Talbert, Thomas Jesse, 1880-

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UNIVERSITY OF MISSOURI COLLEGE OF AGRIC ULTU RE AGRIC ULTURAL EXPERIME NT STATIO N i\ 1. F.l\illI.ER , j Jirec/m CI RCULAR 22 1 Columbia, Missouri MARC H, 1942 Handling Peach Trees After Winter Killing of Fruit Buds T. ]. T A LBERT FOllr - rNU' -<l\d 1 1~ 1l Il' rtn II (·UC·I! tn ·f· :-< l ll,will ~ 1I111HIIII! lind I ,\ ' p t, Hr prllllill g' ai'l e l' nil 111 (' fruit )llId s 11l1d 11('('1) kill t' d I I,\' .-JnIlIlHr ,\' rn lcl . . \ t e mpera ture in th e w in ter o f a bo ut _ IU o to _l ~ o j ,'. is io \\' e no ug h to ca u se ex tens ive peac h bud killin g, a nd if it occurs aft r January in th e mo r e so uth e rn sec ti o ns o f M isso llri , a ll th e fruit bud s may be kill ed. Furthermore, te mpe ra ture o f _ 1.,) 0 to _ 200 F. durin g th e dormant period is li ke ly to d s troy a ll the frllit bud ,; . S till <lnother type of injury to fruit hud s may occ ur at hl oomin g time. Thi s is du e to late s pr in g free z(,s a nd fros ts which may des troy th e prospects for ~I crop, part icularl y ill di s tri ct s w here peach g row in g is 111 0re o r less a haza rd. 2 MISSOURI AGRICULTURAL EXPERIMENT STATION Hardiness of Fruit Buds The resistance of peach fruit buds to low winter temperatures increases until about the middle of January. After that time, if warm unseasonable periods develop, their hardiness decreases rapidly. In case the weather remains cold through the winter season, the fruit buds may become even hardier after that time. I t is also true that pead1 buds on vigorous trees-trees that hold their leaves until late in the fall or early winter and properly mature their wood and tissues-are not so likely to be affected by cold following warm periods of weather in January or early February. This is due to the fact that the more vigorous trees generaHy enter the rest period later than the weak ones, conse-quently, the fanner have more of the rest influence left to delay blooming. The producer, therefore, who can keep his trees healthy and fairly growthy until fall, and then allows them to harden by discontinuing cultivation and by growing cover crops to take up excess moisture and nitrogen, usually produces the hardiest trees and the most profitable orchard. Knowledge of Fruiting Habit Important /\ knowledge of the fruiting habits of the peach is fundamental to profitable and intelligent pruning practices. This is more true with this fruit than with other deciduous fruit trees because the peach bears only upon wood or growth of the past season. There-fore. the pruner must know and be able to locate the l-year-old or fruiting branches. These are found, of course, as terminal growth or as shoot growth from the larger branches and main trunk. The fruit produced each year, therefore, may be farther and farther from the main stem or trunk. Thus in a few years, with-out pruning back practices, the tree branches are likely to become greatly extended and may break in storms or when heavily loaded with fruit. To keep the fruiting wood within bounds, prevent the breakage of branches, and renew the fruiting wood yearly from the scaffold branches and main trunk, the trees should be properly pruned annua:!ly. Such pruning tends to produce trees of long life and with fruiting wood close to the ground and nearer the main stem or trunk. Pruning at Blossom Time With a partial killing of fruit buds in mid-winter it is very difficult to determine accurately the amount of spring bloom to be expected and the resulting prospects for a crop. Moreover, further CIRCULAR 221 3 reductions in the number of fruit buds may be made by late spring freezes and frosts occurring at or neaT the blooming time. Under such conditions it is generally advisable to postpone pruning until the blossoming period. The amount of pruning, both heading back and thinning, but more particularly the severity of the heading back, may then be regulated by the abundance (If the hloom anel the indications of a' crop. When Heavy Crop is Outlook.-In case a heavy crop is ex-pected, the fruiting wood may be thinned and headed back rather severely, removing one-fourth to one-third of the previous year's gro-wth 'with a large number of fruit buds 011 the shoots. Such pruning lightens the subsequent work of crop thinning, and tends to stimulate the production of fruiting wood on one and two year old branches. When Light Crop is Expected.-The sma.Jler the prospecti ve crop , indicated by the amount of bloom, the less severe the heading back and thinning out should be in order to insure a partial to full crop. In fact, if only it very light bloom occurs, little or no pruning may be done so that every blossom may be left if possible to set and develop fruit. . Blossom Time Pruning in Large Orchards.-In large commer-cial orchards it may not be practical in every instance .to delay all the pruning work until the blooming period. However, if time and labor are available, the pruning may be continued profitably after the blossoms drop and as the fruit is setting. Pruning After All or Nearly All Fruit Buds Have Been Killed If the entire crop is destroyed by winter cold or spring frosts, one or both, the orchardist .may take advantage of the situation and head the trees fairly severely, cutting back into as much as 2-year-old wood. This may be needed as the peach tree bears fruit on I-year-old wood which tends to grow farther out on the ends of the branches each year. The exact amount of pruning may be greater or less, depending on the shape and condition of the tree and the amount of injury to the wood. If a similar treatment was required the previous year, the heading need not be quite so severe now, although much of the past season's growth may be removed. After Several Years Fruiting Then Buds Killed.-Where crops have been borne for a number of years, the destruction of alI fruit buds by low winter temperatures or spring frosts affords an oppor-tunity to lower the tops and correct the shape of the trees. Under such circumstances it may be advisable to cut back into 2 or 3-4 MISSOURI AGRICULTURAL EXPERIMENT STATION year-old wood. However, cutting back into wood three or more years old lessens the likelihood of fruit bud formation and reduces , the crop prospects for the following year, even though weather conditions in the following winter and early spring may be favor-able. Such heavy pruning is rarely necessary except where the wood has been injured seriously or killed by cold. Shoot Thinning After Heavy Pruning.-Following heavy prun-ing, the new shoot growth produced may be very rank and thick. Since it tends to grow farther back on the main branches and trunks the shading effect may be increased greatly. Thinning and spacing the shoots, however, about 8 to 10 inches apart, may aid materially in the formation of fruit buds for the next year's crop. The ' work is of greatest value if done fairly early in the summer when the shoots may be pulled easily, thus making unnecessary the use of pruning tools. May Profit from Experiences of 1940 The blizzard and freeze of November, 1940, killed both the fruit buds and wood of peach trees in the northern districts of the state. In the central and southwestern sections the fruit bucls ill most instances were unharmed while more or less serious injury occurred to the cambium or growing layer beneath the bark and next to the wood at the base of the tree trunks and in the crotches of the lower scaffold branches. Following this damage, peach growers throughout the state . were urged to withhold pulling. cutting, and heavy pruning of injured trees. These recommendations were based upon the fact that the extent and severity of the cold injury could not be defi-nitely and a'ccurately determined . By following such a procedtire, it was pointed out, one year on Iy would be lost in starting a new orchard. Moreover, it was also belit!ved that the damage particularly in central and southwest Missour.i although serious might not prevent one more profitable crop of fruit in many instances. The injury, however, wa's sufficient to indicate the death of nearly all the trees after the fruiting season of tht~ following year. Results from Trees Dam.aged in 1940.-All the surveys and information obtained on the recovery and production of peach trees in the storm area , show that fair to good crops were produced ' the following year where the fruit buds were pot injured. Prac-tically all the trees, however, are now dead or they are in a dying condition. Consequently, the removal of nearly all of the trees occurred during the fall and winter of 1941-42. C'Jl(l ' U I. AR 22 1 .1 SU ll ll' IIt'at' lI tn'" prll ll l'd 1It'll' I' :11\ 4's tilllnl, 'd J\ ll l ill~ of UO '1t: oj" lltl' fr uit IJlld ti 1, .\' Wiflil' /' ,'old. 6 MISSOURI AGRICULTURAL EXPERIMENT STATION Treatments After Serious Cold Injury From the experience of November, 1940, and similar damage resulting from cold in many other years, it is believed that peach growers will profit usually by postponing severe treatments until after the growth and fruiting results of the following season have been ohtained. It is common knowledge that severely injured peach trees are often pruned, too heavily. This is true because the trees need generally as much leaf surface as possible in overcoming damage through growth and development. Fertilizing Winter Injured Peach Trees Commercial Nitrogen Fertilizers.-Both spring and fall appli-cations have been profitable. Spring fertilizing at time of bloom-ing or shortly before is generally practiced. Applications of nitro-gen fertilizers like nitrate of soda, sulphate of ammonia and cyan-amid are generally employed. The amount used then is largely dependent upon the prospects for a crop. Regardless of the amount of bloom, if the trees are not making 12 to 18 inches of growth annually, they will respond favorably in most cases to liberal ap-plications of fertilizers. Manure.-Barnyard manure may be particularly valuable in bearing orchards on very poor soil Or where there is too much shade for the growth of a good cover crop. Moreover, it is im-pOl·tant that manure, which is slowly available, be applied in the winter or very early in the spring. Applications made late in the spring or in summer may induce a late tree growth. This would delay maturity, tend to lessen the color of the fruit, a'nd increase the likelihood of winter inj ury. ' Whether to Fertilize.-In every planting, whether to fertilize and how much to use are questions that must be considered. The best answer will usually be found in a study of the growth and yield records of the trees. If an annual growth of less than 12 to ] 8 inches is being made, a nitrate fertilizer should prove worthwhile. Trees in moderately good condition may not require fertilizer treatment unless they bear a crop. Furthermore, the increased set of fruit produced by an early application of nitrogen merely increases the work and cost of crop thinning. By waiting until danger of frost is past, the proper amount of fertilizer to be used can be ascertained by the prospects of a crop and should late frosts kill all the blossoms, the fertilizer ;nay be withheld until it is needed. When peach trees are making a poo'r growth, an applica-CIRCULAR 221 7 tion of nitrogen should generally be made whether a crop is pro-duced or not, and it may be made anytime in the spring. Amount of Fertilizer to Use.-The amount of fertilizer to uSe on peach trees will depend on the fertility of the soil and the con-dition and size of the trees. On the average a moderate applica-tion of manure for large bearing trees would be about 1/5 ton per tree. The same trees would receive in commercial nitrogen about 3 pounds of sodium nitrate, 274 pounds of ammonium sulphate, or 2 pounds of cyanamid. Young trees 2 or 3 years old will not usually require more than Y2 pound of sodium nitrate, 1/3 pound of am-monium sulphate, or 3 to 4 ounces of cyanamid to a tree. In special cases, the exact amount to be used must be determined by the grower on the basis of judgment and experience. Chemical fertilizers for fruit trees are .usually broadcast by hand or drilled in between the rows of trees. Care should be taken to keep the fertilizer away from the tree trunks as there is danger of burning the bark. The distribution may extend a greater dis-tance from the trunk than the branches, as an abundance of feed-ing roots may be found beyond the branches. Use of Phosphate, Potash, and Lime Applications of phosphate, potash, and lime have not in general influenced beneficially the growth and yield of peaches. It is true, however, that the use of these materials may have an indirect value by making possible the growing of larger tonnages of cover crops for plowing under. For Other Information To secure information'upon sprays, spraying practices, peach leaf curl control, combatting San Jose, and the handling of other important problems in the successful ma'nagement of a peach orchard, request assistance from your County Extension Agent or. the Missouri Agricultural Experiment Station at Columbia. 

Handling peach trees after winter killing of fruit buds

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