20. Efficacy of different insecticides against pod borer Helicoverpa armigera in gram field
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Abstract
This study was carried out at Entomology Section, ARI, Tandojam on chickpea variety DG-92. Two applications were done to determine the efficacy of Match 050 EC, Polytrin-C 440 EC, Lorsban 40 EC insecticides at 15 days interval. The observation was recorded before treatment and after 24, 48, 72, 96 hours and 7 to 14 days. The pre-treatment count of the H. armigera in plot application with Match (1.90±0.18) which was decreased to 1.33±0.19, 1.00±0.30, 0.73±0.12, 0.67±0.13, 0.70±0.13 and 0.40±0.09/plant, respectively; followed by the plot application with Polytrin-C the H. armigera population for the observation of pre-treatment (2.70±0.26) which was decreased to 2.00±0.19, 1.70±0.19, 1.53±0.17, 1.07±0.17, 1.03±0.21 and 0.40±0.09/plant after 24, 48, 72, 96, one and two week of application, respectively. in the same way, on the plot application with Lorsban, the pre-treatment pod borer population was (3.17±0.21) reduced to 2.73±0.19, 2.37±0.19, 2.07±0.18, 1.93±0.30, 1.70±0.22 and 1.50±0.24/plant after 24, 48, 72, 96, 1 week and 2 weeks of application, respectively. In case of untreated control plots, the population of the H. armigera remained frequently high all through the study period which was 3.77±0.45 before treatment, 3.97±0.42, 4.00±0.54, 4.20±0.67, 4.23±0.51, 4.80±0.62 and 5.30±0.43/plant after 24, 48, 72, 96 hours , 1 week and 2 weeks of application, respectively. The second application results showed that the H. armigera population varied significantly (P<0.05) when observed after 24, 48, 72, 96, one and two week after of application; while pre-treatment population on the experimental units was almost uniform and non-significant (P>0.05)After second application the population of H. armigera before treatment with Match was (2.00±0.17) declined to 1.60±0.18, 0.97±0.13, 0.83±0.13, 0.70±0.13, 0.57±0.10 and 0.23±0.08/plant.
Keywords: Insecticides, Pod borer, H. armigera Chickpea, Cicer arietinum
http://dx.doi.org/10.19045/bspab.2020.90254