Grains of the old conservative rice cv. Agamy (Sabini) were sown in greenhouse during the two successive summer seasons 1999 and 2000. The aim of this study was to find out the factors that may affect success of controlled crosses in rice cv. Agamy (Sabini) The factors affecting grain set percentages under study were pollen age, stigma receptivity and time (hour) of pollination. Results indicated that pollens over two hours old resulted in a low grain set percentage and pollen viability was greatly affected by the time elapsed since its excursion from the anthers. Pollen viability was greatly decreased as the pollen age increased. Six and twelve hour's pollen ages showed a considerable reduction in grain set percentages.
Stigmas of 1 or 2 days old resulted in the highest grain set percentage. Stigmas of age over 5 days showed a comparable low grain set percentages. Stigma receptivity was greatly affected by its age (the time elapsed since its emergence from the florets) and the proper age for stigmas to receive the pollen was one to two days.
The period ranging between early morning 6 A.M. to mid morning 9 A.M. showed the high mean percent of grain set. Pollination hour after 10 A.M. greatly resulted in a decrease in mean percent of grain set. This reduction reached its maximum at noon hour or later on.