2010 Volume 9 Issue 1 Pages 47-52
The influence of replacing Fe2+ with other divalent cations to inhibit ACC oxidase activity on ethylene production in fruit and on-tree fruit-softening of ‘Saijo’ persimmon was investigated. When studying the effects of spraying treatment of fruit calyx with 1,000 ppm of NiCl2, CoCl2, and CuSO4 solutions (2 days after ethephone treatment) against on-tree fruit softening induced by ethephone, it was determined that a NiCl2 solution at a concentration of 1,000 ppm was most effective for inhibiting fruit softening. Second, when studying the inhibitory effect of spraying NiCl2 solution to prevent on-tree fruit softening, it was observed that treatment during early or mid-September or early October had little effect on inhibiting fruit softening and spraying had no effect after on-tree fruit softening had already occurred. However, by combining the serial application treatment in early September and again in early October, the ethylene concentration in fruit decreased and one-in-three trees treated tended to show inhibition of on-tree fruit softening. The fruit hardiness of flesh receiving two treatments remained higher than that of non-treated fruit. While the possibility of inhibiting on-tree fruit softening by treatment with Nickel solution was shown in this study, further investigation is necessary to clarify and confirm the effect by replication experiments in future years and on other trees.
