Rice is a brief day plant and flowering is promoted in quick day situations and suppressed in long-day condition. the short-day condition allows the manufacturing of flowers in distinct flowering ranges which substantially helps synchronous flowering for sorts that fluctuate of their flowering time. The heading date for synchronization of Paw San Hmwe (PSM) and other four indica rice sorts were studied below a short-day period and neutral day length circumstance and F1 seed set become observed from the hybridization of PSM and indica rice varieties by using hot water emasculation method. results confirmed days to a heading of PSM and different four indica sorts in short day period have been earlier than those in impartial day duration. some of the examined types, PSM changed into rather touchy to high temperature and photoperiod in impartial day length because of no longer most effective flowering in short-day photoperiod circumstance however additionally photoperiod sensitive and past due cultivar.