Cover cropping in guava orchards to reduce population of root knot nematode, Meloidogyne enterolobii

Guava orchards across the countryhave been facing sudden decline in the recent years due to incidence of root knot nematode, Meloidogyne enterolobii and Fusarium sp. Five crops viz., marigold (Tagetus erecta), cowpea (Vignaunguiculata), sunnhemp (Crotalaria juncea), onion (Allium cepa), garlic (Allium sativum) grown around the basin of guava plants were evaluated for their effect on population reduction of M.enterolobii, at two locations in Tamil Nadu, India. It was observed that onion and garlic were more effective in reducing the nematode population in guava, owing to the higher phenol, peroxidase and phenyl alanine lyase activity in these plants leading to repellent effect on the rootknot nematode, M.enterolobii in guava rhizosphere. Cowpea was also effective in reducing the nematode population as it attracted maximum juveniles into its roots, itself acting as a trap crop. Hence, it is concluded from the study to considerably reduce the population of root knot nematode, M.enterolobii.