*Address: Department of Botany, Panjab University, Chandigarh-160014.
This paper deals with the effect of photoperiod on the developmental changes in the shoot apex of Panicum miliaceum during vegetative (formative), gametogenetic and embryogenetic phases. While the periods from sowing to panicle initiation and from panicle initiation to gametogenests were the shortest under SD and longest under LD conditions, the period from the completion of gametogenesis to embryogenesis did not differ under the three photoperiods. The size of the inflorescence and the number of spikelcts were also considerably reduced under SD conditions, although the size of floral organs and the embryo did not differ much with the photoperiod. It is concluded that the shortening of vegetative period of this plant sown in September as compared to that sown earlier as reported in the previous communication is primarily due to the shorter days that prevail during the growing period of that sowing,
