Effects of summer and dormant pruning time on the vegetative growth, yield, fruit quality and carbohydrate contents of two peach cultivars

Abstract

Mature “Earlyred” and Glohaven” peach [Prunus persica (L.) Batsch] trees on peach seedling rootstocks were dormant and summer pruned (June, July, August and September). Average shoot length was lower in the second year than in first year; whereas, shoot diameter was higher in the second year than in first year. Summer pruning treatments reduced shoot growth, but increased shoot diameter. Generally, the control and dormant pruned trees had the highest trunk cross-sectional area (TCSA) increment and yield efficiency (yield per trunk cross-sectional area). Summer pruned trees had a higher average fruit weight and soluble solids content than dormant pruned or control trees but at the two experimental years, fruit acidity showed no consistent response to pruning treatments. Dormant and summer pruning treatments had different effects on carbohydrate contents of peach trees. Generally, control and dormant pruned trees had higher carbohydrate content than summer pruned trees. Earlier summer pruning (June or July) lowered carbohydrate content more than late summer pruning. Key words: Peach, Prunus persica, pruning, dormant pruning, summer pruning, carbohydrate contents.