Evaluation of nematicidal action of some bio-agents and botanicals for eco-friendly management of root-knot nematodes, <i>Meloidogyne incognita</i> on tomato

Abstract

Root-knot nematodes (RKN), Meloidogyne incognita are important pests and major limiting factors for the production of tomato in Ethiopia. Recently, the most efficient chemical control products like methyl bromide have now been restricted due to their toxic characteristics. Biopesticides were evaluated against root-knot nematode, Meloidogne incognita on tomato plants in laboratory and green house conditions of Haramaya University (Ethiopia). The study was conducted with the objectives to evaluate the e ect of some biocontrols i.e. Bacillus firmus, Trichoderma harzianum, neem seed (Azadirachta indica), garlic bulb (Allium sativum) on M. incognita and to compare the potentials of biocontrols for the management of root-knot nematode (Meloidogyne incognita) on tomato. These biologically active factors exhibit the property to resist against M. incognita. Different concentrations for each treatments were used and analysis for the efficiency of bio pesticides was made effect of these concentrations were perceived on egg hatchability, gall formation, number of eggs, final nematode population, plant height, reproduction factor, shoot and root weight. In laboratory tests, an aqueous suspension of bio pesticides at 1, 2, 3 and 4% concentration reduced egg hatching from 8.4 to 100 %, 24 -days after treatment. In green house trials, Bacillus firmus applied at 4 % concentration per pot reduced gall formation by 85.7 %, number of eggs and final nematode population by 37 and 72 %, consequently, improvement of plant height and shoot height was by 51.5 and 55.6 %, respectively as compared to the inoculated control, 50 days after treatment. Application of garlic bulb (Allium sativum) at 4 % concentration per pot reduced gall formation by 77 %, number of eggs and final nematode population by 28 and 61.5 %, respectively. Findings illustrated that the tested bio agents and botanicals were effective for managing root-knot nematodes, M. incognita. However, Bacillus firmus and Trichoderma harzianum revealed their potentials more than neem seed (Azadirachta indica) and garlic bulb (Allium sativum) for managing M. incognita. Thus, they seem to be effective for the management of root- knot nematode and has the potential to be a vital component of integrated management for root-knot nematode.

Keywords: B. firmus, T. harzianum, A. indica, A. sativum, M. incognita, Tomato, Root-knot nematodes