Growth and productivity of (anna) apple trees, Malus domestica borkh., following dormant pruning treatments

This investigation was carried out during three successive seasons (2007, 2008 and 2009) to study effect of different dormant pruning treatments on 5-years old (Anna)apple trees budded on (Malus) apple rootstock grown in El-Kawamel region, Sohag, where soil is sandy, under drip irrigation system determine the optimal degree of dormant pruning severity to increase yield and improve fruit qi Severe dormant pruning treatment (thinning out 60% of one -year-old shoots/tree) significantly decreased number of shoots/branch. In contrast, there were ,clear trends of increase in number of leaves/ specific leaf weight, leaf total chlorophyll content, total soluble sugars, starch percentage and carbohydrates as dormant pruning severity increased. All dormant pruning treatments affected number of flowers/branch, and the effect was decreased as severity of pruning increased. On the hand, the increase in the number of flowers/ spur was positively associated with pruning severity. (thinning out 20% of shoots/tree) and moderate (thinning out 40% of shoots/tree) dormant pruning treatments significantly increased the percentage of fruit set and improved yield (fruit weight/tree;)and the improvement was inversely proportional to the severity of pruning. Dormant pruning treat: increased average fruit weight, but decreased fruit firmness in respect to its severity in the three seasons All dormant pruning treatments affected total acidity and total starch % and the effect was decreased severity of pruning was increased, while the increase in total soluble solids and total sugars were positively associated with pruning severity. Severe and moderate (thinning out 60% and 40 shoots/tree) dormant pruning treatments significantly increased red color% and peel anthocyanin content From the results, it could be recommended that apple (Anna /Malus) growers should prune their trees moderately (by thinning out 40% of shoots/tree) to increase flowering and fruit set, which in turn increase yield and fruit quality.