Management of Meloidogyne incognita in tomato under protected cultivation by using antimicrobial peptides producing native Bacillus subtilis (CRB7).

Abstract

Root knot nematodes (Meloidogyne spp.) are major threat to vegetable crops grown under protected cultivation. Tomato is one of the major vegetable crops highly prone to root knot nematodes under protected cultivation. Management of root-knot nematodes under protected cultivation is a huge challenge because of nematicides has been mostly banned/restricted use and resistant varieties or non-host crops are often not available. Nevertheless, the increasing awareness and demand for organically grown vegetable produce discourages the use of synthetic nematicides due to their potential negative impact on environment and human health. In this endeavor, biological control agents (BCA) have emerged as eco-friendly, safe and cost-effective alternatives to chemical nematicides. Thus, field experiments were piloted in 2017-18 and 2018-19 under protected structure which was severely infested with Meloidogyne incognita. For the management of M. incognita in tomato (cv. Kashi Adarsh) talc-based formulation of antimicrobial peptides producing Bacillus subtilis (CRB7) were used and applied in three different delivery methods such as nursery drench (15 g/m2), soil application of enriched bio agent with vermicompost (5 kg/ha/2 tonnes of vermicompost) as well as soil drench (0.5%) at 30 days interval. These delivery mechanisms were evaluated individually and in combination. In our study, B. subtilis (CRB7) was found to be most effective when applied as a combination of three delivery methods by reducing final nematode population in soil 70.3 and 55.8%, egg mass per root system 63.2 and 48.6% with minimum gall index 1.57 and 2.58 and also enhanced yield to the tune of 30 and 15.3% over control during 2017-18 and 2018-19 respectively. Thus, our study elucidates that, antimicrobial peptides producing native B. subtilis (CRB7) and its combination of delivery methods can be utilized as one of the components in integrated management strategy to combat M. incognita incidence in tomato under protected cultivation.