Screening of coleus cultivars for their resistance to root-knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood and yield under conditions in Kerala

Abstract

Studies were conducted to find out a resistant variety of Solenostemon rotundifolius (Poir) Morton against Meloidogyne incognita (Kofoid &White) Chitwood. Two improved varieties (Sree Dhara and Nidhi), five lines from CTCRI (Line-74, 64, 79, 76 and 71) and two accessions (TC-9 and M-131) from Vellanikkara were screened for the relative tolerance to M. incognita. The variety Sree Dhara showed significant superiority over the rest of varieties/lines/accessions in reducing the nematode population (larvae, females, egg masses, eggs per egg mass) in soil and root. This variety had minimum root-knot index of 1.0 and ranked first in yield. The high yielding variety Nidhi closely followed Sree Dhara in yield and resistance to M.incognita. Considering the ability to resist nematodes and giving very high yield compared to local variety, Sree Dhara can be the best for cultivation in Kerala followed by Nidhi and CTCRI- 74.