ABSTRACT

Groundnut foliar diseases possess a significant threat to groundnut cultivation leading to considerable yield loss due to late leaf spot and rust of groundnut. In the loss assessment experiment, highest per cent loss in pod and haulm yield due to late leaf spot and rust was recorded in JL-24 (40.56% and 44.24%) while, least per cent loss in pod and haulm yield was recorded in Dh-257 (6.56% and 7.92%) and highest per cent loss in test weight and shelling percentage was recorded in JL-24 (15.76% and 6.89%) while, least per cent loss in test weight and shelling percentage was recorded in Dh-257 (1.89% and 1.23%). GPBD-4 exhibited slow rate of disease progression with minimum AUDPC value (41.48) and least ‘r’ value (0.02) and with respect to rust, Dh-257 was identified as slow ruster with minimum AUDPC value (110.81) and least ‘r’ value (0.03).
In the foliar disease management trails, tebuconazole 25.9% EC @ 1 ml/l- tebuconazole 25.9% EC @ 1 ml/l was found effective with least late leaf spot severity (30.57 PDI) and rust severity (25.56 PDI) with highest pod yield (22.64 q/ha) and haulm yield (35.27) q/ha with highest B:C ratio (2.47) over untreated check. The next best treatment was Pseudomonas fluorescens @ 10g/l- tebuconazole 25.9% EC @ 1 ml/l) with late leaf spot severity (34.36 PDI) and rust severity (34.75 PDI) and pod yield (20.99 q/ha) and haulm yield (30.01 q/ha) with B:C ratio (2.32) was also found effective in the perspective of eco-friendly management of LLS and rust.
Among the 40 advanced breeding lines screened against late leaf spot and rust, only four lines (Dh-316, Dh-317, Dh-277 and GND-21) showed resistant reaction against both the diseases.