Studies on Varietal Preferences, Physico-chemical Pod Characters of Groundnut Against Bruchid, Caryedon Serratus (Olivier) and Its Management

Abstract

Studies on varietal preferences, physico-chemical pod characters of groundnut against bruchid, C. serratus (Olivier) and its management were conducted in the Department of Entomology, College of Agriculture, Meerut, during August, 2018 to February, 2019. Ten groundnut varieties were selected, and their pods were assessed for resistance/susceptibility to the bruchid, based on the biological attributes of the pest on the variety. Index of susceptibility (IS) was taken as the criteria for assessing the resistance or susceptibility and the varieties were classified into five categories viz., resistant (0-2.5), moderately resistant (2.6-5.0), moderately susceptible (5.1-7.5), susceptible (7.6-10) and highly susceptible (>10). The groundnut varieties viz., Harithandra, K-1809 and K-1805 recorded less oviposition rate and adult emergence, prolonged developmental period, less growth index with low per cent pod damage and weight loss by C. serratus, and these varieties were categorized as “Resistant” genotypes. Similarly the genotypes, K- 1715 with higher oviposition rate and adult emergence, growth index and shorter mean developmental period with higher per cent pod damage and weight loss by C. serratus were considered as “susceptible” genotypes, whereas, K8-Bold (2.92), K-1621 (4.80) and Chitravathi (2.70) were moderately resistant, while K7-Bold (6.29), K-1930 (5.10) and K-6 (5.56) were moderately susceptible genotypes. Physical parameters of these genotypes showed significant differences for pod length × width, pod shell thickness, pod weight and inter granular space. Shell thickness contributed to resistance, while inter granular space, pods size and weight provided susceptibility. Chemical parameters of these genotypes showed significant differences for pod sugars, pod proteins, pod phenols and pod tannins. Pod sugars and pod protein content had a positive effect on the development of the bruchid. While, pod tannins and pod phenols exerted a negative effect. Study on relative efficacy of some grain protectants i.e. Neem leaf powder, Rhizome powder of turmeric, Lantana leaf powder, Pepper seed powder, Custard apple leaves, Ginger powder, Garlic powder, Chilli powder and control, the treatment black pepper powder showed greater significance of pest control and at par with treatment lantana leaf powder and neem leaf powder.