Management of Alternaria leaf spot and blight of groundnut using fungicides

Abstract

A field experiment was carried out to evaluate the efficacy of different fungicides in managing Alternaria leaf spot and blight in peanut. The results indicated that all fungicidal treatments significantly reduced disease severity compared to the untreated control, with no statistical differences among treatments. Among the tested fungicides, two sprays of Difenoconazole @ 0.025% at 60 and 70 days after sowing (T5) were most effective, recording the lowest disease severity (3.3) against 4.8 in control with the highest per cent efficacy of 32%. Biological, pod, and haulm yields were significantly enhanced by all treatments, with T5 showing the maximum pod yield (1807 kg/ha) and haulm yield (3162 kg/ha) compared to control (1572 and 2752 kg/ha, respectively), resulting in a 13% increase in biological yield. Economic analysis revealed that T5 treatment achieved an incremental cost-benefit ratio (ICBR) of 1:4.8, slightly lower than T1 (1:6.1) due to higher fungicide cost. Overall, Difenoconazole @ 0.025% proved to be the most effective treatment for the management of Alternaria leaf spot and blight in peanut with significant yield improvement.