Biofumigation for nematode management: Advantages and limitations

Plant-parasitic nematodes are the foremost cause of yield loss around 12.3% ($157 billion) globally and 21.3% ($1.58 billion) nationally. The adverse effects of synthetic nematicides on the environment and public health have prompted a reassessment of non-chemical approaches for managing nematodes. One such approach is Biofumigation, wherein fresh plant biomass is incorporated into the soil and covered for two to three weeks with polythene to suppress soil-borne pests and pathogens. The mechanism of biofumigant is due to the release of volatile isothiocyanates by the hydrolysis of glucosinolates present in plants belonging to the Brassicaceae, Caricaceae, and Capparaceae. The production of volatile nematode antagonistic compounds by non-brassica plants expands the scope of Biofumigation. These compounds inhibit nematode movement, cripple the host's finding ability, and may also cause an ovicidal effect. Biofumigation is reported to effectively control fungal pathogens and weeds, improve soil properties, and enhance beneficial soil microorganisms. However, the approach has some limitations, like the unavailability of plant biomass in off-seasons and poor efficacy in dry soil and deeper layers of the soil. The beneficial entomopathogenic nematodes may also be reduced in the presence of a biofumigant. This technique can, however, be cost-effectively included in integrated nematode management for acceptable levels of nematode management.