FLOWERING AND FRUITING ON COMMAND IN BERRY CROPS

Many berry crops are managed by altering growth and environment in commercial production systems, to affect time of flowering and fruiting season. The effect of photoperiod, temperature, and production system on flower bud initiation and development is reviewed for strawberry, raspberry, blackberry and blueberry. While “flowering on command” is still a challenge, research and commercial production systems have been successful at scheduling fruit harvest for many of these crops. In strawberry and biennial cropping red raspberry, pre-conditioned plants, grown to maximize flower bud development, are commonly used along with staggered planting dates (often in tunnels) to time fruit harvest date. In primocane-fruiting raspberry, annual production systems with staggered planting dates, often in combination with pruning techniques, are used to target market windows. This system of production shows promise with primocane-fruiting blackberry. In southern highbush blueberry, cultivars are grown in warm regions using evergreening systems, pruning, and fertilization methods, to produce fruit at desired times. With a good understanding of plant physiology and the factors that affect flower bud initiation and development, bud break, and the production of high-quality fruit, it is possible to manipulate many berry crops to have fruit production target desirable market windows.