Response of Grape Cultivars to Nitrogen and Phosphorus

Abstract

The response of 11 different varieties of grapes treated with different levels of N was studied over a seven-year period Phosphorau fertilizer was applied midway through the study. Tissue samples were tested for total P and NO₃-N content, and yield determined annually. The results showed a positive interaction in tens of increased yield between N and P when sufficient quantities of both nutrients were provided