u* 1 ° f \'4j Division of Agricultural Sciences UNIVERSITY OF CALIFORNIA ^hii^Q PRODUCTION IN CALIFORNIA " A E. H. STANFORD L. G. JONES V. P. OSTERLI B. R. HOUSTON R. F. SMITH A. D. REED CALIFORNIA AGRICULTURAL Experiment Station Extension Service CIRCULAR 442 . . . California's most important cultivated forage crop . Since 1944, there has been a yearly average of nearly one million producing acres of alfalfa for hay or pasturage in Cali- fornia. The principal producing areas are the San Joaquin and Sacramento valleys and southern California. Yields are influenced by climate, soil, and water supply. They range from 2 to 12 tons per acre, with an average, for the state, of 4.5 tons. Climate. Nonhardy types of alfalfa grow when the tempera- ture rises above 50° F, but they stop growing, temporarily, under very high temperatures, such as occur in the Imperial Valley during midsummer. Soil. Alfalfa does best in well-drained, deep, medium- textured soils of the loam, sandy loam, and clay loam types. It is reasonably tolerant to white alkali, but production is sharply curbed if certain soil conditions do not permit good water pene- tration. Water. Mainly an irrigated crop, alfalfa uses 3 to 6 feet, or more, of water per acre per season for maximum production. The crop is successfully grown on dry land, but with lower aver- age yields. THE AUTHORS: E. H. Stanford is Associate Professor of Agronomy and Associate Agronomist in the Experiment Station, Davis. L. G. Jones is Specialist, Experiment Station, Department of Agronomy, Davis. V. P. Osterli is Extension Agronomist, Agricultural Extension, Davis. B. R. Houston is Associate Professor of Plant Pathology and Associate Plant Pathologist in the Experiment Station, Davis. R. F. Smith is Assistant Professor of Entomology and Assistant Entomologist in the Experiment Station, Berkeley. A. D. Reed is Extension Economist, Agricultural Extension, and Associate on the Giannini Foundation, Davis. NOVEMBER, 1954 s grown throughout the state COUNTY DISTRIBUTION OF ALFALFA HAY ACREAGE IN CALIFORNIA (1947-1951 average) a □ UNDER 1 PERCENT v^s. 1 TO 3 PER CENT 3 TO 10 PER CENT OVER 10 PER CENT Data from California Crop and Livestock Reporting Service ALFALFA PRODUCT THIS CIRCULAR is for the commercial grower who produces alfalfa for hay, pasture, or seed. It contains information involving all phases of production, including Land preparation 5 Seed and seeding 8 Irrigation 10 Fertilizers 11 Soil conditions 13 Varieties 15 Pasturing alfalfa 18 Alfalfa hay 19 Seed production 29 Weed control 34 Pest control 35 This circular replaces Extension Circular 35. 3N IN CALIFORNIA ' &kjS ■'^ ■'/".- ";"■ ,■ L,4iVD PREPARATION Since the alfalfa crop occupies the land for a period of three to six or more years, the preparation of the land is espe- cially important. Careful attention to land grading, construction of levees, and proper drainage facilities results in econ- omy of labor for irrigation and use of water, ease of harvesting, and higher yields during the life of the stand. Methods of Irrigation The principal methods of irrigation are: the border method, contour checks, overhead sprinklers, and, occasionally, wild flooding. Except for special condi- tions, the border method is the best and most widely used. The sprinkler or con- tour methods may be used where costs of grading for the border method would be prohibitive. Irrigation and harvesting operations are more difficult with the contour system. The sprinkler method requires the least land preparation for irrigation, but costs of application are high. The Border Method. In the border method of irrigation the field is laid out with a series of parallel levees to control the flow of water. The checks run in the direction of the slope of the land, with no cross slope between the levees. The strip checks may vary in width from 20 to 60 or more feet, depending on the slope of the land, the type of soil, and the head of water to be used. They vary in length from 330 to 1,320 feet or longer. A low, broad type of levee is generally used, which allows harvesting machinery to pass from check to check and permits seeding across the levee. Drainage facilities for disposing of ex- cess surface water at the lower end of the check are desirable. (For a complete discussion of design, construction, and r 5 1 73 d u u o X bo V O M w 2s » ft s * 1 ar H cD I S M P3 o> o3 ts a 43 & t 3 _-4 bo ^3 S d> iS bo ■fi 2 ? 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Except where the crop is to be irrigated up, the seedbed must contain sufficient moisture to germinate the seed when it is planted and to support subsequent growth. Several preliminary cultural opera- tions must be performed before the irri- gation borders are established. These may include plowing, disking, dragging, land planing, and harrowing. The final operations for the seedbed preparation (following establishment of the irriga- tion borders) are similar, but with cer- tain modifications depending upon the time and method of seeding. For most fall seedings the ground is worked in a near-dry state. Following an irrigation or early fall rains, it is har- rowed and planted. A drill, a broadcast seeder, or an airplane may be used. A light harrowing going across the borders follows the broadcast or airplane seed- ing. Additional firming of the soil with a cultipacker or ringroller will provide the desired degree of compactness. If the stand is to be irrigated up, as is the com- mon practice in the Imperial, Coachella, and Palo Verde valleys, and in certain instances in the San Joaquin Valley, the surface may be slightly rougher, and firmness is not so important a factor since the water will do sufficient pack- ing. In a stand that is to be irrigated up, an extremely loose seedbed must be avoided; otherwise the seed may be covered too deeply, and a poor stand will result. Sprinkler irrigation is often used to insure germination and stand establishment. Many growers have sprin- klers as stand-by equipment. Preparation for spring seeding nor- mally requires a disking and harrowing. A preliminary stirring of the soil is often made to allow germination of spring weeds. Another harrowing and either ringrolling or cultipacking should follow seeding. The following procedure has also been successful with spring seed- ings: Prepare the seedbed early. Just before planting, remove weed growth by use of general-contact sprays. Seed im- mediately with as little disturbance of the soil as possible. Well-prepared alfalfa seedbed with properly constructed levees. Drilling, harrowing, and cultipacking will be done across the levees after broadcast seeding. •>:M' SEED and SEEDING Time of Seeding. The time for seed- ing alfalfa varies in different parts of the state. Growers in south coastal counties experience little difficulty in establishing a stand of alfalfa at any season of the year. In the interior valleys, planting may be either in the spring or fall. Spring planting is practiced in the northern counties because the more severe winter conditions may result in winter killing of fall-planted seedlings. Spring plantings should be made as soon as possible after the first of Febru- ary. The earlier the planting is made the easier it is to maintain favorable mois- ture conditions until the seedlings are well established. Weed control is usually easier with spring plantings because it is possible to clip or spray the weeds at the proper time. On the other hand, spring plantings generally yield only about one half of a full crop during the first season. Fall plantings will yield a full crop during the following season. However, the young plants make little growth dur- ing the cool winter months, and may be smothered out by the more vigorously Proper seedbed preparation results in a good stand of seedling alfalfa like the one shown below. growing winter weeds. Fall plantings should be made early enough so that the plants make a good growth before cold weather sets in. Local practice has usu- ally established the best time of seeding for a particular area. For example in the Sacramento Valley, seeding should be done before October 15, while in the southern part of the San Joaquin Valley, plantings up to November 15 have been successful. Method of Seeding. Drilling in the seed has many advantages over broad- casting. The seed is more uniformly dis- tributed and can be planted at a uniform depth to take advantage of the available moisture. A special alfalfa drill which spaces the rows 4 inches apart or a reg- ular grain drill with a grass seed attach- ment which spaces the rows 6 inches apart can each be used equally well. Drilling should be done across the checks so that the top of the levees will be seeded. Unseeded levees mean that not all the land is being utilized. This reduces yield and provides space for the growth of weeds. Following seeding it is a good practice to roll the field with a corrugated roller in order to hold the moisture over the seeds. Depth of Seeding. Young alfalfa seedlings are not able to emerge if planted too deep. In heavy soils, seeds should not be planted more than % of an inch deep, and in light soils, not more than IV2 inches. Because seeds must be in moist soil to germinate, the seedbed should be very carefully prepared. Rate of Seeding. Planting rates for alfalfa in California range from 10 to 55 pounds per acre. If a good seedbed has been prepared, there seems to be little justification for planting more than 20 pounds of seed per acre. In fact, a seed- ing rate of 10 pounds per acre will give an average of 50 seeds per square foot — far more than is required for a good stand. In this field, alfalfa has been seeded in the dry soil and is being irrigated up. Use of a Nurse Crop. Under most conditions it is not advisable to use a nurse or companion crop with alfalfa. The companion crop will tend to shade out the alfalfa and compete with it for moisture. In areas with light soil and considerable wind, however, the shift- ing soil may destroy young seedlings. Under these conditions, a light seeding of rye, barley, or oats will help stabilize the soil and protect the young plants until they are established. Twenty to 25 pounds of grain per acre is ample. In some of these light soils, alfalfa may be seeded directly into the stubble after a grain crop has been removed. Seed. The cost of seed represents only a very small part of the expense of es- tablishing a stand of alfalfa. The few extra cents a pound spent for the best seed available may be repaid many times over during the life of the stand. Good seed of a recommended variety should be free from weed seeds, especially those of noxious weeds. The State Seed Act requires that all commercial seed be labeled, giving content of weed seeds, purity, germination, and per cent of hard seeds. Hard seeds have coats that are impervious to water, and fail to germi- nate during a six-day test on blotters. When planted in the field, however, most of the hard seeds will germinate in two to three weeks. The important considera- tion in buying seed is total germination. This should be at least 85 per cent, in- cluding hard seed. Inoculation. Vigorous and normal growth of alfalfa depends upon the pres- ence of nodules on the roots of the plants. These nodules are formed by bacteria known as Rhizobium, which fix nitrogen from the air for use by the alfalfa plants. Soil in fields where alfalfa, bur clover, or sweetclover have recently grown usu- ally contains enough bacteria to inocu- late the new plantings. In fields where these crops have not been grown, or where there is doubt as to the presence of bacteria, it is good insurance to inocu- late. Commercial cultures of the bacteria are inexpensive, and may be bought from seed dealers. The cultures come with directions for their application. They are usually dated to insure that they are fresh and contain live bacteria. Seed inoculation is recommended rather than the old method of using soil from an old alfalfa field. The latter involves considerably more work, and may be a means of spreading certain alfalfa dis- eases. Seed Treatment. In general, seed treatment has not been necessary except in a few local areas where considerable "damping-off" of seedlings has occurred. In those areas, treatment of seed with either Ceresan M at 6 ounces, or Arasan at 4 ounces, per 100 pounds of seed, has given improved stands. [9] IRRIGATION REQUIREMENTS Alfalfa is a deep-rooted, close-growing perennial crop which requires adequate soil moisture to a depth of 6 or more feet for maximum production. This is particularly important in the case of young stands. Withholding water will not force deeper root development be- cause roots of the young plants do not push down into dry soil in search of water. A young stand that is irrigated early and often enough to maintain a normal rate of growth will produce a greater yield the first year. The soil should be wet to field capacity at the beginning of the growing season. This can be accomplished by irrigation in winter or early spring when there is less danger of a scald from holding water on the land. Wherever such early irriga- tions are to be used, there must be ade- quate drainage facilities to handle all excess surface water. The most common practice on deep loam soil is to irrigate once per cutting, usually as soon as the hay crop has been removed. On light soil or on soil into which water does not penetrate readily, two or more irrigations per cutting are desirable. If irrigation is applied before cutting, it must be regulated so that the surface of the soil will be dry when the crop is cut. Otherwise, curing may be difficult and mold may develop during the process. The need for irrigation can be deter- mined by examination of soil samples taken at various depths and locations throughout the field. The soil tube or auger is used to obtain the samples. Slow plant growth and extra dark-green leaves Improper irrigation practice is costly. In the field shown above, the alfalfa has been drowned out. Adequate drainage facilities to handle surplus surface water will prevent this condition. [10 also indicate limited available soil mois- ture. The amount of water to be applied is important. Excessive amounts deplete soil nitrogen more rapidly, will raise the general level of the water table, and contribute to drainage and alkali prob- lems. There is no point in putting on a greater amount of water than the soil can hold in the first 6 feet. As a useful guide, 1 inch of water will wet a clay soil 4 to 5 inches deep; a loam soil, 6 to 10 inches; and a sandy soil, 12 inches or more. Drainage. Good drainage is essential to a vigorous growth of alfalfa. A high water table is often the result of poor drainage or of overirrigation. In some areas where the water table is naturally close to the surface, with little seasonal fluctuation, the soils and plants have ad- justed themselves to that condition, and good stands and crops are possible. On good soil, alfalfa can be grown with suc- cess if the water table is stationary at least 3 feet below the soil surface. Ordinarily, alfalfa roots grow down- ward until they strike saturated soil. When the water level fluctuates mark- edly, the submerged portion of the roots will rot off, leaving the plants greatly weakened. This is especially likely to occur if the water level rises during the growing season when the roots are ac- tive; at that stage, complete exclusion of air for even a few days may be very injurious. During the winter months, when the plants are more or less dor- mant, the roots will tolerate submergence for longer periods without injury. Mosquitoes and Irrigation Prac- tice. Mosquitoes are a public nuisance and a hazard to human health and com- fort. Water should not stand on an alfalfa field longer than 24 hours following ir- rigation. Excess surface water that is not removed by adequate drainage may provide a breeding ground for large numbers of mosquitoes. The types that develop most rapidly need at least 3% to 4 days in water, to reach the adult stage, even under extremely warm inte- rior valley temperatures. Proper land preparation, adequate drainage, and careful water use will help keep mos- quito populations to a minimum. Dryland Alfalfa. Whether grown for hay or pasture, alfalfa is a persistent and productive plant under dryland condi- tions. Best results are obtained on deep, fertile soils and where the annual rain- fall is 15 inches or more. Ladak variety, because of its winter hardiness, has proved superior in the northern part of the state. In Modoc County, at an elevation of 3,500 feet, Ladak in combination with crested wheatgrass is seeded to reclaimed sage- brush lands. Elsewhere throughout the state, Caliverde will do best for long rotation. Alfalfa is included as one of the legumes in many of the range re- seedings. FERTILIZER REQUIREMENTS Alfalfa will respond to commercial fertilizers on many California soils. Tests conducted by the Agricultural Extension Service in cooperation with the Depart- ment of Agronomy show that the ele- ments most likely to be deficient are phosphorus and sulfur. Potassium is defi- cient in some areas. Previous experience with fertilizers in the immediate locality should always be considered before ap- plying them to your field. Phosphorus. Phosphorus deficiency is rather widespread, with some phos- phorus-deficient soils in nearly every county where alfalfa is grown. However, the areas of actual deficiency are not in well defined, and form no definite geo- graphic pattern. Deficiencies are most common in alluvial, calcareous soils and in soils with definite hardpan or claypan substrates. On the other hand, many of the deep, neutral, alluvial soils are cur- rently well supplied with phosphorus and now require no fertilization. A number of phosphorus fertilizers are available, and give good results on alfalfa. Annual broadcast applications of 200 to 400 pounds of single super- phosphate per acre are sufficient in most cases. In a few instances, higher rates may be desirable on soils of high fixing power or in areas of acute deficiency. In most cases, 36 to 72 pounds of actual phosphoric acid (P 2 5 ) per acre, an- nually, will supply sufficient phosphorus. It makes little difference whether this is applied as 15 per cent single super- phosphate, 42 per cent treble superphos- phate, or as liquid phosphoric acid in irrigation water. A single application of a phosphorus fertilizer should be ef- fective when made in late winter or early spring, before growth starts. Sulfur. Sulfur is used in California both as a plant nutrient and as an aid in correcting alkali in soil. As a plant nutrient, sulfur is an important fertilizer for alfalfa in many areas, principally in nonirrigated regions of northern Cali- fornia and in areas using very pure water for irrigation. Sulfur deficiencies occur in the allu- vial soils of the Sacramento Valley north of Marysville and in the light sandy soils of the central San Joaquin Valley area. Generally, sulfur may be economically supplied either from gypsum or from elemental sulfur. Plants take up sulfur from the soil in the form of sulfates. Therefore, sulfur must be oxidized to sulfate by bacteria in the soil before the alfalfa roots can take it up. Gypsum is sparingly soluble in watei and, ordi- narily, sufficient sulfur is dissolved after an irrigation or rain to correct a defi- ciency in a few weeks. In dry regions, however, broadcast applications of ele- mental sulfur may require several months to be completely oxidized. Single superphosphate contains about 50 per cent gypsum, which is sometimes enough to correct a sulfur deficiency if heavy application is made. (Occasion- ally, both phosphorus and sulfur are de- ficient. In such cases, single superphos- phate is much more effective than treble superphosphate which contains only traces of sulfur.) Applications of 500 to 1,000 pounds per acre of gypsum will usually correct a sulfur deficiency for at least a year. Alfalfa plants may also utilize sulfur from the air. This usually occurs only near cities and industrialized areas where appreciable sulfur dioxide is pres- ent. Growers occasionally report sulfur response of alfalfa following application of ammonium sulfate. Potassium. Soils most commonly de- ficient in potassium, for alfalfa, occur in the Sacramento-San Joaquin Valley delta and in the region around Chico. At Chico, field tests have shown that 500 to 1,000 pounds of potassium sul- fate per acre are necessary to correct the deficiency and restore normal growth for at least a year. Nitrogen. New seedings of alfalfa often may be stimulated by addition of nitrogen. The nitrogen sometimes en- ables the young seedlings to make more rapid early growth, but it also increases the growth of competing weeds. An ap- plication of 20 pounds per acre of actual nitrogen is sufficient. Barnyard Manure. Manure can al- ways be used to good advantage. The best time to apply it is when the land is being prepared for the crop. Six to 8 tons or more per acre, thoroughly in- corporated with the soil, is ordinarily a satisfactory amount. Manure from un- known sources may introduce some troublesome weed species on clean fields unless proper care is exercised. Fall ap- plication is best on established stands. [12] SOIL CONDITIONS and RELATED PROBLEMS A number of unfavorable soil condi- tions can limit plant growth. These in- clude hardpans and claypans, plowsoles and cultivation pans, and alkali or other- wise unproductive soil areas. Frequently, two or more of these conditions are re- lated, and contribute to the problem. Hardpans and Claypans. These are objectionable mainly because they im- pede or prevent the penetration of water and of plant roots, and, if close to the surface, limit the feeding area of the roots. If the impervious layer is 3 or 4 feet or more below the surface, and over- laid with good soil, excellent crops may still be grown provided care is taken not to use too much water per irrigation. Plowsoles and Cultivation Pans. Alfalfa requires a permeable soil. Sub- soiling, ripping, or chiseling prior to seeding are often highly desirable prac- tices. Such treatment will break up com- pacted layers caused by cultivation and heavy equipment used in previous row crop production. Although the benefit is only temporary, it will help the roots penetrate more deeply. Alkali. There are two types of alkali soils which may occur alone or in com- bination. The first type has an excess of soluble salts, such as sodium chloride and sodium sulfate, and occasionally salts of calcium and magnesium. Soil with these characteristics is popularly called "white alkali." The second has substantial amounts of sodium adsorbed on the soil clay, which often leave a black, salty deposit on the surface con- taining sodium carbonate as well as other salts. This type of soil is generally called "black alkali." Good land grading and drainage are essential to reclamation of either type. Reclamation is usually not successful un- less the water table is 4 feet or more below the surface. White alkali soils may usually be reclaimed by leaching alone, especially if the irrigation water contains sufficient amounts of calcium salts. Black alkali soils ordinarily require the use of soil correctives, such as gypsum or sul- fur, in addition to leaching. Consult your University of California Farm Advisor for details on alkali problems. Alfalfa is tolerant of white alkali, but will not thrive or do well where there are appreciable amounts of adsorbed sodium salts (black alkali), at least in the top foot of soil. Old alfalfa plants will tolerate more alkali than will seedling plants, which are quite susceptible and easily de- stroyed. On land that is badly impreg- nated with white alkali, stands have sometimes been obtained by frequent ir- rigation until the plants are well started. Unproductive Areas. Bare, unpro- ductive areas often occur in fields where little or no growth takes place following the first or second cutting. These bare spots may be caused by poor water penetration resulting from various con- ditions, such as hardpan, plowpan, pud- dled soil, alkali, or high spots. High spots can readily be eliminated by proper leveling. Water penetration, under these conditions, may be improved by fall sub- soiling of the spots, and application of gypsum at the rate of 2,000 to 3,000 pounds per acre. In addition to the gyp- sum, heavy fall applications of barnyard manure at the rate of 10 to 20 tons per acre have given good results. Age of Profitable Stands. The length of time that a stand should re- main in to be most profitable will obvi- ously vary with conditions. Ordinarily, a field reaches maximum production the second year, and then starts to decline. A stand is rarely profitable for more than four to six years, even under the best conditions. [13] When stands are thinned to a point where they are unprofitable, they are ordinarily plowed out. However, com- panion crops are sometimes used tem- porarily. Use of a Companion Crop. Oats or barley are sometimes seeded in alfalfa in the winter following a renovation of the field with a harrow or disk. The first cutting in the spring is a mixture of alfalfa and grain hay, the grain taking the place, in part, of the usual weeds. The cereal materially increases the yield of feed from the first cutting. Failures to secure a stand of grain when seeded in alfalfa have been reported. The cause in most cases, however, is improper seedbed preparation. If the field is worked up thoroughly in order to destroy the weeds and provide a good seedbed, a satisfactory stand will normally re- sult. The oats or barley seed is sown at the rate of 40 to 50 pounds per acre, and harrowed in. Another practice used in some of the dairy sections is to sow Sudangrass in the old alfalfa stand after the first cut- ing. After the first crop of hay has been taken off in the spring, the field is irri- gated, and worked up with a spring- tooth harrow; then Sudangrass is seeded at the rate of 15 to 18 pounds per acre, and harrowed in. The cuttings through- out the remainder of the summer are a mixture of alfalfa and Sudangrass. In all cases, the subsequent hay crops are cut when the alfalfa reaches the proper stage of growth. Many dairymen report satis- factory results with this mixture. After a year or two of companion crops, the field is then plowed up, and planted to other cultivated rotation crops. Crop Rotation. Alfalfa is an impor- tant crop in a sound rotation program. Almost any crop will follow alfalfa suc- cessfully — field beans, cereal grain or hay, Sudangrass, and most vegetable crops do well. Ordinarily, a root crop like carrots or sugar beets should not be seeded immediately following alfalfa be- cause the residual decaying alfalfa roots may interfere with tillage operations. Reseeding old stands is not successful in most areas. Most of the seedlings are killed by competing for moisture with the older plants and weeds, shading out by taller plants, and the presence of dis- ease organisms to which the younger plants are susceptible. In a few areas, however, such as the Imperial Valley, reseeding is necessary to maintain satis- factory stands. Likewise, it is difficult to obtain a sat- isfactory stand or growth of alfalfa if an old alfalfa sod is plowed up and re- seeded immediately to alfalfa. Part of the difficulty is caused by the build-up, in the fields, of alfalfa diseases and pests which promptly attack the new seedlings. To avoid these difficulties after an old stand has been plowed up, grow annual crops for two to four years before re- turning to alfalfa. Normally, a nonleguminous crop, such as cereal grain, corn, or Sudangrass, should be grown the season before re- turning the field to alfalfa. Plowing up Alfalfa. Stands should be plowed up in the late summer or early fall. This normally assures a complete kill of the alfalfa plants and permits the planting of a crop the following spring. At other seasons, it is difficult to get a complete kill of the alfalfa plants by plowing alone. Under these circum- stances, the application of 2 pounds of 2,4,5-T in 10 gallons of water, per acre, aids in effecting a quick and complete kill of the old plants. This material should be applied when the plants are in good vegetative growth, and at least two weeks before plowing is to be done. [14] ALFALFA VARIETIES Alfalfa is grown from the equator north to Alaska. No one variety or strain is perfectly adapted to such a wide range of climatic conditions. But there are enough varieties so that, among them, one or more may be found for almost any type of climate. The three major regions of adaptation in the United States are the Northern, Central, and Southern. In the Northern region, a high degree of winter hardiness is required, and such varieties as Grimm, Ladak, and Ranger are grown. In the Central region, a lesser degree of winter hardiness is required, but winter killing is still of some importance. Such vari- eties as Kansas Common, Oklahoma Common, and Buffalo are grown. In the Southern region, which includes most of California, winter killing is not a problem, and nonhardy types, such as Caliverde, are grown. Varieties Adapted to California California Common, sometimes called California Chilean, comprises at present the bulk of the alfalfa acreage in California. It is well adapted to most alfalfa producing areas of the state, and is highly productive. It is upright in growth, makes rapid recovery after cut- ting, and is able to grow at relatively low temperatures. It is susceptible to leafspot, mildew, and dwarf, and very susceptible to bacterial wilt. It will even- tually be replaced by the disease-resist- ant varieties, Caliverde and California Common 49. Caliverde is an improved California Common, and was developed coopera- tively by the Departments of Agronomy and Plant Pathology of the University of California. It was derived by crossing California Common with a wilt-resistant selection of Turkistan alfalfa and back- crossing to Common. Caliverde has all the desirable characteristics of Common, and in addition it carries a high degree of resistance to mildew, leafspot, and bacterial wilt. The following figures show the protein and carotene content of Caliverde and California Common (in the presence of leafspot disease) : PROTEIN (per cent) 18.4 12.9 CAROTENE (ppm) 204 96 Caliverde California Common . . . The hay yield of Caliverde, as com- pared with California Common (in the absence of disease), is as follows: TONS PER ACRE (3-year average) At Davis At Shatter . 8.5 11.3 . 8.3 9.6 Caliverde California Common Both alfalfa plants were inoculated with bacterial wilt when they were four months old. Three months later, right: California Common had been severely attacked; left: Caliverde had made normal growth. [15] v ** .*, * * Alfalfa nursery at the University of California Agricultural Experiment Station, Davis. Yield, growth habits, quality of hay, and susceptibility to disease are studied in field trials. California Common 49 is a corn- posit of a number of lines, selected from California Common, that carry tolerance to the dwarf virus disease. It is like Com- mon in appearance and performance in the absence of dwarf disease, but in the presence of dwarf, it gives better produc- tion and longer-lived stands. Like Com- mon, it is susceptible to bacterial wilt, hence it is only recommended for those areas where dwarf is the major disease. Africa (Hegazi), an introduction from North Africa, is extremely non- dormant in growth habit, making growth late in the fall and early in the spring. Its stems are slightly coarser than those of Common, and it makes rapid recovery after cutting. African alfalfa is suscep- tible to leaf diseases, dwarf, and bacterial wilt. It is a short-lived variety; stands seldom last more than three years. Ladak is very winter-hardy. It is rather slow in starting growth in the spring, and has a tendency to start dor- mancy in late summer or early fall. The exceptionally heavy first crop, however, makes it a preferred variety in areas where only two crops per year are pro- duced. It has done very well in dryland plantings in the northern part of the state. The flowers of Ladak range in color from dark purple to yellow. It has slight resistance to bacterial wilt. Grimm is winter-hardy. It is a fine- stemmed, leafy variety, and the hay is of high quality. Grimm alfalfa has been used in the northern part of the state where irrigation is practiced and is a good yielder in two-crop areas. It is sus- ceptible to leafspot, mildew, dwarf, and bacterial wilt. Lahontan is a synthetic variety de- veloped by the U. S. D. A. at Reno, Ne- vada. Selected for its high degree of re- sistance to the stem nematode, it also has resistance to bacterial wilt. It is some- what more susceptible to leaf disease than is Common. Seed should be avail- able commercially by the fall of 1954 for planting in nematode areas. [16] Varieties Grown for Out-of-state Seed Production Ranger, Buffalo, Atlantic, Narragan- sett, and Vernal are being grown in the state for seed production. These varie- ties are winter-hardy and, under most California conditions, do not produce as much hay as the recommended nonhardy varieties. They should therefore be grown primarily for seed. Varieties Not Recommended India is a variety very similar to Africa in growth habit. It is shorter- lived than Africa, and usually does not yield so well. Hairy Peruvian. Some acreage of this variety has been grown for a long time in the southern part of the state, particularly where the crop is fed green. Africa, because of its better yield and quality, could very well be substituted. Argentine. A considerable amount of alfalfa seed from Argentina has been imported in the past. The quality of seed has been variable, depending on the area in Argentina in which it was produced. Results on the whole have been very dis- appointing. Arizona 21—5, a strain developed in Arizona, makes a rapid recovery after cutting. Yields have been no better than from Common, however, and stands have thinned badly after the second year. Variety Yield Trials Over a long period of years, hundreds of varieties and strains of alfalfa from all over the world have been tested at Davis. New varieties are included in the tests as soon as they become avail- able. A variety is recommended on the basis of longevity of stand, superior pro- duction, and quality of hay. The results of a number of these Davis tests are sum- marized below. YIELD AS PER CENT VARIETY OF CALIFORNIA COMMON Caliverde 101.3 California Common 49 102.5 California Common 100.0 Africa 93.6 India 89.9 Hairy Peruvian 91.3 Buffalo 95.5 Ranger 93.2 Atlantic 86.2 Argentine 92.2 Ladak 73.8 Rhizoma 76.5 Nomad 68.3 Talent 87.8 Du Puits 92.9 Lahontan 92.7 Arizona 21-5 82.2 From the above, it is evident that the California Common type is superior to other varieties tested. Caliverde and Cali- fornia Common 49 are equal to the orig- inal Common, and, because of their disease resistance, will replace that variety. Caliverde is recommended for planting in the Sacramento and northern San Joaquin valleys. In the southern San Joaquin Valley, either Caliverde or Cali- fornia Common 49 should be used, de- pending on whether wilt or dwarf is the more important disease in the particular area. In the extreme southern San Joa- quin Valley, Africa may be used where a short rotation of two to three years is practiced. In those areas where the stem nematode is a serious problem, the variety Lahontan is recommended. The following summary shows com- parative yields of alfalfa varieties grown in the Imperial Valley at the Meloland Field Station. YIELD AS PER CENT VARIETY OF CALIFORNIA COMMON Africa 107.2 India 103.2 Caliverde 100.7 California Common 100.0 Hairy Peruvian 98.6 Arizona Common 85.6 Argentine 79.3 Buffalo 77.1 African alfalfa is recommended for the Imperial and Palo Verde valleys where stands are in production for not 17] more than three years. For longer rota- tions, either Caliverde or California Common is recommended. Tests at Tulelake show that Ladak and Grimm are the best varieties for that area, Grimm commonly being used on land with a high water table, and Ladak on well-drained and dryland plantings. In areas where bacterial wilt is serious, the variety Ranger is recommended. The following summary shows comparative yields in tests at the Tulelake Field Sta- tl0n - YIELD AS PER CENT VARIETY OF CALIFORNIA COMMON Ladak 117.0 Grimm 114.0 Ranger 113.1 Buffalo 108.7 California Common 100.0 PASTURING ALFALFA As far as palatability and carrying capacity are concerned, few plants excel alfalfa for pasturage. Fall and winter grazing after the haying season is most common. Fall growth should not be grazed until cold weather has set in. Early grazing prevents rapid regrowth, thus reducing pasturage; and continu- ous close grazing may permanently dam- age the stand. When alfalfa is grazed regularly and closely, grazed plants die, the stands thin out, and weeds come in. Cattle and hogs are less likely to injure alfalfa than are other types of livestock. Some dairymen pasture alfalfa throughout the entire growing season. Maximum feed and uniform day-to-day quality are most readily attained when a sufficient growth period (30 to 35 days) is allowed following each grazing. No single division in the pasture should be grazed too long. Three days of graz- ing and a 30-day recovery period will require 11 subdivisions. Many dairymen now employ a system of daily rationed, or strip grazing which allows only one day's feed to the herd at a time. This system has produced more feed with far less waste from trampling. The daily rationed system has markedly reduced bloat hazard, and resulted in more uni- form day-to-day milk production. Bloat is always a hazard when alfalfa is pastured. Mowing strips in alfalfa pas- tures to provide dry feed will reduce the incidence of bloat. Hungry cattle should not be turned in on new growth, particu- larly if they have not been pastured on alfalfa previously. They should first be given a fill of dry cereal hay or Sudan hay. Feeding of straw may be of value under some circumstances. Alfalfa hay is less effective in preventing bloat. Stock should be allowed to graze only a very short time each day until they become accustomed to alfalfa pasture. A supply of dry hay or straw, water, and salt should be readily available when grazing alfalfa. Stock held on Sudan pastures at night very rarely bloat when turned into alfalfa for daytime pasturing. Green Sudan pasture and Sudan hay are the most effective feeds known at present for preventing bloat. MAKING ALFALFA HAY The art of making a good quality of alfalfa hay can be acquired only with experience. Although certain general rules may be suggested, the details of the process vary so much with tempera- ture, humidity, season, and the like, [18] that specific directions cannot be given to fit all conditions. The grower should keep in mind the factors that consti- tute quality, and handle his crop to attain the ideal as nearly as possible. Good alfalfa hay should be fine-stemmed, leafy, green in color, and free from weeds, grasses, or other foreign material. If the field is free from weeds and the stand good, so that the growth is not coarse, hay of good quality can be pro- duced provided the crop is cut at the right stage and properly cured. Time of Cutting. The highest quality hay is that cut in the early bud stage. At that stage the plants have a high pro- portion of leaves, are high in protein and low in fiber. If properly cured, this type of hay is palatable to all classes of live- stock. As the plants mature the stems be- come large, and the proportion of leaves decreases. Chemical analyses show a de- crease in percentage of protein and an increase in fiber content in mature plants. However, total yields are higher at maturity. It has also been found that continuous cutting in the early bud stage lowers the food reserves of the plants so that they are more subject to various diseases. As a result the stands are shorter lived. Considering all factors, cutting when the plants are at the 1/10 bloom stage is recommended. (The field is at 10 per cent bloom when flowering has begun on one out of 10 stems or when some color is present generally throughout the field.) In the spring, when days are short, alfalfa is slow to go into bloom. At this season the correct time for cutting can be determined from the new buds at the base of the plant. When these buds start to develop, it is time to cut. Hay Quality. The feed value of hay varies with the degree of leanness, de- gree of green color, and the amount of foreign material. Leanness is most im- portant since two thirds to three fourths of the protein is carried in the leaves. Natural green color is an indicator of good curing, aroma, palatability, free- dom from damage, and relatively high Table 2. Federal Grades for Alfalfa Hay* Class requirements Grade requirements Class Mixture percentage u. s. grade Leanness of alfalfa (minimum per cent of leaves) t Color (minimum per cent of green color) Maximum per cent of foreign material Alfalfa Alfalfa with not It 40§ 60 5 over 5% 2 25 35 10 grasses 3 10 15 Sample Hay which does not come within the requirements grade of any of the numerical grades ; or which contains more than a trace of injurious foreign material ; or which has any objectionable odor; or which is undercured, heating, hot, wet, musty, moldy, caked, badly broken, badly weathered, badly frosted, badly overripe, or very dusty; or which is otherwise of distinctly low quality. * Source: Handbook of Official Hay and Straw Standards. U.S.D.A., P. and M. A. Grain Branch. (Revised July, 1949.) t Does not apply in the classes Alfalfa Heavy Grass Mixed Hay, Alfalfa Heavy Timothy Mixed Hay, Alfalfa Heavy Johnson Mixed Hay, and Alfalfa Heavy Grain Mixed Hay. t Grade No. 1 shall not include hay in which a majority of the alfalfa stalks bear brown and/or black seed pods. § Hay to meet this leanness requirement must have at least one-fifth of the alfalfa leaves clinging to the stems. • [19] carotene content. Foreign material, such as weeds, weedy grasses, dead stems, or stubble, is waste matter in hay. Federal grades for alfalfa hay have been established, based on the require- ments for top quality hay. These are shown in Table 2. Leanness and color are determined largely by method of curing, although they are also affected by local tempera- ture and humidity conditions. Excessive handling when the hay is dry will cause loss of leaves by shattering. Exposure to dew or rain will cause leaching, and undue exposure to direct sunlight will result in excessive bleaching. Hay put up under favorable weather conditions, without rain, may contain 18 to 21 per cent protein, while the same kind of hay damaged by rain or handled when too dry may contain as low as 11 per cent protein. Hay preservatives of one kind or an- other have been used to a limited extent for many years. Under favorable condi- tions they are of little value since top quality hay can be made by proper tim- ing of operations. Crushing of alfalfa has failed to im- prove hay quality. The operation is slower and more expensive than the con- ventional method. The use of salt does not increase the feeding value of hay, nor is its use justi- fied as a means of curing hay. Raking. When hay is cut it contains about 78 to 80 per cent moisture. It should be left in the swath only until thoroughly wilted, then raked into small, compact windrows for further curing. How long the hay may be left in wind- rows depends upon the way it is to be handled. If the process is to be completed in small stacks or cocks, these may be cocked immediately or, at most, only a few hours after raking. If, however, the hay is to be stacked or baled directly from the windrow, it must remain in the windrow long enough to attain the proper degree of dryness. Hay below 55 per cent moisture should not be windrowed except during periods of high humidity, which usually occur during the night or early morning. Under these conditions, drier hay can be safely handled without appreciable loss of leaves. The length of time in the wind- row, where curing is completed, depends on weather conditions and the manner of handling afterward. Hay which is to be baled should contain not more than 17 to 23 per cent moisture. Long hay containing up to 25 per cent moisture can be stacked. Barn-cured hay may con- Left to right: harvesting a heavy growth of alfalfa (the fourth cutting from this field); after alfalfa in swath is thoroughly wilted it is raked into windrows as shown; machine at right picks Z&>y*: r KS „■ tain as much as 50 per cent moisture, if stored as long hay, and 35 per cent when chopped. Heating of Wet Alfalfa. Hay stored with excessive moisture will heat, and spontaneous combustion may result. Thermometer readings are not a com- plete safeguard because no one can pre- dict what may happen after a reading has been taken. Hay in which the temperature is slowly rising to 180° to 200° F should be watched carefully, and temperatures should be taken at least once a day. It is possible that the hay may reach 180° F and still cool down. However, if it con- tinues to heat rapidly above 180° F, there is little chance that it will cool, and it should be removed to guard against fire. Production Costs. Costs of produc- ing alfalfa will vary with location, soil type, water costs, the form of the final product, and other conditions. The sample costs in the tables are representa- tive of conditions in a good producing area, and should be achieved under good management. All estimates are figured on a yield of 7 tons of hay per acre. Baling. Commercially grown hay is normally baled to facilitate handling, storage, and shipment. The three-man, NOTE: For easy reference, all tables concerning production costs (tables 3—9) have been placed together, beginning on page 26. two-wire field baler is most commonly used. The automatic wire-tie, one-man bailer is also used by smaller producers who prefer baled hay. The twine-tie bailer has found limited use because the twine tends to break and stretch, and is subject to damage from mice and natural deterioration. Automatic bale loaders are used to pick up and load bales in the field. Handling Long Hay. Following windrowing and curing, loose hay may be handled by various means. When shocked in the field, the hay is generally loaded manually onto wagons or trucks. Hay loaders and power buck rakes are also used, to a lesser extent, to pick up windrowed hay in certain of the hay producing areas. Production costs with this method will be the same as for baled hay except for the baling operation. All costs estimated will have to be adjusted to local conditions, taking into consid- eration the equipment, number of crops harvested, and other factors. up hay from windrows and bales it for easier handling and transporting. Baling at night or early in the morning will help prevent leaf shatter. Automatic loaders will pick up and load the bales. Truck with detachable baled hay loader that is powered by the ground wheels. Chopped Hay. This process has gained favor among dairymen and live- stock feeders, and many new methods and modifications have been developed. The field chopper with its own power unit is most commonly used. It is gener- ally pulled, with a tractor, in tandem with a covered wagon into which the chopped hay is blown and hauled to storage bins. The main advantages of chopped hay are: (1) it is easy to feed; (2) loss from waste is reduced as fewer stems are rejected by the stock; (3) it conserves storage space, requiring about one third that of long hay; (4) the ex- pense for wire is eliminated. The princi- pal disadvantage of chopped hay is that more complete curing is essential before storage, to prevent spoilage or spon- taneous combustion. Barn Drying. This method of curing hay reduces or eliminates losses result- ing from inclement weather. It is par- ticularly useful in areas where there is considerable damp or rainy weather and where the hay is to be used on the ranch Field chopping alfalfa hay. If the operation of equipment is to be continuous, several vans will be required. [22] where grown. A barn mow haydrier con- sists of a system of ducts through which air is forced by a fan. The circulating air prevents overheating and removes ex- cess moisture. Chopped, long, or baled hay may be placed on the ducts for dry- ing. A complete discussion of the con- struction and operation of barn mow driers is contained in University of Cali- fornia Extension Circular 149 and its supplement, "A Vertical-Flue Haydrier." Alfalfa Meal. Alfalfa meal is either a sun-cured or an artificially dehydrated product of high quality that is used in most livestock feeds and poultry mashes. Demand, however, fluctuates widely, and the price is governed largely by the sup- ply of other high protein feeds, such as cottonseed and linseed meals. Sun-cured alfalfa meal is made from high-quality baled hay. The desired grade of hay is purchased and stored for milling as needed. Alfalfa intended for dehydrated meal is ordinarily cut in the prebud or bud stage. It is usually purchased standing, on the basis of hay yield, and at a price commensurate with that of hay. Ensilage. Alfalfa ensilage makes a feed of excellent quality. For best en- silage, alfalfa should be cut in the 1/10 bloom stage. It should be wilted to about 60 to 68 per cent moisture before it is put into the silo. Sixty to 80 pounds of molasses added to each green ton will improve the quality and provide suffi- cient sugar to insure proper fermenta- tion to preserve the silage. The material should be chopped or cut finely and packed well in the silo. Silage provides an excellent means of utilizing weedy first cuttings and making them into high quality feed during periods when Top: an alfalfa dehydrator used for process- ing freshly chopped green alfalfa into meal. Center: chopping (soiling) is not usually suited to the smaller operator. Bottom: feeding green chopped alfalfa to dairy cattle. The unloading device is powered by its own gasoline engine. weather conditions are not favorable for hay curing. Alfalfa ensilage retains more protein and considerably more carotene than does field-cured hay. Eighty-five per cent of the food value of the green plant is preserved in good silage. Soiling (green chopped alfalfa). With this method, the alfalfa is cut, chopped, and blown directly onto trucks or trailers or cut, windrowed, chopped, and blown into carriers. These are driven through the corral areas and un- loaded, either mechanically or by hand, directly into the feed mangers. When the hay chopper with the cutter bar attached is used, one operation is eliminated. From the chopper, the hay is blown di- rectly into a custom-made, movable- bottomed trailer. As the trailer is drawn along side the feed mangers, it unloads the chopped alfalfa from the side, me- chanically. Some dairymen have equipped their feed racks with wheels. The racks are drawn behind the chopper, loaded directly, and then pulled into the feed corrals. The stage of growth for cutting green hay is the same as for cured hay. For best quality, high production, and welfare of stand, cut at the 1/10 bloom stage. In early spring and late fall when blossoms are scarce, cutting should be done when the hay is mature, or about the time new shoots start growth. There are certain advantages to feed- ing, green chopped alfalfa. Protein and carotene loss is practically eliminated. A consistent, uniform quality of feed is available for the animals from day to day with almost no waste. The quick re- moval of hay permits immediate irriga- tion and allows resumption of growth. The incidence of bloat may be reduced somewhat when feeding green alfalfa in this manner, as compared with pastur- ing. This type of feeding operation re- quires a large investment in machinery, and some extra skilled labor. Thus its use is limited to larger units of opera- [ tion. Machinery maintenance costs are high, and the failure of equipment can cause interruptions in the feeding sched- ule. The irrigation schedule must be planned so that the ground is sufficiently dry before machinery is taken into the field, otherwise soil may be damaged by heavy traffic. Storage. Exposure to weather will cause deterioration in alfalfa hay after it is harvested. Rain-soaked hay molds and spoils, or becomes musty and unfit for feed. Rain also greatly reduces the feed value by leaching out considerable quantities of the mineral and protein constituents. Undue exposure to sunlight will cause the hay to become discolored and less palatable. Although costly, hay sheds or barns are ideal places for storage since the hay is protected from both rain and sun. Hay can be stored in the open with little loss if done properly. Large stacks covered with tarpaulins (see diagram below) will keep spoilage and nutrient losses to a minimum. Volume per Ton. The density of hay varies so greatly that no figure can be estimated with accuracy. If the amount of hay must be determined closely, fair samples of measured volume should be weighed. The following figures are useful in estimating space required to store alfalfa hay: TYPE CU. FT. PER TON Long hay 480 Baled hay 200 Chopped hay 160-170 Chopped hay (%" cut, large stacks) 150 Ground hay (through %" screen) 130 Ground hay (through M/' screen) 100 To compute tonnage of stored hay, multiply the length by the width by the average height (all in feet), and divide 24] by the appropriate figure for volume as shown above. Example. A mow 16 feet wide and 30 feet long with chopped alfalfa hay at an average depth of 6 feet: 16 x 30 x 6 = 2,830 cu. ft. 2,880 150 = 19.2 tons hay Green chopped alfalfa hay requires approximately 45 cubic feet per green (wet) ton. To Compute Tonnage in Stacked Hay. Suggestions for measuring the volume of stacks have been published by the United States Department of Agri- culture (Leaflet No. 72, 1931). These are fairly accurate. The three formulas given below are based on the three types of stacks shown in the diagram. For low, round-topped stacks (0.52 x O) - (0.44 xW)xWL = Volume For square, flat-topped stacks (0.56 x O) - (0.55 x W) x WL = Volume For high, round-topped stacks (0.52 x O) - (0.46 x W ) x WL = Volume In the above formula : O = "over" measured from the base on one side over the stack to the base at the other side, in feet. W - width of stack in feet. L = length of stack in feet. Thus, to determine the volume of a rectangular stack of the high, round- topped type that is 45 feet over, 20 feet wide, and 50 feet long: Volume = (0.52 x 45) - (0.46 x 20) x (20 x 50) = 23.40-9.20x1,000 = 14,200 cubic feet in the stack. Diagram shows three types of stack that may be used to store alfalfa hay in the open with a minimum of spoilage. Stacks should be cov- ered with tarpaulins. (Drawing after Hoster- man.) Feet 15 SQUARE FLAT-TOPPED STACK 10 15 20 25] The following seven tables show various costs for alfalfa production, Table 3. Cultural and Nonharvest Costs of Alfalfa Production Operation Cultural and nonharvest costs : Irrigate (8 times), 8 man hrs. at $1 4 acre ft. water at $7 Fertilize, 2 men, tractor, broad- caster, 0.1 hrs Single superphosphate, 200 lbs. at $32 per ton Miscellaneous expense : Taxes Interest on land and stand, $315 at 5% Compensation insurance Depreciation on stand, $30 for 3yrs Total cultural and nonharvest cost Cost per acre Labor Tractor $8.00 20 $•• Equipment .10 Material $.... 28.00 3.20 Totals $8.00 28.00 .30 3.20 6.50 15.75 .05 10.00 $71.80 Table 4. Costs to Produce Baled Alfalfa Hay Operation Harvest costs : Mow (6 times), man, tractor, 7' mower, 2.4 hrs Rake (6 times), man, tractor (8' side delivery), 2.4 hrs Baling (contract at $4.50 per ton) Roadsiding (contract at $2 per ton) Total harvest cost Cultural and nonharvest cost (from Table 3) Total cost per acre Labor 3.00 3.00 Cost per acre* Tractor $2.40 2.40 * On the basis of 7 tons per acre, cost per ton = $18.50. Equipment Contract $ .48 .96 $.... 31.50 14.00 Totals $ 5.88 6.36 31.50 14.00 $ 57.74 71.80 $ 129.54 [26] Table 5. Costs to Produce Chopped Alfalfa Hay Operation Cost per acre* Labor Tractor Equipment Totals Harvest costs : Mow and rake (6 times), costs same as Table 4 $ 6.00 10.00 $4.80 5.33 $1.44 9.87 5.36 5.33 $ 12.24 25.20 5.36 5.33 Chop and haul (6 times), 2% hrs., 3 men, 2 tractors, chopper 3 wagons Blower Total harvest cost 48.13 71.80 Cultural and nonharvest cost (from Table 3) Total cost per acre $ 119.93 * On the basis of 7 tons per acre, cost per ton = $17.13. Table 6. Costs to Mow Dry, Baled and Chopped Alfalfa Hay Operation Cost per ton* Barn mow haydrying : Baled hay— (24 sq. ft. floor space per ton of hay) : Depreciation: Motor and fan, $20 for 10 years Ducts, $12 for 20 years $2.00 .60 .80 .64 1.50 Interest — $16 at 5% Taxes, repairs, etc. — 2% of $32 Power — $1.50 per ton Total cost per ton $5.54 Chopped hay — (20 sq. ft. floor space per ton of hay) : Depreciation : Motor and fan, $10 for 10 years $1.00 .50 .50 .40 .75 Ducts, $10 for 20 years Interest, $10 at 5% Taxes, repairs, etc., 2% of $20 Power, .75 per ton Total cost per ton $3.15 * On this basis, the total cost of baled hay dried would be $24.04, and of chopped hay, $20.28. [27] Table 7. Costs to Produce Dehydrated Alfalfa Meal Operation Cost per acre* Labor Tractor or truck Equipment Contract Totals Harvest costs : Cut (7 times), man, harvester, 3^ hrs $ 5.69 10.72 $ 12.96 $ 13.98 $ 140.00 $ 19.67 23.68 140.00 Haul (7 times) , 2 men, 2 trucks, 334 hrs Dehydrate and grind, 7 tons at $20 Total harvest cost Cultural and non-harvest cost (from Table 3) 183.35 71.80 Total cost per acre $255.15 * On the basis of 7 tons per acre, cost per ton = $36.45. (grind, sack, and store) = $30.50. Table 8. Costs to Produce Alfalfa Ensilage Operation Cost per acre* Labor Tractor Equipment Totals Mowing and windrowing (6 times), man, tractor, mower, 2.4 hrs $3.00 7.50 7.50 15.00 $2.40 6.00 6.00 $ .90 14.82 1.20 12.00 $ 6.30 28.32 14.70 27.00 Chopping (6 times), man, tractor, field chopper, 6 hrs Hauling (6 times), man, pickup, 2 trailers, 6 hrs Unloading (6 times), 2 men, blower, 6 hrs. Total harvest cost 76.32 71.80 Cultural and nonharvest cost (from Table 3) Total cost per acre $ 148.12 * On the basis of 21 tons, cost per ton = $7.05. [28] Table 9. Costs to Produce Green Chopped Alfalfa Operation Cost per acre* Labor Tractor Equipment Totals Cut and haul (6 times), man, tractor, chopper, trailer, 10 hrs $ 15.00 $ 10.00 $30.00 $ 55.00 Cultural and nonharvest cost (from Table 3) 71.80 Total cost per acre $ 126.80 On the basis of 28 tons, cost per ton = $4.53. ALFALFA SEED PRODUCTION Prior to 1946, alfalfa seed production in California varied between 2% and 5 million pounds annually; since 1946 it has increased rapidly to a high, in 1952, of 40 million pounds. This big increase has been the result of three important developments. First, the average yield has risen from 190 pounds per acre to 460 pounds (in 1952) as a result of re- search on factors affecting seed yields. Second, there is great demand for new, improved alfalfa varieties. Third, it has been found that alfalfa can be grown outside of its area of adaptation for one generation without altering its quality, particularly with respect to winter hardi- ness. Seed production has now become a specialized industry, and the most suc- cessful growers are those who regard seed production as the main objective of their operation, rather than as inci- dental to the production of hay. Factors Affecting Seed Production Recent studies on the factors affecting seed production have taken a large part of the gamble out of this enterprise. Four important factors must be considered to insure a satisfactory seed crop: (1) con- dition of the plant; (2) control of harm- ful insects; (3) weed control; (4) good pollination. Plant Condition. For maximum pro- duction it is necessary to have healthy plants making normal growth. Irrigation should be controlled to keep the plants growing continuously, but overirrigation may result in a lush vegetative growth with a poor production of flowers. When the stand is cut back before a seed crop is taken, the plants should be allowed to reach maturity or the 1/10 bloom stage before such cutting so that the food re- serves in the roots may be replenished. A high root reserve is of considerable importance in seed production. Weed Control. Control of weeds is important from three standpoints. First, weeds compete with alfalfa plants for water and nutrients. Second, weed seeds contaminate the alfalfa seed and may be impossible to remove, thus resulting in rejection of the seed, or in consider- able losses in cleanout. Third, weeds flowering at the same time as alfalfa may be more attractive to bees, and result in poor pollination of the alfalfa. [29] u ■o T5 0) o «/> 8 MB 8 < (A U O £ "o C o \n 0) 8) U) D ■a s w >» £ ca d * »H . 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The most serious insect pests are the Lygus bug, spider mites, grasshoppers, and stink bugs. Lygus bugs alone may best be controlled by applications of DDT. If grasshoppers or stink bugs are also present, they and the Lygus bugs may both be controlled with toxaphene. If the DDT is applied in a sulfur dust it may help to keep down mites. If mites become severe, they may be controlled with aramite, ovotran, or recommended dinitro products such as Elgetol 318 and DN 289. See Table 10 for recommended control measures. Pollination. Satisfactory seed pro- duction depends on the tripping of the flowers and the transfer of pollen from the flowers of one plant to those of an- other. Bees are largely responsible for both tripping and transfer of pollen. Wild bees are the most effective pollina- tors, but are generally not sufficiently abundant and not uniformly distributed. Honey bees are less effective, but if they are present in sufficient numbers they will give a satisfactory seed set. From two to six colonies per acre may be re- quired, depending on the amount of bloom on the plants and the particular area. It is important to time the bloom period on the seed field so that there will be a minimum of other plants in bloom from which the bees might obtain pollen. Harvesting Seed In alfalfa seed harvest, two separate management operations must be con- sidered — the preharvest preparation and the actual threshing. The larger part of the acreage is har- vested by the windrow-combine method. Preharvest spraying, followed by direct combining, is used in areas where strong winds and low humidity are a hazard to seed production. The most commonly used pieces of equipment for windrowing are the stand- [32 ard mower with "curler" attachment and the windrow swather. Windrowing must be done during periods of high humidity or when dew is present on the plants, before the seed heads deteriorate and seeds begin to pop open. Otherwise, serious seed losses will occur. (The research on alfalfa seed har- vesting was conducted as a cooperative project between the Departments of Agronomy and Agricultural Engineering at Davis.) A pickup attachment is used to lift the windrowed material into the har- vester. The pickup should be ground powered, with a peripheral speed 10 per cent to 15 per cent faster than the for- ward speed. This provides a steady ten- sion on the windrow without pulling it apart. The mounting on the header should be such as to prevent back-feeding to the ground. The conventional cutter bar equipped with lifter guards can also be used as a windrow pickup device, but will clip off green stubble which may overload the tailings return system. Preharvest sprays are most effec- tive in mature, open, and erect stands. The dinitro general spray (Dow or Sinox) applied by airplane at from 1 to 3 pints in 10 to 15 gallons of diesel oil per acre is commonly used. Ground rig application is also satisfactory, but requires 50 to 100 per cent more oil, and sufficient water to make an emulsion that can be applied at rates ranging from 25 to 60 gallons per acre. In heavy, dense growth, two applications often give added kill on lower and protected foliage. Combining should start when the leaves are dry, but should be completed before regrowth, head shatter, pod drop, or popping open of pods occur to any great extent. Threshing will normally begin 3 to 5 days after spraying and should be completed within 8 to 10 days after treatment. For direct combining, the standard cutter bar is used. On lodged or row- planted stands, lifters arranged on both sides of the rows or evenly spaced along the cutter bar aid in lifting and properly guiding the material. When properly adjusted, all com- mercial harvesters will thresh alfalfa sat- isfactorily. Excessive seed damage will occur if the peripheral speed of the cylinder (speed of tips of teeth or bars) is too high. The seed from stands conditioned by spraying contains more moisture than does windrowed material, and is less sub- Table 11. Revolutions per Minute Required for Various Peripheral Speeds and Cylinder Diameters With flax rolls* Without flax rolls t Spray-cured^ Cylinder diameter, inches r.p.m. to give 3,600 ft. per min. r.p.m. to give 4,400 ft. per min. r.p.m. to give 4,200 ft. per min. r.p.m. to give 4,800 ft. per min. r.p.m. to give 4,000 ft. per min. r.p.m. to give 5,000 ft. per min. 14 16 18 20 22 24 980 860 760 690 620 570 1,200 1,050 930 840 760 700 1,140 1,000 890 800 730 670 1,310 1,140 1,020 910 830 764 1,090 950 850 760 700 636 1,360 1,190 1,060 950 870 800 * Recommended cylinder speeds, 3,600-4,400 feet per minute. t Recommended cylinder speeds, 4,200-4,800 feet per minute. % Recommended cylinder speeds, 4,000-5,000 feet per minute. [33] ject to threshing damage. Under these conditions the cylinder can be run faster, but in no case should it exceed the upper range of the recommended speeds (Table 11). Uniform and proper machine load is very important. Even at the proper cylinder speed, increasing damage will occur as the cylinder load is reduced. Harvesting rate. For the most effi- cient operation of the combine, a reason- ably heavy load should be maintained, but not to the point of overcrowding any part of the machine. Operating the ma- chine with light loads does not utilize it to the best advantage, and the seed damage is likely to be high. The capacity of the feeder mechanism, the cylinder, the shoe, or the return may determine the amount of material that a combine can handle. Other factors, such as rough ground, high borders, stony land, large weeds, and spotty stands, may also limit the speed at which threshing can be per- formed. Excessive loads on the cleaning shoe will cause very high free seed losses; therefore, when other factors fail to limit the load, shoe losses will determine the most economical rate of operation. The combine should be operated at such a rate that free seed losses over the clean- ing shoe will not exceed 2 to 6 pounds per acre. At this load rate, unthreshed seed losses may run from 4 to 12 pounds per acre when threshing conditions are good, and 12 to 30 pounds when they are poor. Walker losses should be negli- gible. The following table is offered as some indication of the speed at which a 12- to 14-foot combine should be operated to give the best returns in time and re- covered seed. In defoliated crops, a com- bine can operate at somewhat higher rates since the feed is more uniform and the straw has less tendency to break up and overload the shoe. TYPE MPH Windrowed — 10-ft. swath: Light hay crop — 2 tons per acre.... 1.2 to 1.6 Heavy hay crop— 3Mi tons per acre. . 0.8 to 1.1 Spray-cured — 12-ft. swath : Light hay crop — l 1 /^ tons per acre. . . 1.4 to 1.9 Heavy hay crop — 3 tons per acre . . . 0.9 to 1.2 Seed losses should ordinarily deter- mine the rate of speed of thresher opera- tion. Since seed losses as a consequence of rain or wind may greatly exceed those resulting from crowding of the combine, the weather outlook should also be con- sidered in deciding the best over-all rate of operation. Uniformity of feed is important for the most efficient operation of the combine. Therefore, the speed of the combine must be varied to meet the conditions of the field. This is especially important with a windrowed crop. Unless contaminated by insecticide or defoliant that would be harmful to stock, the straw is normally fed. WEED CONTROL Cultural. Good weed control employs the method best suited for the particular weed problem. A field free of weeds be- fore seeding to alfalfa lessens the prob- lem greatly. The use of cultivated row crops in the rotation with alfalfa is good management. Proper land preparation and irrigation practice are good weed preventive measures. Mowing is useful to reduce the com- petition and shading effects from annual weeds which always appear to some ex- tent in first-year fields. The weed growth should be clipped several inches above the ground to avoid disturbing the young alfalfa plants. Chemical. In seedling stands, the small seedling broadleafed weeds can be controlled by using 4 to 6 quarts of di- nitro selective (ammonium dinitro-o- [34 secondary butyl phenol or ammonium dinitro-o-secondary amyl phenol) in 15 to 20 (air application) or 60 to 80 (ground application) gallons of water per acre. Application must be made when the weeds are small. Spraying at air tem- peratures above 85° F may result in in- jury to alfalfa seedlings. Once the alfalfa stand is established, general-contact weed killers can be used. Formulations using 20 to 45 gallons of diesel oil plus 1 quart of general dinitro (dinitro-o-secondary butyl phenol or dinitro-o-secondary amyl phenol) in 40 to 70 gallons of water per acre will kill seedling grasses and small broadleafed weeds. Other proprietary contact weed oils can also be used. Do not let grasses get beyond l 1 /^ to 1% inches tall, nor broadleafed weeds beyond the 2 to 4 true leaves stage of growth before the treat- ment. For control of summer-growing weeds, such as watergrass, the general-contact at the above-mentioned rate can be used immediately following mowing. Yellow star thistle has been successfully con- trolled by applications of 2 quarts of dinitro general in 100 gallons of water, applied between the first and second cuttings. Where only winter-growing grasses are present, I.P.C. (O-isopropyl-N- phenyl carbamate) may be used. It may be applied in the early fall (October 15 through November) and irrigated in, or it can be applied in late February. As a spray, the recommended rates are 3 to 5 pounds of active material in 60 to 100 gallons of water per acre. To be effec- tive, I.P.C. must be retained in the root zone. Excessive water leaches it below this depth, and insufficient amounts may not carry the material deep enough. The best results are obtained when the mate- rial is applied just before the grass seed- lings emerge. Underground irrigation systems are helpful with regard to weed control. For more detailed information on specific weed problems, contact your University of California Farm Advisor. PEST CONTROL Alfalfa may be attacked by insect pests throughout the growing season, and the grower must be continually on the alert to detect infestations. Frequently a prop- erly timed cutting will save the crop, but in some instances it may be necessary to apply chemical or other types of con- trol. The more important insect pests of alfalfa hay in California are discussed below in the approximate order of their appearance through the year. For aid in the identification of insect pests, see your local Farm Advisor. Alfalfa weevil {Hypera postica Gyll.) is a continual pest in the alfalfa districts east of the Sierra Nevada Moun- Side and top view of the alfalfa weevil. [35 •3 o o3 O l- *- c o u u E o X u s E E 3 V) CH 15 be I 3 I S I 5 I ° I I 1 § 1 £ bo .5 C Ci £3 9 * 1 t8 s 8 ft CD ft t+4 n bi •a 3 3-o — w '"' stil bo > o ^3 S d >> o fi '43 U h r< ■§ © f* o ^ s-i •■« — ^ O kg-ri $ > B O bo . •O © tf ^3 n 2 o 5 bo ^ t: « a fl .S S 0) S fe W CO ^ ^ •■i p CO ■»» 5 s s * .a ^ M ° <=> co ■*-» -H -I-* o P a Q .3 § 03 O o 7 7 ? T rH H ft CO M 1 2 >> ft X CO ^ CO CD iH Sec I X o Eh ft © of O S 2 § 5? 2 (N ft " o 2 i g, ■3 § S S 2 _ rf « w «G o » fl g 2 M © © S c« © > jCj bo ft ft o © . CO CO s. © ft -Q © d J5 Pi * ft -o © p © ^3 .8 S3 * •« bp CO CO f~, CI o3 o3 d O © © +■ I >?03 ^ >-i CD •!-< O ft t* •£* ■*■ ft P CO O S ^ i 3 ^ »rt co CO co 8,1 * ft J3 _, is -9 a 0, © Jh O a s °. -a O jh fl (O -3 o © c co «a *^ 3 g ► o € i, ° I* w 10 Pi *- .a s d +2 03 o P a p o § -* i § I § 1 1 2 © ° © * w Q 2 . eg X3 P. 2 d » « £? .2 ► * 2 O e8 O 03 d o . +J CO 03 »d «2 t> 3 o 03 fc- > © 03 > 03 03 S3 o CO CO ho e &, © o CM •d d d o a d 03 > +» 2 ® j=s £S 2 < w ° p. + E-« P P © M 2 K fl Jh o td .bp -d *S H -d a § • SgSS C m eS > W3 O « 03 o va cu « P 2 p. *" i d S* 5 o .2 ~ Pi +» -C3 o p. ^ p> § 03 d .d d e8 -d •2 § 03 - 8 a -d « *- 3 <«> 2 IB p. ft 03 03 M 03 d »h C3 eS 03 ^ * bo | -a 03 «h 55 a bi a> bo d e O 03 ^« eS •a a s-. pd 03 O p. d Pi * rt O CO ■S S3 2 > o pm •d 03 f 03 I is 03 t- I & 5 a 03 C 03 eg 05 M a e 03 >» ea d ! o o Q o o c3 A o 1 . §1 iH tN i-H w d o Is Heptachlor Aldrin Methoxychlor Is a o PI Adult treatment not recom- mended for alfalfa hay. When buds and shoots first appear ragged and it is not practical to cut. CO CD Fh Si CO 2 A § 8 o co £ cu 09 ID Alfalfa weevil adults Alfalfa weevil larvae or Egyptian weevil larvae CO CO 1 CO 'p. CO tains and in the northernmost counties, and an occasional pest in the Tracy-Pat- terson area and in parts of the San Fran- cisco Bay Region. It causes damage to first and occasionally to second or third cuttings. Infestations of economic im- portance can usually be prevented by maintaining a dense, vigorous stand and by cutting the first and second crops as soon as most of the plants are in the bud stage. In areas where economic infesta- tions occur regularly, it may be advis- able to use the chemical treatments as given in Table 12. Egyptian alfalfa weevil (H. brun- neipennis [Boh.]) is very similar in ap- pearance and habits to the alfalfa weevil. It occurs in the Imperial Valley and other parts of southern California. See Table 12 for control measures. When found in combination with the pea aphid, this weevil can be controlled by the same measures as those recommended for pea aphid. Pea aphid (Macrosiphum pisi Kalt.) is a large, green aphid which sucks juices from the tender parts of the plant and, where abundant, causes weak, stunted, and misshapen plants. It is mainly a pest during cooler times of the year. In central California, due to the favorable natural control, the pea aphid is only an occasional pest and early cutting usually takes care of it. In southern California, however, and in the alfalfa areas east of the Sierra Nevada Mountains, it may completely stop plant growth. In regions where the pea aphid is a regular problem, control measures should be applied when economic popu- lations threaten and before the alfalfa is 6 inches high. See Table 12 (p. 37) for treatments. If the DDT treatments are used, the hay should not be fed to lac- tating animals or those being finished for slaughter. Parathion alone does not give much residual action, and a second appli- cation is sometimes necessary. Pasturing until rapid growth can start in the spring is a favorable practice. [38] Grasshoppers are major pests of alfalfa hay production in California. Some kinds develop in uncultivated areas and move into cultivated fields. These should be controlled before they enter the alfalfa fields. Others develop in cul- tivated fields; and alfalfa fields are a common breeding ground. Economically significant levels vary with the growth of the crop, but in general, populations of 15 per square yard or higher are con- sidered severe. The control measures to be taken will depend on the growth of crop and stage of grasshoppers present. See Table 12 for details. The lower dosages are effective against young grasshoppers particularly where the vegetation is short. However, if hatching is continuing or if residual action is necessary, the higher rates should be used. In general, sprays give higher initial kill, continue to kill over a longer period, and require less insecti- cide per acre than do dusts. But they also create a greater residue problem. When applying chemical control for grasshop- pers, every precaution should be taken to avoid residue at harvest time. Baits are not satisfactory where suc- culent alfalfa is also available to the grasshoppers, but it is sometimes prac- tical to bait the fields following harvest. Alfalfa caterpillar (Colias philo- dice eurytheme Bdv.) is the most impor- tant insect pest of alfalfa in California. Areas of severe damage are limited to the commercial hay-growing regions of the warm interior valleys. Damage is usually confined to the period from late June through September. Complete de- struction of the crop is not uncommon. The yellowish-orange or whitish adult butterflies lay eggs singly on the short alfalfa. These eggs hatch into green cater- pillars in three to 10 days. When full- grown, the caterpillars are about 1 inch in length. They are easily distinguished from the other common caterpillars in alfalfa by their velvety green bodies and the white lines along the sides. [39 The development of a damaging popu- lation results from large flights in or near fields when the alfalfa is short. Other factors that contribute to this are slow and uneven growth, lack of parasites, and hot, dry weather. Infestations vary greatly from season to season and from one field to another. Consequently, dur- ing the critical summer period the fields must be checked at least once a week to detect developing populations. An ex- perienced entomologist can examine a field in an early stage of growth and make a prediction for needed control measures. Such a prediction may state that the field will not be damaged be- cause the population is low or because the parasite, Apanteles medicaginis Mues., will destroy the population. When natural control is inadequate, the predic- tion will indicate the need for artificial control measures. Control measures include the applica- tion of virus, early cutting, and chemical treatments. If the infestation is found at an early stage of development, and growth in the field is even, a carefully timed application of a virus suspension can be made. Under proper conditions this will cause the wilt disease of the caterpillars to appear. In other cases, damage may be avoided by early cutting of the crop. This cutting should be timed to avoid serious damage and yet obtain maximum yield. When damage from large populations threatens, and cutting is impractical, it may be necessary to employ chemicals as indicated in Table 12. If methoxychlor is used, allow 10 days of weathering before cutting. If DDT is used, the hay should not be fed to milking animals or meat animals within 60 days of slaughter. Western yellow-striped army- worm (Prodenia praefica Grote) is fre- quently very abundant in alfalfa fields in the Sacramento and San Joaquin val- leys. It is usually black in color, with two prominent stripes and many fine bright ones on each side. At maturity it ] is approximately IV2 to 2 inches in length. This insect may be abundant at any time from June to early September. These armyworms develop more slowly than do the alfalfa caterpillars, and nor- mally the fields may be cut to avoid damage. When the fields are cut, the armyworms migrate. Damage to ad- jacent crops may be avoided by placing barriers around the field before it is cut. The details of these barriers are given in Table 12, page 37. It requires about 2 to 4 pounds of insecticide per 100 feet of barrier. Occasionally, in cool weather, the armyworms do not leave the field, and it will be necessary to treat the stubble with DDT or DDD. Miscellaneous Insect Pests. The beet army worm (Laphygma exigua [Hbn.]) and the beet webworm {Loxo- stege sticticalis [L.]) occasionally be- come abundant in alfalfa. They rarely cause serious damage, and cutting usu- ally gives satisfactory control. Chemical control may occasionally be necessary on young alfalfa. Spider-mites or red spiders are not serious pests of alfalfa hay. Although they may become abundant under dry conditions, especially when the cutting period is unusually long, cutting is rec- ommended rather than chemical treat- ment. Thrips, Lygus bugs, treehoppers, leaf- hoppers, and other pests are frequently abundant in alfalfa fields. Only rarely do they cause economic damage in Cali- fornia. WARNING: Parathion and other phosphates are hazardous materi- als; permits for their use must be obtained from the Agricultural Com- missioner. Most insecticides are poi- sons, and all precautions for their use and storage should be carefully followed. Supervised Control. Insect infesta- tions in alfalfa vary greatly from field to field and from season to season. Un- less the fields are checked systematically and thoroughly about once a week, a severe outbreak may develop unknown to the alfalfa grower. To meet these dif- ficulties and to take advantage of natural control, a new approach to the insect problems of alfalfa, called "supervised control," has been developed. Under this system, a grower or a group of growers hires an entomologist to check the fields and make recommendations concerning control. Unnecessary treatments are eliminated. Chemical treatment is made more effective through improved timing. Full advantage is taken of any biological control available. In some cases, the total infestation in the district is reduced, and the natural control improved. The con- trol measures are tailored for the par- ticular conditions prevailing in the individual field. For further details of supervised control and the practicability of utilizing it in your fields, see your local Farm Advisor. Other Pests Alfalfa stem nematode is a very active, slender, almost colorless, eel-like worm about 1/20 of an inch long. It attacks young shoots of alfalfa when they first appear in the spring. The shoots are frequently killed outright, but if they survive they become thickened, club-like, and deformed. As the season advances, these stems will have swollen, blackened bases which readily break off when pulled. Infestation first appears in limited areas and is indicated by stunted or dy- ing plants. The damaged areas increase in size year after year, especially in the direction of water flow in irrigated fields. The injury is generally most apparent on the first crop, since the cool, moist spring months seem to favor the nema- todes. [40 •»i . 41 . S O^- . Young shoots of alfalfa affected with alfalfa stem nematode. Note how shoots are thickened, clublike, and deformed. Crop rotation is the only known method of control under ordinary field conditions. A three- to four-year rotation with such crops as beans, sugar beets, cereal gains, corn, or peas, will reduce the population. Milo is an excellent one- year rotation crop. Special care must be taken to eliminate all old alfalfa plants and weeds during this rotation period. The variety Lahonton is highly resist- ant to this pest and is recommended for use in areas of severe stem nematode in- festation. In the photo, the two plants at left are affected with alfalfa stem nematode. Plant at right is healthy. All three plants are the same age and have had a similar period of growth since last harvested. [41] Pocket gophers do considerable damage to stands of alfalfa, and more than 50 adult gophers per acre may build up within a few years after plant- ing. The gopher burrows under the ground and gnaws off the plant roots for food. The plants subsequently dry up and die. Some leaves and stems are also eaten. Gopher burrows often cause ditch- banks to wash out or irrigation water to be channeled where it is not wanted. Badgers and other predators often make large holes by digging after gophers. In addition, the mounds of soil the rodent pushes up interfere with irrigation and harvesting. The most effective and economical method of controlling pocket gophers is by poisoning. Trapping is too time con- suming except in small areas or where there are few gophers. Flooding destroys many animals, especially if the irrigator is handy with his shovel or has a good dog to catch the gophers as they are flooded from their burrows. They can be effectively controlled or even elimi- nated over large areas. Persistence is necessary to success. Control may be practiced at any season. Meadow mice occasionally damage fields to the stage where no profits re- sult. These short-tailed, dark-bellied mice live in the fields or in ditchbanks cov- ered with weeds or grass. Meadow mice live both on the surface of the ground and in burrows. Pieces of cut grass are often found along their trails and in the open burrow entrances. The damage is most apparent during the winter when the alfalfa is dormant. When meadow mice are present in great numbers or over a large acreage, it is necessary to use poison. Zinc phos- phide on rolled barley or oats is effective. The poison is broadcast by hand in the vicinity of the runways. More than one treatment may be necessary per season. On large acreage of heavy infestations, it may be simpler to apply the bait by plane. Toxaphene at the rate of 4 pounds in 10 gallons of water per acre has been used with good results for meadow mice control. Any application of the material should be completed at least three weeks prior to pasturing or to cutting for hay. If the grower is not sure about what kind of rodent is causing the damage, he should consult the county Agricul- tural Commissioner for identification. Deer and jackrabbits, in foothill areas, have seriously damaged isolated alfalfa fields surrounded by brushlands. Seven- to 8-foot deerproof fences have proved effective in reducing damage, but such protection is expensive. Deer shooting is permissible under the state Fish and Game Code. Contact the near- est game warden for information on regulations. Shooting is also effective in reducing rabbit populations. For best re- sults, hunt these animals in the early morning or evening when they come out to feed. Diseases of alfalfa are of two types: those which actually kill the plants, re- sulting in reduced stands and lower yields, and those which attack the leaves, resulting in somewhat lower yields and reduced quality. Bacterial wilt is one of the most im- portant factors in the short life of alfalfa DISEASES of ALFALFA stands, and is prevalent in practically all alfalfa producing areas of the state. Diseased plants are stunted in growth and are pale green to yellowish in color. The leaves may be curled upward and may show dead tissue around the edges. The roots of infected plants, when cut diagonally, show a brownish-yellow ring [42] •?* ■ ■.?■:. ;!lM' Diseased plant, right foreground, shows typical field symptoms of bacterial wilt. Surrounding plants are healthy. under the bark. The disease may begin to make its appearance in the second year of life of the stand, but more often becomes apparent in the third or later years. The only satisfactory control is the planting of resistant varieties. Cali- verde, a wilt-resistant California Com- mon, is recommended. Alfalfa dwarf is found in the San Joaquin Valley from Modesto south- ward, and in Riverside, San Bernardino, and Orange counties. Affected plants are short, with numerous fine stems and dark-green leaves. The roots of infected plants show a yellowish-brown ring in cross section, similar to that caused by bacterial wilt. The darker green color of the leaves of dwarf plants distinguishes them from ones infected with bacterial wilt. Alfalfa dwarf is caused by a virus transmitted by the insects known as sharp-shooters. The same virus causes Pierce's disease in grapes. The only practical method of control seems to be the use of resistant varieties. California Common 49 shows a good degree of re- sistance. Crown rot is caused by a number of different organisms. The main symptom, as the name indicates, is decay of the crown of the plant. Infected plants will send up fewer shoots and eventually die. The practice of rejuvenating fields by disking or springtoothing causes crown injuries in which the disease may easily develop. California Common and its im- proved form, Caliverde, seem to be as resistant as any variety, and local strains of Common may be particularly adapted to areas where the disease is severe. Downy mildew is most common in the spring or in the fall after the rains [43] Left: crown rot of alfalfa, caused by Rhizoctonia species. Right: Rhizoctonia root canker. Note stem lesions, rotting of lower root. The latter is common under conditions of excess soil moisture. start. Light-green spots appear on the upper sides of the leaves shortly after infection, and turn red or purple with age. The undersides of the leaves show a grayish, felt-like mass. The quality of the hay is lowered, and in cases where the disease attacks young seedlings, the plants may be killed. The Caliverde va- riety has a high degree of resistance to this disease. Leafspot is more prevalent in the spring and fall, but may be found dur- ing most of the year in the coastal areas. Circular brown spots appear on the lower leaves of the plant. Later the leaves turn yellow and fall off. Caliverde, while not immune, has a high degree of resist- ance so that few leaves are lost. Rhizoctonia root canker causes most serious losses largely in the Im- perial and Palo Verde valleys. It seems to require high soil temperatures for its development. Discolored lesions appear on the tap roots, and may develop so that the entire root is rotted off. The disease is more serious when there is a high water table. Provisions for better drainage may help in its control. In order that the information in our publications may be more intelligible it is sometimes neces- sary to use trade names of products or equipment rather than complicated descriptive or chemical identifications. In so doing it is unavoidable in some cases that similar products which are on the market under other trade names may not be cited. No endorsement of named products I* intended nor is criticism implied of similar products which are not mentioned. Cooperative Extension work in Agriculture and Home Economics, College of Agriculture, University of California, cooperating. Distributed in furtherance of the Acts of Congress of May 8, and June 30, 1U14. J Karl Coke, Direc and United States Department of Agriculture or, California Agricultural Extension Service. 30m-ll,'54(4713)L.L. [44] '< A -if A ^ i;.*- 4 \4 jti X A: :A 'Jk .. . i 14 ■ ':4