Studies on floral biology of spine gourd (Momordica dioica Roxb.)

The floral behavior studies on Spine gourd (Momordica dioica Roxb.) were carried out in rainy season during 2004 and 2005. Small bitter gourd is a rainy season crop and bears flowers during July and August. The single flower bud appeared in every axil on both male and female vines. The male flower buds took 1820 days from visible initiation to full blooming, while the female buds took about 15 days to full bloom. The male flowers began to appear from second week of August and differentiation continued till the first week of October, while female flowers opened from the third week of August and continued till end of September. The pedicle of male flower buds elongated and so they were pushed above the other buds of a vine. Soon these buds swelled and assumed a cup shape. The flower was taken to have opened as soon as the perianth leaves separated from each other. The maximum anthesis was noted at 8:30 P.M at the temperature range of 26.8 to 27 degrees C. The dehiscence started with the appearance of a slit on the anther lobe which resulted into liberation of creamy mass of pollen grains on the surface of anther. The dehiscence started four and a half hour before anthesis and individual flower took about 45 minutes to complete the process. Maximum release of pollen grains was observed at 2:45 to 4:15 P.M. The stigma was receptive up to 12hrs before and after anthesis. The stigma receptivity remained at a peak for 6-9hrs, before and after anthesis.