In spite of the success of hybrid rice, the nonavailability of affordable quality seed of hybrids, particularly those developed using the cytoplasmic male sterility system, remains a serious problem in India. Even achieving the minimum standard of isolation distance is a constraint to quality seed production in hybrid rice. This is mainly because the areas most suitable for hybrid rice seed production are also found in the mainstream of the rice belt. Shrinking natural resources, particularly cultivable land, resulted in growers not wanting to part with their land for other purposes. The only option for growing hybrid rice seed is either time isolation or physical barrier isolation.
Time isolation is not usually resorted to because of growers' preference in growing specific varieties. Therefore, the use of physical barriers is a better option. However, knowledge on barriers' efficiency is insufficient. This study investigated the efficiency of some physical barriers that could be used in hybrid rice seed production.