Management of Yellow Stem Borer Scirpophaga incertulas in Rice Using Transplanting Date and Neem Seed Kernel Extract

Abstract

This field experiment at Pirsabak, Nowshera, tested two rice transplanting dates—5 July 2025 (early) and 30 July 2025 (late)—along with different pest management methods: untreated control, 5% neem seed kernel extract (NSKE) alone, cartap alone, and NSKE plus cartap. All measured factors showed significant differences. For vegetative damage (percent dead hearts), control plots had the most infestation: June transplanting had 18.5±1.2% and July had 12.4±0.9% (mean 15.45±0.8%). Using 5% NSKE alone reduced dead hearts to 9.2±0.7% (June) and 4.2±0.3% (July), with a mean of 6.70±0.4%. Cartap alone resulted in 8.1±0.6% (June) and 3.8±0.2% (July), mean 5.95±0.3%. The NSKE plus cartap combination had the lowest values: 7.5±0.5% (June) and 2.9±0.2% (July), mean 5.20±0.3%. Two-way ANOVA showed significant effects for date (p=0.008), treatment (p<0.001), and their interaction (p=0.041). For reproductive damage (percent white heads), control plots had 13.5±0.9% (June) and 9.1±0.6% (July). NSKE 5% gave 6.7±0.5% (June) and 3.8±0.3% (July). Cartap gave 5.9±0.4% (June) and 3.2±0.2% (July). NSKE plus cartap gave 5.2±0.4% (June) and 2.5±0.2% (July). ANOVA for white heads showed date p=0.004, treatment p<0.001, interaction p=0.037, with pooled standard errors of 0.31 (June) and 0.22 (July), and LSD₀₀. ₀ values of 0.9 (June) and 0.6 (July). Grain yield (t/ha) in control plots was 2.85±0.15 (June) and 3.12±0.12 (July), mean 2.98±0.10. NSKE 5% increased yield to 4.12±0.18 (June) and 4.91±0.14 (July), mean 4.52±0.12, a 51.7% gain over the July control. Cartap alone produced 4.38±0.16 (June) and 5.12±0.11 (July), mean 4.75±0.11, a 59.4% gain. NSKE plus cartap gave 4.45±0.17 (June) and 5.03±0.13 (July), mean 4.74±0.12, a 59.1% gain. ANOVA for yield showed date effect p=0.007, treatment effect p<0.001, interaction p=0.052 (not significant), with LSD₀. ₀₅ for mean yield at 0.28 t/ha. The highest yields (cartap and NSKE plus cartap) were statistically tied for first place, NSKE alone ranked second, and the control ranked fourth. Importantly, early July transplanting with 5% NSKE alone resulted in only 4.2% dead hearts, 3.8% white heads, and a yield of 4.91 t/ha. This performed nearly as well as the full synthetic regime (cartap alone: 3.8% dead hearts, 3.2% white heads, 5.12 t/ha) but avoided the ecological and economic downsides of heavy insecticide use. Therefore, early July transplanting with 5% NSKE is a highly effective, low-cost integrated pest management approach for yellow stem borer in rice at Pirsabak, Nowshera.