EXPLORING THE NEMATICIDAL POTENTIAL OF CASHEW NUT SHELL LIQUID AGAINST ROOT-KNOT NEMATODES: IN VITRO AND GREENHOUSE EVALUATIONS

Root-knot nematodes (Meloidogyne spp., RKNs) remain a major threat to vegetable production and a reason for the overuse of pesticides, particularly in Sub-Saharan Africa. The objective of this study was therefore to investigate the nematicidal properties of cashew nut shell liquid (CNSL) against RKNs on vegetables. Laboratory bioassays and greenhouse pot experiment were conducted to assess the suppressive effects of CNSL on RKN reproduction and damage.Four concentrations (0.01%, 0.1%, 1%, and 10%) of cold- and hot-extracted CNSL were used in the laboratory bioassays to evaluate their nematicidal activity against M. enterolobii juveniles and eggs. The pot experiment consisted of eight treatments (two CNSL types, one concentration, three application doses, and two controls) assessed in a completely randomized block design with five replicates, using tomato (cv. Padma 108 F1) and soil naturally infested with RKNs. Results from the in vitro bioassays showed that CNSL induced juvenile mortality by up to 90% after 48 h of exposure against 2% in the SDW used as control.