The Effects of Different Pruning Treatments on Seasonal Variation of Carbohydrates in 'Hacihaliloglu' Apricot Cultivar

Twelve-year-old apricot trees from the 'Hacihaliloglu' apricot cultivar were pruned in a series of five treatments. In all treatments, one-third of annual shoots (33.3%) were removed between 1999 and 2003. The chlorophyll a, chlorophyll b, total chlorophyll and carotenoid contents in leaves were determined. The starch, total sugar, reducing sugar and sucrose contents in shoots were also determined. In addition, seasonal variation of carbohydrates was studied. The treatments did not affect the carotenoid content of leaves, but they statistically affected the total chlorophyll content. The highest total chlorophyll content in leaves was 5.27 mg/g, and it was found in the post-harvest summer/winter pruning treatment. The highest average total sugar content (6.25%) was observed in the post-harvest summer pruning treatment, while the lowest (2.56%) was found in the post-harvest summer/winter and control treatments. The highest starch content (8.18%) was found in October from the post-harvest summer/winter treatment, whereas the lowest value (3.59%) was obtained in March from the winter pruning treatment. Summer pruning treatments promoted an accumulation of carbohydrates.