In vitro Nematicidal Activity of Composts from Crotalaria retusa and Crateva adansonii on Meloidogyne enterolobii and Assessment of their Phytotoxicity on Tomato under Greenhouse Conditions

Abstract

Meloidogyne enterolobii (Root-knot nematode) is a highly virulent Meloidogyne species that poses a serious threat to agricultural production, particularly vegetable crops. The present study explores an effective and eco-friendly management option in assessing the effect of compost teas (CT) derived from Crateva adansonii (Ca) and Crotalaria retusa (Cr), applied at different concentrations (25%, 50%, 75%, and 100%), on the mortality of M. enterolobii J2s and egg hatching, at various exposure times. In addition, the phytotoxicity of the two composts on tomato under greenhouse conditions was evaluated. The results showed that the mortality of M. enterolobii J2s increased significantly with increasing CT concentrations and longer exposure times. After 72 h, CTs from Ca and Cr caused M. enterolobii J2 mortality rates of 61.40% and 58.80%, respectively. Egg hatching was significantly inhibited by up to 28% and 29.80% for Ca and Cr, respectively, versus 4.4% for SDW after 8 days of exposure. Seed germination rates were 100% and 92% in the Ca and Cr composts, respectively. Plant growth was stimulated by the composts as indicated by the increase in plant height and, in some cases, in leaf number. The composts from Ca and Cr, and their teas are promising alternatives to chemicals in the management of root-knot nematodes, and they represent a source of nutrients for plant growth.