An examination of insect resistance was determined by several steps, i.e. standard sensitivity, resistance diagnosis, and determination of resistance level. Each phase was tested with feeding and residue contact methods at glass tube.... more
An examination of insect resistance was determined by several steps, i.e. standard sensitivity, resistance diagnosis, and determination of resistance level. Each phase was tested with feeding and residue contact methods at glass tube. Resistance ratio (RR) was determined by comparing LC50 value of field population with standard population. Field population of C. pavonana was classified resistant if it had RR 5 4. Biochemistry analysis of resistance was conducted to population of C. pavonana showing resistance to prophenophos insecticide. The activity analysis of acetylcholine esterase (ACHE), esterase, and Glutation S transferase was done with spectrophotometer method. Insect which are resistant to prophenophos insecticide was tested for its sensitivity to Barringtonia asiatica seed extract. Result indicated that C. pavonana population from Pengalengan showed resistance to prophenophos synthetic insecticide. Using contact test, the highest resistance ratio value was 4.04, while by feeding assay the RR was 2.78. The study on biochemical resistance mechanisms of each field population of C. pavonana showed various activities of enzymatic detoxification. This could be due to the difference in the kind of insecticides exposed to each field population of C. pavonana. Since RR value from the contact test was higher than that of the feeding test, the resistance development of C. pavonana to synthetic insecticides was probably caused by physiological and biochemical changes in insect cuticle rather than the activity of detoxification enzyme. Methanolic seed extract of B. asiatica can be used as an alternative of resistance management of C. pavonana to prophenophos synthetic insecticide.
A field trial was conducted at Rice Research Farm of Birsa Agricultural University, RAC (Ranchi Agriculture College) Kanke, Ranchi during Kharif season of 2017 on rice variety Bhadshah Bhog to evaluate the bio-efficacy of different... more
A field trial was conducted at Rice Research Farm of Birsa Agricultural University, RAC (Ranchi Agriculture College) Kanke, Ranchi during Kharif season of 2017 on rice variety Bhadshah Bhog to evaluate the bio-efficacy of different botanical insecticides including untreated control against rice gall midge, Orseolia oryzae. Two sprays at tweenty days interval of ten treatments with three replications were applied in the field. The obtained after each spray revealed that the botanical insecticidal treatments were significantly superior over control in reducing silver shoot infested by gall midge and efficacy was maximum in Neem Baan (Aza. 1.0% EC) @ 1000 ml/ha (4.71% SS) with maximum net profit of Rs. 21325 / ha with B:C ratio 8.5: 1. Neem Baan (Aza. 1.0% EC) could be responsible for realization of the highest grains yield (34.03q/ha) among all the tested botanical insecticides in the present studies. However, when all the treatments including the chemical insecticide, chlorpyriphos (@ 2000 ml/ha) are compared in the context of yield of grains, chlorpyriphos took the lead in the highest yield realization (38.95 q//ha) with net profit of Rs. 31950/ ha with B:C ratio7.7: 1.
