Whey: The Soil Bio-Community Enhancer That Selectively Controls Root-Knot Nematodes

To date, it is mandatory for ecofriendly pest-management tools to be used in agriculture. Whey is a dairy-processing waste, a plant and soil chemical and fungicidal basic substance. The beneficial effect of whey on soil microorganisms, enzymatic activities, and free-living nematodes—combined with its toxic activity on the plant parasites—forms root knot nematodes. In this study, this finding is reported for the first time. A drip-irrigating tomato plant combined with whey in water at 3.125% (v/w) and 6.25% (v/w) dose dependently promoted Gram+ and Gram− bacteria, actinomycetes, and fungi biomass. Respectively, whey treatment and duration augmented the bacterial feeding nematodes along with the soil enzymatic activities, e.g., alkaline phosphatase, dehydrogenase, and urease. The counterpart for these soil organisms’ and enzymes’ functionality is the decomposition of organic matter, nutrient mineralization and cycling. Additionally, whey applied at 6.25% (v/w) every 10 days in a field experiment exhibited an efficacy of 70% on root knot nematodes. It is calculated that the EC50/3d value paralyzes in vitro Meloidogyne javanica, which was 3.2% (v/v). Conclusively, the soil application of whey could be a sustainable and ecofriendly method to combat the root knot nematodes and additionally to enhance soil biotic components.