Abraham, A THariharan, N P2019-10-242019-10-241969http://krishikosh.egranth.ac.in/handle/1/5810132865PGThe experiment was conducted to study the effects of F ,W-450 and 2, 4-D as male gamotocldos In sosamo, at throe stages of growth. The concentrations tried were 1S00 ppm., 2000 ppm., 2S00 ppm. and 3000 ppm. in case of F ,W-450 and SO ppm.,100 ppm., 150 ppm. and 200 ppm. in case of 2, 4-D.2, 4-D was highly toxic to the plants at all concentrations. F,W-450 at 3000 ppm. caused treatment shock expressed as marginal scorching of the loaves. Pollen sterility was tested by acotocarmine staining method, by germination of pollen grains in artificial medium and by crossing the control plants with pollen from treated plants. The first stage of application was more effective in inducing pollen ste rility and F,W-450 could induce 73$ ste rility without too much deleterious side effects. The plants treated with F,W-450 wore vigorous in growth. Maximum pollen ste rility was observed on the 9th day after treatment in a ll tho cases. Ovular sterility was judged by crossing the treated plants with pollen from control plants. Sterility was observed with the application of both tho chemicals but the intensity was directly proportional to the concentration of the chemicals.V iability of the seeds was also tested and it was found that the chemicals reduced the percentage of germination. V iability was too much reduced in seeds from plants treated with 2, 4-D. In short resplendent results wore obtained with F,W-450 and it was comparatively a better male gametocide for sesame. Results with 2, 4-D showed that this chemical w ill not bo a successful malo gamotocide in sesame. The never ending enthusiasm of man and tho highly developed nature of his grey matter are mastering the nature in multidirectional fashion. I am optimistic to believe that this experiment w ill add a speck of information to the heap of modern agriculture.ennullThesis