A Comparative Assessment of Green-synthesized Nanoparticles, Plant Extracts and Conventional Fungicide in Suppressing Phomopsis Blight of Brinjal

Abstract

Brinjal (Solanum melongena L.) is one of the most important vegetable crops, but its productivity is severely constrained by Phomopsis blight caused by Phomopsis vexans. The present study evaluated the antifungal efficacy of green-synthesized silver (Ag) and zinc oxide (ZnO) nanoparticles from different plant leaf extracts, neem aqueous extracts, and a standard fungicide (Carbendazim 12% + Mancozeb 63% WP) using the poison food technique. Results revealed that neem-based Ag nanoparticles at 100 ppm were most effective, recording minimum radial growth (14.50 mm) with 83.89% inhibition, followed by tulsi-based Ag nanoparticles (71.85%) and hibiscus-based Ag nanoparticles (68.30%). Similarly, among ZnO nanoparticles, neem-based ZnO at 100 ppm exhibited 69.63% inhibition, while bael- and moringa-based ZnO nanoparticles showed 67.63% and 64.03% inhibition, respectively. In contrast, aqueous leaf extracts were less effective, with neem extract at 750 ppm showing 45.55% inhibition, followed by parthenium (41.97%) and tulsi (41.74%). The fungicide at 1000 ppm achieved 62.63% inhibition, outperforming plant extracts but remaining less effective than Ag NPs. A clear concentration-dependent response was observed for both Ag and ZnO nanoparticles, whereas extracts showed comparatively weaker effects even at higher doses. Overall, the findings su neem-based silver nanoparticles as the most promising eco-friendly and sustainable alternative to synthetic fungicides for effective management of Phomopsis blight in brinjal.