The influence of cultivar and orchard system on pruning time per tree, per hectare, and per unit of yield

摘要

In 1990 an NC-140 Orchard Systems Trial was established near Blacksburg, VA. The trial had four replications of ten orchard systems, which were combinations of three training systems and several rootstocks. The training systems were Slender Spindle (SS) planted at 2460 trees/ha, Vertical Axe (VA) planted at 1502 trees/ha, and Central Leader (CL) planted at 1111 trees/ha. Rootstocks used with each system were: SS: Budagovsky 9 (B.9), Mailing 9EMLA (M.9EMLA), and Mark; VA: M.9EMLA, M.26EMLA, Ottawa 3 (0.3), Polish 1 (P.1), and Mark; CL: M.26EMLA and Mark. From 1996/1997 through 1998/1999, the time required to prune each plot (same two people each year) was recorded. Pruning times for the winters of 1996/1997 through 1998/1999 were related to yields from these plots from 1997-1999. Yields per tree and per hectare, pruning time per tree and per hectare, kg of fruit per min of pruning time, and estimated cost of pruning per box of fruit all varied with cultivar as well as system. Only estimated pruning costs per box of fruit and pruning time per hectare had a significant interaction between system and cultivar. Compared to 'Empire', 'Delicious' yielded less per tree and per hectare, required more time to prune, and yielded less fruit per minute of pruning with the result that estimated pruning costs per box were 76% higher. Pruning time per tree was lowest for SS/Mark, CL/Mark, and VA/Mark and highest for VA/P.1. Pruning costs per 19.05 kg box of 'Empire' and 'Delicious' ranged from $0.11 and $0.14 for CL/Mark to $0.31 and $0.66 for VA/P.1, respectively.