Vol. 7, Issue 9, Part K (2025)

The present field investigation entitled “Impact of Diverse Nutrient Integration on Insect Pests of Rice” was conducted during the Kharif season of 2024 at the Instructional Farm, College of Agriculture, Dapoli. The study aimed to evaluate the influence of various nutrient management practices on the incidence of key insect pests in rice. The experiment was laid out with 15 nutrient management treatments, including combinations of recommended dose of fertilizers (RDF), organic manures, biofertilizers, and silica and observations were recorded on major pests such as blue beetle (Leptispa pygmaea), rice skipper (Parnara mathias), leaf folder (Cnaphalocrocis medinalis), rice horn caterpillar (Melanitis leda ismene), and yellow stem borer (Scirpophaga incertulas). The effect of nutrient management on pest incidence was noteworthy and statistically significant. Among the treatments, the lowest pest infestations were consistently observed in T₁₂ (RDF 75% + Azotobacter + Azospirillum + PSB + Silica @ 15 kg/ha), followed by T₁₁ (RDF 75% + biofertilizers). These treatments significantly reduced leaf damage caused by all targeted pests throughout the crop growth stages. The suppression of pest population was attributed to enhanced plant vigor, increased nutrient uptake efficiency, induced systemic resistance from biofertilizers, and physical defense offered by silica. In contrast, treatments with high nitrogen levels, especially T₂ (150% nitrogen), and the untreated control (T₁₅) recorded the highest infestation levels, reinforce the understanding that excessive nitrogen can lead to increased pest susceptibility by making foliage more tender and nutrient-rich for pest feeding. Furthermore, organic nutrient sources (T₉ and T₁₀, involving FYM and Gliricidia) and biofertilizer-alone treatments (T₁₃ and T₁₄) exhibited moderate efficacy in pest suppression. In most cases addition of silica provided additional level of protection, enhancing the effectiveness of these treatments. Silica played a crucial role in reducing pest damage by strengthening plant tissues and possibly interfering with insect feeding behavior and oviposition. NPK treatments with silica (T₆, T₈) also showed reduced pest levels compared to their non-silica counterparts, emphasizing the beneficial role of silica across different nutrient regimes.