Abstract
Bulk emasculation in the use of heat was first developed by Stephens and Quinby (1933) in Sorghum and later Jodon (1938) has shown to be adoptable this method to rice.
In our experiments, the treatment was applied by immersing panicles in hot water at the temperatures of 42°C to 45°C contained in thermos bottles and allowed to remain 3 to 10 minutes respectively. After about an hour following emasculations by the treatment, immature florets which did not open were removed and cross pollination had been carried out. According to the experimental results, by treatment at 43°C for 8 minutes was given the highest number of florets which opened and were destroyed the viability of pollen in response to treatment and the highest percentage of seed set, showing that this treatmnt probably would be most effective for obtaining hybrid seeds by means of the hot water method.
