Elucidating the role of nitrogen and silicon regimes in rice blast management and yield performance of Mushk Budji variety under field conditions

Abstract

This study investigated the interactive effects of nitrogen and silicon fertilization on disease incidence, severity, grain yield, and straw yield in susceptible rice variety under rice blast disease pressure across two consecutive years. The results revealed significant variations in disease parameters across different nutrient combinations. The study involved four levels each of nitrogen (N₀: 0 Kg/ha; N₁:50 Kg/ha; N₂: 100 Kg/ha and N₃: 150 Kg/ha) and silicon (Si₀: 0 Kg/ha; Si₁: 60 Kg/ha; Si₃: 90 Kg/ha and Si₃: 120 Kg/ha). The treatments with lower to moderate nitrogen levels coupled with higher silicon rates exhibited the lowest disease incidence and severity, highlighting their synergistic effect in enhancing disease resistance. Conversely, high nitrogen levels with low or no silicon supplementation displayed the highest disease susceptibility, indicating that excessive nitrogen without adequate silicon can exacerbate vulnerability. Notably, increasing silicon levels led to decreasing disease incidence and severity, while the opposite trend was observed for nitrogen, underscoring silicon’s pivotal role in mitigating disease impact. Regarding yield parameters, the highest silicon rate (120 kg/ha) consistently resulted in superior grain yields, particularly when combined with moderate nitrogen levels (100 Kg/ha). The positive effect of silicon on grain yield was more pronounced at lower nitrogen levels, suggesting its potential to compensate for nitrogen deficiency. Moreover, the highest silicon level consistently exhibited superior straw yields across nitrogen levels. However, moderate nutrient levels occasionally outperformed the highest levels, implying an optimum range for maximizing straw yield while avoiding yield penalties associated with excessive application.