How to Grow Fruit & Berry Plants

How to Grow Fruit & Berry PlantsBlackberry and raspberry plants produce an aggregate fruit and are derived from many ovaries from a single flower. The major difference between blackberries and raspberries is that when blackberry fruit are consumed, the receptacle of the inflorescence (known as a torus) is also consumed. By contrast, raspberries when picked ripe for consumption have a hollow center since the receptacle remains on the cane. Raspberries are not generally recommended for the southeastern United States and are discussed only very briefly here. 'Dorman Red' is the only raspberry cultivar recommended for trial in Florida when grown as a perennial crop; however, berry flavor is poor to fair. 'Heritage' raspberry has been grown as an annual crop during the winter in southern parts of the state after it has received its chilling requirement.

Cultivars

'Apache' is an erect, thornless blackberry bush released by the University of Arkansas. In Arkansas, it produces higher yields and larger fruit than the other thornless cultivars, 'Arapaho' and 'Navaho'. 'Apache' produces a 10 g berry, which is the largest of the three thornless cultivars. Berries are conical in shape with a glossy black finish. Soluble solids average 10 Brix, and fruit firmness is acceptable and similar to that of 'Arapaho'. 'Apache' has not been adequately tested in North Florida, although it is expected to do well in areas where 'Arapaho' and 'Navaho' have done well. For additional information, consult Clark and Moore (1999a). 'Apache' is now under trial at the UF NFREC Quincy.

'Arapaho' is an erect, thornless blackberry bush released from the University of Arkansas breeding program (Moore and Clark 1993). It has good fruit quality and ripens before 'Apache' and 'Navaho'. It is moderately vigorous. Symptoms of rosette have not been observed. Yield characteristics in North Florida have been as follows: yield of 1.7 tons/acre, berry weight of 4.5 g, and soluble solids of 10 Brix. For additional information concerning the performance of 'Arapaho' in North Florida, consult Table 1. In Florida, it is likely only adapted to extreme North Florida. 'Arapaho' is now under trial at the UF NFREC Quincy.

'Brazos' is an erect, thorny blackberry cultivar released by the Texas Agricultural Experiment Station (Lewis 1959). Yields have generally been high in North Florida and South Georgia. The fruit are medium in size. Since fruit are high in acidity, 'Brazos' is mostly used for jams, jellies, and baking. 'Brazos' is self-fruitful and generally ripens from mid-May to late May. Rosette disease is a serious problem. This disease contributes to productivity loss in 'Brazos' blackberry plants with age.

'Chester' is a semi-erect, thornless blackberry that may require trellising. 'Chester' has a wide range of adaptability in the United States, but to our knowledge it has not been tested previously in Florida. 'Chester' reportedly produces a high yield. Berry size is medium large (about 5 g), and flavor is mild. Ripening date is July. 'Chester' is currently under trial in North Florida at the UF NFREC Quincy.

'Chickasaw' was released in 1999 by the University of Arkansas. It is an erect, thorny blackberry bush that is among the highest-yielding cultivars in Arkansas. Berries are long and cylindrical. Berry weight is about 7-10 g, and firmness is rated high. Berries are sweet, averaging about 9-10 Brix. Quantitative yield data are not available for Florida. 'Chickasaw' has better postharvest keeping quality than 'Shawnee'. For more information, refer to Clark and Moore (1999b).

'Choctaw' is an erect, thorny, high-yielding blackberry cultivar from the University of Arkansas. The fruit are medium in size (about 5 g) and moderately sweet in flavor. This cultivar is most noted for early ripening, small seed size, and good flavor. Consult Moore and Clark (1989a) for more information.

'Flordagrand' was released in 1964 by the University of Florida for home and local markets. Flordagrand is adapted to Central Florida, where it is evergreen in growth habit and requires a pollenizer. 'Flordagrand' has a trailing growth habit. The berries are oblong in shape, shiny black in color, and average just over 5 g. The berries are tart in favor (high in acidity), and soluble solids average 8 Brix. It is not often grown any longer. For more information, refer to Shoemaker et al. (1964).

'Kiowa' is a large-fruited, erect, thorny cultivar from the University of Arkansas breeding program. A large fruit size (> 10 g) is maintained throughout the season. It has good firmness and flavor. 'Kiowa' averages 10 Brix. For more information, consult Moore and Clark (1996). 'Kiowa' is now under trial at the UF NFREC Quincy.

'Natchez' is an erect, thornless blackberry recently released and patented by the University of Arkansas. 'Natchez' has produced very high yields in Arkansas and is expected to supplant or replace 'Arapaho'. Average berry weight is medium to high (5-8 g). Soluble solids average 8.7 Brix. Berries are very firm and attractive. 'Natchez' has not been tested previously in Florida, although it is currently under trial at the UF NFRE Quincy. For more information, consult Clark and Moore (2008).

'Navaho' is an erect, thornless blackberry cultivar from the University of Arkansas breeding program. Yields in Arkansas are moderate to high. In Florida, yields have been 1.8 tons/acre or slightly higher than that of 'Arapaho'. The berries are small to moderate in size (3.5-4 g) and moderately sweet in flavor (9 Brix). Disadvantages include late ripening and a prolonged ripening period. Consult Moore and Clark (1989b) for more information. 'Navaho' is now under trial at the UF NFREC Quincy.

'Oklawaha' was released by the University of Florida in 1964. It is semi-evergreen to evergreen and has a trailing growth habit. 'Oklawaha' requires trellising. It was released as a pollenizer for 'Flordagrand'. Similarly, 'Oklawaha' is self-unfruitful and requires a pollenizer. Berries are moderate in size. Soluble solids average about 8 Brix. It is not often grown any longer. Refer to Shoemaker and Westgate (1964) for more information.

'Ouachita' is an erect-growing, thornless cultivar released from the University of Arkansas breeding program (Clark and Moore 2005). It is expected to do well where 'Apache', 'Arapaho', and 'Navaho' have performed well. Desirable characteristics of 'Ouachita' include consistent high yields, large fruit size, and good postharvest keeping quality. Fruit averages about 10 Brix and is larger than that of 'Arapaho' and 'Navaho'; yields are comparable to 'Apache'. For more information, consult Clark and Moore (2005). 'Ouachita' is now under trial at the UF NFREC Quincy.

'Prime-Ark' is a recently (2009) patented cultivar from the University of Arkansas breeding program. This is one of three Arkansas cultivars that fruits on current-season primocanes (denoted by the prefix "Prime"). It is erect and thorny. Yields appear to be more consistent in diverse locations than 'Prime-Jim' or 'Prime-Jan'; however, temperatures above 85F can reduce fruit set and fruit quality on primocanes. Berries are medium large in size with an average of about 6 g. Soluble solids have been measured at 10"12Brix. For more information, consult Ruple et al. (2010).

'Prime-Jan' is a primocane-fruiting, erect, thorny cultivar that was released and patented by the University of Arkansas breeding program in 2004. Yield varies with location, and it has not been tested in Florida. There may be a fruit set problem with temperatures exceeding 85F; therefore, it is not likely well adapted for Florida. Average berry size is 5 g with a range from 3 to 15 g. Soluble solids average 9-10Brix. 'Prime-Jan' is only recommended for home garden use due to erratic yields, poor postharvest keeping quality, and shipping potential. For more information, consult Clark et al. (2005).

'Prime-Jim' is a primocane-fruiting, thorny, erect cultivar that was released by the University of Arkansas breeding program in 2004. Yield varies with location, and it has not been tested in Florida. There may be a fruit set problem with temperatures exceeding 85F; therefore, it is not likely well adapted for Florida. Fruit size is about 5 g but varies from 3 to 10 g. Soluble solids average 8Brix. 'Prime-Jim' is only recommended for home garden use due to erratic yields, poor postharvest keeping quality, and shipping potential. For more information, consult Clark et al. (2005).

'Shawnee' is a 1984 release from the University of Arkansas breeding program. It has a prolonged ripening period during which the fruit retain a large size throughout. This cultivar has largely been replaced by 'Choctaw,' 'Chickasaw,' and 'Kiowa'.

'Triple Crown' is a semi-erect, thornless blackberry that may require trellising. 'Triple Crown' is very productive with large, sweet berries. Berries are firm with a good sugar/acid balance. Ripening date is early July. 'Triple Crown' is grown in central and northern North America. To our knowledge, 'Triple Crown' has not been tested previously in Florida, but it is currently under trial at the UF NFREC Quincy.

'Tupi' is a thorny, semi-erect blackberry that was developed in Brazil and is the most common commercial blackberry cultivar in Mexico. In low-chilling areas of Mexico, flower bud development is promoted by chemical defoliation and application of gibberellic acid. 'Tupi' produces a large fruit with a good sugar/acid balance. 'Tupi' has not been tested previously in Florida, but is currently under trial at the UF NFREC Quincy.

Site Selection and Site Preparation

Ideally, a prospective commercial blackberry grower should select a site with good air and water drainage. Low-lying areas should be avoided to minimize the probability of flood injury during periods of excess rainfall and frost injury to flowers and newly developing fruit. Blossoms can be injured by temperatures below 28F. For the homeowner, site selection is often limited by availability and practicality. The site should be located conveniently to a source of water as the period of fruit ripening is often quite dry in many parts of the state. Hilltops often accord the grower improved air circulation during the growing season and can be a prime location if the soil has not been eroded by previous agricultural use.

Prior to planting, in-row strips about 5 feet wide can be treated with an herbicide such as glyphosate to kill all weeds and vegetation. In-row strips should be thoroughly disked to at least a depth of 1 foot. In some regions of the country, green manure crops are grown on the site and plowed under. Although blackberries do well in most soils, deep, well-drained soils are ideal. Blackberries perform best at a soil pH between 5.5 and 6.5. In general, to increase pH 1 unit, mix 5 lb of dolomitic lime with 100 square feet of soil. To decrease pH 1 unit, mix 1 lb of elemental sulfur with 100 square feet of soil. In addition, components of the irrigation system should be in place to provide water once the blackberries are planted. Drip irrigation, as compared to overhead irrigation, minimizes subsequent weed control efforts, which can be a substantial portion of the labor involved in cultivating blackberries. Polyethylene mulch or landscape fabric can serve as an excellent means of weed control.

Planting and Spacing

Planting is best performed from December through February. Upon arrival, bare-root plants should be kept moist but not wet. If these plants arrive prior to the anticipated planting date, they can be stored in the refrigerator (in small quantities) or heeled in a trench (in larger quantities) to stay moist. To heel plants in, simply dig a trench and cover the roots with damp soil. During planting, do not allow the blackberry roots to dry out. Cut back the shoots to about 6 inches in length and plant to the same depth they were in the nursery. Spread the roots around the hole, but try to avoid excessive root bending. Remove air pockets by compacting the soil.

Plant spacing is cultivar dependent. In general, erect cultivars and trailing blackberries are spaced from 2 to 4 feet apart and from 3 to 5 feet apart within a row, respectively. The spacing between rows can be 10-15 feet, depending on plant vigor and farm machinery limitations.

Pollination

Blackberry fruit is borne on the current year's growth with usually 10-20 flowers per cluster. Blackberries and raspberries are an aggregate fruit with individual pistils that form drupelets. To obtain a large, well-formed berry, most of the individual pistils in an inflorescence should be pollinated. Drupelets only form around fertilized ovules. Thus, berry size for a given cultivar is dependent on the number of seeds. Inadequate pollination results in smaller or imperfect fruit since not all seeds and drupelets are formed. Blackberries range from completely self-fruitful to completely self-unfruitful. Most erect blackberries (including all the Indian-named Arkansas blackberries) are self-fruitful and do not require a pollenizer. Blackberry flowers produce nectar and pollen that attract bees, which serve as pollinators. Honey derived from blackberry flowers is reported to be light in color with good flavor.

Bloom date for most cultivars is during early March, although 'Oklawaha' and 'Flordagrand' may bloom as early as mid-February. Bloom date tends to be earlier as one progresses farther south. Frost injury can be a problem in some locations. Open flowers can be injured by a temperature of 30F or less. Sprinkler irrigation can be employed to reduce the risk of freeze injury.





Blueberries

Blueberries are native to eastern North America. They are one of the few crop plants that originated here. The rabbiteye blueberry (Vaccinium ashei) occurs mostly in certain river valleys in northern Florida and southeastern Georgia. The highbush blueberry (Vaccinium corymbosum) is native in the eastern third of the United States and southeastern Canada. Florida is rich in other native Vaccinium species. The woods and swamps of Florida are populated with at least eight wild blueberry species. No area of the state lacks wild blueberries, except where soil pH is above 6.0.

A short-lived commercial blueberry industry was established in Florida over a century ago when wild rabbiteye blueberries were transplanted from the woods to cultivated fields. This may have been the first attempt to cultivate blueberries commercially anywhere in the world. However, the enterprise was short-lived because of poor fruit quality and marketing problems. During the next few decades there was little interest in commercial blueberry production in Florida. However, during the 1960s small plantings of rabbiteye blueberries were established for local consumption. During the 1960s and 1970s, rabbiteye blueberries were not planted in Florida for commercial harvest, packing and shipping because they flower late, have long fruit development periods and actually ripen later than highbush blueberries grown in North Carolina. After 1950, highbush acreage in North Carolina and the northern states expanded rapidly. These highbush varieties could not be grown in Florida because they had a high chilling requirement.

In 1976, the University of Florida blueberry breeding program released three new southern highbush blueberry varieties which were bred specifically for Florida's mild climate and showed promise for producing early-ripening, good quality fruit. By 1983, a small blueberry shipping industry was established in Florida. Because Florida's southern highbush blueberries ripen earlier than blueberries from other areas, they brought very high prices. High prices and ready markets have lead to expansion of Florida's blueberry acreage. Between 1982 and 2002 Florida blueberry acreage has increased from less than 1000 acres to approximately 2000 acres and additional plantings are anticipated. During the 1980s and early 1990s more than half of the Florida blueberry acreage consisted of rabbiteye varieties. During the last decade, most new plantings have been southern highbush varieties. Southern highbush varieties, on average, ripen 4 to 6 weeks earlier than rabbiteye varieties. Currently, well over half of the total Florida acreage is southern highbush and virtually all plantings established during the last 8 years for commercial shipping are southern highbush. A survey in 1999 indicated that about one-third of the total blueberry acreage in Florida was less than 3 years old. Many new southern highbush plantings have been established in the central Florida counties of Polk, Hillsborough, and Lake, while several large rabbiteye plantings in north and northwest Florida have been abandoned.

As many new southern highbush plantings have come into bearing, annual statewide blueberry production has steadily increased from about 1.5 million pounds in the early 1990s to over 3.5 million pounds in 2003. Fresh fruit prices have remained high for early-ripening southern highbush varieties. However, production problems have been many and severe. Although many aspects of blueberry growing in Florida are better understood than they were a decade ago, blueberries remain a difficult crop to grow in Florida.

The major incentive for growing blueberries in Florida is the excellent market window available for blueberries that ripen before May 20. In recent years, blueberries have been planted in the southern hemisphere for shipping to the northern hemisphere during the period from November to March. Southern highbush varieties are being planted along the Gulf Coast from south Georgia to east Texas and in California. Nevertheless, the market period from April 1 to May 10 is still available almost exclusively to Florida growers, and fruit prices are usually high until late May when harvest of the North Carolina crop begins.

Blueberry Varieties

Two types of blueberries are grown in Florida; southern highbush and rabbiteye. The earliest ripening southern highbush varieties ripen about 4 to 6 weeks earlier than the earliest rabbiteye varieties grown at the same location. Because they ripen earlier, southern highbush normally bring much higher prices than rabbiteye berries.

Rabbiteye blueberries grow best in regions of Florida where winters are as cold or colder than those in Ocala. Depending on the variety, southern highbush blueberries may be adapted from Sebring, Fla., up the Florida peninsula, into southeastern Georgia. Overhead irrigation for freeze protection is generally required for reliable fruiting of southern highbush blueberries because they flower so early. Cross pollination between, or among, varieties is needed for maximum production for both types of blueberries. Therefore, multiple varieties are needed of either southern highbush or rabbiteye. Rabbiteyes are needed to pollinate other rabbiteyes and southern highbush are needed to pollinate other southern highbush.

Southern Highbush Varieties. Southern highbush blueberries were developed by crossing northern highbush varieties from Michigan and New Jersey with wild blueberries native in Florida and other southeastern states. The first three southern highbush varieties were released from the University of Florida in the mid 1970s. Since then, many newer and improved southern highbush varieties have been released.

Southern highbush blueberries grown in peninsular Florida are the earliest blueberries to ripen in North America. These are the varieties that are currently grown for commercial shipping in Florida. Southern highbush blueberries are generally considered more difficult to grow than rabbiteyes. Very early flowering makes southern highbush blueberries quite susceptible to late winter/early spring freezes. Southern highbush blueberry plantings without overhead irrigation for frost protection frequently lose their crops as far south as Highlands County. Moreover, compared to rabbiteye varieties, southern highbush blueberries are less forgiving in soil requirements, more susceptible to excessive soil moisture and drought, and generally more susceptible to a number of diseases such as Phytophthora root rot and blueberry stem blight than are most rabbiteye varieties. Because of their early ripening season, southern highbush blueberries are particularly attractive to birds (especially cedar waxwings). Bird damage has been quite severe on some farms in some years. Prospective southern highbush growers should be aware of establishment costs such as freeze protection, which requires overhead irrigation, and soil preparation, which usually requires large quantities of pine bark.

Rabbiteye varieties. On suitable blueberry soils in north and north central Florida, rabbiteye blueberries are more vigorous, longer lived, and easier to care for than most southern highbush varieties. They are more drought tolerant than southern highbush blueberries and can grow satisfactorily in soils which are lower in organic matter. Currently, commercial rabbiteye blueberry production is not recommended for areas with winter temperatures milder than in Ocala because of the possibility of inadequate chilling. On the other hand, severe crop losses to spring freezes are not uncommon in north Florida, especially for early-season rabbiteyes which bloom before mid- to late-season rabbiteyes. For home gardeners and u-pick growers, late flowering varieties such as Powderblue and Brightwell usually produce good crops without freeze protection at most locations in northern Florida.

Rabbiteye fruit is generally firmer than southern highbush and, in many cases, they are capable of being mechanically harvested for the fresh market. However, berries of highbush and rabbiteye are enough alike that most consumers do not distinguish between the two. Generally, rabbiteyes are better suited for u-pick and local sales while southern highbush are better suited for commercial shipping. Rabbiteye blueberries grown in Florida can be divided into early-, mid-, and late-season varieties. Home gardeners and u-pick growers who do not require an early harvest season will find that mid- and late-eason varieties are more reliable in fruiting.

 

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