Enhancing systemic resistance against powdery mildew in vegetables using neem-enriched organic manures and inoculation of beneficial soil microbes

Modern vegetable production methods, driven by excessive use of agrochemicals and intensive irrigation, have increased crop vulnerability to disease outbreaks. One such disease, powdery mildew, can cause significant yield losses in various vegetable crops, ranging from 10 to 90%, depending on the crop, disease severity, and environmental conditions. In contrast, balanced nutrient management using neem leaf-enriched organic manure combined with plant growth-promoting microorganisms (PGPMs) has proven effective in strengthening the plant’s natural defenses against diseases. Long-term research conducted at the College of Agriculture, Sumerpur-Pali, evaluated the effects of six different combinations of chemical fertilizers and neem leaf-enriched organic manures, supplemented with PGPMs, on inducing systemic resistance against powdery mildew in vegetable crops. The results showed that replacing chemical fertilizers with neem leaf-enriched organic manures, along with PGPMs, significantly improved plant immunity and reduced powdery mildew damage. Compared to conventional inorganic fertilization, this integrated approach achieved the following reductions in powdery mildew incidence: 75.59% in cucumber, 85.92% in okra, 79.60% in bottle gourd, 86.35% in cluster bean, 64.07% in muskmelon, 81.25% in round gourd, 84.50% in cowpea, 72.30% in ridge gourd, 80.39% in sponge gourd, 80.38% in green peas, and 83.03% in phoot kakdi. These findings highlight that combining neem leaf-based compost and microbial bioinoculants offers a sustainable and effective strategy for inducing systemic resistance against powdery mildew in vegetables. This approach not only reduces reliance on agrochemicals but also supports food safety.