Abstract
Experiments were done to clarify whether an incidence of blossom-end rod (BER) in fruits of tomato was induced by faulty nutritional conditions in plant associated with elevated nutrients or high temperatures. Their results were as follow. The incidence of BER increased with raising temperature from 20 to 30°C, especially in air temperature as compared with rootzone temperatures. An increase in electrical conductivity (EC) of nutrient solution from 1.2 to 1.8 mS cm-1 also increased the incidence of BER. The BER incidence due to higher temperatures was correlated with a rapid growth rate of fruits during early stages of fruit development in high temperature. There was no difference in fruit size at different EC values of nutrient solutions. Ca Content in fruits tended to decrease in the treatment inducing high BER incidence. The distribution of Ca giving 0.67-fold at the fruit apex and 0.9-fold in content at the fruit base in BER fruit at compared with that in healthy fruits. Contents of K and N in distal and basal part in BER fruits were high as compared with those in healthy fruits. The ratios of P/Ca, K/Ca and N/Ca in fruits with severe BER were high. Conclusively, the incidence of BER in fruits of tomato was induced by faulty nutritional conditions in plants associated with the rapid growth rate of fruits, high temperatures, and water deficits due to high EC values of nutrient solutions.
