Flowering and fruit set of improved population of Jatropha curcas L. under climate of Northern Lombok, Indonesia

Abstract

In order to understand flowering and fruiting of an improved population of Jatropha curcas L. grown in Northern Lombok Island, flower and fruit development timeline is needed to solve the low fruit set problems. The investigation was carried out by daily observations on bud and flower initiation, anthesis of male and female flowers, floral morphology, fruit initiation and development, fruit-set, and flower characterization. Anthera dehiscence and stigma receptivity were also observed. For floral and fruit development, observations were based on macro morphological changes, and vegetative shoots were tagged and observed for their developmental changes up to fruiting stage. The results show that, there was significantly different in fruit set between improved populations of IP-1 NTB and IP-2 NTB, but not for most flowering and fruiting variables. The genotypes are monoecious, the male and female flowers were found separately in the same inflorescence. The male floral bud developed earlier (20 to 23 days) than the female ones (22 to 25 days) to bloom. Maximum flower opening was occurred from 07.00 to 09.00 A.M for male flowers, and 08.00 to 09.00 A.M for female ones. The anthera dehiscence was observed between 07.00 and 09.00 hours. The receptivity of stigma started toopenfrom08.00 to 11.30 A.M. The number of days required for fruit development and maturity after anthesis ranged from 45 to 60 days. Average of fruit set for IP-1 NTB and IP-2 NTB under open pollination was 56.40% and 68.54%, respectively.