Sustainable management of Root Knot Nematodes in Pomegranate: Impact of Biocontrol Agents on Yield and Grower Profitability

Fruit crops like guava, pomegranate are good hosts to root knot nematodes, but only few studies were previously conducted for management of root knot nematodes. Pomegranate is a perennial crop which is a host to root knot nematodes, can harbour high nematode populations causing heavy yield losses and death of plants by secondary infection of soil borne pathogens. This is the first study where the bio control potential of P. lilacinum, P. chlamydosporia, and B. subtilis at different doses were explored to manage Meloidogyne incognita infestations in pomegranate at two locations, Haryana and Rajasthan for three consecutive years. Results revealed that both the fungal and bacterial biocontrol agents effectively reduced nematode galling and the overall nematode population in soil while concurrently boosting pomegranate fruit yield. The number of galls remained consistently high in control plants and was second highest in plants treated with neem cake. Treatment with B. subtilis exhibited the lowest gall count (225-99), while remaining treatments also showed fewer galls, particularly in later years. Moreover, in Rajasthan, the number of galls per 5 grams of roots was lower than in Rohtak, with B. subtilis showing the lowest gall index, especially in the third year. Over time, all the treatments showed progressive increase in plant height across time i.e. June 2021 to June 2024. B. subtilis at highest dose achieved maximum height at every point from December 2021 onwards. Also in both the locations plant width expanded greatly in plants, treated with B. subtilis exhibiting the significant difference from the control plants.