Abstract
Because it has been reported that calyx-end fruit cracking is not likely to occur in fruit with large calyxes in ‘Fuyu’ persimmon, we investigated Forchlorfenuron as a possible plant growth-regulating substance to promote calyx growth. Forchlorfenuron in a 10-ppm solution was sprayed on young shoots of ‘Taishu’ persimmon trees at leafing time. The treatment increased the calyx size significantly, with the calyx width being 1.26 times and the length between the vertices of the calyx being about 1.15 times those of non-treated plants. The percentage of fruit with calyx-end cracking in treated plants (16.1%) was lower than in non-treated plants (46.9%). In addition, the cracking severity was significantly lower in treated than in non-treated plants. The treatment was ineffective for the fruit weight, and slightly retarded fruit skin coloring and sugar accumulation in fruit harvested at the same time as fruit from non-treated plants.
