Vol. 12, Issue 3 (2023)

Author(s):
Hem Chandra Chaudhary, Sunil Zacharia, Abhilasha A Lal and Sabita Simon

Abstract:
Maize (Zea mays L.), commonly known as corn, is a highly adaptable crop that is widely grown across the world. It has been dubbed a "miracle crop" due to its versatility and ability to thrive under various agro-climatic conditions. However, this crop is susceptible to maydis leaf blight (MLB), a disease caused by the fungus Bipolaris maydis (Nisikado & Miyake) Shoemaker. MLB can cause a significant reduction in maize yields, ranging from 9.7 to 11.7% (Harlapur et al., 2000), and under certain weather conditions, the disease has been associated with yield losses of up to 70% (Wang et al., 2001). To address this issue, a study was conducted in the laboratory of the Department of Plant Pathology at Naini Agricultural Institute, Sam Higginbottom University of Agriculture Technology and Sciences, Prayagraj (UP), to investigate the effectiveness of fungicides, aqueous plant extracts, and bio-agents against Bipolaris maydis in vitro. Two non –systemic and two combi- fungicides at 1000 ppm, 1500 ppm and 2000 ppm and four systemic fungicides at 500 ppm, 1000 ppm and 1500 ppm. In addition, nine different plant extracts and two bio- agents were evaluated against B. maydis Among the non-systemic and combi-fungicides, propiconazole 13.9% EC + difenoconazole 13.9% EC was the most effective at inhibiting the growth of B. maydis. It showed 80.33%, 88.44%, and 100% inhibition at 1000 ppm, 1500 ppm, and 2000 ppm concentrations, respectively. The next best was carbendazim 12% EC + mancozeb 63% EC, which showed 61.22%, 65.10%, and 78.22% inhibition, respectively. Among all systemic fungicides, propiconazole 25% EC was found to be the most effective, inhibiting 100% of B. maydis growth at all concentrations tested. Difenoconazole 25% EC was also very effective, inhibiting mycelial growth completely at 1000 ppm and 1500 ppm concentrations. The study showed that garlic clove extract is effective in inhibiting the growth of B. maydis, with a 76.11% reduction in mycelial growth at a concentration of 10%, and a 97.11% reduction at 15%. Neem leaf extract also demonstrated significant inhibition, with reductions of 62.33% and 73.78% at 10% and 15% concentrations, respectively. In terms of bio-agents, Trichoderma viride was the most effective in inhibiting mycelial growth, with a reduction of 73.44%, followed by Pseudomonas fluorescens at 57.44%.