Efficacy of biorationals and botanical formulations against Helicoverpa armigera hub. in sunflower

Abstract

Field investigations were conducted to check the efficacy of biorational and botanical formulations against capitulum borer, Helicoverpa armigera Hub. infesting sunflower. The results revealed that significant differences existed between the treatments at two days after first spray and third and seventh days after second spray. At three days after second spray, lowest population of H. armigera was recorded in spinosad and profenophos treatments (0.05 per plant), followed by garlic chilli kerosene extract (GCKE) (0.11 larvae per plant) and V-Bt (Bacillus thuringiensis) (0.16 larvae per plant), however, untreated check recorded the highest H. armigera larval population (4.53/plant). Among the different biorationals, the V-Bt treatment recorded highest seed yield (3528 kg/ha.), volume weight (55.14 g/100ml) and oil content (37.78%). The cost: benefit analysis revealed that the highest benefit: cost ratio was recorded in Parthenium leaf extract treatment (37.29), whereas, intermediate C: B ratios were recorded in Neem seed kernel extract (20.17) > Pongamia seed kernel extract (12.54) > profenophos (8.81) > spinosad (8.36) > IPM module (5.34) > HaNPV (3.85) > V-Bt (2.49) > GCKE (1.48) > panchagavya (0.29) > Bt-Halt (0.04), in that decreasing order. The findings throw light on the fact that biorationals viz., Bacillus thuringiensis, NSKE and PSKE, show promise in the suppression of H. armigera, besides being economical and ecofriendly.