Enhanced Efficacy of Combined Plant Extracts on Rice Leaf Folder, Cnaphalocrocis medinalis (Guenée)

The rice leaf folder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae), is a prominent and noxious pest in rice production, particularly in the Cauvery Delta region of Karaikal of Puducherry and Tamil Nadu, India, where rice is cultivated predominantly as a monocrop during the Kharif and Rabi seasons. Field experiments were conducted during Kharif and Rabi 2019-20 at PAJANCOA and RI, Karaikal, to evaluate the efficacy of plant extracts against leaf folder. Across both seasons, chemical insecticide treatments, Novaluron and Thiamethoxam resulted in 49.03% and 54.90% reduction in leaf folder damage, respectively. Among the botanical treatments, 5% garlic and chili extract consistently showed the lowest leaf damage, recording 6.27 and 6.49% in Kharif 2019 and Rabi 2019-2020, respectively. This represents a 40.40 and 40.02% reduction in damage compared to the untreated control. Thus, garlic and chili extract at 5% proved highly effective in minimizing leaf folder incidence under field conditions and offers a sustainable, eco-friendly alternative to chemical insecticides by reducing the risk of resistance development.