Study of the Effect of Nitrogen Fertilization Supplied by Foliar Sprays or by Fertigation in Apple Trees - Preliminary Results

摘要

Nitrogen overfertilization of 'Golden Reinders' apple trees, applied as extra doses to the soil or as a foliar aqueous solution led to different effects on plants. While soil applications had no effects on growth and cropping parameters, as compared with the control trees, foliar sprays promoted shoot growth and leaf extension, and resulted in a decrease in yield and crop-load, presumably due to a greater preharvest fruit drop. Phytotoxic damage was observed on leaves, but net photosynthesis remainedunaffected, and mineral element concentration did not change due to the overfertilization, except for N, which increased only in the foliar spray treatment, and only late in the growing season.