Microbiology Research Journal International

A field investigation was conducted to assess the impact of nutrient application and pesticide delivery methods on the severity of brown spot disease in rice. Results revealed that at 30 and 60 DAT, application of 100% RDF (100% RDF reduces disease severity because it maintains a balanced nutrient status, improves plant health and defense, strengthens tissues, and prevents the negative effects of either excess or deficiency of nutrients) recorded the lowest disease severity (17.78% and 31.10%, respectively), performing on par with 50% RDF and 150% RDF, while maximum severity was observed under control. Evaluation of pesticide application methods showed that drone-based spraying was consistently superior to knapsack spraying. At the maximum tillering stage, drone-applied tebuconazole + trifloxystrobin and isocycloseram recorded the lowest disease severity (1.11% at 7 DAS and 0.37% at 14 DAS), compared to higher values in knapsack spraying. Similarly, at the booting stage, drone-applied picosystrobin + propiconazole and chlorantraniliprole significantly reduced disease severity compared to knapsack application. Overall, the findings highlight that balanced nutrient management combined with drone-based pesticide spraying effectively minimizes brown spot incidence in rice.