Growing Tree Fruits PDF - Oregon State University

HO-104 Growing Tree Fruits By Jeff Olsen, Extension agent, Willamette Valley, and Anita Nina Azarenko, Extension horticulture specialist; both at Oregon State University. Adapted for Kentucky by John Strang, Extension horticulture specialist (ret.), University of Kentucky....

HO-104 Growing Tree Fruits By Jeff Olsen, Extension agent, Willamette Valley, and Anita Nina Azarenko, Extension horticulture specialist; both at Oregon State University. Adapted for Kentucky by John Strang, Extension horticulture specialist (ret.), University of Kentucky. General types of apples include old style, cider, English, or In this chapter: flavor varieties. If you want to have fresh-off-the-tree apples for a long period of time in the summer and fall, choose varieties Planning 01 with staggered maturity dates (Table 22.2). When buying trees for Kentucky, select disease-resistant Pruning Terminology  03 varieties (Table 22.3) to reduce the impact of apple scab, cedar Planting and Fertilizing 05 apple rust, fireblight, and powdery mildew. Irrigating 05 Fruit Thinning 06 Rootstock Selection When choosing a fruit tree, check to see what rootstock it Harvest and Handling 06 uses. Rootstocks are not chosen for their fruit. Most originally Insect and Disease Management 08 were selected for their ability to control overall tree size. Some Pruning  09 were selected for other characteristics, such as the following: Efficient yield production For More Information 10 Disease resistance Tolerance of different soil conditions, including poorly drained soils G rowing tree fruits or nuts can provide a great deal of Cold hardiness satisfaction, but it takes a commitment to care for your trees year-round. Apples The greatest choice in rootstocks exists with apples. The Planning most vigorous apple rootstocks are seedlings, which are simply sprouted apple seeds. When an apple variety is grafted onto a Variety Selection seedling rootstock, the tree can easily grow more than 30 feet tall. Most home orchardists can’t efficiently spray, thin, and When planning your orchard, choose varieties that not harvest a tree this tall. only are family favorites but are easy to care for. Remember Researchers in England developed the Malling series of that dwarf trees are always the best choice for home orchards. apple rootstocks, which offers the opportunity to select trees Generally, the more varieties of fruit you grow, the more that grow to specific heights. The height may be anywhere from complex it is to manage them. However, if you enjoy a lot of dwarf (4 to 12 feet) to semidwarf (16 to 18 feet). Each rootstock different fruits and the management challenge, by all means in this series is identified by the letter “M” (for Malling) or “MM” plant a wide range. (for Malling Merton) and a number. Higher numbers don’t Nearly all fruit- and nut-tree varieties (including some hazel- represent taller trees (Figure 22.1). nuts) are grafted to a genetically different root system, called a The following list shows approximate sizes as a percentage rootstock. When you choose a variety based on flavor, harvest of the size of a tree on seedling rootstock: period, disease resistance, color, etc., it is the grafted variety you are choosing—not the rootstock. Rootstock Percent The ultimate size of a tree depends on the vigor of both the MM.111 90 rootstock and the grafted variety. By knowing the vigor ratings MM.106 60 - 75 of both, you can determine how big a tree will grow. See Table M.7, G.30 55 - 65 22.1 for vigor ratings for some apple varieties. See the section M.26, G.11 40 - 50 on Rootstock Selection to learn more about vigor of various M.9, Bud 9 25 - 35 rootstocks. M.27 < 25 Not all recommended varieties are included in the lists in this chapter. For apples alone, hundreds of varieties exist, Most home orchardists select dwarf rootstocks, such as Bud and other fruits could have many more varieties. Consult the 9, which are especially appropriate if you want to train a tree to resources listed under “For More Information” to learn about grow along a trellis. Dwarf trees should be supported by stakes, additional varieties. poles, or wires. CHAPTER 22 Growing Tree Fruits Table 22.1. Apple variety vigor ratings. Cherries High vigor Low vigor Most cherry trees in Kentucky are grown on Mazzard root- Earligold Spur Delicious stocks. However, recent research on growth-controlling rootstocks Lodi Spur Golden has produced more choices. New dwarf varieties are now being Mutsu or Crispin Spur Granny Smith grown on Gisela rootstocks, and new European rootstocks are Moderate vigor Very low vigor being tested each year. The most common Gisela rootstocks are Akane Jonagold Spur Arkansas Black Gisela 5, Gisela 6, and Gisela 12. They produce trees that are 50 Arkansas Black Jonathan Spur Delicious Cortland Liberty Spur Rome percent, 70 to 90 percent, and 60 percent of Mazzard, respectively. CrimsonCrisp Melrose Super Spur Other new rootstocks include MxM2 (100 percent of Mazzard), Delicious (red) Mollies Delicious MxM60 (100 percent of Mazzard), and MxM14 (75 to 85 percent Empire Newtown of Mazzard). They bear earlier and have better disease resistance Enterprise Pixie Crunch Freedom Pristine than Mazzard seedlings. Fuji Redfree Sweet cherries generally do not survive or produce well Gala Sansa in Kentucky. Some of these newer rootstocks are available to Golden Delicious Rome Beauty home gardeners from a few mail-order nurseries in the Pacific GoldRush Stayman Granny Smith Suncrisp Northwest. See HortFact 3002, Fruit and Nut Cultivar Nursery Idared Sundance Sources, which is listed in the “For More Information” section Jersey Mac William’s Pride at the end of this chapter. See Table 22.4 for cherry varieties. Pears The M.27 rootstock is the only choice for growing apples in containers. For container plantings, use spur-type varieties, Most European pears are grown on one of many selections which are the least vigorous. from the Old Home-Farmingdale cross. Asian pears sometimes M.7 produces semidwarf trees that normally do not require use these rootstocks but also are grown on two species of Pyrus: staking. However, some support might be required if early Pyrus betulaefolia and Pyrus calleryana. See Table 22.5 for production is encouraged. pear varieties. MM.106 and MM.111 produce larger trees that require Plums and Peaches no staking and are suitable for the home orchard. In nursery Plums are produced on a wide variety of Prunus rootstocks, catalogs, these trees are identified as semistandard. such as peach, plum, apricot, and almond. Peaches usually are The ultimate height of any tree can be greatly influenced by grown on peach seedling rootstocks. There are no suitable pruning, but rootstocks that impart more vigor make it harder dwarfing rootstocks for peaches. See Tables 22.6 and 22.7 for to contain trees to the height and width desired. nectarine and peach varieties. Other commercially available apple rootstocks provide vigor control, disease resistance, and winter hardiness. The Budagorsky (Bud) series was introduced from central Russia. The G series was developed at Cornell University at the New York State Agricultural Experiment Station in Geneva, New York. 100 90% 90 80 60-75% 70 55-65% 60 Percent 40-50% 50 40 25-35% 30 20 10 0 M.9 M.26 M.7 MM.106 MM.111 Seedling Bud 9 G.11 G.30 Figure 22.1. Approximate size of mature trees grown on various rootstocks, as a percentage of maximum height (100 percent) grown on seedling rootstock. 22-2  Growing Tree Fruits CHAPTER 22 Table 22.2. Apple varieties grouped by general time of maturity. Pruning Terminology Early Midseason Late Crotch angle—The angle formed between the trunk and a limb. Akane William’s Pride Jonathan Idared The strongest crotch angle is 45° to 60°. Dayton Empire Liberty Jonagold Erligold Freedom Arkansas Black Melrose Leader—The uppermost portion of a scaffold limb. Jersey Mac Gala Cortland Mutsu or Scaffold limb—A large limb that forms a tree’s framework. Lodi Ginger Gold CrimsonCrisp Crispin Mollies Delicious Newtown Shoot—The length of branch growth in one season. The bud Delicious (Golden and Pixie Crunch scale scars (ring of small ridges) on a branch mark the start of a Monark Red) Rome Beauty season’s growth. Pristine Empire Stayman Redfree Enterprise Sun Crisp Spur—(1) A short shoot that bears flower buds on the end (termi- Sansa Fuji Sundance nally) or on the sides (laterally). (2) A short shoot that fruits. GoldRush York Granny Smith Table 22.3. Disease-resistant apples.1 Resistance To Stores Variety AS CR FB PM Comments Harvest Until Skin Color Pristine2 VR S S R Good quality for season, not as tart as Lodi, early July short Light yellow with red blush makes excellent applesauce storage Williams Pride VR S MR R Good quality for season, corkspot frequently mid-July short 70-80% dark red observed, subacid, yellow flesh storage Redfree2 VR VR S S Firm, summer apple, juicy late July Oct 90-100% dark red on yellow Dayton2 VR R MR R Similar to Prima mid-Aug Sept Up to 90% bright, medium red Liberty2 VR R3 R R Fruit similar to Macoun, crisp, juicy, yellowish late Aug Dec 90% dark-red stripes on flesh, tart at harvest green-yellow Nova Easygro VR VR R S Fruit similar to Cortland, fair quality (for trial) early Dec 80% dark red on green-yellow Sept Spartan2 MR R MR R Firm McIntosh type, needs thinning to develop early Jan Dark to pale red, depending on size Sept weather Jonafree2 VR S S R Fruit similar to Jonathan, but less acid early Dec 90% red stripes Sept Pixie Crunch2 VR — — — Small, sweet flavored, super crisp, kid’s apple early Dec Deep red Sept Macfree VR VR3 MR S Similar to McIntosh, mealy under hot conditions mid-Sept Dec 75% medium red over green-yellow Priscilla2 VR VR3 VR R Tart, firm, somewhat coarse textured, crisp, juicy, mid-Sept Nov 70-90% dark-red blush over small fruit size yellow-green SirPrize2 VR S R R Fine grain, crisp, tender, bruises very easily, sterile mid-Sept Dec Greenish yellow, slight red blush pollen CrimsonCrisp VR MR S S Medium-sized red fruit, firm, crisp, tart, stores mid-Sept March 95% red very well Enterprise2 VR VR3 MR R Sprightly, subacid, slightly aromatic and spicy, early Oct Feb Washed, 90% light to medium red crisp, fine-grained juicy flesh, stores well GoldRush2 VR S MR S Fruit very crisp, firm, tart at harvest and sweetens mid-Oct April Deep yellow with red blush up after storage, very susceptible to black rot. Will store for 11 months. Sundance2 VR VR VR VR Excellent quality with fruity flavor like mild pine- mid-Oct March Yellow, occasionally russet in stem apple, fruit does not drop cavity AS = Apple Scab, CR = Cedar Apple Rust, FB = Fire Blight, PM = Powdery Mildew VR = Very Resistant, R = Resistant, MR = Moderately Resistant, S = Susceptible, — = Insufficient Information Note: All apples require cross-pollination by a different variety. Winesap and SirPrize cannot serve as pollinizers because they have sterile pollen. 1 Resistance to diseases other than scab has not been fully evaluated and may differ in some locations from that reported here. 2 Produces high-quality apples in Kentucky. 3 Although these cultivars are resistant to cedar apple rust, they are susceptible to cedar quince rust. 22-3 CHAPTER 22 Growing Tree Fruits Table 22.4. Table 22.5. Table 22.6. Pollination Methods Cherry varieties. Pear varieties. Nectarine varieties. Trees can be grouped into two categories: those that bear Sweet European Nectarines fruit through self-pollination (called self-fruitful) and those that Black Gold Blake’s Pride Fantasia must be pollinated by another variety (called self-unfruitful). Hedelfingen Harrow Sweet Flavortop Lapins Honey Sweet Red Gold Peaches tend to flower during spring when frosts and cold Sweetheart Kieffer Sunglo weather are still very common in Kentucky. Peach trees can Tart Magness be grown throughout the state but the peach crop is often Potomac diminished due to cold temperatures in spring. The somewhat Danube Seckel Montmorency milder climate of Western Kentucky makes this region better North Star Asian for backyard peach production. Surefire Chojuro Korean Giant Olympic Cherries Megietsu Lapins, Black Gold, and Sweetheart are self-fruitful sweet Shinko cherry varieties, as are tart (pie) cherries. Yoinashi Some sweet cherries do not set fruit unless they are pol- linized by another pollen-compatible variety. Hedelfingen is Table 22.7. Peach varieties. pollinated by Lapins or Sweetheart. Maturity Apples July August September Some apple varieties, such as Rome Beauty, Newtown, Gala Allstar Encore Harrow Diamond Biscoe Flamin’ Fury PF-27A and Transparent, are self-fruitful, but most varieties of apples Garnet Beauty Blushing Star (White) Flameprince do not set fruit unless they are pollinated by another pollen- Redhaven Bounty Laurol compatible variety. Most apple varieties that don’t set fruit when Sentry Contender Ouachita Gold self-pollinated do have pollen that sets fruit on other varieties. Topaz Coralstar Victoria Cresthaven For example, Red Delicious doesn’t set its own fruit with its Ernie’s Choice own pollen, but sets fruit on Golden Delicious, and vice versa. Glowing Star Gravenstein requires an early-blooming pollinizer such as Lodi, John Boy but does not produce good pollen for other varieties. Mutsu Loring Madison does not pollinize other varieties, but requires another variety Redskin to set fruit itself. McIntosh is self-unfruitful but pollinizes other Summer Breeze early-blooming varieties such as Gravenstein. Other Fruits Table 22.8. Nut varieties. Most varieties of pears do not set fruit unless they are pol- Hazelnuts (filberts)* Walnuts, Persian linated by another pollen-compatible variety. Gamma Allegheny Jefferson Coble No. 2 Most European plums are self-fruitful. Santiam Kaiser See Table 22.8 for nut varieties. Yamhill Walnut, Black Planting for Pollination Leon Pounds II Neel No. 1 Plant pollen-compatible trees within 100 feet of each other to Rowher ensure adequate pollination, which depends mostly on bees and Sauber No. 1 to a lesser extent on other insect activity. For nuts, pollination Surprise Thomas-Myers depends on wind. The bloom periods of the main and pollinizer varieties must overlap enough to provide at least several days for *Complete resistance to eastern filbert blight (EFB). Note: Gamma, Santiam and Jefferson are good pollinators for the best variety, cross-pollination to take place. Orchards with many pollinizers Yamhill. are more fruitful than those with only one pollinizer. If no pollinizing varieties are growing nearby, cut a bouquet of blooms from another variety and place it in a pail of water beside your tree while it is in bloom. Or, if you have a single fruit tree that needs a pollinizer, graft a compatible variety onto the main variety. 22-4  Growing Tree Fruits CHAPTER 22 Tree Spacing Apple trees typically are spaced from six feet apart (high density) to more than 20 feet apart. Spacing between rows for other fruit trees ranges from 12 to 24 feet because they often lack growth-controlling rootstocks. True genetic dwarf trees can, of course, be planted closer. Dwarf trees trained on trellises have the closest spacing. In planning your orchard, compare the amount of space available to the number of trees you want to grow. Spacing trees very close together does push them into earlier production, but tightly spaced trees require more pruning at an earlier age in order to keep them productive, and foliage does not dry out as rapidly, which can lead to more disease problems. drip line Planting and Fertilizing Orchard trees grow best in deep, well-drained soils. To have adequate room for root development, trees need at least four feet of soil above an impenetrable soil layer or water table. In main feeder root zone poor soil conditions, raised beds can be helpful. Always choose a spot that gets full sun. Figure 22.2. A tree’s drip line. Fruit trees usually are sold bare root. It’s very important to plant a tree at the right level. Try to plant the tree at the same each year, it is thriving. Overapplication of nitrogen may cause level at which it was growing in the nursery. Make sure the graft excessive tree growth as well as physiological problems in the union is aboveground; if it is not, the rootstock will produce fruit, such as bitter pit in apples. shoots that may overpower the grafted or budded stock. The Most gardeners use a complete fertilizer (one with nitrogen, scion (grafted variety) may also produce roots that lessen the phosphorus, and potassium) around the yard and vegetable effect of the rootstock. garden. These fertilizers are fine for fruit trees, but if they are Dig a hole large enough to comfortably accommodate the used every year, phosphorus and potassium levels build up far tree’s root system. Don’t leave smooth soil on the sides of the in excess of the tree’s actual need. hole—roughen the sides with a shovel so the roots can grow into Most home orchardists do not apply boron to their fruit the soil. Place the roots over a low mound of soil in the hole. trees. Although boron is needed only in small amounts (it is a Paint the trunk with a white, water-based indoor latex paint micronutrient), it is essential for plant health and productivity, to reflect sunlight and help prevent sunburn. To save paint and especially for fruit set. Trees that are low in boron have poor make it easier to apply, you can dilute the paint with water to 50 shoot growth and poor fruit set. or 70 percent paint. A tree protector placed around the trunk An easy source of boron is Borax. If you need to apply boron will protect it from damage from small animals and sunscald. to a fruit tree, add a tablespoon of Borax to two gallons or more Protection from deer is important, too. Fencing is the best of water and apply it to the soil within the tree’s drip line (Figure method, but caging also works. Hanging soap, human hair, 22.2). If you think your soil has boron deficiency, it is best to animal scents, or other deer repellents will help prevent dam- have the soil analyzed before adding more. Too much boron age for only a short time. is toxic to the trees. A tree’s need for fertilizer varies according to the amount of minerals available in the soil. Soil types vary within a specific area and regionally. For example, fruit trees generally don’t Irrigating need much phosphorus in the Central Kentucky area, but they respond to phosphorus applications in most other areas The amount of water fruit trees need depends on rainfall and of the state. Consult your county Extension office for specific soil type. The best way to determine your trees’ needs is to check recommendations. the soil moisture in the root zone at 12 and 24 inches deep. Fruit trees do need nitrogen. The amount needed varies To test, remove some soil with a soil probe or shovel and from very little to two pounds of actual nitrogen per tree for squeeze a handful of it into a ball. If it crumbles when released, fully mature trees. The best way to gauge nitrogen needs is to the trees are dry and need water. If the ball of soil stays together watch the amount of annual growth and check for yellowing of but does not feel wet, the trees have adequate moisture. If older leaves. If a tree has at least 12 to 18 inches of new growth the soil ball drips water when squeezed, there is more than enough moisture. 22-5 CHAPTER 22 Growing Tree Fruits Remember that young trees have an undeveloped root sys- How to Thin tem and cannot absorb much water at a time. In warm weather, watering young trees regularly is very helpful to get them off Apples to a good start. Home orchardists generally thin by hand. With apples, Drip irrigation is preferred by many orchardists because it remove the smaller fruit first, remembering that the relative allows the foliage, flowers, and fruit to remain dry, an impor- sizes of the fruit do not change throughout the season and tant factor in disease prevention. If you drip-irrigate, take care that the largest fruit early in the season will be the largest fruit not to overwater, especially near the base of the trunk, where at harvest. excessive moisture can lead to crown rot. Decide how much fruit to leave on the tree based on the vigor and general condition of the tree. In cultivars that tend toward biennial bearing (every two years), leaving every other Fruit Thinning spur without fruit and spacing fruit six inches apart helps ensure Thinning of apples, peaches, and Asian and European pears is adequate return bloom. an important part of orchard management. It removes some of Asian Pears the developing embryos that otherwise would produce flower- Asian pears must also be thinned. Thin early to get large ing inhibitors. It improves the size and quality of fruit and helps fruit. Each blossom cluster contains several flowers. Save the ensure an adequate crop the next year. blossom/fruit in the middle and remove the rest. Research has The effect of fruit thinning is greatest on cultivars that tend shown that this middle fruit is the roundest. By keeping that in to have a heavy fruit set. Determine the size of fruit you want mind and by counting the flowers as they appear starting from and thin accordingly. the base of the cluster, you can determine which fruit to remove. There are three ways to thin fruit. Picking the tiny fruit For example, if there are seven flowers, save the fourth fruit or blossoms by hand is the most commonly used method. from the base of the cluster. Depending on the tree’s vigor, you Mechanical thinning involves using a tool to knock fruit off might experiment by leaving two fruits per spur and checking the tree. Plant-growth regulators are sprayed onto apple and the fruit size response. pear trees in commercial orchards during and after bloom to thin the crop. Peaches Thin peaches to about six to eight inches from one another. Timing This spacing gives them adequate room to mature to full size. Early thinning of blossoms or fruit helps stimulate flower initiation for the next year’s crop, especially on cultivars that tend toward biennial bearing (bearing fruit every other year). Apples Harvest and Handling initiate flower buds for the following year’s crop within 40 days Nursery catalogs, Cooperative Extension publications, and of full bloom, so thinning has a positive effect on the next year’s other sources give a general idea about when given varieties bloom if done within this period. Pears form buds a little later, so ripen. However, ripening times may vary from year to year you can thin them within 60 days of full bloom. Attaining adequate depending on the weather. Keep in mind that apples with return bloom on peaches is seldom a problem, but early thinning codling moth damage drop about one to one-and-a-half weeks generally helps. before the crop is ripe. Thinning also helps increase the size of harvested fruit The best and most time-tested method of judging when to by stimulating cell division in the remaining fruit. More cell pick fruit is the taste method. When enough starch has been division means more cells per fruit and thus larger fruit. The converted to sugar and the flavor is developed, the fruit is ready period of cell division for apples lasts four to five weeks after to eat. Fruit continues to ripen in cold storage, so pick fruit petal fall. For peaches, it lasts four weeks after petal fall, and before it is ripe if you intend to store it. pears continue cell division for seven to nine weeks after petal Fruit changes color as it ripens. The base color, or ground fall. All fruits continue some cell division in the epidermis layer color, is the color underneath the red striping or blush of (the skin) much longer than in the main part of the fruit flesh. peaches, apples, pears, and cherries. In most fruits, the fruit Sometime during the cell-division phase, cell enlargement is ripening when the ground color turns green to yellow. The begins. Enlargement continues throughout the growth of the surface color may develop before the fruit is actually mature. fruit and often is positively influenced by fruit thinning. If storing fruit, cool it as soon as possible after picking. The More information on the developmental stages of different sooner heat is removed from freshly picked fruit, the longer fruit crops can be found in Figure 22.3. the fruit will keep. Handle fruit for storage gently. Bruises and wounds allow pathogens to infect the fruit, and disease will spread to adjacent fruits once it gets started. 22-6  Growing Tree Fruits CHAPTER 22 Apple Pear Peach Tart Cherry Plum and Prune Dormant Dormant Dormant Dormant Dormant 1 Stage Silver tip Swollen bud Swollen bud Bud burst Swollen bud 2 Stage 10% kill 10% kill 10% kill 10% kill 10% kill 15° F 15° F 18° F 17° F 14° F 90% kill 90% kill 90% kill 90% kill 90% kill 2° F 1° F 2° F 5° F 1° F Green tip Bud burst Half-inch green Green tip Bud burst 3 Stage 10% kill 10% kill 10% kill 10% kill 10% kill 18° F 20° F 23° F 25° F 18° F 90% kill 90% kill 90% kill 90% kill 90% kill 10° F 7° F 5° F 14° F 3° F Half-inch green Green cluster Pink Tight cluster Green cluster 4 Stage 10% kill 10% kill 10% kill 10% kill 10% kill 23° F 26° F 25° F 26° F 26° F 90% kill 90% kill 90% kill 90% kill 90% kill 15° F Apple 15° F Pear 18° F Peach 17° F Tart Cherry 16° Plum F and Prune Tight cluster White bud Bloom Swollen bud White bud 5 Stage 10% kill 10% kill 10% kill 10% kill 10% kill 27° F 26° F 27° F 27° F 26° F 90% kill 90% kill 90% kill 90% kill 90% kill 21° F 22° F 24° F 24° F 21° F Pink Bloom Petal fall Bloom Bloom 6 Stage 10% kill 10% kill 10% kill 10% kill 10% kill 28° F 28° F 28° F 28° F 27° F 90% kill 90% kill 90% kill 90% kill 90% kill 25° F 23° F 25° F 25° F 23° F Bloom Petal fall Fruit set: Petal fall Petal fall 7 Stage shucks on 10% kill 10% kill 10% kill 10% kill 10% kill 28° F 28° F 28° F 28° F 28° F 90% kill 90% kill 90% kill 90% kill 90% kill 25° F 24° F 25° F 25° F 23° F Petal fall Fruit set Fruit set: Fruit set Fruit set 8 Stage shucks off 10% kill 10% kill 10% kill 28° F 28° F 28° F 90% kill 90% kill 90% kill 25° F 24° F 25° F Fruit set 9 Stage 10% kill 28° F 90% kill 25° F Figure 22.3. Phenology (growth development) stages of several fruit crops. 22-7 CHAPTER 22 Growing Tree Fruits Insect and Disease Management Larvae feed for about three weeks then pupate in protected places. Many insect and disease problems can affect home orchards. Second-generation adults emerge one to two weeks later, in You can control or prevent them by knowing the probability of early July. such problems and by closely monitoring trees. Keep insects These adults lay eggs on fruit during July and August. in check through a system called integrated pest management Eggs hatch in six to seven days, and larvae enter fruit to feed. (IPM), which integrates cultural, mechanical, chemical, and Larvae stay in fruit for a month then emerge and look for biological controls in addition to taking the environment into overwintering sites. consideration. The IPM approach differs from a standard calendar Pheromone-Trapping Program for Codling Moth approach, which uses dates and developmental stages of the Place traps in the orchard by mid-May. plant to determine when to apply control sprays regardless of Place the traps along all sides of the orchard. whether pests are present. Check the traps once per week through mid-September. Successful IPM programs are based on solid research and Replace the lures every four weeks. practical experience. One of IPM’s cornerstones is accurate pest If you want to use a threshold approach, apply an insecticide monitoring. You can use visual inspection, trapping, and phenol- control 250 degree days, base 50°F, after you catch five moths ogy models (crop development stage models) to determine the per week in a trap. presence or absence of a pest and then measure its population Follow spray recommendations for codling moth con- density. Figure 22.3 shows growth stages of several tree fruits. trol listed in the UK Cooperative Extension publication Economic thresholds are the level at which pest damage jus- Disease and Insect Control Programs for Homegrown Fruit tifies the cost of control. Economic thresholds are important in Kentucky Including Organic Alternatives (ID-21). in IPM. Of course, economics are not as important in home If you want to use a calendar approach to control, spray 15 orchards as in commercial situations. Each orchardist must to 21 days after petal fall for the first generation and again decide how much damage to allow before applying a control. two weeks later. The level of damage considered acceptable can vary from one For the second generation, spray the first week in July and gardener to another. again two weeks later. Pheromones are chemical messengers used by animals to communicate with each other. Pheromones are used in IPM Sprays for Disease and Insect Control in the following ways: Female sex pheromones are used to attract males to a trap. Dormant (Winter) Sprays Small pieces of glass or plastic containing female sex phero- Most home orchardists try to control overwintering mites, mones are spread throughout an area to confuse males. aphids, and scales with a dormant (winter) oil spray, which Pheromones are mixed with pesticides, such as an insecti- essentially smothers the pests. cide, to attract pests to the chemical control. Winter sprays are also used to control diseases that enter the tree through the buds. The UK Cooperative Extension publication Kentucky Follow two general rules when applying winter sprays on Backyard Apple Integrated Pest Management Manual (IPM-9) fruit trees: provides a more in-depth discussion of IPM. Use a sticker, unless the label says not to. Stickers improve Learning the life cycles of important insects and diseases the spray’s adherence to leaves. that may attack your orchard is part of IPM. The next section Obtain good coverage. Timing and the choice of material are discusses some of the more common orchard insect pests and important, but if the spray doesn’t cover the tree and stay in their IPM-control strategies. place, pests will not be controlled. Peaches need winter sprays to control peach leaf curl Codling Moth and bacterial canker. For peach leaf curl, which causes red- Following are the stages in the life cycle of the codling moth, dish, twisted, distorted leaves, spray after leaf drop in the fall. which typically produces three generations per year. Chlorothalonil or fixed coppers are effective. It overwinters as a mature larva under loose bark on trees, in leaf litter under trees, or in other protected places. Blossom Sprays It pupates in spring and emerges as an adult in late May to Ideally, blossom sprays should be applied at three stages: early June. pink, full bloom, and petal fall (Figure 22.3). Use fungicides and Adults begin depositing eggs two or three days after emer- insecticides listed in the UK Cooperative Extension publication gence and continue depositing eggs for a month. Disease and Insect Control Programs for Homegrown Fruit in Eggs hatch in 12 to 14 days, and larvae enter fruit. Kentucky Including Organic Alternatives (ID-21). 22-8  Growing Tree Fruits CHAPTER 22 Cherries, peaches, and plums—Applying protective fungicide potential. For a more complete discussion of pruning, see sprays before, during, and after the blossom period can control Chapter 17. The discussion here covers only guidelines specific brown-rot blossom blight on cherries, peaches, and plums. to pruning fruit trees. Brown-rot blossom blight is caused by fungi. These fungi overwinter on infected peach, plum, and cherry fruit (causing Fruiting Habits what’s called “fruit mummies”) and on buds and cankers. The Pruning strategy should take into account the fruiting habit fungal spores are spread mostly by wind but also by splashing of each tree. The type and age of wood that bears fruit varies rain. with the kind of tree. Some fruits bear on more than one kind The fungi infect blossoms, and from there they can travel of wood. For example: into twigs to cause twig blight and cankers. They also infect Persian walnuts produce fruit on the current season’s fruit later in the season, entering maturing fruit more easily shoots. than green fruit. Hazelnuts, nectarines, and peaches produce fruit on the Apples and pears—Blossom sprays can also control apple scab, previous season’s shoots. cedar apple rust, and powdery mildew on apples and pears. Sour cherries, some apples, and some pears produce fruit Apple scab must be controlled each year on most variet- on the previous season’s spurs and shoots. ies. Scab infects leaves and fruit. It overwinters on leaves, so Some apples, sour cherries, sweet cherries, pears, and plums sanitation can help control the problem by removing sources (European and Japanese) produce fruit on long-lived spurs. of inoculum (fungal spores). Apply sprays at the prepink, pink, calyx, and first-cover stages. Good light penetration is necessary for fruit spur forma- Cedar apple rust must also be controlled annually on most tion and productivity, so trees that fruit on spurs should be apple varieties with sprays from pink through second cover. maintained in a fairly open form. Those that form their crop Fire blight is a serious problem on susceptible apple and pear on one-year-old wood (such as peaches and hazelnuts) benefit varieties. A final copper spray during the dormant period and from pruning because it stimulates new wood formation (and streptomycin sprays during bloom are recommended. more fruit). Powdery mildew sprays are recommended for four stages: prepink, pink, calyx, and first-cover. Pruning Guidelines Summer Sprays Prune all fruit and nut trees at planting time. Cut just above the height where you want the lowest branches to grow If an orchard has a mite, aphid, or scale problem, a dormant (usually 30 to 40 inches above the ground). oil spray in winter can reduce populations of these insects. Prune young trees very lightly; heavy pruning delays fruiting. However, some summer control often is necessary. Prune mature trees more heavily, especially if they have Look for scale in June. The timing of summer control is shown little growth. important for these tiny insects. You must apply the spray when Prune the top portion of trees more heavily than the lower the insects are in the crawler stage, which is when the young portion. scales move out from their protective shells and are vulnerable Train young trees in the first few years after planting to avoid to pesticides. corrective pruning later. Spread main scaffolds to a 45° to 60° Place double-sided sticky tape or black electrical tape with angle from the trunk. the sticky side out around infested branches. This traps the To keep trees small (unless they are dwarf trees), prune crawlers so you can see them with a hand lens (20-power is moderately every year and do not apply excess fertilizer, good). Spray when there is substantial insect activity. manure, or compost. Prune during the dormant season (after fall or early winter Bagging freezes, but before full bloom in spring). Bagging individual apples and pears on a tree when they When removing large limbs, first cut partially through from are about an inch in diameter provides excellent insect and the underside about six inches out from the collar, then make disease control for the rest of the season. See the Apple Bagging a second cut from the top a little farther out, cutting all the Alternative Pest Management for Hobbyists (ENTFACT-218) way through until the branch falls away. Finally, cut the stub and the video Apple Bagging (VHO-1386). Both are available back to the branch collar. Do not remove the branch collar. through county Extension offices. There is no need to paint pruning wounds. The best protec- tion for a wound is to leave the branch collar intact so the tree is protected from wood-rotting fungi. Pruning Pruning is a necessary part of home orchard care. Prune trees to direct growth, maintain health, and manage fruit-bearing 22-9 CHAPTER 22 Growing Tree Fruits For More Information Tree Fruit UK Cooperative Extension publications Apple Scab (PPA-24) Bagging Apples: Alternative Pest Management for Hobbyists (ENTFACT-218) Fruit/General Apple Cultivar Performance (HortFact-3006) Cultivar Evaluations of Apple, Peach, and Grape Cherry Fruit Flies (ENTFACT-217) Disease and Insect Control Programs for Homegrown Fruit in Codling Moth (ENTFACT-203) Kentucky Including Organic Alternatives (ID-21) Controlling Apple Insect Pests (ENTFACT-201) Dry Pesticide Rates for Hand-Held Sprayers (HO-83) European Red Mite (ENTFACT-205) Fertility Guidelines for Home Fruit and Nut Plantings Fire Blight (PPA-34) (HortFact-3004) Green Fruitworms (ENTFACT-214) Fruit and Vegetable Insect and Disease Identification Picture Growing Peaches in Kentucky (HO-57) Sheets Peach Fruit Diseases (PPFS-FR-T-09) Fruit Insect-Pest Calendar for Kentucky Kentucky Backyard Apple Integrated Pest Management Manual Home Composting: A Guide to Managing Yard Waste (HO-75) (IPM-9) Home Fruit Variety Recommendations (HortFact-3003) Leafhoppers on Apples (ENTFACT-215) Fruit and Nut Cultivar Nursery Sources (HortFact-3002) Leafrollers (ENTFACT-216) Rootstocks for Kentucky Fruit Trees (HO-82) Lesser Peachtree Borer (ENTFACT-213) Reproducing Fruit Trees by Graftage: Budding and Grafting Oriental Fruit Moth (ENTFACT-212) (HO-39) Peach Cultivar Performance (HO-6) Peachtree Borer (ENTFACT-200) Nuts Plum Curculio (ENTFACT-202) European Red Mite (ENTFACT-205) Rosy Apple Aphid (ENTFACT-211) Nut Tree Growing in Kentucky (ID-77) Rust Diseases of Apple (PPA-23) Nut Weevils (ENTFACT-206) San Jose Scale (ENTFACT 204) Pecan Insects (ENTFACT-210) Training and Culture of Dwarf Apples Using the Vertical Axis System (HortFact-3501) Revised 01-2024