Abstract

Significant differences were noticed in the percentage infection of seed-borne pathogens and white tip nematode (Aphelenchoides besseyi christie) in 33 seed samples of IR 20 rice belonging to three generations of multiplication produced at 11 locations. (6 in Madurai District of Tamil Nadu and 5 from Pondicherry) Of them, seeds from periyakulam recorded very low infection of seed- borne pathogens. The seed produced at Theni were totally from nematode infestation. Besides, nine samples of certified seed produced at eight selected locations in Madurai District and one from Karaikal also revealed significant differences. Certified seeds from Sedapatti, Theppampatti and Thirumangalam were free of seed-bome pathogens and seeds from Kottampatti, Thirumangalam and Vinayagapuram were completely free from nematode infestation.

Keywords: Rice, Seed Health, Provenance, Generation Time, Effect