UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION BERKELEY, CALIFORNIA CIRCULAR 328 January, 1933 THE BABCOCK PEACH' GEO. P. WELD0N2 and J. W. LESLEYS The Babcock peacli. INTRODUCTION In the subtropical regions of southern California, Georgia, Florida, the low veldt of South Africa, and many other parts of the world, the peach and several other deciduous fruits frequently fail to complete their dormancy cycle as this cycle is completed by those plants that are i Paper No. 274, University of California Graduate School of Tropical Agricul- ture and Citrus Experiment Station, Eiverside, California. 2 Pomologist, Chaffey Junior College, Ontario, California. 3 Assistant Plant Breeder in the Citrus Experiment Station. 2 University of California — Experiment Station adapted to subtropical conditions. As a result, spring growth, especially of leaf buds formed in the preceding season, is delayed or entirely pre- vented ; also blooming, while it may be profuse, is late and long contin- ued, and fails to produce a set of fruit. It has been shown that in south- ern California this condition is general with most of the present varieties in commercial orchards. It varies in intensity from season to season, being at its worst during springs that follow winters of abnormally high temperatures. 4 The condition was formerly known as ' ' delayed folia- tion, ' ' but it is now somewhat more appropriately termed ' ' prolonged dormancy. ' ' The peach crop in southern California was affected more or less se- verely in five out of the last nine seasons. In 1926, Home, Weldon, and Babcock 5 gave an account of prolonged dormancy and of the mitigating effect of shade in winter. They also described the remarkable differences in behavior among peach varieties in seasons of prolonged dormancy ; varieties of the Peento and Honey groups were practically unaffected, while those of the Chinese Cling and ' ' Persian ' ' groups were severely affected, and certain varieties of mixed racial origin were intermediate. ORIGIN OF THE BABCOCK PEACH The hybridization of varieties of the Peento and Honey groups with varieties in the affected groups having more desirable fruit characters was begun by E. B. Babcock at the Southern California Plant Pathology Laboratory at Whittier, California, in 1907, where the original hybrids were grown for several years. Much of the hybridizing and selfing of hybrids was done there by C. O. Smith. Selfed seeds from the original hybrids were sown at Berkeley by Babcock ; 139 second-generation seed- lings were obtained from this planting and were grown at Berkeley for two years. Budded trees from the original hybrids at Whittier, and from the second-generation plants and a few backcross seedlings at Berkeley, were sent to the Citrus Experiment Station at Riverside. The breeding investigations showed that resistance tends to be a dominant character and that new combinations of resistance and several other characteristics may occur. The project resulted in the production of at least one variety of practical importance. * Weldon, Geo. P. Deciduous fruits in southern California. Pacific Bural Press. 122:319. Oct. 3, 1931. s Home, Wm. T., Geo. P. Weldon, and E. B. Babcock. Kesistance of peach hy- brids to an obscure disease. Jour. Heredity 17:98-104. 1926. Cm. 328] The Babcock Peach 3 On the basis of careful observations on 162 first-generation, second- generation, and backcross seedlings, made chiefly by H. B. Frost and C. 0. Smith of the Citrus Experiment Station, 30 of the seedlings were selected for further trial. In 1925, budded trees of the selected hybrids were planted in the experimental orchard of Chaff ey Junior College at Ontario, where they came under the observation of the senior author. One seedling, which had been selected in the first instance as an inter- esting, unusually sweet-tasting type, was now recognized as having qualities of great practical value and as being superior, probably, to any available variety maturing at the same time, for planting in southern California and perhaps in other subtropical and semitropical regions. This hybrid originated in the second generation from a cross between Strawberry and a Peento type. Strawberry, the seed parent, is ex- tremely subject to prolonged dormancy. At Ontario and Riverside this variety blooms and leafs late, even when prolonged dormancy is at a minimum as in 1932 ; but in 1931, when symptoms were severe, blooming was delayed until March 30, or two months later than a tree of the Peento type nearby. The pollen parent belonged to the Peento group, which is least subject to prolonged dormancy, and undoubtedly had the early-blooming and early-leafing characters which are closely corre- lated with resistance to this injury. From its progeny it is inferred that, like other Peento types, it was rather large-flowered, and had early- maturing fruit and white flesh. The hybrid, as the description will show, represents a new combina- tion of characters. In honor of its originator, Professor E. B. Babcock, of the University of California, this Strawberry-Peento hybrid is named the Babcock peach (frontispiece, and fig. 1). The Babcock peach has been under observation for several years in the experimental orchards of the Chaff ey Junior College and of the Citrus Experiment Station, but has not been grown on a commercial scale. Although grown on the poorest soil in the Chaffey orchard, it sized much better than Early Imperial, the principal early market variety in the southern part of the state. It is recommended to growers for trial as a fairly early dessert peach adapted to a subtropical climate. Its flavor will appeal especially to those who like a very sweet peach with little acidity. Bud wood of the Babcock peach has been distributed free to several growers and nurserymen, and no restriction will be placed upon its dis- tribution, except that which may be necessary to secure its widest pos- sible introduction. At present a supply of buds is available from trees University of California — Experiment Station o o W) > A £3 o fl 3? o> bfl ft'E O r^J pq bo Cm. 328] The Babcock Peach 5 growing at Chaffey Junior College, Ontario. Also some nurserymen in the vicinity of Ontario have already begun the propagation of trees of the new variety. DESCRIPTION OF THE VARIETY The Babcock peach is a white-fleshed freestone. It is a second-genera- tion hybrid from Strawberry x Peento (Saucer). During the ripening period of 1932, at Ontario, good color developed as early as June 9. The fruit will ripen if picked as soon as it is well colored. It was at its best for market when picked about June 20. Fruits picked on that date rip- ened well in 48 to 72 hours. The last fruit was picked from two trees on July 18, when some fruits were sound and still in good condition for the fresh-fruit market. The fruit is very hard for at least two weeks after considerable color has developed. The flesh possesses a character- istic crispness. If left on the trees for a time after color begins to develop, the peach will increase in size without becoming overripe. It clings so tenaciously that few fruits fall to the ground until they are very much overripe. Sometimes the seeds will cling to the trees after the flesh has been eaten by birds. Tree. — Size, medium to large; vigorous; inclined to be spreading rather than upright in habit of growth ; very productive ; early-leafing ; well adapted to subtropical regions ; comes into leaf and blossom from early to late February in southern California; in five seasons of pro- longed dormancy, foliation was not delayed and the yield was heavy. Leaves. — Light green ; glandular ; glands small, cuplike, circular in outline, approaching the globose type. Fruit. — Spherical to ovoid-spherical ; sides usually about equal. Size, uniform; diameter, 2% to 2% inches. Color, exposed portions, deep purplish red ; unexposed portions, light pink with delicate blush ; scat- tering of white dots near apex ; color extremely attractive. Pubescence very light, some specimens almost as smooth as a nectarine. Cavity, deep, abrupt. Suture, often deep at cavity ; not prominent ventrally. Apex, small, sometimes depressed ; usually with rather prominent apical su- ture, extending for about % inch dorsally and ventrally. Skin thin but fairly tough, separating readily from flesh when fruit is ripe. Flesh, nearly pure white ; red near pit ; very juicy, tender. Quality, good ; very sweet, mild flavor, little acid, pleasing aroma ; crisp until ripe. Stone, small; average length 1% 6 inch; average width, % inch; average depth, % inch; ventral suture, prominent and deeply grooved along the edges ; dorsal suture, grooved ; grooves about equal in depth to ven- tral surface sutures. 8m-l,'33