In vitro efficacy of some fungicides for the management of Rice Blast Pathogen Magnaporthe oryzae

Abstract

Fungicides are used in agriculture for the management of plant diseases for effective food production. In this study, we conducted an in vitro experiment using three synthetic fungicides on mycelium growth of Magnaporthe oryzae. Among the tested fungicides, percent mycelial growth inhibition was higher in Contaf 100 % concentration (86.1%) followed by Contaf 50 % concentration (85.0 %). The least inhibition was observed in Raksha 50% concentration with 43.3% inhibition. We also evaluated the effect of seed dressing chemicals on the percentage germination of rice seeds. The results showed that all seeds treated had over 80 % germination at 7 days after sowing (DAS) compared to untreated (control) seeds which had only 65 % germination. Germination was higher (85 %) at 7 days after sowing, with seeds treated with Raksha, followed by Star-dress with 84 % while the least germination was observed with the seeds treated with Apama plus 81 %. Furthermore, the impact of seed dressing chemicals on the rice seedling vigor was also evaluated. Highest seedling vigor was observed on seeds treated with Star-dress with mean seedling length of (22.5 cm) which showed the highest vigor index of 1893, followed by Apama plus with mean seedling length of (22.1 cm) and a vigor index of 1792. Least seedling length of (18.9 cm) was observed with Raksha which was even lower than the control (20.4 cm). Our results suggested that fungicides can be effectively administered for the management of plant diseases to support seed germination and seedling vigor.

Keywords: seed germination, seedling vigor index, seed dressing chemicals, Magnaporthe oryzae