Chapter 17: Small fruits.
After completing this chapter, you should be able to:
* Describe a fertilizer program for a vineyard
* List the characteristics of ripe grapes
* Name the procedures for weed control in vineyards
* Explain how to select a site for a vineyard
* Describe a site and its preparation for strawberry production
* Explain the cultural practices of weed control, mulching, and fertilizing
* List eight steps for better strawberry production
* Diagram four planting systems for strawberries
* List the three main soil requirements for highbush blueberry production
* Identify the two types of commercially grown blueberries
* Outline a fertilizer and pruning program for bramble fruits
* List five key points to consider when selecting a site for brambles
* Identify seven measures for disease prevention in raspberry planting
* Describe currant and gooseberry production
Grapes are a popular homegrown fruit as well as an important commercial crop. Grapes have many uses and are very nutritious. They are the best known vine fruit. They are consumed fresh, as juices and wines, as raisins, jam and jelly, and as frozen products. Grapes are native to the United States. Many of the domesticated varieties have native wild grape ancestry in at least one parent. American fine wine grapes are native to central Asia. Grapes are easily grown commercially in most areas of the United States and have a wide range of flavors. They do not grow well in arid sections and in areas having extremely high temperatures and very humid conditions.
Basically, three kinds of grapes are grown in the United States.
1. European or Old World grapes (Vitis vinifera). These make up about 95% of the grapes grown in the world and are used for table, raisin, and wine grapes.
2. North American grapes (Vitis labrusca or Vitis rotundifolia). These are hardy, native, disease-free grapes. Well-known examples include the Concord, Delaware, and Niagara.
3. Hybrids. These grapes are crosses between the European grape varieties and the native American species. They are selected for the quality of fruit from their European ancestors and for their disease and insect tolerance from their native American ancestors. Grapes, shown in Figure 17-1, require 3 to 4 years for the vines to mature before producing fruit. They also require a growing season of at least 140 frost-free days.
[FIGURE 17-1 OMITTED]
A standard variety like Concord needs 160 to 165 days. Variety selection will depend on the growing season. The varieties listed in the variety section are early to midseason varieties. The vines are healthier if good weather occurs after the crop is produced so the vines recover from producing the crop and have time to get ready for winter.
The soil should be well drained, 30 inches deep, and have a pH from 5 to 8. An excessively rich soil, high in organic matter, produces heavy, late maturing crops with a low sugar content. Light soils produce light yields of early maturing fruit with high sugar contents but vine growth is weak. There should be a minimum of cold-warm-cold cycles during the winter. Exposure to alternating cold and warm temperatures causes winter injury. The site should allow for good air drainage to reduce the amount of frost injury.
When selecting varieties, growers consider the number of days required to mature the crop and the cold temperature hardiness. Varieties listed next mature fairly early and are hardy. Other varieties should be considered only if they mature in a time comparable to the growing season for a specific area. Other characteristics would be the type and uses of the fruit.
* Concord--160 to 165 days, a blue variety, hardy, fruit good for juice, jelly, jam, wine
* Niagara--150 to 155 days, a white grape, somewhat less hardy than Concord
* Delaware--150 to 155 days, a pink red grape, somewhat less hardy than Concord, low vigor
* Fredonia--146 to 151 days, a blue variety, less productive than Concord
* Golden Muscat--a white variety, vigorous, productive
* Moore Early--146 to 151 days, a blue variety, fruit quality not as good as Concord, the fruit sometimes cracks badly
* Beta--very early, very hardy, productive, a blue grape, berries with high sugar and acid
* Seyval--Early midseason, a white grape, moderately vigorous, productive
Fresh table grapes come in three basic colors: green (sometimes called white), red, and blue-black. More than 50 kinds of table grapes are currently in production, but the following list describes 17 major varieties. Each variety possesses a distinct color, taste, texture, and history.
Table grapes are often covered with natural bloom, which is a delicate white substance common on many soft fruits. The bloom protects the grape from moisture loss and decay.
* Perlette Seedless--The first grape of the season, the Perlette, is light in color, almost frosty green with a translucent cast; the berries are nearly round. Perlette means "little pearl" in French.
* Thompson Seedless--Almost everyone is familiar with this grape's light green color, oblong berries, and sweet, juicy flavor. The variety may have originated in southern Iran.
* Sugraone--The Sugraone berry is bright green and elongated. The fruit offers a light, sweet flavor and a distinctive crunch.
* Calmeria--This grape carries the nickname "lady fingers" so called for its elongated, light-green and delicately sculpted berries. A winter treat, this seeded grape has a mild, sweet flavor with an unforgettable tang.
* Flame Seedless--The result of a cross between Thompson Seedless, Cardinal, and several other varieties, the Flame Seedless is a round, crunchy, sweet grape with a deep-red color.
* Crimson Seedless--This blush-red variety has firm, crisp berries with a sweetly tart, almost spicy, flavor.
* Premium Red--This red seedless variety has medium-sized berries with a sweet flavor.
* Emperatriz--These red, medium-sized berries show slight yellow hues throughout their firm skins. The Emperatriz is sweet and fruity.
* Rouge--These seeded, dark red berries are large and oval with a firmly crisp, thick-skinned texture and a mildly sweet, earthy flavor.
* Ruby Seedless--Grown commercially in the San Joaquin Valley since 1968, the Ruby Seedless is a deep-red, tender-skinned grape.
* Emperor--Large, deep-red clusters and a lasting flavor characterize this seeded variety that was first planted in California in 1863. In East Coast cities, where European traditions remain strong, the Emperor is very popular.
* Red Globe--The large, remarkable clusters of the Red Globe contain plum-sized seeded berries. The Red Globe is popular for both eating and decorating during the holiday season.
* Christmas Rose--Another relative newcomer, this light-red seeded variety ripens through December. Developed from four older varieties, the berries are large with a tart-sweet flavor.
* Exotic--Born in 1947 in Fresno, California, Exotic berries are plump and juicy and grow in long, beautiful clusters. A cross between the red Flame Tokay and the Ribier, this seeded grape is crisp and mild in flavor.
* Fantasy Seedless--These blue-black sweet berries are oval, thin-skinned, and firm. Fantasy's conical clusters have medium-sized berries with pale green flesh and a mellow flavor.
* Ribier--This dark blue-black seeded grape crossed the Channel from Orleans, France, in 1860 to become an English "hothouse" variety. The skins are firm and the taste is mild.
* Niabell--This Concord-type variety features thick-skinned, round berries ranging in color from purple to black with an earthy, rich flavor.
Growers plant grape vines in the spring. Nurseries offer either one-year- or two-year-old plants. The two-year-old plants cost more than one-year-old plants. At planting time, the dead or broken roots are cut off and the tops are pruned back to two or three buds. The grower should set vines at 8 foot spacings in rows 8 to 9 feet apart and plant the vines 2 inches deeper than they were growing in the nursery.
PLANT BREEDERS PRODUCE NEW BERRY VARIETIES Producing better varieties of plants is an on-going challenge for plant breeders. Thanks to the work of scientists at the Fruit Laboratory in Beltsville, Maryland, growers will have four new selections of commercially available blueberries to choose from. The Little Giant variety is bred for the cooler climates of Washington, Oregon, Michigan, New Jersey, and North Carolina. It offers an alternative variety for frozen and processing markets, and can be planted with other northern highbush blueberry varieties for cross pollination. Pearl River, Magnolia, and Jubilee are new varieties and more suited to the warmer climates in the Gulf Coast and southeastern United States. They can be interplanted with other southern highbush blueberry varieties to ensure fruit set, early ripening, and maximum yield. Each of the four new varieties is productive and disease resistant. Also, two new June-bearing strawberries have been introduced by the Agricultural Research Service (ARS) plant breeders for the Middle Atlantic and adjacent regions. Primetime is a midseason berry. It bears fancy, good-quality, large fruit. Latestar is a late-season variety. It produces large, attractive fruit. Both varieties are recommended for shipping and local markets and resist multiple fungal diseases. They produce well on either light or heavy soils, and in matted rows or in hill culture. Plants are available in season at nurseries.
Grapes are propagated commercially by hardwood cuttings. If a disease-resistant rootstock is needed for certain varieties, plants are grafted or budded to a disease-resistant seedling rootstock.
Only one type of trellis and training method will be discussed. The trellis is the two-wire trellis. Growers should use durable posts about 3 inches in diameter. About 2 1/2 feet of the 8-foot-long post should be buried in the ground. Posts are set at 16 foot intervals along the row. End posts may need to be longer to give good support and strength. If the end posts are weak or poorly braced, the trellis will be weak and sag.
Wires fasten to the post so they slide through the fastening device. This allows the tension on the wires to be increased to keep them taut. The bottom wire should be 3 feet from the ground, the top wire about 5 feet. Number 10 galvanized wire is suitable for use on grape trellises.
The training system described is called the four-arm Kniffin. Plants trained to the four-arm Kniffin system will consist of a vertical stem that reaches to the top wire plus an upper and lower branch on each side of the trunk. These branches are tied to the wires. During the first year, the strongest shoot is trained to grow upward and is fastened to the first wire. During the second growing season, it reaches and is tied to the top wire. During the winter, cut off the portion of the trunk that extends above the wire. During the second growing season, the vine will have sent out side branches near the bottom wire. One branch on each side of the trunk should be trained to grow on the bottom wire. During the second winter, these side branches should be pruned back to five buds each at the time the excess trunk is cut off. During the third growing season, the upper branches form.
Fruit is only produced on the previous year's wood. Vines allowed to grow for many years without pruning accumulate much old, unproductive wood. The object of pruning is to remove all the old wood and leave four canes that will produce next year's crop. The four canes are the four arms or branches described in the training section. In addition, two to four other canes, called renewal spurs, are left to produce the fruiting canes for the following year. Renewal spurs only have two to three buds and like the four fruiting canes originate from the trunk.
Grape pruning regulates the health and vigor of the vines. This is done by pruning the vines so the fruit load is about what the vines are able to mature. The system is based on the vigor of the vines in the previous growing season.
Grapes are pruned during the dormant season in late winter or early spring. Buds that have begun to swell are easily knocked off during the pruning operation. When pruning, growers select the four canes that will be the fruiting wood for the coming growing season. They also select the canes to serve as the renewal spurs. The renewal spurs should originate on the trunk near the point where a wire crosses. This positions canes properly. Once the renewal spurs and fruiting wood have been selected, all other growth is removed. The wood left should be dark brown and slightly larger than a pencil.
Weed Control and Fertilizing
Weeds are controlled by cultivating no deeper than 3 to 4 inches. The amount of fertilizer needed varies with the soil. Soil testing and foliar analysis will help monitor plant needs. Growers avoid giving too much nitrogen.
Grapes should be left on the vine until fully ripe because ripening stops once the grapes are harvested. Color is not a good indicator of ripeness as it changes two to three weeks before the grapes are ripe. The stem of ripe grape clusters will be brownish and wrinkled. Ripe grapes are easily pulled from the cluster.
Grapes are sprayed for insects and fungal diseases. Growers should consult a local county agricultural agent or locate the recent USDA bulletin on spraying grapes. Major diseases that require control are black rot, powdery mildew, and downy mildew. The major insect pests include the flea beetle, leaf hopper, berry moth, and Japanese beetle.
The strawberry is moderately easy to grow when compared to other types of fruits. A strawberry planting lasts about 3 years before it needs replanting.
A good site slopes about 2 feet in 100 feet. This allows good drainage of both water and air. Good air drainage allows the cold air to flow off reducing susceptibility to frost injury. Plants in low areas may be covered by water during winter thaws. Then, when the temperature drops after the thaw, the freezing water may kill the plants.
The best growing conditions are full sun and sandy to gravely loam with a pH of 6.0 to 6.5 and a good supply of organic matter. Good drainage is essential for best growth. Strawberry runners root better on light soils. Everbearing varieties may give the best results on rich soil. Growers avoid sites infested with nutsedge, quackgrass, or persistent problem weeds and spray problem weeds with herbicides before planting the strawberries. If the strawberries follow sod, there could be problems with white grubs or wireworms.
Flower Bud Formation
June bearers form flower buds in the short days of late summer and fall. This is why the strawberry patch should not be neglected after the berries have been picked. Poor care late in the season leads to a poor crop the following year. Low temperatures are needed for the flower buds to complete their development. Everbearers form flower buds in the longest days of summer and flower and fruit in summer and fall. The longer days of summer trigger runner formation (see Figure 17-2).
[FIGURE 17-2 OMITTED]
Many varieties of strawberries are available. Some varieties are listed. Everbearing varieties may not be as productive or have as high a quality as June bearing varieties. Some varieties include--
* Raritan--Midseason, good flavor and yields but susceptible to stele and wilt diseases.
* Delite--Late, resistant to stele and wilt but forms too dense a matted row.
* Redchief--Midseason, resistant to stele and wilt but berries are hard to cap.
* Holiday--Midseason, large, firm berries but plants are not very disease resistant.
* Guardian--Midseason, resistant to stele and wilt but berries are light fleshed, rough and green tipped.
* Earliglow--Early, resistant to stele and wilt.
* Midway--Midseason variety.
* Marlate--Late, high-quality berries but low yields; berries have light flesh, hard to cap.
* Gem--Everbearer, hardy and productive but a poor runner producer, berries are soft, acid.
* Ozark Beauty--Everbearer, best everbearer for north central United States.
* Scarlet--Midseason variety for home gardens.
Strawberries fit into a crop rotation system when grown in the vegetable garden. Strawberries should not follow strawberries, tomatoes, peppers, or eggplants. These crops are all susceptible to verticillium wilt. Where wilt has been a problem, growers should use only disease-resistant varieties. The soil should be tested before planting. The best yields of strawberries, as seen in Figure 17-3, are obtained from new plants set new each year. Everbearers give the best crop the year they are planted. June bearers give the best crop the year after they are planted.
[FIGURE 17-3 OMITTED]
Growers purchase virus-free plants. Healthy strawberry plants have medium to large crowns and large root systems consisting of light colored roots. Plants with black roots are old and should not be planted.
Strawberries can be planted as soon as the soil can be worked in the spring. When the plants arrive, they should be unpacked and either planted or heeled in. Heeling in is the temporary planting of plants in a trench. Plants should not be left heeled in for longer than 2 to 3 weeks.
Strawberry plant crowns should be at soil level. If set too deep, the crown rots. The roots should not be allowed to dry out while the plants are waiting to be planted. Roots are spread out like a fan when planting then firm down the soil around them. The spacing depends on the training system used. Early spring planting promotes the formation of highly productive runner plants.
The most common system is the matted row because it is easy to establish. The plants are set at 2 feet in rows 3 to 4 feet apart. Plants should not be allowed to form too many runner plants. An overcrowded matted row produces small berries. The runner plants should be 4 to 6 inches apart with the matted row 15 to 18 inches wide. The finished rows should be about 18 inches apart. This system is used most with June bearers but it is the least productive training systems for strawberries.
In the hedgerow system, plants are set 15 to 18 inches apart in rows spaced 24 to 30 inches apart. Only two runners are allowed to grow, one from each side of the plant. The runners are trained to grow in line with the row, not out to the sides. In the double hedgerow system, each plant is allowed to form four runners that are placed diagonally from the row. Looking down on a double hedgerow system row it would look like a row of X's. The mother plant would be at the center of each X, and the runners would form the four arms. In either hedgerow system, the runner plants end up being about 1 foot apart. This system produces high-quality fruit but considerable time is spent getting it established.
To establish the spaced bed system, plants are set 24 to 36 inches apart in rows that are 42 to 48 inches apart. The runners are placed by hand to create a finished row that is 15 to 24 inches wide. Plants are spaced 8 inches apart, and after the bed is filled, all other runners are removed. A great deal of labor is involved in this system. Once established the planting must be gone over to remove surplus runners. The spaced bed system produces larger berries and higher yield than the matted row.
The hill system is used for everbearers. Plants are set 12 to 15 inches apart. Because all runners are removed, three rows can grow together to form one large row. The three rows are spaced 1 foot apart. Growers stagger the plants so they do not line up across the row. Space the triple rows 2 feet apart. All the runners are removed before they are 2 weeks old. This system produces the maximum size berries.
Before planting, build up soil organic matter. Well-rotted manure is good for strawberries. Ten days after planting, growers fertilize with 12-12-12 at the rate of 2 to 3 pounds per 100 feet of row. The application is repeated in four to six weeks. Fertilizer should not be more than 4 inches away from the crown. Fertilizer can be broadcast over a row if the foliage is dry. Applying too much nitrogen causes the plants to make excessive leaf growth and causes soft berries that rot easily. Too much nitrogen will also delay ripening.
Bearing beds should not be fertilized in the spring. Growers wait until after the berries are harvested.
Removing Flower Stalks on New Plants
The flower stalks should be removed from new plantings. Stalks are removed as soon as they appear until the first of July. Allowing the plants to set fruit reduces the amount of runner formation. This reduces the number of plants thus reducing the yield the following year. Varieties that form many runners may only need the flower stalks removed until the plants are established. Blossoms are taken off everbearing varieties for the first 60 to 80 days, and then the plants can be allowed to set fruit. There is no benefit gained by allowing the fruit to form and then not picking it.
In home plantings, the primary weed control methods are shallow cultivation and hoeing. Problem perennial weeds are killed with herbicides before planting the strawberries. Mulching will help control weeds. Chemicals may control some weeds in strawberry plantings.
Mulching strawberry plantings is strongly recommended. The mulch provides winter protection, eliminates dirty berries, delays blooming, reduces weed growth, conserves moisture, and decreases fruit rot. Mulch for winter protection is applied when the temperature is consistently about 20[degrees]F, normally in November. Plants may be damaged if the mulch is applied too early or too late. If applied to early, a number of warm days may injure the plants. If applied too late, some crown injury may occur due to cold temperatures. Crown injury occurs at temperatures below 20[degrees]F. The mulch should be put on before the ground freezes. A 2- to 3-inch layer of straw or hay may be used for mulch material. A 1-inch layer of sawdust may be used. The mulch should be left on as long as possible to delay bloom in the spring. Check the plants often. When the leaves begin to grow yellowish green, growers remove the mulch. The plants will grow through a thin layer of mulch.
Strawberries need generous watering during and immediately following bloom. If the plants get too dry while developing fruit, the fruits will be smaller than they should be. Daytime waterings should be about 1 to 1 1/2 inches of water per week. This includes any rain that occurs during the week.
Sprinkling can be used for frost protection. As water freezes on the plants it gives up heat. This heat can prevent plant injury even though they will be covered with ice. Sprinkling provides protection down to 22[degrees]F. Sprinklers are started as soon as the temperature at plant level reaches 32[degrees]F. The sprinklers will have to run as long as there is ice on the plants. Once all the ice has melted, the sprinklers may be turned off. Another method of frost protection is covering the plants with the recently removed winter protective mulch.
The first ripe berries appear about 30 days after the first blossoms open. Hot weather hastens ripening, shortens the harvest season, and makes frequent picking necessary. In moderate weather harvesting, every other day should be sufficient. In hot weather, it may be necessary to harvest every day. Growers pick the berries in the morning when they are cool, and harvest only the ripe berries at a single picking. Berries to be frozen should be left on the plants until fully mature. When harvesting, diseased, rotted, or injured berries should be picked and thrown away to help control rots.
Renovating the Bed
A strawberry bed may last only two to three years. The best year will be the first year after planting, but by the third year the yield will be down by about two-thirds. A strawberry patch should be renovated only if the plants are vigorous and healthy. The first step, once harvest is done, is to mow off the foliage about 1/2 inch above the crown. The plant crowns are injured if the mower setting is too low. Then the rows are narrowed down 10 to 12 inches and thinned, leaving only the most vigorous looking plants.
For renovation to succeed, it must be done right after harvest. After renovation, manage the bed just as though it were a new planting. If the mowing and renovation is delayed too long, yields the next year will be reduced. The yearly application of fertilizer should be put on right after renovation.
The lowbush blueberry is the low growing type that grows wild. The highbush blueberry is the type usually planted in commercial plantings. This information applies to the highbush blueberry. Blueberries, shown in Figure 17-4, do not need cross-pollination in order to produce a crop. Some varieties are: Bluecrop, Bluejay, Rubel, and Jersey. Grow varieties that mature at different times to prolong the harvest.
Highbush blueberry needs an average growing season of 160 days and is badly injured by temperatures of 20[degrees] to 25[degrees]F.
A loose soil is best. A mixture of sand and peat gives excellent results. Heavier textured soils are suitable if acidic and high in organic matter. Peat soils may stimulate late growth that fails to harden before winter or such soils are often in frost pockets. Blueberries must have an acid soil with a pH between 4.0 and 5.1. The pH can be lowered with applications of sulfur. If the pH is very high, it may not be practical to try to lower the pH. A soil with a constant moisture supply is best. The water table should be within 14 to 22 inches of the soil surface most of the time, but good surface drainage is needed.
[FIGURE 17-4 OMITTED]
Good air drainage reduces frost injury and helps control diseases. Problem weeds should be controlled before the blueberries are planted. Unless a home gardener has almost ideal conditions for blueberries, it may be wise to grow some other fruit.
The best planting stock is two or three years old. The three-year-old stock usually costs more. The best planting time is early spring. Set the plants 4 feet apart in rows 10 feet apart. The plants should be set about 2 inches deeper than they were growing in the nursery. Growers can mix a shovelful of acid peat into each hole at planting time if the soil is sandy and low in organic matter.
Blueberries are shallow rooted so cultivation should be no deeper than 2 to 3 inches. A cover crop may be sown after harvest.
Most organic materials may be used, but they should be allowed to weather before being applied to the blueberries. The mulch should be about 6 to 8 inches deep. Until the mulch has decomposed, the amount of nitrogen should be doubled. Leguminous mulches such as clover or soybean vines may be harmful.
Growers avoid using nitrate forms of nitrogen and chloride forms of potassium. The nitrate and chloride may be toxic to blueberries. Growers use a blueberry fertilizer such as 16-8-8-4. The 4 refers to magnesium. New plants should be fertilized four weeks after planting. Established blueberries are fertilized in April before growth starts. The fertilizer should be spread evenly and kept off wet plants to prevent injury. A very sandy soil may need a second fertilization. A foliar analysis may be helpful in identifying specific nutritional needs.
Fruit is produced on the previous season's wood. New plantings need no pruning until about the third year. Growers prune during the dormant season to remove the small twiggy growth near the base of the plant. After the third year, growers remove dead or injured branches, fruiting branches close to the ground, spindly bushy twigs on mature branches, and older stems of low vigor. Heavier pruning yields larger berries but fewer of them. Old black canes are removed at ground level.
Blueberries need 1 to 2 inches of water at 10-day intervals during dry weather.
Blueberries ripen over a period of several weeks. Three to five pickings are needed to harvest all the berries. Pick only the ripe berries. A reddish tinge means the berry is not yet ripe.
Diseases and pests of blueberries include mummy berry, other fungal diseases, scale insects, plum curculio, fruit worms, leaf hoppers, and the blueberry maggot. Occurrence of these depends on location. These can be controlled with insecticides and fungicides.
Red raspberries are considered a bramble. Other brambles include the loganberry, boysenberry, dewberry, and tayberry. Once established, a red raspberry planting should produce over a number of years, as shown in Figure 17-5. The most productive years are usually the third through the sixth.
[FIGURE 17-5 OMITTED]
Some varieties include: Latham, Heritage, Fall Gold, Taylor, September, Amber, Canby, Fall Red, Golden Queen, Hilton, Sentry, and Newburgh. Sodus and Clyde are varieties of purple raspberries. Black raspberry varieties include: Logan (New Logan), Cumberland, Allen, Bristol, and Huron.
A site with some slope to aid water and air drainage is preferred. Protection from wind will help. The junction of the cane and crown is quite weak so strong winds may cause the cane to fall over, especially if the cane is carrying a heavy fruit load. If protection cannot be provided, a trellis will support the plants.
When possible, red raspberries should be 300 feet away from other cultivated or wild raspberries to help control virus disease. Raspberries should not follow tomatoes, eggplants, potatoes, peppers, and other raspberries. These crops are susceptible to verticillium wilt, a soilborne disease that builds up if susceptible crops are grown. Black and purple raspberries are most susceptible.
The best soil is a well-drained, slightly acid loam or clay loam although raspberries are fairly tolerant. Growers avoid sites with a subsoil that prevents good drainage or good root penetration.
Herbicides control problem perennial weeds before the raspberries are planted.
Red raspberries can be planted in early spring as soon as the soil can be worked. When the plants arrive from the nursery they need to be kept cool or, if they cannot be planted right away, they should be heeled in or stored. If stored, the storage area should have a temperature of about 35[degrees]F.
The plant spacing depends on which of the several possible training systems is used. During planting, the plants should not dry out and plant them about 1 inch deeper than they were growing at in the nursery. The portion of the stem that was below ground is a different color. The hole should be big enough to allow the roots to spread out normally. The soil is firmed around the roots and the tops are cut back to about 6 inches. Cutting back may be done before or after planting. There can be a heavy loss of newly planted raspberry plants, but suckers produced by the surviving plants can be used to fill in gaps.
The hedgerow is the most common system for growing red raspberries. The plants are set 2 1/2 to 3 feet apart in rows from 6 to 10 feet apart. Where space is limited, use closer spacings. Suckers will fill in the row, but do not allow rows to get wider than 1 to 1 1/2 feet. Wider rows are more difficult to spray and harvest. A two-wire trellis, with one wire running down each side of the row can be used on windy sites. A single wire, running down the middle of the row and to which plants are tied, may also be used. Everbearing varieties especially need support.
To establish the hill system, plants are set 5 to 6 feet apart in rows 5 to 6 feet apart. A stake is driven into the ground next to each plant. As the plant produces suckers, five to eight healthy, vigorous suckers spaced at intervals around the stake are kept. The canes produced by the suckers are tied to the stake with two or three ties during the spring pruning. The tied suckers form a roughly triangular outline. The canes are cut back to the height of the stake in the spring.
The linear system is established just as is the hedgerow system. The only difference is that all the suckers produced by the plants are removed. The new fruiting canes come from the plant crown and are not suckers. The suckers come up at a distance from the plants. The crown shoots all arise from the plant crowns.
Growers fertilize 10 to 14 days after planting. Fertilizer should be 3 to 4 inches from the shoots and canes. The second year fertilization can be increased. After the last cultivation, a cover crop may be sown. Any annual crop, such as oats or Sudan grass, which dies during the winter, may be used.
Raspberries use much water, especially when fruiting. They need about 1 inch of water per week and perhaps more during hot windy weather. A lack of water is a serious problem during the time from just before fruiting through the fruiting period. Watering is most critical from the time the fruit begin to show color until picking has been completed. A good water supply in late summer enhances cane vigor and enhances productivity in the following year. Water raspberries during the day.
Cultivation controls weeds but should not be deeper than 3 to 4 inches to avoid injuring raspberry roots. Growers cultivate until harvest, then once or twice after harvest. Herbicides labeled for use on raspberries may also be used.
Red raspberries are pruned when dormant and after canes have fruited. The canes are biennial so a cane emerges and grows during one year then bears a crop of berries and dies the following year. The exception would be everbearers. Remove canes that have fruited right after harvest. The early removal of these canes may help control pest problems and maximize the water and nutrients available to new canes. Everbearers produce a crop during the late summer and fall of the same year. The same canes have a crop the following spring but it is not as large as the fall crop. The cane dies after the spring crop is harvested and can be removed. This gives growers an opportunity to do different types of pruning. If the large, fall crop is enough to satisfy family needs, the canes can be cut to the ground during the winter or early spring. This effectively eliminates the spring crop. It also eliminates doing both an after harvest and a dormant pruning. Only one pruning will be needed. If the second crop is wanted, prune off any winter killed cane tips during the dormant season. Remove canes completely when they have finished bearing the spring crop.
Other types of red raspberries need a dormant pruning to remove weak or damaged canes. In the linear or hill systems thin the canes to six to eight per hill. In the hedgerow, the canes should be spaced 8 inches apart. In the hill and linear systems, shorten the canes to about 5 1/2 feet. In the hedgerow system, shorten the canes to 4 feet. If the canes are shorter than these heights, take off only the portion that has been winter injured. Dormant pruning is done before the buds swell in the spring. If pruned too early, winter kill may reduce the height further. Dormant pruning reduces the number of suckers to keep the rows from becoming jungles.
Insects are not usually as destructive to raspberries and other bramble fruits as are diseases. Control of disease introduction is most important, but some spraying may be necessary depending on location. Growers should consult a local county extension agent or university for details on spraying and controlling diseases in their location.
The two types of blackberries are erect and trailing. The trailing blackberry is also called dewberry. These are usually tied to trellises and ripen earlier than the erect types.
Trailing varieties may not be as hardy as the erect types in some climates. Lucretia is a trailing blackberry variety. Some erect blackberry varieties include: Alfred, Baily, Darrow, and Hedrick (see Figure 17-6).
[FIGURE 17-6 OMITTED]
A good moisture supply is needed, especially when the fruits are ripening. If the site is low or poorly drained, winter hardiness of the plants is reduced.
The erect types are propagated by suckers or root cuttings with root cuttings preferred. Trailing types may be propagated from root cuttings or tip layers. Thornless varieties only come from tip layers.
Plants that cannot be planted immediately can be heeled in. If the plants are dry, soak them in water for several hours prior to planting. Before or just after planting, cut the tops back to 6 inches. The planting depth should be the same as it was in the nursery. Plant erect types 5 feet apart in rows 8 feet apart with trailing varieties 4 to 6 feet apart in rows 8 feet apart. Vigorous trailing varieties are spaced at 8- to 12-foot spacings in rows 10 feet apart.
Erect blackberries are most easily trained to a single wire suspended 30 inches from the ground. As canes grow, they are tied to the wire when they cross it. The trailing types are trained to a two wire trellis. The first wire is 3 feet from the ground, and the second wire is 5 feet from the ground. The canes are tied horizontally along the wire or the canes are fanned out then tied to a wire where they cross. Sometimes the canes fruiting this year are tied on one wire and canes fruiting the following year are tied on the other wire.
The cane tips of erect blackberries are pinched out in summer when the canes are 30 to 36 inches tall. The pinching stimulates the formation of laterals. In winter, cut the laterals back to 12 inches. Fruiting canes are removed once the crop has been harvested. When the fruiting canes are being removed, thin out the new canes. Leave three to four new canes on each plant or five to six canes per linear foot or row. Remove all suckers that appear between the rows.
Pruning trailing types is not as complicated. When the fruit have been harvested, remove the canes that produced the crop. At the same time, thin the new canes. Leave 8 to 12 canes or if the variety is semitrailing leave 4 to 8 canes.
Blackberries are fertilized when they blossom. Growers use 5-10-5 fertilizer at 5 to 10 pounds per 50 feet of row.
Cultivation is the primary means of weed control. Growers cultivate only 2 to 3 inches deep near the row, and stop cultivating about a month before freezing weather arrives.
Currant and Gooseberry
Currants and gooseberries cannot be planted in some areas unless a permit is obtained because black currants can be a host to white pine blister rust. A planting of currants or gooseberries should last for 10 to 12 years.
Some red currant varieties include: Red Lake, Wilder, Cascade, Prince Albert, and Viking. White grape is a white currant variety.
Two types of gooseberries are available--American and European. The European varieties have larger and more flavorful fruits. The American varieties are healthier and hardier. American gooseberry varieties are Downing, Houghton, and Poorman. European gooseberry varieties include: Fredonia, Chautauqua, and Industry.
Currants and gooseberries prefer cool moist growing conditions. The soil should be well drained and high in organic matter avoiding light sandy soil. A dry soil may cause premature leaf drop on gooseberries causing the fruit to sunscald due to lack of shading. Gooseberries like a partially shaded growing area. Select a site with good air circulation and avoid frost pockets.
Growers control any problem perennial weeds before planting. The soil should be worked the fall before planting and if available work in well-rotted manure in the fall or early spring prior to planting. Fall planting right after the plants go dormant is best. Spring planting will have to be very early, as currants and gooseberries are quick to begin growth. Use one- or two-year-old plants and space them 4 to 5 feet apart in rows 8 to 11 feet apart. Remove any broken or injured roots or branches. Prune the top to within 6 to 10 inches of the ground. Set the plants so the lowest branch is just below the soil surface. Make sure the soil is firmed down around the roots.
Cultivation and Mulching
Cultivation should be shallow and continued until the harvest is completed. Mulches may be used as a substitute for cultivation, however, a 6-inch layer of mulch can attract mice. Any natural material may be used as a mulch.
The best fertilizer for currants and gooseberries is manure. If applied annually, the plants will be productive. On infertile soil, use a fertilizer with a 1:1:1 ratio such as 12-12-12. Fertilize in the fall after growth stops or in the spring before growth starts. If fresh sawdust or straw are used as a mulch, double the fertilizer rates the year the mulch is applied.
Growers prune when the plants are dormant in late winter or early spring. At the end of the first season, remove all but six or eight of the most vigorous shoots. At the end of the second season, leave four or five one-year shoots and three to four of the two-year shoots. At the end of the third season, leave three to four first-, second-, and third-year shoots. Each plant should have a total of nine to twelve canes.
Prune older plants so they have six to ten fruiting canes and three to four replacement canes. Leave only enough new canes to replace the older canes that are removed. Wood older than 3 years produces inferior fruit. Remove all branches that lie on the ground. The center of the bush should be fairly open.
Harvesting may last over a period of time as long as a month.
National Grower/Horticultural Organizations
The following organizations address growers' concerns nationwide through dialogue, annual meetings, and publications.
* North American Bramble Growers Association. c/o Harry J. Swartz, Department of Horticulture, University of Maryland, College Park, MD 20742.
* North American Strawberry Growers Association. P.O. Box 1245, Tarpon Springs, FL 34688.
1. Grapes, blueberries, strawberries, and brambles are considered small fruits.
2. Brambles include red, black, and purple raspberries, and the erect and trailing blackberries. Also included as brambles are loganberry, boysenberry, dewberry, and tayberry.
3. Small fruits are grown in a variety of locations and climates, depending on the type. Many are able to grow in cooler climates.
4. Small fruits require a wide variety of cultural practices, depending on type, use, and location.
5. Small fruits are propagated by asexual methods.
6. After harvesting, which is often by hand, the small fruits may be eaten fresh, preserved, or further processed.
Something to Think About
1. How often should red raspberries be picked?
2. Describe two trellis types used in grape production.
3. What is the best test for ripeness in table grapes?
4. What type of use can be made of the new day neutral everbearing strawberries?
5. Why should strawberries not be planted in soil recently planted with tomatoes, potatoes, peppers, or eggplants?
6. What is the best pH range for the cultivation of blueberries?
7. How can root rot of blueberries be prevented?
8. Why are blueberries pruned?
9. List the three main soil requirements for highbush blueberry production.
10. Identify the two types of commercially grown blueberries.
11. List five key points to consider when selecting a site for brambles.
12. Describe the characteristics of ripe grapes.
13. What is the best site for a vineyard?
14. Discuss eight steps for better strawberry yields.
15. Diagram four planting systems for strawberries.
16. Name seven points to consider when selecting a strawberry variety.
17. Outline a fertilizer and pruning program for bramble fruits.
18. Identify seven measures for disease prevention in bramble fruit planting.
Adams, C. R., and M. P. Early. 2004. Principles of Horticulture. 4th Ed. Boston, MA: Butterworth-Heinemann.
Eck, P. 1988. Blueberry science. New Brunswick, NJ: Rutgers University Press.
Ellis, M. A., R. H. Converse, R. N. Williams, and B. Williamson, Eds. 1991. Compendium of raspberry and blackberry diseases and insects. St Paul, MN: American Phytopathological Society.
Jennings, D. L. 1988. Raspberries and blackberries: Their breeding diseases and growth. San Diego, CA: Academic Press Limited.
Maas, J. L., Ed. 1998. Compendium of strawberry diseases. St Paul, MN: American Phytopathological Society.
Pearson, R. C., and A. C. Goheen. 1988. Compendium of grape diseases. St Paul, MN: American Phytopathological Society.
Poincelot, R. P. 2004. Sustainable Horticulture: Today and Tomorrow. Englewood Cliffs, NJ: Prentice Hall.
Pritts, M., and A. Dale. 1989 Day-neutral strawberry production guide. (Inf. Bull. 215). Ithaca, NY: Cornell Cooperative Extension.
Reader's Digest. 2003. Illustrated guide to gardening. Pleasantville, NY: The Reader's Digest Association.
Rieger, M. 2006. Introduction to Fruit Crops. Binghamton, NY: Food Products Press.
Internet sites represent a vast resource of information. The URLs for Web sites can change. Using one of the search engines on the Internet, such as Google, Yahoo!, Ask.com, or MSN Live Search, find more information by searching for these words or phrases: grapes, strawberries, blueberries, brambles, raspberries, blackberries, small fruits, loganberry, boysenberry, dewberry, tayberry, and vineyards.
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|Title Annotation:||PART 5: Plants and Society|
|Publication:||Fundamentals of Plant Science|
|Date:||Jan 1, 2009|
|Previous Article:||Chapter 16: Vegetables.|
|Next Article:||Chapter 18: Fruit and nut production.|