Redefining Isolation Distance Standards for Quality Seed Production in Hybrid Pigeonpea [Cajanus cajan (L.) Mill sp.

Abstract

Background: Adopting adequate isolation distances is one of the very crucial principles and practices of quality seed production. Upon research and continuous evaluation, isolation distances for each crop, kind and cultivar have been determined in almost all cultivable crops. The development of hybrids through various mechanisms has led to redefining isolation distances in a few crops like pigeonpea based upon the principles of pollination ecology and the activity of various pollinators. Methods: Our study on the direction of male and female blocks, activity and frequency of pollinators and their effect on production potential and quality of seed was systematically conducted at various isolation distances viz., 100, 150, 200, 250, 300 and 400 m between female (A) and male (R) lines. Result: Our empirical information depicts that an isolation distance of 400 m between male and female parents reduces the chances of genetic contamination and hence the isolation distance in case of hybrid seed production of pigeonpea shall be redefined as 400 m.