Response of groundnut (Arachis hypogaea L.) cultivars to late leaf spot disease (Passalora personata) under different sowing dates

Experiments were conducted to investigate the effect of date of sowing on groundnut cultivars against late leaf spot disease severity, defoliation, frequency and size of the leaf spot which revealed that all these aspects were significantly influenced by the date of sowing and crop varieties which directly affect the pod yield and test weight. The crop sown early on 25^th June exhibited maximum mean late leaf spot disease severity (range 43.63 to 54.05%), defoliation (range, 17.22 to 22.30%), frequency (range, 1.32 to 1.78/mm²) and size (range, 1.49to 1.56/mm²) and thereby gave reduced pod yield (range, 1225 to 1720 kg/ha) and test weight (28.66 to 32.97 g) followed by 10^th July and 25^th July. Among the groundnut cultivars, susceptible cv. JL24 exhibited maximum mean disease severity (range, 35.94 to 54.05%), defoliation (range, 11.61 to 22.30%), frequency (range, 1.23 to 1.78/mm²) and size (range, 1.26 to 1.56/mm²), followed by TAG 24 and TG 26. However, LGN 1 exhibited least mean disease severity, defoliation, frequency and size with the highest pod yield (ranges, 1720 to 2332 kg/ha) and test weight (ranges, 32.97 to 38.59 g).