The male flower opening process of chestnut can be roughly divided into four stages: filament exposure, filament straightening, anther cracking and filament withering. The whole flowering process is about 10 ~ 15 days. On a male inflorescence, the male flowers at the base always bloom first and gradually extend upward, with a difference of about 15-20 days. The flowering period of female flower spike is about 5-7 days later than that of male flower.
Female flowers have no petals, and the observation of female flower opening process is mainly based on the growth and development of stigma. The flowering process can be divided into five stages: female flower appearance, stigma appearance, stigma bifurcation, stigma expansion and stigma inversion.
During this period, the stigma remains fresh, and the villi on the stigma secrete mucus for about half a month, which is the main pollination period. At this time, the high temperature and sufficient sunshine are beneficial to pollination and fertilization of chestnut, which in turn affects the yield of chestnut.
It takes 3 months from female flower pollination to nut ripening and harvesting. Mid-June is the peak flowering period in Yanshan area, and the process of pollination and fertilization is completed. By early July, 65,438+06 small white ovules were arranged in a circle on the upper part of the ovary, and the ovules were oval. At this time, the fertilized ovule is dormant, and its shape and size are almost the same as those at the beginning of pollination. The middle and late July is the development period of immature embryos, and the weight of immature embryos is less than 1g in the middle and early August, and then it increases slowly, with the fastest growth rate before maturity.