Host Suitability of Winter Cover Crops for Meloidogyne enterolobii

The guava root-knot nematode (Meloidogyne enterolobii) is a highly aggressive species of root-knot nematode that is not manageable with currently existing nematode management methods. This study was conducted to evaluate the suppressive ability of winter cover crops against M. enterolobii. Eleven winter cover crops (rye, wheat, barley, triticale, oat, Austrian winter pea, crimson clover, balansa clover, hairy vetch, purple top turnip, and daikon radish) were evaluated against M. enterolobii in a growth room environment. Root-knot nematode-susceptible tomato (Solanum lycopersicum cv. Rutgers) was used as a control. Nematode reproduction on cover crops ranged from 1 to 501,373 eggs/g root, with oat supporting the least nematode reproduction and crimson clover supporting the greatest nematode reproduction. The crops significantly suppressing egg production on roots and second-stage juveniles in the soil relative to the control were oat, winter pea, wheat, barley, rye, and triticale. Hairy vetch, purple turnip, daikon radish, and crimson clover were good hosts, while balansa clover, wheat, winter pea, barley, rye, triticale and oat were poor or non-hosts, with the latter four crops producing substantial biomasses. Employment of these cover crops that suppress or do not support M. enterolobii reproduction while adding substantial biomass to the soil may lead to sustainable nematode management.