Stigma receptivity and seed set in cassava

Abstract

The duration of stigma receptivity and the best pollination time in cassava where studied by pollinating at different time intervals in two clones of cassava. In OP-4, there was reasonable seed set when pollinations were done from 6am to 2 pm on the day of anthesis; in OP-7, significant seed set could be obtained even at 6 pm, indicating differences in the duration of stigma receptivity in the clones. The degree of clefting in the sigmatic papillae may be taken as an indicator of the duration of stigma receptivity. Though the pollen tubes reached the embryosacs in 24 h in OP-4, it took about 48 h in OP-7. The presence of stigma receptivity in the morning hours could advantageously be utilized by adopting forced pollination in the morning hours, thereby avoiding the cumbersome re-bagging under the hot tropical sun during noon. By adopting the modified pollination method, 200 flowers could be easily pollinated in 1 ½ hrs by two people.