Influence of K/Ca ratio and drought on physiological disorders in tomato.

Abstract

In pot trials with tomatoes cv. Renova the effects were assessed of low and high K:Ca ratios and 4 successive periods of water stress on fruit quality. Each drought period lasted 4 or 6 days and started when the fifth fruit of the first, second, third or fourth cluster, respectively, had attained 1 cm in diameter. Water stress lowered the Ca concentration and raised the K:Ca ratio in the fruit. There was little difference between the yields of droughted and normally watered plants, and the fruit quality of vigorously growing plants was enhanced by drought. The incidence of blossom-end rot was much higher with a high K:Ca ratio and was aggravated by drought, an effect associated with the reduced Ca content. By contrast, the incidence of blotchy ripening was lower with a high K:Ca ratio, and was lessened by drought. The incidence of green-back was little affected, either by differing K:Ca ratios or by drought. (Abstract retrieved from CAB Abstracts by CABI’s permission)