basin or check system. The objection to the furrow system is that water may not be uniformly distributed through the soil and it is nearly impossible to wet the entire soil mass. The contour method of irrigation is particularly adapted to small heads of water and steep grades, but a modification is also used on fairly level slopes. Brainage}^ — Excessive use of irrigation water should be avoided. The judicious use of water is an important means of checking the rise of ground water and the consequent alkali injury. Ditches should be provided to take care of the runoff and to prevent standing- water. The practical way to lower the water table is to install a drainage system of tile or ditches. Drainage alone, however, ^vill not satis- factorily correct an alkali condition.^ ^ PEACH DISEASES AND THEIR CONTROL Common diseases occuring in California peach orchards may be divided into three classes, diseases resulting from: (1) bacteria, (2) fungi, and (3) diseases not caused by organisms, but attributed to functional disorders. Symptoms of Diseases. — Diseases usually have characteristic symp- toms. In some cases the same symptom may indicate any one of several diseases or even possibly an insect pest, as, for example, the presence of gum. It is advisable for the peach grower to be familiar with the characteristics of the more important diseases so as to be able to recognize them if tliey appear, and to apply a remedy if feasible. 1" Huberty, M. R. and J. B, Brown. Irrigation of orchards by contour furrows. California Agr. Ext. Cir. 16:1-16. 1928. 18 Weir, W. W. Drainage on the farm. California Agr, Exp. Sta. Cir. 304-1-30 1926. 19 Kelley, W. P. and E. E. Thomas. Reclamation of the Fresno type of l)lack- alkali soil. California Agr. Exp. Sta. Bui. 455:1-37. 1928. 38 California Agricultural Extension Service [Ciro. 42 The Control of Peach Diseases. — Peach diseases are usually con- trolled in one or more of the following ways : (1) by planting a variety that is immune or resistant to the disease; (2) by planting a variety only in the locality where the disease is not serious; and (3) by the use of direct control measures, such as spraying or disinfection.-" The quarantine service is a means of preventing the introduction and spread of new diseases and insects within the state. Fig. 10, — Peach roots of young tree infected with crown gall. Crown Gall, Bacterium tiimefuciens S. & T. — The bacterium caus- ing crown gall or root knot is found in many soils. Swellings or tumor- like enlargements are formed on the crown and the main roots and sometimes on above ground parts of the tree (fig. 10). A tree affected by this disease shows a loss of vigor, and may eventually die. The trouble may be lessened by inspecting and rejecting diseased nursery trees, and by care in cultivation so as not to wound the trees. Examine the crown and main roots of stunted trees for evidences of the disease 20 Home, W. T., E. O. Essig and W. B. Herms. Plant disease and pest control. California Agr. Exp. Sta. Cir. 265:1-132. 1927. 1^30] Peach Culture in California 39 and if found the galls should be chiseled off. The wounds should then be disinfected with a solution containing one ounce of mercuric chloride and one ounce of mercuric cyanide dissolved in four gallons of water. Then cover the wounds with a thick coating of Bordeaux paste. If the tree is badly affected it should be taken out, using fresh soil when replanting. Bacterial Gummosis, Bacterium cerasi Griffin. — This disease at- tacks buds, branches and trunks producing a copious, yellow to amber colored gum. The bacteria are probably transmitted on pruning tools and enter at the wounds, spreading in the conducting tissues of the tree, being active during cool, moist weather. If the disease has not progressed too far it may be checked by cutting out the gum pockets and scraping the cankers so as to remove the affected darkened tissues. Disinfect the wounds with a solution of one ounce of mercuric chloride and one ounce of mercuric cyanide dissolved in four gallons of water. For the bud and twig form it is suggested that the diseased parts be pruned out. No further recommendations are available but studies are being made for more accurate diagnosis of a number of forms of gumming. Brown Rot, Sclerotinia spp. — Brown rot is not often serious on peaches in California but may attack orchards in moist districts or near the coast. Occasionally it attacks blossoms causing them to turn brown and wither. Spurs or twigs may become infected and exude small amounts of gum. Ripening fruit and packed fruit is attacked and rots, becoming covered with grayish spores. The fungus remains alive in the dead twigs and mummified fruits. Where this disease is prevalent, spray with Bordeaux mixture 5-5-50 or liquid lime-sulfur, 6 gallons to 100 gallons of water, or its equivalent with dry lime-sulfur at the 'pink stage.' Pick off mummified fruits that are hanging to the tree and burn them. Leaf Curl, Taphrina deformans (Fel.) Tul. — This is a common peach disease but is easily prevented. Young leaves show a red ruffled distortion and become markedly curled before they finally drop. Twigs and fruit may also become blistered and deformed. If the weather is moist and cool, spores continue to germinate and produce infections throughout the spring months causing further injury by a loss of leaves. Spraying either in the fall or spring before the buds open will control this disease. Use Bordeaux mixture 5-5-50 or lime-sulfur, at the rate of 6 gallons to 100 gallons of water, any time after the leaves have dropped in the fall up to the time the fruit buds begin to open in the spring. 40 California Agricultural Extension Service [Circ. 42 Peach Blight, Corxjneiim heijerinckii Oud.— This has been a com- mon disease in the interior valleys of California bnt may be readily controlled. The fungus causing the trouble is active in the winter, attacking buds and twigs. In the spring the spores may infect new leaves and sometimes the fruit. Buds are infected, and later gum and dead areas appear in the twigs, frequently resulting in girdling and the loss of much fruiting wood. Red spots may also appear in the fruit when infected. Spraying with Bordeaux 5-5-50, or with liquid lime-sulfur, 6 gallons to 100 gallons of water, or its equivalent in dry lime-sulfur, in the fall between November 1 and December 15, will effectively control this disease. Peach Mildew, Sphaerotheca pannosa var. persicae (Wallr.) Lev. — Peach mildew is becoming more prevalent in certain districts. White powdery patches appear on young leaves, twigs and fruit. The fungus affects the epidermal tissues and checks their growth. The whitish patches on the fruit later turn brown and result in flattened areas. Definite control measures have not been determined but it is suggested that sulfur dust be applied in the early summer at the first indication of the disease in the district and that applications be repeated if necessary. Peach Rust, Tmnzsclielia punctata (Pers.) Arth. — Peach rust has recently appeared, causing serious loss in certain districts of Califor- nia. It attacks principally the mid-summer clingstone peaches but has also been found on other varieties. There are three places of infection, namely, new twigs, leaves and fruits. Spores infect the current season twigs in the fall. Bark pustules appear the following spring and give oft' spores to infect surrounding leaves and young fruits. Yellow angular spots appear in the leaves and dark pitted areas are formed on the fruit. Spraying with liquid lime-sulfur, 6 gallons to 100 gallons water, or its equivalent in dry lime-sulfur, early in the fall (October 15-November 1) will control this disease. If the disease appears in the leaves in early summer the fruit infection may be prevented by spraying as soon as possible with liquid lime-sulfur 1 gallon to 100 gallons of water. A stronger spray will be injurious to the foliage. Oak Root Fungus, Armillaria mellea (Vahl.) Quel. — This is a root disease which spreads underground. Affected trees may fail gradually or die suddenly, at any season of the year. By removing the bark from near the crown of the tree the yellowish-white, fan-shaped mycelium of the fungus which is responsible for the wood decay may be observed. The disease spreads mainly by. underground, slender, 1930] Peach Culture in California 41 thread-like fibers (rhizomorphs) from tree to tree. It presumably originates in areas where oak roots have decayed. Therefore, such areas if known, should be avoided or planted to a resistant tree. There is no known method of control. Surgery may be practiced on a tree if not too far gone. Isolating the diseased trees by digging trenches or constructing underground barriers around the infected area may be suggested but this seems to be impractical in most cases. The Cali- fornia black walnut (JiigJans calif ornica hindsii), the fig (Ficus carica) and the French pear {Pyrus comniunis) roots seem to be three species which are resistant to this disease and are used in replanting in oak root infected spots. ^^ Sour Sap. — Sour sap is a general term applied to a trouble that is, so far as known, not caused by a definite parasite, although some forms may be due to specific organisms. The ordinary forms of sour sap are associated with extreme variations in soil moisture and temperature. It seems to appear on hardpan soils or during periods of surplus water in the soil. Good drainage is essential. A furrow may be dug in early winter on either side of the tree row to provide surface drainage and prevent the soil from remaining saturated for long periods. In certain cases where injury has been noted from a temporary high water table, which has later subsided, recovery has been aided by removal of soil from around the trunk and main roots so as to expose them to air. Die-Back, Gumming, Yellows, and Split Pit. — -These are abnormali- ties, the causes of which are not as yet known. Most of these troubles seem to be related to abnormal soil conditions. Trees standing over old barnyards or on hardpan soils, or under conditions of irregular soil moisture are likely to show some of these troubles. The most promising methods of treatment are to increase the humus content of the soil by means of green manure crops, to break up the hardpan and to irrigate so as to insure a uniform moisture condition in the soil to a depth of several feet. Where these troubles are serious and persistent it may be better to grow some other crop. THE CONTROL OF INSECTS AND OTHER PESTS The insects may be placed in two groups, namely, chewing and sucking insects. Chewing insects remove and swallow parts of the plant surfaces. Such insects are controlled by the application of stom- ach poisons. On the other hand, the sucking insects withdraw the plant 21 Hendrickson, A. H. Oak fungus in orchard trees. California Agr. Exp Sta. Cir. 2:89:1-13. 1925. 42 California Agricultural Extension Service [Circ. 42 juices from the interior and, therefore, are not subject to control by poisons on the surface of the leaves, bark, or fruit. Instead some material must be applied directly to the insects and thus cause death by contact. Such materials are called contact insecticides. A few insects of the peach are not readily controlled by either contact or poison materials, but require special means of control. Fig. 11. — Using paradichlorobenzene for control of poach borer. Lett, Tlie ring method, first step: leveling the surface of the ground for a space of two or three feet in diameter about the tree. Right, second step : the paradichlorobenzene applied in a ring two or three inches wide, the inside about three inches from the bark of the tree. (From California Agr. Exp. Sta. Bui. 411.) Pacific Peach Tree Borer, Aegeria opalescens Hy. Edw. — This insect is serious in certain counties and is distributed throughout coastal, central and southern parts of the state. The dark wasp-like moth lays its eggs in the early spring on the trunk of the tree a few inches above the ground. The larvae which hatch in fifteen to thirty days, burrow into the trunk and main roots, and may girdle the tree, thus killing it. Gum and frass indicate the presence of the borer. Control measures are simple since the discovery of the paradichloro- benzene treatment. This crystalline material is sprinkled in a circle around and near the base of the tree and covered with soil (fig. 11). The heavy vapor penetrates the soil and burrows, killing the insects. The material should be applied in the late summer and fall when the soil is warm and the moisture not excessive. Flat-headed Apple Tree Borer, Chrysolothris mail Horn. — The beetles lay their eggs, especially in sunburned or injured areas or on 1980] Peach Culture in California 43 trees showing low vigor. The whitish larvae, having a flattened portion just behind the head, hatch in the spring and mine the inner bark and sapwood and may girdle the branch or trunk. Prevent sunburn by proper pruning and whitewashing, and avoid injuries or wounds to the tree. Keep the tree vigorously growing by supplying sufficient water and thus discourage egg laying by the beetles. When borers are in the tree the only feasible control is digging them out. Fig. 12. — Fruit damaged by peach twig-borer, showing surface injury. (From California Agr. Exp. Sta. Bui. 355.) Peach Twig-Borer, Anarsia lineatellaZell. — This is a small reddish- brown caterpillar about one-half inch long, which burrows into and kills buds and twigs, and may infest the fruit. The larvae hibernate just beneath the bark in crotches of the smaller branches, and emerge in the early spring to infest buds and new shoots. Later they change to tiny moths which fly about the orchard depositing eggs. These give 44 California Agricultural Extension Service [Circ. 42 rise to a second and to subsequent generations of caterpillars which infest fruit. By their feeding the late caterpillars sometimes destroy large amounts of marketable fruit (fig. 12). Where this pest is serious it may be controlled by spraying with liquid lime-sulfur, 9 gallons to 100 gallons water, before the buds swell. Where Bordeaux mixture is preferred combine with arsenate of lead, 3 pounds to 100 gallons of spray. Nicotine sulfate, % pint to 100 gallons of water, will also kill this insect if applied at the time the caterpillars are present on the surface. Leaf Eating Caterpillars. — There are various kinds of chewing insects which eat peach foliage, including cankerworms, red-humped caterpillars, tent caterpillars and leaf rollers. Different methods of control may be used, but in general, spraying with basic arsenate of lead, 3 pounds to 100 gallons of water, at the time the insects first appear will give good results. Pyrethrum or buhach powder, 2yi> to 5 pounds soaked over night in 5 gallons of water, and then enough water to make 200 gallons of spray, has been effective in the control of cankerworms. Pyrethrum is non-poisonous to humans and may, therefore, be used in preference to arsenate of lead when spraying the fruit near harvest time. Black Peach Aphis, Anuraphis persicae-niger Smith. — This is a shiny black plant louse that appears in great numbers on tender shoots and fruit in the spring. They are easily controlled by spraying with 1 ])int of nicotine sulfate and 4 to 5 pounds of fish oil soap to 100 gallons of w^ater, or by dusting with nicodust, as soon as the insects appear. This insect also sometimes infests the roots and may be killed by the paradichlorobenzene treatment. Scale Insects. — Various scale insects such as San Jose scale (Aspid- iotus perniciosus Comst.), the black scale (Saissetia olene Bern.), the peach scale (Lecanium persicae Fab.), the brown apricot scale {Lecanium corni Bouche) and others may become serious pests on the peach. The lime-sulfur sprays which are applied for other pests will generally keep these insects under control. However, if they become severe, oil sprays applied in the winter months (December-January) may be necessary. Red Spiders. — There are two forms of red spider which may infest peach trees; namely, the brown mite {Bryohia praetiosa Koch) and the common red spider {Teiranychiis telarius Linn.). The former hiber- nates in the ^^^ stage on the trees, adults appear in early spring, and may become numerous during the summer. It is rarely troublesome but when it is serious one of the heavy oil sprays applied in the winter months will control this form. The common red spider, on the other 1930] Peach Culture in California 45 hand, which is most widely destructive, hibernates as an adult in the soil or crevices on the bark of trees as well as on other plants. Adults of this form appear about May or June and continue feeding and egg laying- thoughout the summer. Summer oil and sulfur sprays and sulfur dusts seem to be effective against this pest. Red spiders are less injurious in orchards that are well supplied with soil moisture than in orchards that are suffering from drought. Gophers. — There are five methods used for destroying gophers, namely, (1) poisoning, (2) trapping, (8) fumigating, (4) flooding, and (5) protection of the gopher's natural enemies, especially the barn owl and the gopher snake. A combination of two or more of the above methods is more certain than miy one of them. Traps are especially satisfactory for individual gophers in orchards. Poisoning and fumigation are used when gophers are numerous over a large acreage. Flooding is automatic when the orchard is irrigated and it is easy to kill the gophers which are flooded out.'^- Ground Squirrels. — Ground squirrels may be controlled by the methods employed for gophers except that flooding is not effective. These methods are used at various times depending on the dampness of the soil and the habits and life cycle of the squirrels. Poisoned grain is used to a considerable extent and is perhaps the most satisfactory remedy. Rabbits and Deer. — Rabbits and deer are sometimes abundant and become serious pests in young orchards. Shooting, poisoning and fencing are the principal means of protection. SPRAYING AND DUSTING It is practically impossible to grow peaches commercially without the use of sprays or dusts, or both, because of the various disease and insect pests. The use of fungicides and insecticides has become a regular part of the orchard business. There are many kinds of standard spraying and dusting machines as well as reliable materials that the fruit grower may purchase for use in his orchard. As has been stated previously, peach trees require spraying at critical times with certain materials. In order to do this efficiently a power sprayer is almost essential. For emergency purposes, where quick and economical methods are imperative, a power duster is often advisable. The spraying or dusting machinery should be kept in good condi- tion and ready for action when the time arrives for its use. The 22 Dixon, Joseph. Control of pocket gophers and moles in California. California Agr. Ext. Cir. 29:1-16. 1929. 46 California Agricultural Extension Service [Circ 42 proper spray materials should be obtained with the view of securing the best for the particular pests to be combatted. While it is sometimes advisable to make sprays at home it is now generally considered more satisfactory to purchase proven proprietary compounds from reliable spray companies. With standard materials and average sized trees, it costs from 6 to 8 cents per tree including labor for each application. This application of the sprays or dusts to the trees is a most important consideration. Too many growers slight this operation. It is well for the grower to study the pests and to learn about their habits in order to apply control measures more intelligently. The proper timing of the application is sometimes more important than anything else. Thoroughness is another warning that must be repeated. The spray or dust should be applied to completely cover the parts of the tree where the pest is or will be expected. TABLE 3 Expenses per Acre on Full Bearing Orchards in Stanislaus County, 1925-192823 Average Item annual costs Pruning and brush disposal $26.47 Irrigation 6.50 Cover crops 3 12 Cultivation 15.89 Thinning 28 32 Propping 4 26 Harvesting 54 04 Hauling to cannery 14 83 Spraying 13.85 Miscellaneous 4 97 General expenses 7 72 Irrigation taxes '. 5 84 County taxes 8.07 Average sub-total $187. 16 Interest and depreciation on trees 41.98 Interest and depreciation on improvements 1 03 Interest and depreciation on equipment 5 46 Interest on investment in land 20.84 Total cost $256.48 Total acres in study 156. 21 COSTS OF PEACH GROWING The cost of producing peaches is profoundly modified by many variable factors. The most accurate and far reaching information regarding costs is that now being obtained by the Agricultural Exten- ds Data for tables 3, 4, and 6 taken from: Fluharty, L. W., F. E. Wilcox, and A. A. Jungerman. Summary of the peach efficiency study for Stanislaus County, 1925-28. (Mimeographed.) Agricultural Extension Service, University of Cali- fornia. 1929. 1^30] Peach Culture in California 47 sion Service. In Stanislaus Comity costs on a number of full-bearing orchards have been completed and summarized for the past four years. In Tulare County similar work has been conducted for the past three years and in Sutter County for one year. The work in each county is designed to cover a period of at least five years. It is felt that any information covering a shorter period may not be representative of true conditions. Information presented in tables 3, 4, 5, 6, and 7, should be considered in the light of conditions which have prevailed for the years covered. Costs, returns and profits in 1929 may show a different picture from that presented here, showing that a long period is necessary in order to determine actual costs with a high degree of accuracy. TABLE 4 Expenses per Ton on Full Bearing Orchards in Stanislaus County, 1925-1928 Average Item annual costs Pruning and brush disposal 12. 11 Irrigation .54 Cover crops .24 Cultivation 1.26 Thinning 2.27 Propping .29 Harvesting 4.40 Hauling to cannery .90 Spraying ■. 1.17 Miscellaneous .21 General expenses .72 Irrigation taxes .49 County taxes .67 Average sub-total $15.49 Interest and depreciation on trees $3.52 Interest and depreciation on improvements .08 Interest and depreciation on equipment .46 Interest on investment in land @ 6% 1.75 Total cost $21,30 Tons per acre 12 23 Tables 3 and 4 give the average annual costs of production per acre and per ton respectively, for a period covering four years (1925 to 1928 inclusive) in Stanislaus County. These tables include all varieties and only those orchards over six years old. A total of one hundred and fourteen records are included in the average. Tables 5 and 7-^ show general costs of growing canning peaches in Sutter County for the 1928 season when prices received by the grower were $20.00 a ton. All important varieties are included in this table. 24 Data for tables 5 and 7 adapted from peach cost report for Sutter County by E. H. Klamt, Farm Advisor, 1928. 48 California Agricultural Extension Service [Ctrc. 42 TABLE 5 The Average Costs and Eeturns of Canning Peaches in 1928, Sutter County Item Dollars Labor cost per acre 141.36 Material cost per acre 17.99 Cash overhead per acre 19.01 Other overhead per acre 101.05 Total cost per acre 279.41 Total income per acre 238.28 Net loss per acre 41. 13 Labor cost per ton 11.85 Material cost per ton 1.51 Cash overhead per ton 1.59 Other overhead per ton 8.47 Total cost per ton 23.42 Total income per ton 20.00 Net loss per ton 3.42 Number of records 29.0 Total acres 287.5 Acres per record 7.37 Trees per acre 102.0 Tons per acre 11.93 TABLE 6 Comparison of Costs, Yields, and Returns per Ton, by Varieties, on Full Bearing Orchards for 1928 ; Stanislaus County Tuscan Mid- summers Free- stones Phillips Number of records 8 32.75 9 77 8 7 66 11 83 7 10 74.5 14 4 8.2 13 Total number acres 66.8 Average tons per acre 15 3 Average age trees 9 6 Pruning and brush disposal Cost per ton f2 42 1.37 .08 1 05 3 44 .18 7.52 .32 1.49 .31 .91 60 .78 v^osiperton $1 87 .30 .17 .77 1.97 .37 4 23 1.01 1 52 .12 .62 .46 .64 Cost per ton $1 65 57 .07 .82 .81 .52 3 61 .51 .70 .14 .55 .42 .55 Cost per ton %i.n Irrigation .24 Cover crops .12 Cultivation .65 Thinning 2 35 Propping .23 Harvesting 4 35 Hauling to cannery .84 Spraying 92 Miscellaneous .10 General expenses .58 Irrigation taxes .35 County taxes .57 Average sub-total $20.47 $14 05 $10.92 $13 12 Interest and depreciation on trees $4.32 .21 1 59 2.36 $3.77 .16 .44 1.77 $2 85 .16 33 1.46 $2 80 Interest and depreciation on improvements .09 Interest and depreciation on equipment Interest on investment in land .44 1 25 Total cost $28.95 $20 19 $15 72 $17 70 Average income per ton*.... $20.00 $19.70 $19 56 $20 00 Net profit or loss per ton -$8.95 -$49 $3.84 $2.30 * The income per ton is based on the average price paid by the California Canning Peach Growers Association for various grades in 1928. 1930] Peach Culture in California 49 When peach prices are low it is evident that the Tuscan variety is not profitable, and it appears likely that this early peach will be replaced by other varieties. TABLE 7 Comparison of Costs, Yields and Eeturns peii, Ton by Varieties on Full Bearing Orchards for 1928, Sutter County Tuscan Midsummers Phillips 10 17 12 51 9 123.35 112 25 5.19 7 25 9 36 95 00 100 00 102.00 7 36 12 86 13.03 $119.48 $147.01 $145 27 16 12 18 30 18 50 19 32 19 82 17.93 90 39 105 43 101 16 245 31 290 56 2S2.91 147 15 257 11 239 72 93 16 33 45 23 19 16 24 11 41 11 15 2 19 1 42 1 42 2 6; 1 54 1 38 9 61 8 19 7.77 30 67 22 59 21 72 20.00 20 00 20,00 10.67 2 59 1.72 Number of records Total acres Acres per record Trees per acre Tons per acre Labor cost per acre Material cost per acre Cash overhead per acre . Other overhead per acre Total cost per acre Total income per acre Net loss per acre Labor cost per ton Material cost per ton Cash overhead per ton... Other overhead per ton... Total cost per ton Total income per ton Net loss per ton The Tuscan variety in Sutter County, as is true in Stanislaus County, is less profitable than the later varieties of canning peaches. This is accountable to a lower yield of merchantable and high quality fruit. HARVESTING AND HANDLING Within a comparatively short period the larger part of the groover's peach crop is harv^ested, and the profit for the year's work is greatly dependent upon how well this is done, whether the crop is sold fresh, canned, or dried. The cost of harvesting peaches ranges between $4.00 to $5.00 per ton. Fresh Fruit. — When suitable for market the fruit is fully developed and almost fully colored. The flesh is firm and will withstand hand- ling. When fully ripe the peach is well colored and the flesh is soft and so easily bruised that it will not withstand shipping. Between market ripeness and full ripeness, peaches increase in sugar. During a similar period the total weight of the fruit increases almost 12 per cent. This indicates the importance of permitting peaches to remain uDon the trees as long as possible and yet arrive upon the market in 50 California Agricultural Extension Service [Circ 42 good condition. The grower gains in the weight of the crop by this delay and the consumer receives a higher quality of fruit. -^ Under California conditions for long distance shipment, the peaches are picked somewhat more immature than is desirable for local mar- kets (fig. 13). At the packing house the peaches are graded and each individual fruit is wrapped and packed in standard California peach boxes. The packed fruit may be precooled and shipped in iced refrig- erator cars to eastern markets. Fig. 13. — Harvesting operations in a peach orchard. Pickers using metal picking pails which are emptied into lug boxes shown stacked in the row. Automobile trucks haul the lug boxes to the packing house, shipping point, or cannery. Drying Peaches. — Peach drying is most extensively practiced in the Sacramento and San Joaquin valleys. Some peaches are dried in southern California ; but few along the coast or in the foothills. Only firm yellow freestone varieties, principally the Muir, Lovell and Elberta, are dried commercially. In the San Joaquin Valley peach drying begins as early as July 15 with the Muir and continues into September with the Lovell. In the Sacramento Valley most of the peaches are dried during August. The drying ratio of Muir and Lovell varies from 4 :1 to 6 :1, while the Elberta will shrink from 6 :1 to 8 :1. 25 Duruz, W. P. Harvesting and handling California peaches for eastern ship- ment. California Agr. Exp. Sta. Cir. 241:1-21. 1922. 1930] Peach Culture in California 51 A general average drying ratio would be about 5:1. The average yield of dried peaches is about 1% tons per acre.^^ Peaches for drying are picked when they have a uniform yellow color, are fully mature and have begun to soften but are still reason- ably firm, and can be easily cut with a sharp knife and yet retain their shape. Peaches are cut by running a sharp knife around the line of the suture so that the knife blade returns to the point where the cut began. The halves of the peach are separated, the pit removed and the two halves laid on a clean tray with the cut surfaces up (fig. 14). The Fig. 14. — Tray of peaches in the process of drying. full trays are placed on a low truck and when the stack is completed it is transferred to the sulfuring house (fig. 15). Peaches are normally exposed for from three to three and one-half hours to dense fumes of burning sulfur which is used at the rate of about seven pounds per ton of fresh fruit. After sulfuring is complete, indicated by the moist cut surface and disappearance of red color, the trays of peaches are transferred by truck to the dry-yard where they are exposed to the sun. The fruit should remain exposed to direct sunshine until it is from a quarter to half dried and has acquired a uniform color. This requires from one to five days according to the temperature and air movement. The trays should then be stacked in a staggered pile with the open ends in the direction of the prevailing winds. After two to six days in the stack the fruit will be dry enough for storage as indicated bv the 26 Christie, A. W. and L. C. Barnard. The principles and practice of sundrying fruit. California Agr. Exp. Sta. Bui. 388:1-60. 1925. 52 California Agricultural Extension Service [Circ 42 leather}^ texture of the product. The total drying time varies greatl}^ with locality and weather conditions but averages eight days for peaches. Before the dried fruit from each tray is scraped into lug or sw^eat boxes, discolored pieces, pits, or other foreign matter, should be picked out. This important culling can be done much more efficiently and economically at this point than at any later time. The dried fruit is then transferred fiom the dry-yard to the storage building, where it is 'sweated' so as to equalize the moisture content, and is there held until marketed. \ i ^v Fig. 15. — Typical sulfur houses with counterpoised door hinged at top. Note transfer and tray cars. (From California Agr. Exp. Sta. Bui. 388.) Canning Fruit. — The fruit is shipped or hauled to the nearest cannery. The cannery has certain requirements as to the condition of the fruit that is accepted and gives the grower instructions regarding the desired maturity for harvest. Fruit of 2% inches or more in diameter is demanded for grade No. 1, and it must be firm, ripe, clean and free from blemishes. The cannery may, however, accept No. 2 grade of smaller sizes and also some slightly bruised or overripe fruit for making jams and for pie fruit. The fruit when canned must have a pleasing golden color (if a yellow fleshed variety), be firm in texture, high in flavor, and of high sugar content. The flesh must not 'rag' in the syrup or show red at the pit. The syrup should remain clear. These requirements are demanded by the consumer. 1930] Peach Culture in California 53 MARKETING The subject of marketing is a complex one and an adequate discus- sion of it is not within the scope of this publication.-^ Because of the probable heavy production continued difficult marketing conditions may be expected for several years, unless the crop is abnormally reduced by frost or other unfavorable conditions. During the next few years when the profit from peach growing in many districts is likely to be uncertain, growers should make every effort to economically produce and market high quality fruit. Peaches that are small in size, or of poor quality and condition, cannot be profitably marketed and tend to depress the price of high quality fruit. Proper cultural, handling, and marketing practices are especially important at this time (fig. 16). Fig. 16. — Properly packed boxes of peaches present an attractive appearance. (From California Agr. Exp. Sta. Cir. 241.) Fresh Peaches. — Peaches are sold fresh in four ways : ( 1 ) at local sales; (2) to independent buyers; (3) to independent associations or distributors; and (4) to bona fide growers' organizations. The larger proportion of California fresh peaches are marketed in the area west of Chicago and north of Omaha. In this area during August, 1925, Portland was the most important market, followed by Chicago, Minneapolis, St. Paul, Omaha, Milwaukee, Seattle, Spokane, and Denver. Other peach producing sections ship to these markets whenever the prices make it justifiable. The development of refrigera- tion and fast freight makes it possible for each of the main producing 27 Wellman, H. R. Peaches. California Agr. Ext. Cir. 1:1-64. 1926. 54 California Agricultural Extension Service [Circ 42 sections to reach the principal markets in the United States. There- fore, other states are potential competitors even though they are separated by the width of the United States. The prices received by California growers for fresh peaches are determined by factors over which they have little control. These are : (1) the level of prosperity in the consuming markets; (2) the weather conditions at the time the fruit arrives; (3) the competition of other fruits and vegetables; and (4) the total amount of peaches offered for sale, which in turn depends upon the total production of fresh peaches in the United States. Drying Peaches. — Growers may market their dried fruit through agents of independent packers who pay what appears to be a fair price, and thus the prices received will depend upon the reliability of the agent and the demand for dried fruit. Dried fruit may also be sold through cooperative associations, who return to the growers the market price received, less operating charges. The amount of total x)roduction of dried peaches exported has within recent years varied from 10 to 25 per cent. The production of dried peaches reached a maximum about 1915, and since that time it has gradually dropped off due to the lessened demand. In 1924 Germany was the most important market for our dried peaches taking about 43 per cent of the total export. The United Kingdom followed with 17 per cent; Canada with 15 per cent; Netherlands 11.5 per cent, and Sweden with nearly 5 per cent. Canning Peaches. — Since producers of canning fruit have not been organized in many of the peach districts, they have sold their crop largely to local canneries or agents of distant canneries generally for a contract price. Growers who belong to a cooperative association are relieved of the direct responsibility of marketing. They are directed as to where the fruit should be delivered, and receive their payments from the association. The export of canned peaches to foreign markets has steadily increased during recent years. In 1925 about 15 per cent of the total pack was exported. The United Kingdom took approximately 79 per cent, with Cuba, Canada, and Germany ranking in the order named. 1930] Peach Culture in California 55 ACKNOWLEDGMENTS The writers desire to express their appreciation of the helpful suggestions received from the following individuals : F. W. Anderson, Kirkman Nursery Company; J. P. Benson, Farm Advisor, and H. R. Keller, Assistant Farm Advisor, Fresno County; H. M. Butterfield, Division of Agricultural Extension, University of California; Frank A. Dixon, Canners' League of California; A. A. Jungerman, Farm Advisor, Stanislaus County; F. W. Read, California Fruit Exchange; M. M. Winslow, Farm Advisor, Riverside County; R. D. McCallum, Farm Advisor, Placer County; M. A. Rounds, Farm Advisor, Los Angeles County; W. E. GilfiUan, Farm Advisor, Tulare County; R. H. Klamt, Farm Advisor, and E. F. Serr, Assistant Farm Advisor, Sutter County; N. I. Nielsen, Fruit Statistician, California State Depart- ment of Agriculture ; W. C. Tesche, Pacific Rural Press, and George P. Wejdon, Chaffey Junior College. AGRICULTURAL EXTENSION SERVICE CIRCULARS No, 1. Series on Califorina Crops and Prices: Peaches. Home Preparation of Jelly and Marma- lade. 3. Feeding Beef Cattle in California. 4. Irrigation by Overhead Sprinkling. 5. Series on California Crops and Prices: Lettuce. 6. Care and Management of the Milk Goat. 7. Suggestions on Grapefruit Culture in Imperial Valley. 8. Diseases and Parasites of Poultry in California. 9. Rabbit Raising. 10. The Home Preparation of Fruit Candy. 11. Cauliflower Production. 13. The Manufacture of Monterey Cheese. Selection and Care of Electrical Equip- ment Used in Dairy Manufacturing. Pork Production in California. Irrigation of Orchards by Contour Fur- rows. 2. 14 No. 17. Liver Fluke and Stomach Worm of Sheep. 19. Artificial Incubation of Eggs. 20. Pear Blight Control in California. 21. Bovine Tuberculosis. 22. Thinning Sugar Beets. 23. Strawberry Culture in California. 24. Enterprise Efficiency Studies on Cali- fornia Farms. 25. Bush Fruit Culture in California. 26. Tlie Home Vegetable Garden, 29. Control of Pocket Gophers and Moles in California. 30. Elements of Grape Growing in Cali- fornia. 31. Powdery Mildew of the Grape and Its Control in California. 32. What to Do About Bovine Tuberculosis. 33. Rearing Dairy Heifers free from Tuber- culosis and Abortion Disease. 34. Plum Growing in California. 35. Alfalfa Production. 14m-4,'30