Comparison of Structural and Nutritional Composition between Low Yielding and Annual Bearing Trees of Japanese Persimmon (Diospyros Kaki Thunb.) 'Maekawa Jiro'

Abstract

Differences in structural and nutritional characteristics of Japanese persimmon 'Maekawa Jiro' trees which consistently had low yields (Low Group) and annual bearing ones (Control Group) were assessed. There were up-rooted, dissected, and their structural and nutritional status examined ; the data was then compared with their previous histories. 1. Trees in the Low Group had fewer normal flowers and fruits, a higher percentage of physiological fruit drop, and lighter fruits at harvest compared with the Control Group. 2. While the Low Group was of equal size to the Control Group up to the early years of bearing, the former had larger framework and roots, a reflection of the low yield, than had the latter by end of the experiment. 3. Prior to uprooting, the Low Group had low leaf P while the 1-yr-old dormant wood had low N and P contents. After being up-rooted, the N in the relatively thick roots and P in most parts were found to be low. 4. Analyses of 1-yr-old dormant wood revealed the carbohydrate contents of the Low Group were similar to those of the Control Group. Thus, while the trees sizes of both groups were similar during their early bearing ages, trees of the Low Group which consistently yielded poor crops became larger, initiated fewer flowers, and accumulated less mineral nutrients than did those of the Control Group. Because of the low yield, the roots of the Low Group grew larger and contained more stored carbohydrates than did those of the Control Group in the winter.