Studies on environmental conditions and pollination management in hybrid rice seed production

In order to understand the effect of environmental conditions in development of hybrid seed production technology of Pusa Rice Hybrid 10 (PRH-10), an experiment was conducted in the Indian Agricultural Research Institute, New Delhi during 2005. The results indicated that in hybrid seed production of PRH-10, application of GA₃ @ 90g/ha and two time supplementary pollinations at 10:30 hrs and 11:30 hrs in a favourable condition during flowering period would give the highest hybrid seed yield upto 4.2 tons/ha. Most favourable ecological conditions for maximizing hybrid rice seed production were temperature ranging from 18.6–34.5°C, relative humidity ranging from 34–91%, mean sunshine as 9.5 h/day and mean wind velocity of 4.1 km/hr during the flowering period. Higher hybrid seed germination and seedling vigour were recorded in seeds produced under favourable condition than that under unfavourable condition. Incidence of seed borne fungi was higher in seed lots with higher dose of GA₃ application and in seeds produced under unfavourable growing conditions.