Efficacy of authentic bio-nematicides against the root-knot nematode, Meloidogyne javanica infecting tomato under greenhouse conditions

Abstract

The root-knot nematode (RKN), Meloidogyne javanica is considered one of the most widely distributed and economically damaging plant-parasitic nematodes worldwide. Given the exacerbation of the environmental pollution problem with chemical nematicides, the use of biological nematicides is one of the most acceptable alternative methods in nematode management by the farming community. Four bio-nematicides namely: NT (Steinernema feltiae), MM (Ascophyllum nodosum and Bacillus amyloliquefaciens), GA sol+ (A. nodosum, B. amyloliquefaciens, and Trichoderma harzianum), and Ortie-Prele (aqueous extract of nettle and horsetail (Equisetum arvense)) were evaluated for their efficacy against M. javanica infecting tomato plants under greenhouse conditions. Their efficiencies were compared to a positive control and NemGuard Granules (garlic granule extract) as a standard nematicide. Treatment effects on the growth parameters were also examined. All tested treatments gave high nematicidal effect, except for the Ortie-Prele. The highest reductions in root galling (63%), as well as the number of egg masses (98%), eggs (96%), second-stage juveniles (J2s) (93%), and the reproduction factor (RF = 2.36) were obtained by the NT treatment, which was superior to the efficacy of the standard nematicide 52.63%, 91.58%, 88.30%, and 92.07%, respectively. The Ortie-Prele treatment gave the lowest reduction for the previous nematode criteria 0%, 53.96%, 12.39%, and 11.84%, respectively. On the other hand, all treatments, significantly improved tomato growth parameters; plant length, shoot fresh weight and, root systems when compared to the standard nematicide (Nemguard Granules), and the positive control. The highest increase in shoot length (30.90%), root length (58.13%) and shoot weight (30.98%) were obtained by GA sol+, while Ortie-Prele recorded the highest increase in root weight systems (91.89%). Therefore, our results indicated that NT, MM, and GA sol + proved to be crucial components for an integrated management of M. javanica in tomato crops.