Effect of irrigation and N levels on fruit quality and nutrient distribution in 'Fuyu' persimmon tree parts during the final stages of fruit growth

摘要

Irrigation levels with or without nitrogen had an impact on the fruit growth of 'Fuyu' persimmon (Diospyros kaki) during the final stage of its growth. Pot-grown, 4-year-old trees were irrigated with 0.7, 1.4, and 2.1 litre per 30 litre pot from 21September to 15 October. Twenty-three grams of nitrogen (N) as urea fertilizer were applied during the irrigation period to determine the effect of N supply. Dry weight of the 10 November tree was higher than that of the 21 September tree. Both the irrigation levels and N did not affect dry weight. Fruit diameter at harvest was larger with increasing level of irrigation without N. In 2.1 litre trees, fruit diameter increased by 12.3 and 15.2% with and without N, respectively. Dry weight of fruit increased with increasing level of irrigation. The irrigation levels did not affect N content in all parts of the tree. N content in the leaves ranged from 1.1 to 1.7%, while that of all other parts of the tree increased with an increase in N supply. Sugar concentrations in the leaves were higher with increasing level of irrigation but there were no differences between with and without N. Sugar concentrations of other parts of the tree except leaves were higher with high level of irrigation and without N. On the other hand, N supply did not affect starch concentrations.