A common comment heard at the produce auction – “We need more berries!” Growers and buyers alike recognize the need. In addition to great market demand, these crops (strawberries, blackberries, blueberries, raspberries) are valuable crops, with a reliably profitable return for growers. Tunnel production offers potential to extend the harvest season earlier and later for berries, and in some cases can allow production in regions otherwise illsuited for certain berries (raspberries in southern Missouri, blackberries in northern Missouri). The establishment and maintenance costs for these crops are affordable, especially when compared to tree fruits or grapes. Equipment needs are similar to those used for vegetable production.
Berries have many of the same cultural requirements as vegetables a site with full sun; moderately fertile, well-drained soil; and an adequate supply of water for irrigation. Site preparation is also similar – remove perennial weeds, apply soil nutrient amendments and organic matter as guided by a soil test, and consider cover crops in advance of planting. Berms or raised ridges can greatly benefit berry crops – a berry berm is typically 2-3 feet wide and 12-18 inches high.
As is the case with vegetables, berries are usually hand harvested. Berries are perishable, and must be promptly cooled and held under refrigeration to preserve quality and shelf life. Berries for sale at produce auctions are often packaged in ½ pint, pint, and quart containers, typically plastic clam shells. The clam shells are packed in cardboard flats that have 6, 8, or 12 containers.
Pest management with berry crops, though generally less intense than for tree fruits or grapes, recently was complicated by the arrival in Missouri of the spotted wing drosophila (SWD), a tiny fruit fly that attacks berries as the fruit ripens. The resulting tiny white larvae within the fruit are a serious problem for growers and consumers alike. Initial observations in Missouri (confirmed by experience elsewhere) suggest that SWD overwinters in small numbers, and populations build during the spring until reaching damaging numbers in late June and July. Junebearing strawberry, early ripening blueberry, and early ripening floricane blackberries and raspberries may escape serious damage. Later ripening berries are at risk. Management at present is focused on trapping to monitor SWD populations, and the consistent, frequent application of insecticides to the fruit near harvest that target the adult fly. Details on labeled insecticides (both organic and inorganic) are found in the Midwest Small Fruit and Grape Spray Guide. Additional information on SWD, including assistance with trap construction and use, as well as SWD identification, is available from the Lincoln University IPM program.
Blueberry plants are hardy and consistent producers of tasty fruit, which ripens in June and July. A planting may remain in profitable production for 20 years or more. The fruit is less perishable than other berries, and fruit that is promptly chilled and properly stored can have a 7 day shelf life. With the exception of SWD and birds, pest management is reduced compared to other fruits and many vegetables. On the negative side, blueberries may require additional site preparation to lower soil pH and raise organic matter level.
Strawberry offers potential for field and tunnel production. June bearing or short day strawberries ripen in May and early June (or as early as late April in tunnels), and day neutral strawberries produce fruit through the summer and fall (except during hot periods). Shelf life is shorter than blueberry (3-5 days), but better than brambles. Junebearing strawberries may ripen before SWD populations build to damaging levels, but the later day neutral harvest will be at risk. Strawberries are commonly grown as a perennial crop (matted row); annual plasticulture offer potentially greater yields of good quality fruit, though the input costs are also greater.
Brambles (raspberry and blackberry) are available in either floricane (single crop) or primocane (double crop) types. Field plantings typically produce profitable crops for 8-10 years. Tunnels offer huge potential for brambles - raspberries in particular respond well to tunnel production, especially in warmer climates; blackberry production is now possible in colder climates in tunnels. SWD is a serious problem with the primocane (late summer-fall) bramble crop, and can attack the floricane (late spring-summer) crop as well. Tunnel growers are exploring the use of screening to exclude SWD from tunnels. Bramble fruit is quite perishable (2-3 days) and growers must market fruit promptly.
REVISED: November 20, 2015