CROP-LOAD EFFECTS ON VEGETATIVE GROWTH, MINERAL NUTRIENT CONCENTRATION AND LEAF WATER POTENTIAL IN (CATHERINE) PEACH

Variations of crop-load in the peach (Prunus persica (L.) Batsch.) cv. Catherine bg thinning the fruitlets at petal fall affected fruit and vegetative growth of trees. Shoot length, and fresh and dry weight decreased exponentially as the cropping level increased, while the relative increment in trunk girth decreased linearly. Yield increased following a quadratic pattern, while fruit size, measured as mean fruit weight, decreased exponentially as the crop load increased. Mineral element analysis in leaves has shown that Mn concentration decreased linearly with increasing numbers of fruits borne by the tree, both before and after harvest, while the other elements analysed (P, K, Ca, Mg, Fe, Cu, and Zn) did not show any variation. Leaf water potential during the time of fruit growth also decreased exponentially as the crop-load increased.