Response of Adult Brown Planthopper Nilaparvata lugens (Stål) to Rice Nutrient Management.

Nitrogen (N) limitation is well documented for the brown planthopper (BPH) Nilaparvata lugens (Stål), but phosphorus (P) and potassium (K) limitation is poorly studied. We studied the effects of N, P, and K application on chemical composition of rice plants and its consequences on life parameters-adult longevity, fecundity, and egg hatchability of BPH. Life parameters of BPH were regressed as function of plant chemical composition. A completely randomized design with four replicates in a factorial scheme was used considering N, P, and K levels as factors. Nitrogen application increased N and soluble proteins (SP) and decreased silicon (Si) content in the plants resulting in increased adult longevity, fecundity, and egg hatchability of BPH. Phosphorus fertilization increased P content and showed markedly increased fecundity, but not egg hatchability or adult longevity. Significant interaction between N and P was observed for fecundity of BPH. Potassium supplementation increased K content but reduced N, Si, SP, and total free sugars (TFS) content in the plants, but it had no significant effect on life parameters of BPH. The association of BPH life parameters with N, SP, TFS, and P content was significant and positive, but it was negative with the content of Si. Thus, N and P fertilization on rice plants enhanced BPH fitness. In conclusion, judicious nutrient application can be helpful in avoiding generalized infestation of BPH to rice.