Flowering behavior and spatial-temporal distribution characteristics of Jatropha curcas in Luodian.

To have a grasp of the overall situation of flowering characteristics of Jatropha curcas,which would provide basis for the further flower control experiment and produce higher yield of Jatropha curcas,continuous observation and statistical analysis on flowering behavior and spatial-temporal distribution characteristics of Jatropha curcas were carried out in Luodian.The results indicated that: Jatropha curcas can form flower bud many times in one year.It shoots out twigs more than once on which flower buds begin to take shape.At Luodian,Jatropha curcas is in bloom from May to September,during which there are two high tides of blossom generally and are characterized by vegetative stage and ripening stage.Vegetative Buds Germination is a main sign of Jatropha curcas entering critical period of bud physiological differentiation stage.Dichasial inflorescence grows on top of new branches.There was no significant difference in amount of inflorescence,leaf beneath the inflorescence,small flower of a inflorescence and female flower in a inflorescence in all directions: north,south,east and west,and in the upper,middle,lower of the tree.It takes about 40-50 days from inflorescences emerge to the entire small flowers blossom.A small flower is flowering for 2-5 days.One inflorescence has an average of 134 small flowers which contain 4 female flowers.Female-male ratio is 1 ∶ 33.There was great significant correlation between the distribution of female and the location of inflorescence branch.69% females grow on the terminal of different level branchs in inflorescence,including 48% female growing on the first bifurcation of the primary rachis branch and the terminal of inflorescence.At different bifurcation in an inflorescence,the number of fruit increased with that of the female flowers,as against the percentage of set fruit decreased.