 |
|
 |
  |
|
Raspberries and blackberries are the group of cultivated fruit crops referred to as brambles. Raspberries and blackberries are distinguished in the following way: when picked, the white receptable (core) comes off with the blackberry fruit, whereas it remains attached to the raspberry plant. Considerations before Planting: Cultivar Selection: Many cultivars of raspberries and blackberries are available to the home grower. It is important to choose cultivars which can withstand the winter temperatures in your area. Also consider productivity, use, season of ripening and quality as well. The thornless blackberries are of marginal hardiness in the Northeast and should be planted only in a protected area. In addition, they are susceptible to rodent damage.
Site Selection and Soil: Brambles grow best on a sunny site in sandy loam soil. Although brambles tolerate a broad range of soil types, they require soil with good drainage. A common cause of death in brambles is the disease Phytophthora root rot, which tends to infect plants predisposed by "wet feet" - meaning there is standing water in the subsoil. In addition, excessive water, either on the soil surface or below, can be troublesome during winter when alternate freezing and thawing of surplus moisture in flat ground causes considerable damage from heaving. For this reason do not plant raspberries in sites where water accumulates after a rainfall or where the water table is within 4 feet of the soil surface. If this is not possible, plant raspberries on a raised bed at least 10 inches in height. Selecting a site somewhat higher than nearby land improves drainage and reduces the danger of cold injury and late spring frosts. Keeping the planting free of disease is most important for successful growth. Because the principal source of disease is wild brambles, choose a site far from woodlots and old fields and, if possible, destroy all wild brambles growing within 500 feet of your site. A previously cultivated site is best, but only if crops susceptible to the disease Verticillium wilt - raspberries, strawberries, tomatoes, potatoes, peppers or eggplants - have not grown there before. If you choose a new site, till the sod under and plan a cover crop one year before planting. Adequate moisture during the growing season is essential for good cane growth and fruit production, particularly during periods of drought. For ease of irrigation during the growing season, locate the planting near a water source. Early Care: Planting: Maintenance: Fertilization
and Irrigation: Irrigation will likely be required between bloom and harvest. When necessary, irrigate early in the day after plants have dried from morning dew. Plants which remain wet during warm nights are more susceptible to disease. Trickle irrigation is particularly suited to small fruit crops and is an effective and efficient way of using available water. Drip tubes, tricklers or emitters drip water continuously or intermittently into the root zone around the plant so that the plant receives as much water as it can use but no more. Inter-row spaces remain firm and dry, and the root zone remains moist at all times. Very little water is lost from evaporation, wind drift or too deep penetration. Cultivation: Cultivate the area between rows from early spring to mid-July to control weeds and eliminate suckers. To avoid injuring roots, cultivate no deeper than 2 inches. A grass strip can eventually be established between rows. Grass seed germinates best if seeded in September. Pruning Systems: Pruning has a major effect on the production of quality fruit. The systems used affect growth rate, fruit number, size, sweetness and susceptibility to diseases. Primocane Fruiting Raspberries: This type of raspberry plant produces fruit at the top of first year canes in late summer and on the lower portion of these same canes in early summer of the second year. Most growers choose to sacrifice the early summer crop in favor of a smaller but higher-quality late summer crop, because pruning is then easier and fruit quality is higher. When pruning primocane fruiting raspberry plants for a single late season crop, cut canes to the ground in early spring. Primocanes grow and fruit in late summer of the same year. It is important to cut old canes as close to the ground as possible so buds break from below the soil surface. Floricane Fruiting Raspberries and Blackberries: Floricane fruiting types produce buds on second year canes. Unlike primocane fruiting types, canes must remain intact throughout the winter and until the completion of harvest the second year. During second year flowering and fruiting, new canes are growing. These primocanes can interfere with spraying and harvesting, shade leaves and laterals of fruiting canes, and compete with floricanes for water because each shares a single root system. It is important to minimize this interference by proper pruning and trellising. The traditional method of management is to permit primocanes to grow through the season and fruit the next year, then cut them at ground level after fruiting. In early spring, the remaining canes are topped to a reasonable height and thinned to a desired number. Diseased or winter-damaged wood is removed. Another way to reduce plant interference and competition is to mow half of the planting alternately each year during the dormant season. During the spring after mowing, primocanes emerge and grow without interference from fruiting canes. The following year, the floricanes flower and fruit and are then cut to the ground. Advantages of this system are that cane thinning and pruning are not necessary and spray material costs are reduced. Disadvantages include a reduction in fruit quality, berry size and yield. A third alternative is to remove all but 4 or 5 primocanes per linear foot of row in June. With this system, primocanes are selected that will be carried into the following year for fruiting. Primocanes that are not selected are cut when they reach about 8 inches. Advantages of this system are that those primocanes not selected are removed when they are small and succulent rather than when they are large and thorny, and fruit size and production of the current season's crop are increased. Trellising: Many growers of primocane fruiting raspberries have found that a temporary trellis is necessary during the fall harvest season. One system that works well consists of T-shaped wooden or metal posts approximately 7 feet long with 3-foot crossarms. The end of each crossarm contains a screw eye or other device that holds a length of bailing twine, which is cheap and disposable yet strong enough to hold canes erect temporarily. Holes are dug 25 to 30 feet apart in the center of each row; they are 3 feet deep and slightly wider than the diameter of the bases of the posts. Immediately after the holes are dug, a 3-foot section of plastic pipe is set into each hole to maintain integrity. Near the time of harvest, the T-posts are inserted into the plastic-lined holes. After harvest, the twine is cut and the posts are removed and stored for another year. Because the plastic pipes are buried, they do not interfere with cane-cutting operations. Trellising of floricane fruiting raspberry and blackberry plants helps reduce primocane interference and improves production. Without trellising, fruiting canes must be cut short in the dormant season to prevent canes from breaking or tipping over. Because most of the fruit buds are on the top half of the cane, topping low can significantly reduce the productivity of a planting. Staking brambles in a hill is a trellis system that is occasionally used. Advantages are low cost, ease of harvest and suitability for two-way cultivation. The disadvantage is low yields per unit area. Trellising to a single wire 3 or 4 feet above the ground prevents cane breakage but allows only a small amount of light to reach the lower portions of canes and forces primocane growth toward the aisles; this growth can interfere significantly with spraying and harvesting. Cane interference can be reduced and yields increased by using a trellis that separates the fruiting canes from vegetative canes. One such system is the V-trellis. This trellis can be constructed with two sets of opposing posts; each placed into the ground at a 20 to 30-degree angle. Fruiting canes are tied to wires on the outside of the V in early spring; and primocanes are permitted to grow in the middle of the V. Spraying, harvesting and pruning are easier because floricanes are pulled to the outside where they are accessible and primocane interference is minimal. Thepresence of primocanes in the middle forces lateral growth outward. Yields of several raspberry cultivars have been increased using a V-trellis, primarily because the amount of light reaching the plant canopy is increased. A similar system can be constructed using two T-posts. Generally, the T-post requires an additional crossarm between the ground and upper arm to support the fruiting canes. The disadvantage of theT-trellis is that adjustments to accommodate annual variations in cane height are difficult to make. Although cane heights are estimated before constructing any trellis system, theV-trellis allows adjustments of the wire heights to be made at any time. Select trellis posts and anchors from readily available materials. Monofilament plastic wire, now the material of choice for trellis systems, is as strong as wire but much lighter and easier to handle. Inexpensive devices are available to hold the monofilment taut at the anchoring post and to rejoin lines that have accidentally been cut. When designing a trellis and choosing materials, keep in mind the potential 15-year life of the planting. Pruning Specifics: Different types of brambles require specific pruning treatments. Red Raspberries: Prune off winter-damaged tips in mid-March. Top canes as high as the trellis permits but below the point of winter injury. Tie canes loosely to the trellis wire to prevent wind damage. Leave 3 or 4 canes per linear foot of row when thinning out canes. Black Raspberries: Remove at least 4 inches of tip from primocanes when black raspberries reach a height of 24 inches. By the end of the season, primocanes will be branched with long laterals; these should be supported by trellis wires in winter to prevent breakage from snow. Shorten laterals in early spring to remove any winter-damaged wood and to maintain berry size. Leave 2 to 3 canes per linear foot of row when thinning out canes. Purple Raspberries: Vertical growth of purple raspberries is substantial. Primocane pinching will reduce cane height, but cane diseases may invade the wound left by pinching. To thin, leave 3 fruiting canes per linear foot of row. Thorny Blackberries: Tip primocanes when they reach a height of 3 to 4 feet to stiffen canes and induce lateral branching. Shorten lateral branches to 12 to 16 inches in early spring, and thin canes to 2 per linear foot of row. Alternate-year mowing helps avoid the difficult task of pruning. Thornless Blackberries: Shorten fruiting canes to the top trellis wire in early spring or weave around the wire. Shorten laterals to about 18 inches. Low-growing laterals are more easily protected during winter than upright canes. For good production maintain 6 to 8 canes per hill. Harvest: Raspberries do not keep well on the plant and must be harvested every 2 or 3 days. Expect a small crop the first year after planting. Everbearing reds may produce a small crop in fall of the planting year. Production reaches its peak the third year after planting and slowly declines in subsequent years. Many growers choose to replant a site after 10 years. To store raspberries for later use, proper post-harvest care is critical. Select only berries in good condition and immediately cool them to as close to 33 degrees F as possible. Wrap in plastic; allow them to come to room temperature before removing the plastic wrap to make sure condensation forms on the wrap, not on the berries.
The information
for this fact sheet was taken from: The Home Fruit Planting, Information
Bulletin 156,
|
