Vol. 11, Special Issue 2 (2022)

Author(s):
Anita Sharma, Purushotam Sharma, Suman Choudhary, Manisha Sharma, KC Kumawat and SK Khinchi

Abstract:
The insecticides viz., malathion and fenvalerate (0.05, 0.075 and 0.1%) and plant oils viz., neem, castor and mustard oil each at three concentrations (5.0, 7.5 and 10%) were evaluated by impregnating the gunny bags against Caryedon serratus (Olivier) (Coleoptera: Bruchidae). The pod damage and weight loss were recorded after six months of storage groundnut, Arachis hypogaea (L.). The per cent pod damage decreased with the increase in the concentration of test compounds. Among the plant oils, the mean pod damage (21.65%) was observed in neem oil followed by castor oil (27.36%) and mustard oil (33.79%). In neem oil, the pod damage was 28.50 per cent at the initial dose level (5.0%) which reduced to 13.59 per cent at highest dose level (10%). While assessing the effect of chemicals, the mean pod damage 0.85 per cent and 2.90 per cent was observed in fenvalerate and malathion, respectively. The fenvalerate was found to be most effective treatment in which pod damage was 2.11 per cent at the initial concentration (0.05%) while no infestation was recorded at the highest concentration of 0.1 per cent. The mean per cent weight loss decreased with the increase in concentration of test compounds. Among the plant oils, the mean weight loss (1.35%) was observed in neem oil followed by castor oil (2.21%) and mustard oil (2.76%). In neem oil, the weight loss was 1.37 per cent at the initial dose level (5.0%) which reduced to 1.13 per cent at highest dose level (10%). However, similar trend was observed in other treatments. With regards to chemicals, no weight loss was observed in all concentrations of fenvalerate. In malathion, 0.56 per cent weight loss was observed at initial concentration (0.05%) whereas no weight loss was revealed at 0.075 and 0.1 per cent concentrations. The fenvalerate and malathion were the best treatment for impregnation of gunny bags resulting in which no infestation caused by C. serratus. Among the plant oils the neem oil was the best treatment for impregnation of gunny bags having minimum pod damage and weight loss while mustard oil was the least effective.