Effects of pruning on 'Climax' rabbiteye blueberry

‘Climax’ rabbiteye blueberry (Vaccinium ashei Reade) with excessive fruit set often exhibits delayed vegetative bud emergence. A four year study was initiated to determine if spring fruit removal or pruning would enhance vegetative bud initiation and growth and if these one- time treatments would influence plant growth and fruiting characteristics over an extended period of time. Five methods of fruit removal/pruning were applied once in the spring of 1997. Removal was accomplished by 1) Cane removal, about 25% of plant density removed by cutting older canes from the base of the plant; 2) 25% Topping (T25), mechanical removal of approximately 25% of the plant top; 3) 50% Topping (T50); 4) Fruit removal, about 25% of green fruit removed; and 5) Control. By June 26, 1997, shoot number per stem and total shoot length had increased linearly with increased plant top removal. Plants with canes or fruit removed did not leaf out sooner or have vegetative growth greater than unpruned plants. In 1997, T50 plants produced one half the fruit yield of the control plants, while T25 plants showed no difference from the control plants in fruit yield. Plant top removal (either 25 or 50%) in the spring of 1997 resulted in increased vegetative coverage in 1998 and 1999. This influence was less in 1999 than in 1998. In 1998 floral bud development was delayed approximately 4-6 days in plants with either 25 or 50% of tops removed as compared to control plants. In that year, fruit yields were highest (approx. 2X control) in plants topped at 50%. Plants with 25% of their tops removed did not differ from control plants.. Regardless of treatments and resulting yields, berry size did not significantly differ in any year. Removing approximately 50% of the plant top resulted highest fruit yields of all treatments the second and third year after pruning. In 1998, and 99, ‘Climax’ plants were pruned on 3 dates (Mid-Feb, Mid-Mar, and Mid-April; 0 and 25% flower/fruit removal) to simulate late-freeze damage. One year after treatment, bud development and vegetative cover ratings were taken. Fruit yields were taken the year pruning treatment were applied and each succeeding year. Data taken in 1998, 1999, and 2000 shows no significant patters of vegetative growth, floral bud development, or fruit yields due to treatments. Data indicate vegetative growth in ‘Climax’ rabbiteye blueberries can be accelerated by removing about 25% of the plant top without reducing fruit yield.