Chapter 17 Fruit Gardening Learning Objectives 627

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1 Chapter 17 Fruit Gardening Bob Polomski Learning Objectives Be familiar with the kinds of tree and small fruits that can be grown in South Carolina. Know the basic cultural practices for tree and small fruits. Be familiar with common fruit pests and their management. Portions of this chapter were adapted from Fruit Gardening, Ch. 10, Kathryn C. Taylor and Gerard W. Krewer, and Ch. 24, Diagnosing Fruit and Vegetable Problems, Kris Braman, Kathy Taylor, George E. Boyhan, and W. Terry Kelley, Georgia Master Gardener Handbok, 6th ed., Edited by Marco T. Fonseca and Kristin L. Slagle, The University of Georgia Cooperative Extension Service, CES Handbook 2. Fruit Gardening 627

2 Fruit Gardening Introduction Unlike some plants that thrive on neglect, fruit crops require proper care and hard work to produce quality fruit year after year. You can improve your chances for success if you select fruits which match your interest and level of commitment as well as the amount of growing space that is available. Knowing that small fruits such as strawberries and blackberries require little effort and space for the amount of fruit produced, compared to tree fruits such as peaches and plums, may save a lot of time and money. Also, matching fruit crops to areas where soil and weather conditions closely meet the crop s optimum growing conditions will improve your chances for harvesting a quality crop. Apples, for example, can be grown throughout South Carolina, but the odds for achieving success are better in the upper corners of the state. Nevertheless, there are a wide variety of fruits that can be cultivated in South Carolina gardens and landscapes. As you read this chapter, keep in mind that successful home fruit growers plant only as much as they can properly care for. Location Ideally, fruit crops should be planted in areas that receive full sun. A location close to home is best, solely for the sake of convenience, especially at harvest time. Fruit crops can be grown next to or in place of ornamentals. Consider planting dwarf fruit trees or small fruits in limited spaces. Dwarf apples and pears produce full-sized fruit sooner after planting and occupy less space than standard-sized trees. Strawberries may be used as a ground cover or as a border for a flower bed. Grapes and blackberries may be planted alongside the garden on a trellis or on a fence. Blueberries may be planted to form a hedge or used in a foundation planting around the home. Always consider the mature size of the tree or small fruit plants when evaluating a particular location. Plants growing in the wrong location must either be severely pruned or moved. If fruit crops are planted too close together, they become weakened and less fruitful because of inadequate sunlight. Insects and diseases also tend to prevail in overcrowded conditions. Dense plantings favor disease outbreaks because little or no air movement allows leaves to remain wet for a longer period of time. The available water gives fungal spores ample time to infect plant tissues and to spread from plant to plant. To avoid such problems, plant trees and small fruits no closer than the minimum distances listed in Table Soil and Site Fruit crops grow best on fertile, deep, welldrained soils. A sandy loam or sandy clay loam is an ideal soil; however, poor soil can be improved by adding organic matter and improving water drainage. In sloping landscapes, plant fruits at the highest elevation or on the sides of slopes, away from cold air which drains downhill to the low spots. Avoid planting fruits in low areas or frost pockets where late spring frosts may kill flowers and wipe out the year s crop. On south-facing slopes which warm up early, fruits tend to bloom early and can be injured by freezing temperatures; therefore, select late-flowering cultivars for these locations. Variety Selection When choosing fruit crop cultivars, commonly referred to as varieties in the trade (these terms will be used interchangeably in this chapter), select those that are adapted to the soil conditions and climate of the area. Also, consider those varieties with Fruit Gardening 628

3 Table 17.1 Spacing requirements, bearing age, and life expectancy for tree and small fruits. Suggested Minimum Distance Between plants in row Between rows Bearing age Life expectancy Tree fruit (feet) (feet) (years) (years) Apple - standard Fig Variable - highly dependent on winter survival Peach Pear - standard Pecan Persimmon Plum Pomegranate Variable - highly dependent on winter survival Small fruit Blackberry Semitrailing Erect See text Blueberry Rabbiteye Southern highbush Grape, bunch Grape, muscadine Kiwifruit Erect red raspberry Strawberry fewest insect and disease problems. Look at cultivars that have special uses, such as freezing, canning and preserving. It may be worthwhile to plant several cultivars of the same kind of fruit which mature at different times to prolong the picking season. Be aware of the pollination requirements for each cultivar. Fruit cultivars may be either selffruitful or self-unfruitful. A self-fruitful cultivar can reproduce sexually by itself in contrast to a selfunfruitful cultivar which requires pollen from one or more different cultivars to ensure a crop. Either a self-fruitful or a self-unfruitful cultivar may pollinate a self-unfruitful cultivar. Fruit varieties that can pollinate one another have compatible pollen and overlapping flowering dates. Refer to Table and 17.3 for a list of fruit crops that are covered in this chapter, along with remarks regarding their pollination requirements and potential success for the South Carolina garden and landscape. For the most up-to-date variety recommendations, visit the web sites listed at the end of this chapter. Fruit Thinning Under favorable conditions, trees usually produce more fruit than they can mature to a desirable size. Thinning, or removing some of the fruit from the tree, will increase the size and improve the color and quality of the remaining fruit, reduce limb breakage, and stimulate flower bud production for next year s crop. Thinning apple trees allows the tree to maintain a regular bearing cycle. This is particularly important in some cultivars which will produce a crop every other year if fruit is not thinned as described. Fruit Gardening 629

4 Table 17.2 Tree fruits: pollination requirements and probability for success in South Carolina. Tree fruit Apple Cherry Fig Peach Pear, Common Pear, Asian Pecan Persimmon Plum Pomegranate Remarks Generally self-unfruitful; select two or more varieties to ensure pollination. Note: Apples grow best in northern and northwestern counties; lack of cold weather causes delayed blooming and poor fruit set, while higher temperatures make some diseases difficult to control. Sweet cherries are self-unfruitful so one or more varieties must be interplanted. Be careful: many varieties are cross-incompatible. Sour cherries are self-fruitful. Self-fruitful. Self-fruitful; most varieties produce a satisfactory crop with own pollen. Generally self-fruitful; include two or more varieties to insure good fruit set. Note: Pears are not easily grown in South Carolina because of their susceptibility to fire blight. Partially self-fruitful, but expect better yields with cross-pollination of two or more cultivars. Requires cross-pollination. Self-unfruitful male and female flowers on separate plants. Oriental or Kaki persimmon (Diospyros kaki) will set fruit without pollination (seedless fruit). However, fruit retention is improved when seeds are present. Partially or wholly self-unfruitful; interplant or closely plant at least two varieties to furnish adequate pollen. Self-fruitful. Fruit often splits before ripening. Fertilizing Generalized fertility recommendations are made for the various fruits and nuts discussed in this chapter. Ideally, a soil test combined with periodic plant tissue testing is the best way of knowing the fertility requirements of your particular crop. For information regarding plant tissue sampling guidelines, contact the HGIC. Watering Although most tree and small fruit plantings can survive droughts, a shortage of soil moisture can seriously reduce yields and fruit size. Generally, fruits require about one inch of water per week during the growing season. A rain gauge may be helpful in keeping track of daily rainfall accumulations and in determining how much additional water should be added to deliver one inch of water per week. Water deeply, about 6 to 8 inches. Mulching your plantings with pine needles, compost, or other organic materials should conserve moisture and reduce watering requirements. Trickle or microsprinkler systems are convenient and inexpensive, and easy-to-build or modify using readily available flexible plastic tubing and fittings. Such systems apply water only to the desired plants, a major savings on your water bill. Sanitation Destroying or discarding harboring places for insects and diseases plays a large part in controlling pests in plantings. Here are some practices to help control pests: 1. Rake, collect, and dispose of fallen leaves, fruit, and other debris; 2. Remove loose bark from trunks, crotches, and main limbs of apple trees; 3. With sharp pruning tools, prune out and discard all dead, diseased, and insect-infested limbs, branches, and twigs; and 4. Sterilize pruning shears in a 20% bleach and water mixture (1 part household bleach [sodium hypochlorite] to 4 parts water) to control the spread of diseases. Alternatively, disinfect your Fruit Gardening 630

5 Table 17.3 Small fruits: pollination requirements and probability for success in South Carolina. Small fruit Blackberry Blueberry, Rabbiteye Remarks Most modern blackberry varieties are self-fruitful, few are self-sterile, and some wild forms are functionally dioecious (male and female flowers occur on separate plants). Most varieties partially or completely self-unfruitful; plant two or more varieties for crosspollination and higher yields. Note: Being vigorous, drought- and heat-tolerant, and highly productive with a short rest period, this plant can be grown anywhere in the state. Grows best on acid soils with a ph between Blueberry, Self-fruitful, although larger fruit and better set are obtained with cross-pollination with Southern varieties that bloom at the same time. Note: Ideal soil ph is Highbush Grape, bunch Grape, muscadines Kiwifruit Red raspberry Strawberry Self-fruitful. In general, select cultivars that are resistant to Pierce s Disease (PD) and are highly resistant to diseases that attack the foliage and fruit. The PD-resistant Florida hybrid bunch grapes possess both of these qualities and may show promise throughout South Carolina. Many commercial grape growers in the region suggest that PD, a fatal bacteria-like disease spread by leafhoppers, is limited to elevations below 1,000 ft. So, homeowners in the Piedmont and Mountains may be able to grow PD-susceptible cultivars including those belonging to Vitis vinifera (e.g., Chardonnay and Cabernet Sauvignon ) and V. labrusca (e.g., Concord ). However, varieties of V. vinifera and V. labrusca are poorly suited to our climate and are very susceptible to fruit rots without an extensive fungicide program. Either self-fruitful or self-unfruitful in this case, having only functional female muscadine flower parts (male parts do not fully develop and so are not functional). Can be grown anywhere in the state with few pest problems. Like other fruits, they require watering during drought periods. Beware of fruit rots when rains are frequent. Note: Muscadine (Vitis rotundifolia) is known by many other names such as Scuppernong for bronze-fruited types, bullis, or muscadine for dark-fruited types; however, all of these names refer to the same species. Self-unfruitful; must plant male plant as a pollinator. Avoid areas with poor drainage and maintain ph between 6.0 to 6.5. Self-fruitful. Red everbearers, which bear fruit in the spring and fall, are ideally suited for South Carolina. Self-fruitful. pruning tools with equal parts of Lysol and water, which is less corrosive than the traditional bleach:water mixture. Training and Pruning Training and pruning are two essential practices for growing fruit successfully. Fruit size and quality and pest management are influenced by training and pruning. Untrained and unpruned fruit crops become entangled masses of shoots and branches which produce little or no fruit and harbor insects and diseases. Consider the following tips when training and pruning fruit crops: 1. Before training or pruning a plant, visualize the results of the action. Training mistakes may easily be corrected; but once a branch is pruned out or removed, it cannot be replaced. 2. Train as much as possible and remove as little as possible. Bending and tying shoots instead of cutting them out, especially on apple and pear trees, can induce early fruit production. 3. Use sharp pruning tools to make clean cuts. 4. Discard or compost pruned out shoots and branches. These plant parts will serve as dwelling sites for insects and diseases and should be removed from the area to reduce pest populations. Fruit Gardening 631

6 Figure 17.1 Major parts of a tree. Weak, narrowcrotch angle Training begins at planting and may be required for a few years for tree fruits and every year for small fruits. Pruning is an annual management practice. Two basic pruning cuts heading and thinning--will be discussed in this chapter. Heading or heading back removes the terminal portion of shoots or limbs. Thinning removes an entire shoot or limb to its point of origin on the main branch or lateral. For a further discussion of pruning, refer to Chapter 12. Light pruning can be performed throughout the growing season to remove broken, injured, or diseased branches and to improve air circulation to control foliar diseases. Major removal of twigs and branches should be done during the dormant season, preferably before active growth begins in the spring. Training and pruning procedures vary according to the type, age, and variety of fruit crop. The major parts of a tree which are discussed in the following sections are illustrated in Figure Tree Fruits and Nuts Apples Trunk Crown Leader Spur Tap root Water sprouts Terminal Strong, wide crotch angle Lateral Scaffold branch Root sucker The soil and climatic conditions in the northern and northwestern counties of South Carolina are well-suited for growing apples (Malus domestica). The high temperatures and humidity levels in other parts of the state which encourage disease outbreaks, further increase the difficulty of growing apples. Site and Soil Requirements Sunlight, and plenty of it, is a key to increasing fruit production. Trees should be in the sun most or all of the day. The early morning sun is particularly important because it dries the dew from the leaves thereby reducing the incidence of diseases. If the planting site does not get plenty of sun, then performance from the tree will be inferior. Although apple trees will grow well in a wide range of soil types, a deep soil ranging in texture from a sandy loam to a sandy clay loam is preferred. Apple trees will not thrive in a soil that is poorly drained. In areas of poor drainage, roots will die, resulting in stunted growth and eventual death of the tree. Conversely, apple trees will also perform poorly on droughty soils. Shoot growth can be stunted and fruit size and quality reduced. Most fruit plants, including apples, grow best when the soil ph is between 5.8 and 6.5. Since the natural ph of most South Carolina soils is below that level, it is necessary to incorporate lime before planting to raise the ph to the desired level. A soil test is always the best method of determining the fertilization needs of the crop. The soil test report will also indicate if lime is required. About every 3 years, the soil ph should be rechecked. Purchasing Trees The old adage of you get what you pay for is an important consideration when buying apple trees. Often, bargain plants are not healthy or may not be a cultivar adapted to the area. Serious gardeners should only buy trees of recommended cultivars from a reliable source. Keep the following points in mind when purchasing apple trees: The preferred type of tree for planting is a healthy one-year- old whip that is about 4 to 6 ft. tall and has a vigorous root system. A small tree with a good root system is more desirable than a large tree with a poor root system. Trees that are older than 2 years do not usually grow as well as younger trees. Frequently, older trees do not have sufficient buds on the lower portion of the trunk to develop a good framework of fruit-bearing limbs. Do not purchase trees that appear stunted, poorly grown, diseased or insect injured. Check the tree labels closely to make sure they are the desired cultivar and rootstock. Fruit Gardening 632

7 Variety Selection There are apple varieties adapted to most parts of South Carolina. Variety selection should be based on the geographic areas of the state (Chapter 1, Figure 1.5, p. 9). The Coastal Plain is not ideally suited for apples. In most years, late frost will kill some of the apple flowers on some cultivars recommended for this area, thus reducing the yield. In addition, fruit diseases can be more severe in the Coastal Plain. Table 17.4 lists the recommended varieties for the various areas of the state. Some apple varieties such as Red Delicious and Golden Delicious are also available in various strains. A strain is a mutation of a certain cultivar selected for an improved characteristic and vegetatively propagated by grafting. A strain may differ in fruit characteristics or tree characteristics or both. There are many strains of some varieties; for example, about 100 different strains of Red Delicious have been described and cultivated. The most common strain difference that the backyard grower needs to be concerned with is spurstrains versus non-spur strains. A spur-type apple is a strain that has fruit spurs and leaf buds which are more closely spaced than on nonspur or standard types. Spur-types have a stiff, upright growth habit that minimizes limb breakage and enables the trees to hold heavy crop loads without having their limbs propped up or tied. Spur-types offer a size and space advantage to the home garden because they are naturally dwarfing trees. Spur strains of a cultivar may grow 60 to 70% as large as the nonspur strains of that cultivar. Most importantly, spur-type strains produce fruit at an earlier age than standard strains. Spur-types, because of their compact form of growth, are ideally suited for home gardens with limited space. Growth on spur-types is more compact because fruit spurs and leaf buds are spaced closer together than on nonspur trees. Also, 2-yearold wood on spur-type trees will usually form fruit buds rather than develop side shoots. Several varieties are available in spur and nonspur strains. As a general rule of thumb, spur-strains of the same variety on the same kind of rootstock as nonspur strains will result in trees only 70% as large as the non-spurs. Thus, a spur-type strain grown on a seedling rootstock will result in a semidwarf tree and a spur-type grown on a semidwarf rootstock will result in a dwarf tree. Fruit Production in the South Carolina Lowcountry Production of temperate zone fruit in the warm Lowcountry climate presents special challenges, almost all of which are somehow related to the weather. In some years the winter can be so mild that the requirements for chilling units* may not be met for many varieties. In contrast, an early period of cold weather can satisfy the cold requirement before the end of December, causing the trees to bloom and leaving them susceptible to subsequent frost. There is little that the gardener can do to ensure that there will be a crop of fruit every year. Another big problem for the Lowcountry is the inevitable hurricane force winds that will bend or break the trees. Gardeners should be prepared for disappointment when a hurricane passes near their area. Insects, diseases, and weeds all thrive in the warm, humid Lowcountry climate. Brown rot is especially hard to manage because of the unpredictable blooming cycles. In spite of the many challenges, Gardeners in the Lowcountry can enjoy the taste of homegrown fruit if they are willing to put the extra effort into pest management and can face up to the occasional disappointments that the weather is sure to bring.--dr. James W. Rushing, Professor and Postharvest Specialist, is also curator of the trial fruit planting at the Clemson University Coastal Research and Education Center in Charleston. *See Chilling Requirements, p Standard Trees vs. Dwarf Trees The two major factors influencing size are rootstock (see the box on p. 636) and type of strain used (spur or nonspur). Other factors that will have an influence on ultimate tree size include general care, variety, soil type, earliness of fruiting, location within the state, and timing and severity of pruning. Rootstock influences apple size. There are three general categories of tree size: standard, semidwarf, and dwarf (Figure 17.2). Standard trees are propagated on seedling rootstock and produce large trees that may get to be 15 to 20 ft. tall. Semidwarf trees are trees propagated on one of several clonal (vegetatively propagated) rootstocks that produce trees Fruit Gardening 633

8 Table 17.4 Apple varieties recommended for home use in the different zones of South Carolina. Potential Variety 1 Area 2 Characteristics 3 Cross-pollenizer 4 Anna CP Excellent shape fruit with blush of red; ripens mid June to early July; Dorsett Golden spur-type. Dorsett CP Yellow apple of good quality; ripens mid-june to early July; spur-type. Anna Golden Jerseymac M, P, SR Very early crisp red apple of excellent quality; good for fresh eating, Delicious, sauce, and pies; ripens in July; nonspur. Jonagold Ginger Gold M, P, SR Very early (bloom to crop in 90 days), crisp yellow apple of excellent quality; Gala, Mollie s good for fresh eating, sauce, and pies; ripens in late July-early August; nonspur. Delicious Gala M, P, SR Excellent quality apple; good for fresh eating or salads; Golden Delicious ripens in early August; nonspur. Priscilla M, P, SR Red skin color; crisp flesh; mildly sub-acid; excellent dessert quality; Red and Golden ripens in late July to early August; nonspur. Delicious Mollie s M, P, SR A versatile apple; good for fresh eating, pies, and sauce; susceptible Red Delicious Delicious to fire blight; ripens in late July; nonspur. and Yates Ozark Gold M, P, SR Matures late July to early August; yellow, russet-free apple of excellent Priscilla and quality; nonspur. Golden Delicious Red Delicious All Early fall variety ripening in late August to mid-september; large, firm, crisp; Golden Delicious sweet; good for fresh eating or salads; nonspur and spur strains available. Gala Golden All Early fall variety ripening in September; large, firm, crisp; sweet; Red Delicious, Delicious good for fresh eating or salads; nonspur and spur strains available. Gala Jonagold M, P, SR Ripens in September; very large, yellow apple with red blush; very high Red Delicious, quality sweet, juicy apple. Gala Fuji M, P, SR Fall variety ripening in October; does not color well, but quality is superb; Gala, Delicious, good for cooking, eating, and baking; nonspur strains available. Jonagold Yates M, P, SR Small, subacid, mellow, juicy. Jerseymac, Jonagold, Delicious Mutsu M, P, SR Ripens late September to early October; yellow apple of exceptional Red Delicious, (or Crispin) quality; crisp and juicy; slightly tart; all purpose. Jonagold, Yates Rome Beauty M, P Ripens early October; red apple that is primarily grown for baking; Fuji, Red and spur and nonspur. Golden Delicious, Gala Stayman M, P Ripens early October; rusty red finish; superb quality all-purpose apple that Gala, Golden is tart; fruit cracking a problem when dry period is followed by rainy period. Delicious Granny Smith All Matures in October; yellow-green apple of excellent quality; good all-purpose Gala, Red and variety; nonspur and spur strains available; susceptible to fire blight. Golden Delicious, Rome Beauty 1 Listed in order of ripening. 2 M - Mountains; P - Piedmont; SR - Sandhills and Ridge; CP - Coastal Plain. 3 Ripening dates for all cultivars except Anna and Dorsett Golden are based on averages from Clemson, South Carolina. Ripening dates for Anna and Dorsett Golden are based on averages from Monticello, Florida. Nonspur refers to growth habit as previously described under Cultivar selection. 4 Since most apple varieties are self-unfruitful (require pollen from another variety to set fruit), plant two or more varieties so fruit set will occur. Stayman, Mutsu, and Jonagold have sterile pollen and should not be used as pollen sources for other varieties; therefore, plant at least two other varieties with any of these varieties. Flowering crabapple trees also can be used as a pollenizer as long as the bloom periods of the crabapple and apple variety overlap. Fruit Gardening 634

9 Figure 17.2 Relative size of various apple rootstocks Very Dwarf Dwarf Semi Dwarf M27 1, 2 M.9 1, 2, 3 M.7 2, 4, 5 MM.106 6, 7 M.9/MM.111 M.7a 2, 4, 5 MM interstem 2, 3, 7 M.26 1 Resistant to collar rot diseases (Phytophthora cactorum). 5 Tends to produce a lot of sucker growth from the roots. 2 Susceptible to wooly apple aphid. 6 Resistant to wooly apple aphid. 3 Susceptible to fire blight (Erwinia amylovora). 7 Especially sensitive to soil compaction and/or poor 4 Resistant to fire blight. soil drainage. which will be about 3 / 4 the size of standard trees if grown under similar circumstances. The most common semidwarf rootstocks used for apples in South Carolina are MM.106, MM.111, and M.7. Trees on M.7 will produce the smallest trees in the semidwarf category while MM.106 will produce trees nearly as large as trees on seedling rootstocks. True dwarf trees will be about 30 to 40% as large as standard trees and require support by either a trellis or a post. The most common dwarf rootstocks are M.9 and M.26. Trees grown on M.9 are the smaller of the two. If space is greatly limited, use dwarf and semidwarf trees. The rootstocks M.9, M.7, and MM.111 are better adapted to the piedmont and mountains, while MM.106 has shown promise in the lower half of the Piedmont and the Sandhills and Ridge. In Semi Vigorous Table 17.5 Suggested tree spacing based on rootstock and tree form (nonspur versus spur) % of the Coastal Plain, only standard trees (seedling rootstock) are recommended because of poor performance of semidwarf and dwarf rootstocks. See Table 17.5 for tree spacing recommendations. Soil Preparation and Planting Have the soil tested several months prior to planting. If liming is recommended, soil preparation should be done at this time so the lime will be incorporated into the soil at the time of planting. If phosphorus is recommended, it should be incorporated along with lime before planting based on soil test results. Lime an area 10 ft.-by-10 ft. where each tree will be planted. Plow or spade the area, followed by disking or raking to smooth the surface. When fruit trees arrive from the nursery, open the bundles immediately. Soak the roots in water for 6 to 12 hours if they are not moist. The trees should then be planted if the soil is not too wet. If the soil is not prepared where the trees are to be planted or the ground is too wet, heel the trees in by placing them in an open trench deep enough to cover all roots. The north side of a building is the best place for heeling-in because the trees will remain dormant longer. Place soil over the roots to Between Trees in Row (feet) Between Rows (feet) Rootstock Nonspur Spur Nonspur Spur Seedling MM MM M.7, M.7a, M M.26, M.9/MM Not recommended 16 Not recommended M.9 8 Not recommended 14 Not recommended Fruit Gardening 635

10 Dwarf trees have been grown in the U. S., Europe, and elsewhere for many years. Much research is now being done on dwarf trees. Two fruits apples and pears can be obtained on size-reducing rootstock that are successful and can be recommended to the home dweller. Brachytic dwarf peaches (also called patio peaches ) are ideally suited for home plantings. Small Trees have the following advantages: Because of the low height, they are easily pruned and sprayed. Most of the fruit can be harvested from the ground. Fruit is well-colored and usually larger than is produced on a normal size tree. Bearing starts at a very early age. How Trees Are Reduced in Size Dwarf trees are produced by propagating the scion or cultivar onto a rootstock which restricts top growth or by grafting an interstem a small section of stem which induces dwarfing between the rootstock and the variety (Figure 17.3). Depending on the rootstock and interstemrootstock combination, dwarf and semidwarf apple trees may be produced which are ideally suited for the home garden. For instance, most dwarf or semidwarf apple trees are propagated on certain Malling (M.) and Malling Merton (MM.) series of rootstock, whereas pears are produced on Angers Quince rootstock. In addition, a 6-inch piece of one of the M. series can be grafted onto standard roots and then the desired cultivar propagated onto the stem piece. This stem piece will reduce the size of the top in relation to the normal size of the series from which it was taken and the vigor of the root. Normally, dwarfing is less desirable by using an interstem piece because of the added propagation expense of making two graft unions instead of one. Trees propagated directly onto dwarfing rootstock are more desirable. Planting and Spacing Almost all aspects of Dwarf Fruit Trees planting are similar to planting regular apple or pear trees; however, the depth of planting is different. Trees propagated on dwarfing or semi-dwarfing understock, especially M.9 and M.26, require support from a stake or trellis system because of limited and brittle roots (M.9) and weak trunk (M.26). Do not plant the tree so that the scion (the fruiting cultivars grafted onto the rootstock) will come in contact with the soil. If the scion comes in contact with the soil, the scion will root and the dwarfing effect is lost. See Table 17.5 for suggested spacings of dwarf or semidwarf trees. Culture Good care is necessary if a dwarf planting is successful. Clean cultivation is recommended. Do not allow weeds or grass to grow any closer than 6 ft. from the trunk. A thin layer of mulch (no more than 2-inches in depth) can help maintain soil moisture, but care must be taken to control voles that like to live in the mulch layer and feed on fruit tree roots and trunk. Fertilization of dwarf trees is similar to that of standard trees fertilizer recommendations are given with each fruit. Pruning After planting, cut the trees back to 30 inches. At the end of the first growing season, select four to six well-spaced branches with good angles along the central leader, and maintain these thereafter for fruiting branches. Use clothes pins, toothpicks, or ties to bend new shoots to obtain a good wide crotch with the trunk. Remove branches only when it is necessary. Remove cross branches of any other branches that interfere with easy access to the fruit. Keep the tree compact and well-balanced by pruning back branches that grow faster than others. Remove blossoms from the trees until about the fourth year to insure the growth of a good tree. Even in the fourth year, remove the blossoms from the upper two to three feet of the leader to permit full growth and development of the tree. Fruit Gardening 636

11 Figure 17.3 Tree at the left illustrates the middle piece or interstem method of dwarfing. The root is a vigorous domestic seedling; the interstem is the dwarf stock; the top is the variety or scion. The tree on the right shows a single graft of the scion directly attached to the dwarfing rootstock. } Scion Interstem Root stock the depth they will be planted. Before planting, cut off all broken or mutilated parts of roots with a sharp knife or pruning shears. Keep root-pruning to a minimum. Dig a hole large enough to receive the roots freely without cramping or bending from their natural position. Set the plants with the graft or bud union 2 inches above the soil line. Work soil in and around the roots. When the hole is half-filled, firm the soil with your feet before completely filling the hole. When the hole is filled, pack the soil firmly. Do not leave a depression around the tree. Also, do not place fertilizer in the planting hole or fertilize immediately after planting. Post-plant Care After planting, apply sufficient water to soak the soil thoroughly. Watering will help bring the soil into closer contact with all sides of the roots and eliminate air pockets around the roots. Keep weeds out of a 3 ft.-by-3-ft. area around the tree because they compete with the tree for moisture and nutrients during the growing season. This will also keep mowers away from the trees and reduce trunk damage. Mulching will help control weeds as well as conserve moisture. Training and Pruning The day apple trees are planted is the day to begin to train and prune for future production. Too often backyard growers plant apple trees and leave them untended for several years. This neglect results in poor growth and delayed fruiting. Apples are trained to a modified leader system. The tree should be developed with one central leader or dominant trunk in the center with several wide-angled limbs spaced around the leader. The tree should be pyramid-shaped with a pointed top and a wide base (Figure 17.4). Training and pruning will be easier around the home by using spur-type strains or growing apples on dwarfing rootstock. Spur-type and dwarf trees produce fruit at an earlier age than full-sized trees. Moreover, these trees are easier to manage and harvest than their full-sized counterparts. If one-year-old unbranched whips are planted, head to the desired height about 28 to 32 inches for standard and 30 to 35 inches for spur-type and semidwarf trees (Figure 17.5). When the buds grow out to 4 to 5 inches, select a central leader and scaffold branches. Scaffolds or side branches should be spaced vertically at least 6 inches apart and spaced horizontally at equal intervals around the trunk. Between three and six branches may be selected as scaffolds during the first summer or may be left to grow throughout the season and selectively pruned out during the dormant season. If young trees are branched when they come from the nursery or garden center, remove any broken branches and those which form angles less than 45 o with the main trunk (Figure 17.6). Forked terminals should be eliminated by removing one of the least desirable branches. Head-back the central leader by one-third in the second year. Make the cut close to a bud which is growing in a suitable direction or to a lateral branch. Keep pruning to a minimum during the early years to encourage the trees to produce fruiting wood. Apples generally bear fruit on short spurs which form on 2-year-old wood. Some cultivars flower and set fruit on the terminal shoots of the previous season s growth. Two important steps should be followed to develop a well-shaped central leader tree: Fruit Gardening 637

12 Figure 17.4 Properly trained central leader apple tree exhibiting a pyramidal shape. Credit: SC Nursery and Landscape Association Certification Manual, Reprinted with permission. Figure 17.5 Heading back an unbranched apple tree whip at planting. Figure 17.6 Prune young branched apple trees by removing narrow-angled branches and eliminating forks. Credit: SC Nursery and Landscape Association Certification Manual, Reprinted with permission. Fruit Gardening Control any branch that is competing with the leader by complete removal, heading back, or bending of that branch. The central leader should always be the highest point of a central leader tree. 2. Keep the top growth under control. Do not allow growth to be too vigorous to overgrow or shade out the bottom portion of the tree. Focus on creating the cone-shaped tree made up of a framework of well-shaped horizontal branches radiating from the central leader. To develop a cone shape, the upper branches are kept shorter than those below. Early fruit bud formation may be encouraged on young trees by training the limbs to form angles between 45 and 60 o from the vertical (Figure 17.7). Limb spreading is especially useful in training varieties such as Red Delicious, which have a tendency to form branches with narrow angles and tend to grow more upright than to spread. Begin training the limbs with the first dormant pruning and continue each year until the tree produces its first good crop. Steel wire about one-eighth of an inch in diameter or wooden strips with finishing nails in each end are inserted between the selected scaffold limb and the main trunk of the tree to form a desirable crotch angle between 45 and 60 o. This should be done early while the limb is still pliable enough to be trained in the desired position. New shoots can be bent in early to mid summer by using wooden spring-type clothespins or toothpicks. Place the clothespin or toothpick between the main trunk or branch and the new succulent growth. The clothespin will force the new growth outward and upward and form the strong crotch angles needed to support fruit in the future. In general, maintenance pruning of the bearing apple tree consists of four parts: removing watersprouts and diseased, broken, and insect-injured branches; removing thin, unfruitful wood, usually in the shaded part of the tree; opening up the top by judicious removal of higher branches to allow sunlight to filter through the center of the tree; and heading the tree at a manageable height. The tree in Figure 17.8 is about four-years-old. Proper training, spreading, and pruning have resulted in the development of flower buds that will produce a good crop in the coming season. Notice that the upper (second) set of scaffolds is shorter than lower (first) set. The second and succeeding scaffold layers should always be kept shorter that the layer below it by dormant pruning.

13 Figure 17.7 Using wooden limb spreaders to improve branch angles. Figure 17.8 Well-developed apple tree with flower-budladen shoots. A properly trained and pruned central leader tree should conform to roughly a pyramidal Christmastree shape. Pruning Neglected Trees Many people will purchase a house where an apple tree was planted on the property several years ago. Often, the previous owners did not take the time to properly prune the tree. The tree has become bushy and weak and will produce very poor quality apples. Such a tree requires extensive corrective pruning. The main objective in pruning such a tree is to open up the interior to allow good light penetration. The first step is to remove all the upright, vigorous growing shoots at their base that are shading the interior. As with the young apple trees, it is necessary to select 3 to 5 lower scaffold branches with good crotch angles and spaced around the tree. Limbs with poor angles, and excess scaffold limbs, should be removed at their base. In some cases it is advisable to spread the corrective pruning over two to three seasons. When severe pruning is done in the winter, the trees should not be fertilized that spring. Pruning and Training to the Trellis Nonspur cultivars on M.9 and M.26 and spur cultivars on M.7 are best trained to a trellis. Start by planting the trees midway between the posts (Figure 17.9). Remember to keep the graft union above the ground. Cut the trees off at a height of 2 ft. and loosely tie it to the bottom trellis wire. Allow young shoots to develop in the spring and early summer. Some shoots will develop that are not in the plane of the trellis (project out away from the wire). These shoots should be pruned out, or bent and tied to the wire so that they fit the plane. After the first growing season, tie the developed limbs to the wire so that each will form an angle of 45 o with the main trunk. Avoid training limbs horizontally or flat along the wire as vigorous upright sprouts will develop along the upper surface of the limb, at the expense of flower buds. Remove undesirable limbs. Prune back the terminals of the tied limbs as well as the central trunk. Pruning after the second growing season should be done similarly to the first season. The goal should be to fill up the trellis area with limbs the first 2 or 3 years following planting to encourage tree growth. Once fruiting begins, the amount of necessary pruning will be reduced. Periodically, limbs get old and production decreases. If a limb starts declining, prune it out and train a new one to take its place. Girdling may result where the limbs and trunk are tied to the wires. Check these ties periodically to make sure that they are still loose. Fertilizing Generally, apple trees in South Carolina need to be fertilized each year. Tree vigor, variety, rootstock, and soil fertility should be considered when making fertilizer applications. Nitrogen is the most important nutrient needed. Two other nutrients, phosphorous and potassium, are needed in relatively large amounts, particularly on young trees. After the trees reach maturity, fertilization with phospho- Fruit Gardening 639

14 Figure 17.9 Training an apple tree to a trellis. rus and potassium will probably not be required. Do not put any fertilizer in the hole before or during planting. To fertilize apple trees the year they are planted, broadcast over a two-foot circle 1 cup of fertilizer about a month after planting. In June following planting, broadcast another cup of fertilizer around the tree. In early spring of the second season, broadcast 2 cups of fertilizer over a three-foot circle. Repeat this application again in June. In succeeding years, the following guidelines should be followed for the different trees: Standard Trees Increase the diameter of the broadcast circle and the amount of fertilizer ( ) by 2 cups per year. When the tree is 6 years old and older, only nitrogen fertilizer is needed. Use 8 cups of sodium nitrate (16-0-0) or calcium nitrate ( ) per tree for trees six- to eight-years-old and 12 cups for trees nine-years-old and older. For severely pruned trees, do not apply any Think about this... From a cross between two good parents, about one of 50,000 apple seedlings will be as good as the parents. Over the last 300 years in the U.S., only a handful of all the chance seedlings that came up were good enough to become a commercial variety. The summer apple, Ginger Gold, was a chance seedling discovered by Clyde Harvey, a fruit grower in Nelson County, Virginia, after Hurricane Camille blew through his orchard on August 20, By 1975 the tree bore golden fruit and found its way into commercial production. fertilizer that year. Likewise, if growth is excessive, omit fertilizer for a year or two until growth is reduced to a desirable length (ideally, terminal growth on bearing trees should average between 10 to 16 inches per year). Semidwarf Trees Increase the diameter of the broadcast circle and the amount of fertilizer by 2 cups per year. Once the trees reach 4 years of age, apply 8 cups of per tree. Apply this amount in years 5 through 7. For trees eight-yearsold and older, apply 8 cups of sodium nitrate (16-0-0) or calcium nitrate ( ) per tree. If in any given year the trees are severely pruned or the trees are growing too vigorously, omit fertilizer that year. Dwarf Trees During the third and fourth season, broadcast over a four-foot circle 4 cups of around each tree each year. Trees in their fifth and sixth leaf or season should receive 6 cups of per tree broadcast over a five-foot diameter circle. Seven-year-old and older trees should receive only nitrogen at a rate of about 2 cups of ammonium nitrate per tree. Broadcast this over a five-foot diameter area. Caution: When fertilizing, never dump large amounts in a small area because root injury may result. Also, keep fertilizer 6 inches or more away from the trunk. Always broadcast the fertilizer evenly over the recommended area. Once the trees begin to bear, use shoot growth to determine if you need to reduce or supplement the fertilization rates previously suggested. Ten to 16 inches of growth are ideal for bearing trees. If growth is more than this, reduce the rate of fertilization for a year or two until growth is reduced to a desirable amount. If growth is less, apply a little extra fertilizer the next season. Thinning for Annual Fruit Production Apple trees grown under favorable conditions will set more fruit than they are capable of successfully carrying to maturity. Therefore, the removal of excess fruit from the trees is essential to assure satisfactory development of color, shape, and size of the apples remaining on the tree. Failure to remove the Fruit Gardening 640

15 excess fruit will decrease flower formation for the following year and cause the tree to only produce a crop every other year. The earlier that thinning is completed, the more effective it will be in achieving the desired results. Midsummer thinning will help to improve fruit size, but will not aid in the formation of next year s flower buds. Because apple trees initiate flower buds early in the season, thinning must be done within 40 days after full bloom. Hand-thin the young apples when they are about the size of a dime, leaving one fruit per cluster and six inches between fruits. The center apple in each cluster is derived from the king flower, and is the best apple to leave since it usually develops into the largest fruit. Harvesting When picking apples, it is important to be careful to avoid injuring the fruit. The apple should be removed from the spur by pulling upward and outward while rotating the fruit slightly. On some of the thin, long-stemmed cultivars such as Golden Delicious, it is sometimes necessary to firmly place the index finger at the point of attachment of the stem and spur to prevent the spur from breaking. Apples should always be picked with their stems attached to the fruit; otherwise, they will not keep as long. Pests There are several diseases and insects that must be managed to produce the best quality fruit. Producing store quality apples requires attention to pruning, cultural practices and following a regular preventative spray program. Typically, 12 to 18 applications are required per season. The sprays are usually a combination of fungicide and insecticide applied at the same time. In the home garden, planting the apple varieties Liberty or Freedom can help to reduce many disease problems. These are both resistant to apple scab and have some resistance to cedar apple rust, powdery mildew and fire blight. Both are susceptible to the summer diseases, which include black rot, bitter rot, white rot, sooty blotch, flyspeck, Brooks fruit spot and black pox. Summer diseases are particularly devastating in South Carolina and can result in complete crop loss. The quality of both cultivars is better in the Mountains. In South Carolina the recommended crabapple varieties that are resistant to many common diseases include Adams, Mary Potter, Professor Sprenger, Red Baron and Indian Magic. Many diseases commonly occur on apple and flowering crabapple trees, which can reduce flowering and the fruit quality. Planting resistant varieties is one of the best ways to reduce many of these disease problems. Diseases common to apples that should be controlled are scab, black rot, bitter rot, and fire blight. Damaging insects are apple tree borers, red spider mites, scales, aphids, and fruit worms. Controlling these diseases with chemical applications may be difficult on large trees. Some of the most common disease and insect pests are discussed below. For more detailed information about the biology, prevention, and treatment of these pests, refer to the HGIC web site (hgic.clemson.edu). Diseases* Apple scab (Venturia inaequalis) is a problem wherever apples are grown; however, it s more serious in temperate areas that experience cool, wet weather in spring and early summer. The fungus affects cultivated apples and ornamental crabapples as well as hawthorns, firethorn (Pyracantha spp.), and loquat. The principle source of infection is the fruiting bodies that overwinter on fallen leaves and fruit. When the litter is moistened by rain or heavy dew in late winter, the fungus begins to grow and eventually discharges wind-borne spores which land on emerging leaves and flowers. The spores are capable of traveling 300 to 600 ft. from their source. Spores are discharged over a five- to nine-week period, with the peak infection period occurring between the pink to petal fall stages of apple blossoming. Infected leaves and fruits become sources for secondary infections that can occur throughout the summer and early fall. A single leaf lesion can contain up to 100,000 summer spores which can be carried by wind or rain to infect other leaves and fruits, although mature leaves are less susceptible to infection than young ones. This disease is conspicuous on foliage. Velvety brown to olive spots develop on the undersides of the leaves as they emerge in the spring, and turn greenish-black to black. Severely infected leaves are *Adapted from Apple and Crabapple Diseases, N. Doubrava, R. W. Miller, Jr., and J. H. Blake, HGIC Fruit Gardening 641

16 shed sometimes leaving the plant defoliated. Infected fruit have lesions that eventually turn brown and corky. Often the lesions occur at the blossom end of the fruit; later in the season they occur anywhere on the fruit surface resulting in deformed, cracked fruit that stores poorly. Scab will not kill apple trees, but defoliation, especially in midsummer, can affect next year s flowering because of the lack of flower bud formation on trees. Reduce future infections by collecting and disposing of fallen leaves. Pruning to improve air movement and sunlight penetration will help to dry off the leaves quickly. Plant resistant varieties for best control. Rake and remove leaves to reduce early spring infection sources. If disease is severe enough to warrant chemical control, apply a recommended fungicide. The most important time for application is from tight cluster to 3 weeks after petal fall. General purpose orchard spray mixtures contain these fungicides; however, better protection can be achieved when you apply the fungicides separately. Cedar-apple rust (Gymnosporangium spp.) is a fungal disease of apple and crabapple that requires another host plant, eastern red cedar (Juniperus virginiana) or other ornamental junipers to complete its life cycle. The disease spreads from the cedar to the apple and then back to the cedar. It can be a severe problem wherever these two are grown together, and most ornamental crabapples and apples are susceptible. This disease has raised spots on leaves that are bright orange-yellow. Leaves and fruit can drop from the tree. Severe defoliation can lead to reduced bloom the next season. Spots develop primarily on the leaves in mid- to late spring. Infected fruit is often small and distorted. On the Eastern red cedar, hard brown galls up to 2 inches in diameter form near the ends of branches in the summer. In the spring following a rain, the galls produce large, orange, gelatin-like tendrils, full of spores, which can blow up to a 1 2 mile to infect nearby apple or crabapple trees. Plant resistant varieties. If possible, remove red cedars from the area or prune out galls on nearby cedars. If disease is severe enough to warrant chemical control, apply a recommended fungicide. Fire blight is a devastating disease caused by a bacterium (Erwinia amylovora). This hard-to-manage disease develops rapidly in early spring during rainy weather when temperatures are above 60 F and the tree is in bloom. Blossoms and young leafy twigs show the first symptoms, appearing wilted or shriveled and turning brown to black. The tips of infected young twigs wilt and die, forming a shepherd s crook as the disease moves down the branch. Dead leaves often remain attached to the branch. During wet weather, a milky-like, sticky liquid containing bacteria can be seen on the stems and branches. Remove all infection sources, such as blighted twigs and cankers, before growth starts in the spring. Pruning cuts should be made 12 to 18 inches below any sign of infected tissue. Disinfect all pruning tools between each cut, using a solution of 1 part household bleach to 4 parts water. Succulent new growth is easily infected, if injured by insects, hail or wind. Avoid high nitrogen fertilization, which increases succulent growth. Powder mildew (Sphaerotheca spp. or Podosphaera spp.) is most prevalent during dry, hot periods. The fungus causes gray-white powdery patches on leaves and new shoots. New growth is often stunted, curled and distorted. Fruit may turn russetcolored and develop poorly. Prune out branches or infected twigs early in the season. If disease is severe enough to warrant chemical control, use a recommended fungicide. Highly susceptible crabapple varieties infected by Black rot (or Frogeye leaf spot) (Physalospora obtusa) may lose most of their leaves, which weakens the tree and reduces flowering the next year. This fungal disease begins on the leaf as a purple speck that enlarges to have a brown or tan center, which looks like a frog s eye. Heavily infected leaves drop from the tree. Limbs may have slightly sunken, reddish brown areas called cankers. Infected fruits begin with tiny red or purple spots occurring opposite the stem end. After a few weeks the spots enlarge and have alternating zones of black and brown. The rot eventually affects the entire fruit, which wrinkles, mummifies and often remains attached to the tree. Remove and discard dead branches and diseased fruit, called mummies, where the fungus overwinters. Recommended fungicides are effective if applied early and at regular intervals throughout the season. Flyspeck and Sooty Blotch (Schizothyrium pomi and Gloeodes pomigena, respectively) infect the surface of the fruit and are mainly cosmetic problems. They often occur together, although they are distinctive fungal diseases. Although unsightly, the Fruit Gardening 642

17 fruit is still edible. You can wipe off sooty blotch from the fruit, fly speck cannot be removed. True to its name, flyspeck disease looks like groups of very small superficial black dots on the surface of the fruit. The dots are slightly elevated and occur in groups of six to 50. Sooty blotch looks like a 1 4 inch diameter brown or black blotch on the fruit. Spots may coalesce to cover the entire fruit. During the summer these diseases develop during cool rainy weather, particularly in dense, unpruned trees with poor air circulation. Maintain good air circulation by pruning, to keep trees from becoming too dense. Thinning of fruit is also important. If disease is severe enough to warrant chemical control, use an appropriate fungicide. Insect pests of leaves There are several pests or groups of pests that feed on apple leaves. Most of them cause little real damage to the tree and are often best left alone. There are many natural enemies that feed on these pests. Green apple aphid (Aphis pomi) and the spirea aphid (A. spiraecola) are two major kinds of aphids that affect apple trees, especially during the summer. Both species are green-colored, and are commonly found on the tender young leaves on branch tips and on watersprouts. While feeding, the aphids produce honeydew, which is often colonized by black sooty mold. Aphids produce several generations in a season. Aphids are attacked by lady beetles, syrphid fly larvae and other predators and parasites. In many cases, these beneficial insects may keep the aphids under control if insecticide treatments are avoided. Two-spotted spider mites (Tetranychus urticae) and European red mites (Panonychus ulmi) can be serious pests of apples. If mite populations are high, feeding activity can reduce the quality of the current crop and reduce flower bud-set the following year. While both mites produce the same type of damage, there are some significant differences. Both mites produce several generations a season. Japanese beetle (Popillia japonica) adults feed on the leaves during June and July. The beetles skeletonize the leaves, eating the soft leaf tissue and leaving the leaf veins behind to give the damaged leaves a lacy appearance. Occasionally, they may Insect pests of apples was written by Clyde S. Gorsuch, Ph.D., Clemson University. feed on damaged fruit. Japanese beetle traps may suppress Japanese beetles, but the traps must be placed at least 30 feet away from the plants to be protected. The traps will attract adult beetles. If the trap is too close to the plant to be protected, the beetles may stop and feed for a while before entering the trap. Several kinds of leafrollers (Archips spp., Choristoneura rosaceana, and Sparganothis sulfureana) feed on apple leaves. The biggest problem with leafrollers is that sometimes they will tie the leaves to the fruit and feed on both the surface of the fruit and on the leaves. There are a number of predators and parasites that feed on the leafroller caterpillars. If an insecticide treatment is needed, one of the Bacillus thuringiensis materials (Dipel and others) will not harm the natural enemies of the leafrollers and will kill the young caterpillars. Insect pests of fruit Codling moth (Cydia pomonella) is probably the number one pest of apples. It s responsible for producing the proverbial wormy apple, which is the caterpillar stage of the codling moth. The mature larvae leave the apples in the fall and spin a silk shelter under loose bark. They spend the winter in this shelter. In the spring, they change to the adult moth. The moths emerge shortly after bloom and lay eggs on leaves near fruit clusters. The larvae enter the young fruit at the calyx end where the petals were attached. Another generation of moths occurs in July. These moths lay eggs directly on the surface of the fruit. Again, the larvae burrow to the core of the fruit and feed. A third generation occurs in August. Insecticide treatments must be directed toward the adult moths or the newly hatched larvae. Once the larvae enter the apples they are protected. Parasites and predators feed on the eggs and larvae. Tarnished plant bugs (Lygus lineolaris) and stink bugs (Acrosternum species and Euschistus spp.) feed on young fruit. As the bugs penetrate the fruit with their needlelike mouthparts, they inject a saliva that kills the plant cells around the puncture as they suck juices from the fruit. As the fruit continues to grow, depressed areas appear around the feeding sites. Keeping early blooming weeds cut in the area where the apple trees are growing reduces the number of plant bugs. The plum curculio (Conotrachelus nenuphar) is Fruit Gardening 643

18 a native American weevil that attacks apple fruit. The adult weevils spend the winter in protected areas near the apple trees. They return to the trees in the spring after 3 or 4 days when the temperature is above 70 F. After petal fall, the female weevil makes a crescent-shaped cut through the fruit skin and inserts an egg under the flap. Usually, the larva will be killed by the rapidly growing fruit. The scar will show up at harvest. If the fruit becomes infested it will be misshapen and often will drop to the ground. Insecticide sprays applied immediately after bloom may reduce plum curculio damage. Removal of wild plums in the area and practicing sanitation around the apple trees will reduce the problem. Insect pests of branches, trunk, and roots One of the most important pests of the branches is the San Jose scale (Quadraspidiotus perniciosus). The adult scale insect is about 1 10 inch in diameter. It has a gray cover that hides the insects. Scale insects have threadlike mouthparts that are inserted into the bark. They feed on the sap. There are four generations a year in South Carolina. A single female scale can produce about 400 young over a six-week period. The young are called crawlers and move to a new area. They then settle down, insert their mouthparts, begin to feed and secrete the covering over their body. When populations are high, the crawlers may settle on the fruit. This produces a red measles-like spot on the ripe fruit. Heavy scale infestations can kill individual branches. The best control for scale insects is a good application of dormant oil in the spring. This should be applied before the leaf buds begin to open. During the season, insecticide sprays will kill the crawlers. Insecticide sprays will not kill the scales once the cover is secreted. The woolly apple aphids (Eriosoma lanigerum) are covered with a mass of long waxy filaments. They feed on the bark of small twigs, around pruning cuts, and also on the roots of apple trees. The feeding causes the tree to form knobby galls on twigs and on the roots. Heavy feeding damage reduces the vigor of the tree. Above-ground forms can be controlled with an insecticide whenever aphids are present. Rootfeeding colonies cannot be controlled. Apple trees that are under stress from planting, drought or other causes may be attacked by the flatheaded appletree borer (Chrysobothris femorata). This borer is found primarily on young trees. The adult beetle is about 1 2 -inch long, somewhat flattened, and varies from dark metallic brown to dull gray. The larva is legless, yellow to yellowish-white, and has a broad, flattened area immediately behind the head. Mature larvae grow up to inches long. The larvae damage the trees by boring in the trunk and main branches. The galleries will be filled with sawdust-like frass or excrement. Infested trees will often have cracks in the bark that ooze sap. Initial attacks are usually on the sunny side of the tree. Eventually the galleries can girdle the tree and cause death of the tree. Adult beetles are present from late spring to November. There is one generation a year. Vigorous trees will often produce enough sap to drown the larvae in the galleries. The only good control is to keep the trees healthy and vigorous. Pears Pears are adapted to nearly all of South Carolina. It is not uncommon to find fifty-year-old trees still producing fruit. At one time pears were grown commercially on a large scale throughout the U.S. However, because of the prevalence of fire blight in the humid eastern and southern states, most of the pear production has been relocated to the drier areas of the Pacific Northwest. Site and Soil Requirements Air drainage and freedom from spring frosts are important in the location of pear trees. Pear trees bloom relatively early, normally from one to several weeks before apples. Thus, they are much more subject to the hazards of spring frosts. As with all fruit trees, sunlight is a key to maximizing fruit production. Pick an area where the trees will be in the sun most or all of the day. The early morning sun is particularly important because it dries the dew from the leaves, thereby reducing the incidence of diseases. If the planting site does not get plenty of sun, do not plant pear trees. Variety Selection and Pollination Requirements Many pear cultivars cannot be successfully grown in South Carolina because of susceptibility to fire blight. Bartlett is the most recognized pear in the U.S., but is not adapted to the southeast because of susceptibility to fire blight. It should not be Fruit Gardening 644

19 planted in South Carolina. See Table 17.6 for a list of recommended varieties. Certain varieties are self-fruitful. Thus, if only one pear tree is desired, select a self-pollinating variety. Orient, Baldwin, Kieffer, and Spalding are at least partially self-fruitful. Other pear varieties require cross-pollination. If cultivars are planted that require cross-pollination, choose varieties that bloom at the same time. Two cultivars, Waite and Magness, produce sterile pollen; plant two other cultivars to insure pollination of all varieties. Asian pears will probably cross-pollinate with the other recommended pear cultivars, but information is limited. As such, planting several Asian pear cultivars together is recommended. Planting Plant unbranched whips (grafted on Pyrus calleryana or preferably P. betulifolia rootstock) 20 ft. apart. Head or cut them back to 24 to 30 inches from the ground. This will encourage several buds to grow from below the cut. These new branches will be the starting framework of the tree, which will be trained to a modified central leader similar to apples. With a larger nursery tree, one or two wellshaped primary scaffolds or framework branches may be retained. At planting, prune the trees back to single whips 24 to 30 inches from the ground. After a single growing season, the tree should look similar to the one in Figure A. The best time to prune these one-year-old trees (entering their second growing season) is when the risk of a hard freeze is over but the trees are still dormant, usually in early spring (late February to early March). The topmost new branch is now the new leader ; this leader should be cut back 20 to 24 inches above where the tree was cut back the previous year. Leave 4 to 6 branches below the leader spaced about 4 to 6 inches apart. Remove any crossing, broken and/ or diseased limbs. Also, prune out any root suckers. Figure B illustrates what a one-year-old pear should look like after pruning. Pear trees are extremely susceptible to fire blight, a disease that kills limbs and sometimes whole trees. Diseased branches should be removed as soon as they appear. When pruning out a diseased limb, cut at least 6 inches below the area where any infection appears. After each cut, dip the cutting surfaces of the pruners in a chlorine bleach and water mixture (1:4) or Lysol and water (1:1). Figure (A) One-year-old pear tree before dormant pruning; (B) The same tree after pruning. A or head back Remove the diseased prunings from the site. Pear trees are difficult to train. They grow more vigorously and upright than apple trees. If left alone, this growth pattern will result in narrow branch angles, poor light penetration, and poor fruit production. These problems make it even more critical to start training and pruning early. After the first season s growth, begin training branches to the most desirable angle: 45 to 60 o from the vertical. This will open up the tree to sunlight, reduce vigor, and increase fruit production. If a branch angle is too narrow, remove it; or, if its location is desirable, use limb spreaders or strings to change the angle (Figure 17.11). Two-year-old trees (entering their third growing season) can also be pruned in early spring. There should now be two whorls of branches along the main trunk, giving the tree an inverted cone shape. The leader should again be headed back to 20 to 24 inches above last season s growth. Select three to four scaffold branches from the top whorl and head these back to 18 to 24 inches if needed. Heading back these branches will enable side branches to form. Remove all other unwanted growth and any watersprouts (upright shoots) or root suckers. Tip the branches on the scaffolds closest to the bottom (in the lowest whorl). The tree will begin to take shape at this stage. Prune three-year-old trees similarly to two-yearold trees. Again, cut the leader back to 20 to 24 inches above last season s growth. Select 3 or 4 of the tree s best one-year-old scaf fold limbs from the top whorl. Tip the second and third whorl branches to maintain the inverted cone shape. If necessary, thin out some of the excessive growth on the bottom whorl of the scaffold branches. Be sure to re- B Fruit Gardening 645

20 Table 17.6 Pear varieties recommended for home use. Pollination Variety Area 1 Characteristics Code 2 Orient All An excellent pear for most of the state; resistant to fire blight; very large B,C fruit; flesh white; a good keeper; very large fruit. Carrick M,P,SR Excellent for preserving; trees resistant to fire blight. B Waite M,P,SR An excellent pear for the northern half of the state; resistant to blight; C pollen sterile; plant with Orient. Kieffer M,P,SR Large; skin yellow; poor quality; subject to fire blight in wet years; A,B good for preserves. Hood CP Good quality, but subject to internal breakdown if allowed to become A fully ripe; blooms early. Flordahome CP New release from Florida; good quality; blooms early. A Baldwin CP An excellent pear for the southern half of the state; resistant to blight. Magness All Pollen sterile; plant with Orient; fruit excellent quality but not very productive. C Moonglow All Vigorous tree that produces fair to good quality fruit; nearly free of grit cells. C Starking All An excellent pear for the northern half of the state; fruit excellent C Delicious 3 quality; moderately vigorous. Dawn All Good quality fruit; almost entirely free of grit cells; moderately vigorous tree. C Spalding SR,CP Quality fruit that ripens early; subject to fire blight. A,B Warren SR,CP Very high quality fruit; resistant to blight. B,C Asian 4 Area Characteristics Crosspollinator Shinko All Golden-russetted fruit. Hosui Chojuro All Brownish-orange fruit. Hosui, Shinko Hosui All Golden-brown fruit. Shinko, Chojuro Kosui All Greenish-yellow fruit. Hosui, Chojuro 1 M - Mountains; P - Piedmont; SR - Sandhills and Ridge; CP - Coastal Plain. 2 Plant two or more varieties followed by a common letter. Multiple letters by some varieties indicate that they will pollinate other varieties followed by either letter. 3 Considered by many experts to be the same as Maxine. Fruit Gardening 646

21 Figure (A) Two-year-old pear tree trained with strings secured to scaffold limbs in the dormant season. Train limbs to a 45 angle. Head-back here Remove vigorous upright sprouts move any diseased, dead, or unwanted wood. Older trees (four-years-old or more) require light pruning to maintain the established shape. By the fourth year allow the tree to bear its first crop. Allowing the tree to produce fruit before it is trained to support it can cause permanent damage. Pruning Bearing Trees The bearing pear tree is pruned to maintain a balance between vegetative growth and fruit production. The first 3 years should be spent on training only, but by the fourth and fifth years, the trees can be lightly cropped. Pruning these fruit-bearing trees is critical to maintain healthy fruiting wood. Remove weak, shaded-out wood, diseased or dead wood, watersprouts, and root suckers. Tree height can be controlled by cutting back the top portion of the tree to weak lateral branches. For flower buds to develop well, all branches of the tree should be exposed to adequate sunlight. This can be a challenge in the lower portion of the tree. On the lowest whorl of secondary scaffolds, merely tip the terminal shoots of these branches rather than cutting them back to laterals. If the fruit quality and yield diminish in older trees, some heavy pruning may be done carefully to restore tree shape and allow more sunlight to penetrate into the tree. Summer pruning Summer pruning is advised, especially for removing waterspouts, rootsuckers, and fire-blight - infected wood. Summer pruning can also be used during the first 3 years of tree training to produce the desired tree shape. Undesired growth should be removed in early summer or after harvest between late August and early September. Also, note that pruning should be focused on thinning out rather than heading-back. Heading-back cuts may stimulate new growth in the area of the cut. Fertilizing Pears do best in soils with a ph of 5.8 to 6.5. Test soil before planting, and follow the recommendations. Shoot growth on bearing pear trees should average only about six inches annually. Thinning Pear trees grown under favorable conditions will set more fruit than they are capable of successfully carrying to maturity. Therefore, remove excess fruit to assure satisfactory development of fruit remaining on the tree. Failure to remove the excess fruit will decrease flower formation for the following year and cause the tree to only produce a crop every other year. Remove fruit by hand leaving one pear per cluster. Space the fruiting clusters about every 6 inches along the limb. To remove the fruit without damaging the spur or other pears on the spur, hold the stem between the thumb and forefinger and push the fruit from the stem with the other fingers. The earlier that hand-thinning is completed, the more effective it will be in achieving the desired results. Midsummer thinning will help to improve fruit size, but it will not aid in the formation of next year s flower buds. Most of the flower buds for next year are initiated during a 4- to 6-week period following full bloom, so thin before this time. Harvesting To attain highest quality, pears must be harvested before they are ripe. If picked too early, they are undersized and lack sweetness and flavor. When picked too late, the fruit ripens quickly, is gritty in texture, and is subject to core breakdown. Asian pears are best ripened on the tree. One measure of maturity are the fruit lenticels. These are the small dots or indentations on the fruit s skin. Lenticels of immature pears are white; however, as cork cells develop the lenticels become brown and shallow. The brown in the lenticels is a good indication that the fruit is ready to be picked and will ripen without shriveling. Color between Fruit Gardening 647

22 the lenticels also becomes lighter green than at the lenticels. Diseases and Insects Diseases common to pears are scab, black rot, bitter rot, pear leaf spot, and fire blight. The two most common diseases are fire blight and pear leaf spot. Fire blight is a disease that can attack pears throughout the growing season, but it usually begins during bloom. Blighted tissues become water soaked then quickly wither and blacken. The disease moves down the branch from the point of infection. The tissue under the bark of the most recently killed leaves or flowers will be darkened and moist in appearance. During periods of high humidity or rain, the blighted areas will usually ooze a milky fluid. This fluid becomes reddish brown as it dries. Pear trees can be protected from fire blight by a spray program beginning at bloom and continuing through the summer. Once a tree has been infected, the diseased portions should be cut out and discarded. Sprays will not control the disease in infected branches. Make cuts 6 to 8 inches below any dead tissues. After each cut, soak the clippers for a few seconds in a 20% household bleach:water solution. When cutting is completed, rinse clippers in running water, dry them, and then oil lightly. Many other conditions such as nutrient imbalances, winter damage, or drought stress can cause pear leaves to blacken and die. In these cases, the tissue under the bark in the afflicted area will remain green or have a dry, brown appearance. Pear leaf spot begins as small purplish-black spots on the leaves or fruit. The spots gradually enlarge to form brown lesions about 1 / 8 inch to 1 / 4 inch in diameter. A small, black blister may appear in the center of these spots. Leaf spot can only be controlled with a spray program beginning as the first leaves appear and continuing through July. Much like apples, pear trees are subject to infestations by mites and scales. Dormant oil applications applied during the dormant season will suppress these pests. Mite infestations during the growing season will sometimes require miticide treatments. Pear fruits are sometimes scarred by plum curculio, as well as by some of the fruit-attacking caterpillars associated with apples. These pests typically cause little internal injury to pears. However, their feeding and egg laying activities will frequently produce cosmetic scarring of pears. Non-cosmetic damage is found with the later maturing varieties, which can have fruit caterpillar damage in the core remain unnoticed until the fruit is eaten. Stink bug feeding is the most common insect injury to pears in South Carolina. It produces shallow depressions in fruit that are often corky or woody in texture. Peaches and Nectarines Growing peaches and nectarines can be both fun and rewarding. However, the success of your enterprise will depend largely on the care and attention the trees are given throughout their lifetimes. This section offers guidelines on the selection and care of peaches and nectarine trees in the landscape or backyard orchard. Since nectarines are nothing more than fuzzless peaches, their culture is the same as peaches. For simplicity, the term peach used in this section refers to both peaches and nectarines. Site and Soil Requirements Sunlight, and plenty of it, is the key to maximizing fruit production. Pick an area where the trees will be in the sun most or all of the day. The early morning sun is particularly important because it dries the dew from trees, thereby reducing the incidence of diseases. If the planting site does not get plenty of sun, then you can t expect the best performance from the trees. Avoid very steep or badly eroded hillsides and areas having poor air circulation and poor soil water drainage. Although peach trees will grow well in a wide range of soil types, a deep soil ranging in texture from a sandy loam to a sandy clay loam is preferred. Peach trees are extremely sensitive to poorly drained soils. In areas of poor drainage, roots will die, resulting in stunted growth and eventual death of the tree. Most fruit trees, including peaches, grow best where the soil ph is near 6.5. Since the natural ph of most South Carolina soil is below this level, it is necessary to incorporate lime before planting to raise the ph to the desired level. Follow soil test results to determine soil ph and fertility levels. Purchasing Trees The adage you get what you pay for is also important when buying peach trees. Keep the following points in mind when purchasing peach trees: Fruit Gardening 648

23 1. The ideal tree is young (one year of age), healthy, about 3 to 4 ft. tall, and has a good root system. Trees that are two-years-old or older do not usually grow as well as younger trees Frequently, older trees do not have sufficient buds on the lower portion of the trunk to develop a good framework. 2. Avoid trees that appear stunted, poorly grown, diseased, or insect-injured. 3. Check the trees closely to make sure that you are getting the cultivar and rootstock that you desire. Variety Selection There are peach varieties adapted to most areas of South Carolina. Tables 17.7 and 17.8 list recommended peach and nectarine cultivars for each area in South Carolina. Varieties with low chilling requirements are recommended for coastal areas (see the shaded box titled Chilling Requirements ). Rootstocks For most of South Carolina, Lovell has been the best rootstock. In the Coastal Plain Nemaguard rootstock was used because of widespread root-knot nematode problems. However, it has been replaced by a new rootstock called Guardian ( BY520-9 ), which was developed by Clemson University and the USDA-ARS and released in Guardian has proven to be superior to other rootstocks on infested soils, including ring and root-knot nematodes. Pollination Peach flowers are self-fruitful. Therefore, it is not necessary to plant more than one peach variety in the backyard. Soil Preparation and Planting Peach trees should be planted while fully dormant from early December to mid-march. Because root growth may occur during relatively mild winters, plant as early as possible so the roots will establish before spring growth begins. When the fruit trees arrive from the nursery, open the bundles immediately. Soak the roots in water for 6 to 12 hours if they are not moist. The trees should then be planted if the soil is not too wet. If the soil is not prepared where the trees are to be planted, or the ground is too wet, heel the trees in by placing them in an open trench deep enough to cover all roots. The north side of a building is the best place for heeling because the trees will remain dormant longer. Place soil over the roots to the depth they will be planted in the garden or landscape. Before planting, prepare the soil thoroughly by plowing or spading followed by disking or raking to smooth the surface. If you have not adjusted the soil ph to 6.5 previously, liming should be done before you prepare the soil so that the lime will be mixed throughout the planting area. When added to the surface and not plowed in, lime takes years to move down into the soil. Lime an area 10 ft.-by-10 ft. where each tree is to be planted. Similar to lime, phosphorus moves down through the soil slowly and thus should be incorporated along with lime before planting based on soil test results. When planting, dig holes large enough to receive roots freely without cramping or bending from their natural position. Before planting, cut off all broken or damaged roots with a sharp knife or pruning shears. Keep root pruning to a minimum. Set the plants at about the same depth they were planted at the nursery so that the uppermost root is not more than 1 to 2 inches underground. Work the soil in and around the roots. When the hole is half-filled, firm the soil with your feet before you finish filling the hole. When the hole is filled, pack the soil firmly. Do not leave a depression around the tree. Do not place fertilizer in the planting hole or fertilize immediately after planting. Post-plant Care After planting, apply sufficient water to thoroughly soak the soil in the area of the tree roots. This watering will help bring the soil into closer contact with all sides of the roots and eliminate air pockets around the roots. Keep weeds out of a 3-by-3-ft. area around the tree because they compete with the tree for moisture and nutrients during the growing season. This will also keep mowers away from the tree and reduce trunk damage. Mulching will help to control weeds as well as conserve moisture. Training and Pruning Peaches are usually trained to an open-center system (Figure 17.12). Cut back newly planted trees to about 30 inches in height, just above a lateral branch or bud. If the tree is branched when it comes from the nursery, select three or four laterals Fruit Gardening 649

24 Table 17.7 Peach varieties recommended for home use. 1 Variety 2 Area 3 Characteristics Harvest Date 4 Flordaking CP Large size clingstone; medium quality; yellow flesh. May 5-10 Springprince SR, CP Clingstone; deep red blush; excellent quality for an early May season peach. Junegold SR, CP Large-sized clingstone with bright reddish blush; fine texture; May yellow flesh. Goldprince SR, CP Light reddish blush, yellow flesh; firm; good flavor. May 25-June 5 Southern Pearl P, SR, CP White-fleshed, large, excellent quality. June Garnet Beauty M, P, SR Medium to large; yellow flesh; excellent yields. June Sureprince M, P, SR Yellow flesh peach of excellent quality; requires heavy June thinning; medium to large, semi-freestone. Redhaven M, P, SR Medium size; very red skin; skin is tough and firm; freestone; June very good for picking, canning, and freezing; non-browning. Harvester SR, CP Medium to large size with bright red skin color; has golden June 25-July 2 yellow flesh of excellent quality; freestone. Nectar M, P, SR Excellent quality freestone, white flesh peach; outstanding for its June 25-July 2 sweetness and aroma. Redglobe M, P, SR Medium to large, attractive deep-red freestone; yellow flesh; July 5-15 good quality. Winblo M, P, SR Medium to large, attractive round peach; red blush with July golden undercolor; yellow flesh; exceptional quality for fresh eating and freezing. Georgia M, P, SR Medium to large, white flesh freestone; skin red blush; excellent July Belle for eating; fair for freezing and poor for canning. Cresthaven All Large, freestone fruit; yellow flesh with red at pit; reliable; July very attractive; good for canning and freezing. China Pearl M, P New North Carolina release, white, low acid. July Jefferson M, P, SR Reliable producer; yellow flesh peach of excellent quality; July 25-Aug 5 buds and flowers tolerant to blossom season frost. Flameprince M, P, SR Tasty, some red in the flesh, very attractive. Aug List assembled by Billy Newall, peach and nectarine breeder, Clemson University. 2 Bacterial leaf spot is serious some years, causing fruit spot and leaf drop. Variety selection is the only means of control in the home orchard. The above recommended varieties are classified as follows: Susceptible Junegold, Suwanee ; Moderately Resistant Redhaven, Nectar, Redglobe, Georgia Belle and Jefferson ; Resistant Harvester and Winblo. 3 M - Mountains; P - Piedmont; SR - Sandhills and Ridge; CP - Coastal Plain. 4 Average ripening dates for Byron, Georgia, which are similar to the Sandhills and Ridge region. Dates may vary according to season. Piedmont and Mountains are 7-10 days later, and Coastal Plain is 7-10 days earlier. Fruit Gardening 650

25 Table 17.8 Nectarine varieties recommended for home use. 1 Variety Region Characteristics Harvest Date 1 Sunsplash CP Yellow flesh; semi-freestone. May Sungem CP Medium size fruit; good quality; blooms early; very low-chilling May well-suited for regions immediately along the coast. Karla Rose P, SR, CP White flesh; semi-freestone. June 5-12 Sunfire CP Medium size fruit; good quality; yellow flesh; very low-chilling --well-suited for regions immediately along the coast. June 5-12 Sunfre CP Medium size, yellow-flesh; semi-freestone; good quality. June 5-12 Juneprincess M, P, SR Medium-large freestone; 80-90% bright red. June Durbin P, SR, CP Medium size, semi-freestone fruit; yellow flesh with red pit; June 20 good quality; firm fruit. Roseprincess M, P, SR White flesh; semi-freestone. June 25-July 2 Sunglo All Large size freestone fruit; excellent quality; yellow flesh. July 8 Redgold All Large size, freestone fruit; excellent quality; yellow flesh. July 15 Fantasia SR, CP Large size, freestone fruit; yellow flesh; very high quality; July 20 firm fruit; excellent color. 1 List assembled by Billy Newall, peach and nectarine breeder, Clemson University. 2 Average ripening dates for Byron, Georgia, which are similar to Sandhills and Ridge region. Dates may vary according to season. Piedmont and Mountains are 7-10 days later, and Coastal Plain is 7-10 days earlier. with wide-angle crotches (greater than 45 o ) spaced evenly up and around the trunk for the permanent scaffold limbs (Figure 17.13). The lowest limb should be about 15 inches and the highest about 30 inches from the ground. If no desirable laterals are available, head the tree to the desired height and cut out all side branches to one bud. A number of shoots will develop during the season which can be selected for scaffold limbs. Select scaffold limbs during the summer or wait just before growth begins in the second season. Another approach that produces desirable scaffold branches on first year trees is to avoid pruning in late winter. Instead, head-back several of the uppermost shoots by half in early June. Their growth will be suppressed, which encourages the growth of the lower shoots that develop wide crotch angles. In the following winter remove the small bush from the center of the tree. First Growing Season--At the end of the first growing season, the tree should look similar to Figure Prune in mid-february to early March before budbreak. First, remove diseased, broken and low-hanging limbs. Next, remove vigorous upright shoots that may have developed on the inside of the main scaffolds to develop an open-center (vaseshaped) tree. Once the scaffold system of the young peach tree is established, prune as little as possible until the tree becomes mature enough to fruit, usually the third or fourth year. Peaches are produced on wood that grew during the previous season. Do not prune trees from October to January. In the Mountains and Piedmont, wait until mid February to prune. Pruning in late winter reduces the chance of winter injury and infection by the bacterial canker organism. Second and Third Growing Seasons--Follow the same principles used after the first growing season. First, remove low-hanging, broken, and/ or diseased limbs. To maintain the open-center, remove any vigorous upright shoots developing on the Fruit Gardening 651

26 Figure (A) Peach tree trained to an open-center system with widely spaced branches. Credit: SC Nursery and Landscape Association Certification Manual, Reprinted with permission. Figure A branched peach tree from the nursery pruned to retain strong, wide-angled branches for permanent scaffold limbs. Credit: SC Nursery and Landscape Association Certification Manual, Reprinted with permission. inside of the tree, leaving the smaller shoots for fruit production. Prune out poor quality fruiting wood, such as shoots less than pencil-size in diameter or branches that hang downward and are shaded. The desirable wood left for production should be about the diameter of a pencil and from 10 to 15 inches in length. If the length exceeds 10 inches, cut off about one-third of this fruiting branch. Finally, prune the vigorous upright limbs on the scaffolds by cutting them back to an outside growing shoot. Mature peach trees Figure illustrates a mature peach tree before pruning. Figure illustrates the same tree after pruning. The same principles used to develop the tree are used to annually maintain the size and shape of the mature peach tree. Remove low-hanging, broken, and dead limbs first. Next, remove the vigorous upright shoots along the scaffolds. Lower the tree to the desired height by pruning the scaffolds down to an outside growing shoot at the desired height. Prune out extremely vigorous shoots developing on the inside of the tree because they shade out the center. Leave the small shoots alone. Do this in early or mid July. Never prune a bearing peach tree heavy enough to make eventual thinning of the fruit unnecessary. Such heavy pruning drastically reduces the crop as well as the size of the tree. Lightly head back terminal growth on the scaffold limbs to outward growing laterals to maintain the open center or bowl-shaped tree. The objective is to open up the tree to allow sunlight penetration and air movement and to improve spray coverage. When the tree is well grown, pruning consists mainly of moderate thinning and heading back to outward-growing laterals to keep the tree low and spreading. A height of 8 to 9 ft. is preferred. Fertilizing Fertilizing peaches starts with adjusting the soil ph to 6.5 before planting. Incorporate the lime at least a foot deep and over an area about 10 ft. by 10 ft. where the tree will be planted. In March after the trees have been planted and the soil settled by a drenching rain, broadcast 1 cup of fertilizer over an area 3 ft. in diameter. Do not allow fertilizer to accumulate around the tree trunk. In early June and again in early August, broadcast 1 / 2 cup of calcium nitrate ( ) or equivalent over an area 3 ft. in diameter. In the second year, fertilize the trees twice a year in early March and around the first of August. Use these rules-of-thumb for the two fertilizer applications: 1. Early March application: apply 1 cup of fertilizer per year of tree age to a maximum of 10 cups for mature trees. 2. August application: apply 1 cup of calcium nitrate or equivalent per year of tree age to a maximum of 4 cups for mature trees. Do not make the August application if the crop was lost to a freeze. Do not apply until the harvest of late season varieties is completed. Thinning Fruit A peach tree cultivated under favorable conditions will set more fruit than it is capable of successfully carrying to maturity. Branches may break and Fruit Gardening 652

27 Figure Properly pruned tree at the end of first growing season. the fruits typically have poor color and taste. To prevent limb breakage and ensure good fruit quality, excess fruits must be removed or thinned. Handthin peach and nectarine trees about 4 to 6 weeks after full bloom, spacing the fruit about 6 inches apart on the limb. Early maturing peaches and nectarines should be spaced 8 inches apart. When thinning by hand, grasp the stem or branch firmly between the thumb and forefinger and pull the fruit off with a quick motion of the second and third fingers. Diseases and Insects It is very difficult to grow top quality peaches in the home orchard without conducting a rigid pest control program throughout the growing season. The most damaging peach disease is a fruit rot commonly called brown rot. Other diseases of peaches include scab, bacterial spot, rhizopus rot, leaf curl, peach phony, and nematodes. Brown Rot attacks flowers, shoots, and fruit. Diseased flowers wilt and turn brown very quickly. Shoot infections result in fairly small elongated (1 to 3 inches long) gummy cankers. These cankers provide the disease spores for fruit rot. Infected fruits rot completely to become mummies, which carry the disease over the winter. Sanitation is a valuable component of brown rot control. Collect diseased fruit as soon as it appears and remove infected twigs and mummies from the trees to reduce the carryover of brown rot disease to the next season. Peach Scab appears as small (usually less than 1 / 8 inch in diameter) dark, somewhat velvety spots on fruit. Large black areas may result from numerous closely spaced infections. This disease is easily controlled with chemical sprays applied at the shuck split stage and every 14 days for the next 4 to 6 weeks. Shuck split is the stage after bloom when the dry flower parts split and fall free of the small green fruit. Disease symptoms occur only on the outer skin. Infected fruit looks bad but eating quality is not affected. Peel fruit to remove all traces of the disease. Bacterial Spot infects peach fruit and leaves. Infected leaves develop small reddish-purple spots, often with white centers. These spots often drop out to give the leaf a tattered or shot hole appearance. Infected leaves eventually turn yellow and drop. This leaf-loss weakens the tree. Infections on fruit appear as small dark spots. Close examination reveals these spots to resemble open sores rather than the velvety spots characteristic of peach scab. In years of severe infection, diseased areas of the fruit may develop severe cracks. The best way to control bacterial spot is to select resistant peach varieties. This is not a problem in the Mountains and Piedmont. However, in the Sandhills and Coastal Plain, cultivar selection is limited by a lack of winter-chilling necessary for bud development. Some problems with bacterial spot will occur in these areas. Fortunately, spots seldom penetrate deeply. Peeling fruit removes most traces of the disease. Plum Pox (Sharka) is caused by the plum pox potyvirus. It is vectored by aphids or through budwood. Infected fruit display yellowish to bluish rings on the fruit surface that can necrose into the fruit flesh, ruining its edibility. Any siting of this very serious disease should be reported to your Clemson Extension agent or HGIC specialists. Peach Leaf Curl is common from the Mountains to the Sandhills and Ridge, and much less common in the Coastal Plain. The disease attacks the peach leaves and occasionally the green fruit. Leaf infections occur at bud-break and the disease becomes evident around bloom time. Infected leaves appear thickened and badly puckered or twisted, and will often be tinged red. Infected leaves usually drop in early summer. The disease seldom kills trees, but the heavy leaf-loss weakens them. Infected fruit will have raised wrinkled areas often reddish in color. Chemical sprays before budbreak provide good leaf curl control. Phony Peach is a bacterial disease that is Fruit Gardening 653

28 Figure Mature peach tree before pruning. Figure Mature peach tree after pruning. transmitted to healthy trees by leafhoppers. It is important to remove wild plum bushes, which are common sources of phony, before planting peaches. Also, peaches and plums should not be planted together in the Coastal Plain. This disease cannot be controlled with chemical sprays. Oak Root Rot is caused by a soilborne fungus that attacks and kills peach roots. The fungus will survive for many years in the soil on roots of hardwood trees that have long since been removed. There is no control. Thus, peaches should not be planted where land has been recently cleared of hardwood trees, or planted in spots where peach trees have been removed. Infected peach trees maintained in a healthy condition survive much longer than weakened trees. Once a peach tree is infected with the oak root rot fungus, it may survive for 2 or 3 years before it dies. Root-knot nematodes are microscopic soilborne roundworms that attack the roots of numerous plants, including peach, and shorten their life spans. Chilling Requirements Stone fruit trees such as peaches develop their vegetative and fruiting buds in the summer and, as winter approaches, the already developed buds go dormant in response to both shorter day lengths and cooler temperatures. This dormancy or sleeping stage protects these buds from oncoming cold weather. Once buds have entered dormancy, they can tolerate temperatures much below freezing and will not grow in response to midwinter warm spells. These buds remain dormant until they have accumulated sufficient chilling units- -temperatures of 45 F or less. When enough chilling units accumulate, the buds are ready to grow in response to warm temperatures. As long as there have been enough chilling hours, the flower and leaf buds develop normally. If the buds do not receive sufficient chilling temperatures during winter to completely release dormancy, trees will develop one or more of the physiological symptoms associated with insufficient chilling: (1) delayed leafing-out and flowering; (2) reduced fruit set and increased buttoning --small, misshapen fruit; and (3) reduced fruit quality. The roots of infested trees show numerous small swellings or knots. Diseased trees may grow poorly and always appear hungry or nutrient-deficient. Never plant a peach tree in an old vegetable garden site. Root-knot nematodes can build up in many vegetable garden soils. The safest planting sites are portions of the yard where bermudagrass or other lawns have been established for years. Trees are more tolerant to rootknot nematode if they are grafted on Guardian or Nemaguard rootstocks. Information on nematode sampling can be obtained from the HGIC. Root-knot nematodes cannot be treated or corrected after planting. Peach tree short life has been responsible for changing the face of the peach industry in the Southeast. This replant disease is associated with sites infested with the ring nematode (Mesocriconema xenoplax). Trees planted in ring nematode infested soil are more likely to acquire the disorder if the ph is 5.5 or less, the trees are pruned during the months of October-January, or if the trees develop bacterial canker. This disease can be avoided by planting the trees on Guardian rootstock. There are a number of insects that dam- Fruit Gardening 654