1. Maximum temperature was found to influence the time of opening of flowers. Optimum temperature favouring maximum anthesis of flowers in Muscat White was determined to be 37–38°C.
2. Time of dehiscence varied in different varieties and no general sequence was found with the time of anthesis. In Patiala dehiscence started prior to anthesis whereas in Muscat White it started afterward. There was virtually no dehiscence at night. Dehiscence was affected by maximum temperature as well as by atmospheric humidity.
3. No difference was observed in time of anthesis and in mode and time of dehiscence among hermaphrodite, intermediary and male types of flowers in all the varieties under study.
4. In the varieties studied, the pollen grains were of different sizes, but their general shape was the same except in G.B.-1 in which the presence of a ring like band on the pollen surface was noticed. Pollen grains of all the varieties were highly fertile.
5. A definite seasonal variation in pollen size and fertility was noticed.
6. Different media for artificial pollen germination were tried and 12.5 per cent sugar and 12 5 per cent sugar + 0.5 per cent agar were found to be most suitable for pollen germination.
7. Stigma attained maturity one day before anthesis and receptivity remained at peak on the same and second day after anthesis and it gradually went down till the third day after which it abruptly sank into non-receptivity.
