M„ A Publication of The College of Agriculture UNIVERSITY Of CALIFORNIA w ' A WARM ER CLIMATE 5UY JYL M. WINSLOW CALIFORNIA AGRICULTURAL EXPERIMENT STATION CIRCULAR 406 PEACH VARIETIES F JLor or a number of years, plant breeders have been working to develop peach varieties with a low enough winter chilling requirement to produce well in southern California, and thus help to restore what was once a major fruit industry in that area. They have had some success. While the main reason for the shrinkage in peach acreage in southern California since the early 1930's was economic, a secondary but highly important reason was that most of the better-known peach varieties needed more winter chilling than is provided by the normal climate in that area. The varieties described here were developed at the University of California's Agricultural Experiment Station. All are relatively new; all have moderate or low chilling requirements and should produce well in southern Califor- nia. Their faults, as well as their good points (based on their behavior at Riverside) are listed. THE AUTHORS: J. W. Lesley is Geneticist in the Experiment Station, Riverside. M. M. Winslow is Senior Administrative Assistant, Riverside. FOR A WARM WINTER CLIMATE J. W. LESLEY • M. M. WINSLOW About 25 years ago, peaches were an important crop in southern California, with over 27,000 acres being planted to this fruit. During the ensuing period, however, economic conditions such as low prices, and poor varieties which suffered from a condition known as delayed foliation influenced many farmers to turn to other crops. Thus the 1950 report of the California Crop and Livestock Service showed that in that year peaches in southern Califor- nia accounted for only a little over 5,600 acres, bearing and nonbearing. However, in a few localities in south- ern California (notably the Ontario and Yucaipa districts in San Bernardino County, and the Beaumont and Banning Heights districts of Riverside County) table peaches are still important in the local market. And it is felt that the re- cent large increase in population of the metropolitan areas of southern California should provide an expanding market for locally grown fresh peaches. Development of New Varieties As early as 1907 it was found that many varieties of peaches then being grown were not well adapted to the lower elevations of southern California where a subtropical climate prevails. It was ob- served that most of these varieties were subject to prolonged dormancy, due mainly to lack of chilling during the rela- tively warm winters which are character- istic of the region. Therefore plant breeders initiated a program to attempt to develop new varie- ties that would require a relatively short period of winter chilling — that were bet- ter adapted to the warmer areas of south- ern California. The first successful variety was the Babcock peach. Subsequently, further work along this line was undertaken at the University of California Citrus Ex- periment Station, at Riverside, and the varieties described in this circular were all developed at that Station. The descrip- tions of the varieties given below are based on their behavior at Riverside. Effect of Winter Chilling on Peaches The amount of chilling weather en- countered during any given winter will affect the time of both blooming and often of fruit ripening of peach trees. The flower buds of peaches normally open after they have received enough winter chilling followed by weather that is warm enough to induce their opening. Thus a warm spell early in February will cause the flower buds of a very short-chilling variety to open, but not those of a long- chilling variety — the latter has probably not received sufficient winter chilling at that early date and may not bloom until a month or more later. After an unusually cold winter and spring, long- and short- chilling varieties differ much less in date of blooming. After a mild winter, the ripening date of short-chilling varieites in some years is advanced by as much as 2 or 3 weeks, whereas the ripening date of long-chilling varieties is little affected. Short-chilling varieties have their drawbacks too. If, after an unusually warm winter, a late frost occurs, very short-chilling varieties may lose their crops if freezing temperatures come dur- ing or after bloom. Therefore, varieties [3] Bonita tree, 5 years from budding. that require less chilling than those in grade 3 may be undesirable for the inter- mediate zones of southern California. In the coastal belt there is much less danger from spring frost, and at high elevations the colder spring weather tends to delay blooming sufficiently to escape frosts. The varieties described here are graded from 1 to 7 on their requirements for chilling. Grade 1 signifies the shortest chilling requirement; grade 7 the long- est. The grades given are based on the behavior of the varieties at Riverside. All of these varieties are freestones, with the exception of Ramona, which is a cling. All are self-fertile — will produce fruit from their own pollen. All, with the exception of Anza, were developed for the areas in southern Cali- fornia having warm winters (graded 4 or less for chilling requirement) . All but Prenda, Golden State, and Ramona can be obtained from several California nurs- erymen. Here Are the New Varieties Anza The tree is rather upright and only moderately vigorous. This attractive, yel- low-fleshed freestone is firm, sweet, and juicy. The flesh is of good texture and Fruit of the Bonita variety. quality. Anza has possibilities in the areas mentioned for the Rubidoux (see below), but is not recommended for low elevation areas in southern California. Anza falls in grade 5 for winter chilling and requires less, by one grade, than the J. H. Hale. This variety begins to ripen the second week in August. Bonita The Bonita is a vigorous, upright type of tree. The foliage is dark green. The leaves hold on late in the fall. It is an excellent producer. The fruit is medium to large in size. The skin color is a light yellow with a deep red blush. It is an attractive fruit. The flesh is yellow with a dark pink seed cavity, and with fingers of pink extending into the flesh. The flesh contains some fiber. The flavor is sweet with a touch of bitterness in some sea- sons. The quality is good. It is a promis- ing peach for the home garden and for small commercial plantings near the coast. Bonita falls in grade 2 and requires less winter chilling than Babcock. It ma- tures late in July. Golden State The tree is a vigorous, upright grower at Riverside. The fruit is large and firm. The skin is a lemon-yellow color with a [4] Hermosa tree, 5 years from budding. marbled red blush on one side; not at- tractive in appearance. The flesh is light yellow with a light pink seed cavity and rather coarse. The flavor is fair and slightly subacid. This variety is an irregular producer, subject to preharvest drop, and therefore not promising. Golden State falls in grade 3 for winter chilling. The first fruits ripen the first week in August. Fruit of the Hermosa variety. Hermosa The tree of the Hermosa is of fair vigor with a rather spreading type of growth similar to the J. H. Hale. It has large, conspicuous flowers. It is a heavy bearer, coming into production early. The fruit is medium in size. The skin color ranges from pink to solid red. The flesh is white, with a pink seed cavity. The flavor is sweet and mild. Hermosa falls in grade Fruit of the Prenda variety. [5] Fruit of the Ventura variety. 3 for winter chilling. The fruit begins ripening the middle of August. The va- riety has sold well at roadside stands. It is recommended for the home gardener who likes a sweet, nonacid-tasting fruit. Ramona This cling peach is borne on a vigor- ous, upright tree. The fruit is of a good- size, yellow fleshed, and produces an excellent canned product. It tends to pro- duce many twin fruits thus lessening its commercial value. It is later than the Fontana, another cling with a short chill- ing requirement. Ramona falls in grade 3 for winter chilling. This cling is the last of the varieties to ripen, being ready for harvest about the second week in Sep- tember. Prenda The Prenda is a vigorous, upright- growing tree, and a good producer. The leaves are a dark green. The fruit is me- dium to large in size. The smooth skin is a light cream color with a red blush on one side, near the stem end. The flesh is white, smooth in texture, and juicy. The flavor is mild, sweet, and pleasing. Like most white peaches, the aroma is attrac- tive. It has not been grown outside of the Riverside area and is not yet avail- able from nurserymen. It is also subject to preharvest drop of the fruit. Prenda falls in grade 2 for winter chilling. It ripens with Golden State. Rubidoux The tree is vigorous, and moderately spreading. It retains its leaves into late fall. Good production can be expected. The fruit is medium in size. The skin is greenish-yellow with a dull red blush. It is one of the best keepers of those de- scribed. The flesh is light yellow and the deep red of the seed cavity extends into the surrounding flesh. The flesh contains some fiber. This sweet, well-flavored peach has promise for the higher eleva- tions in southern California. It merits a trial in the upper San Joaquin Valley. Rubidoux falls between grades 3 and 4 for winter chilling. The fruit starts to ripen the last of August. [6] Sunglow The tree is a vigorous, upright grower. The foliage is dark green. This variety produces well. The fruit is medium-large in size. The skin color is golden yellow with a red blush. The flesh is light yellow with a medium-pink seed cavity. The tex- ture is smooth. This juicy, rich-flavored fruit should be popular with consumers. It certainly has a place in the home gar- den. It is somewhat subject to preharvest drop. Sunglow falls in grade 4 for winter chilling. It starts to ripen the first week in August. Ventura This variety first produced fruit in 1942 as seedling 202-10. It is the earliest to ripen of the varieties listed, maturing early in July. The tree is 'vigorous and upright. For winter chilling it is in grade 2. It was named after Ventura County on the southern coastal plain where it is reported by C. C. Delphey, Agriculturist in the Agricultural Extension Service, to show some promise. The fruit is slightly flattened at the poles, almost without a pointed tip; at- tractive in appearance, but rather small in size. The skin is yellow with a red blush. The flesh is yellow, contains very little red color, and is free from the pit. The fruit often shows a twig mark due to the short pedicel or stem. The flavor is subacid and the quality fairly good. LITERATURE CITED The following articles and publications were used as source material in the preparation of this circular: Chandler, W. H., M. H. Kimball, G. L. Philp, W. P. Tufts, and Geo. P. Weldon. 1937. Chilling requirements for opening of buds on deciduous orchard trees and some other plants in California. California Agr. Exp. Sta. Bui. 611. Chandler, W. H., and Dillon S. Brown. 1951. Decidous Orchards in California winters. Calif. Agr. Ext. Cir. 179. Lammerts, W. E. 1941. An evaluation of peach and nectarine varieties in terms of winter chilling requirements and breednig possibilities. Proc. Amer. Hort. Sci. 39:205-211. Lesley, J. W. 1939. Five new peach varieties especially adapted to mild winters. Univ. of Calif. Agr. Exp. Sta. Bui. 632. 10m-4,'53(A3034)W.P. Second Printing [7] test tube farming pays off for you Not all of the agricultural research done by the University of California is field work. Much useful knowledge comes to light through work done under controlled laboratory conditions. This information, after thorough checking and application to field problems, becomes available to all California farmers. Distribution of this knowledge is made through: LITERATURE: Circulars, bulletins, lithoprints, and leaflets by specialists are available free. There publications cover many subjects re- lating to agriculture in the state. For a catalog of this litera- ture write to the Office of Agricultural Publications, 22 Giannini Hall, University of California, Berkeley 4. COUNTY FARM ADVISORS: Farm Advisors are agricultural specialists with a background of practical knowledge. They serve 52 counties throughout the state and their mission is to help farmers work out their problems. Get to know your Farm Advisor — take advantage of his services. MAIL INQUIRIES: If you prefer to put your questions in a letter, mail them to the Public Service Office of the College of Agriculture, Uni- versity of California, either at Berkeley or at Davis. Your problem will be referred to the person or department best ^ able to give you the exact information you need. THE COLLEGE OF AGRICULTURE UNIVERSITY OF CALIFORNIA