Optimal Training of Apple Trees for High-density Plantings
An experiment was initiated at the Univ. of Kentucky Research and Education orchard, Princeton, Ky., to determine the training practices needed to obtain early production and optimal fruit size from trees trained to either the slender spindle or the French axe system on vigorous sites. One-hundred-eighty trees (five rows, 32 trees per row) of `Golden Delicious' on M.9 rootstock were planted in May 1997, in a randomized complete-block design with eight treatment combinations, consisting of two training systems and four levels of training intensity. Trunk circumference averaged 61 cm at planting and did not vary significantly among rootstocks. A trellis was constructed, and trickle irrigation was installed. All trees are currently alive. Each season, over half the total time spent training the trees was spent during the first 5 weeks the trees were trained. About 2 minutes per week was needed to train each tree during the first 5 weeks, but only 45 seconds per week was needed in the sixth through the 16th week. Trunk circumference, yield, and average weight per fruit did not vary significantly in the analysis of variance. Training per kilogram of fruit averaged 4.2 minutes.