Effectiveness of different insecticides against whiteback plant hopper Sogatella furcifera (Horvath) on rice crop at Dokri [Pakistan]

Seedlings of rice variety IRRI-6 were planted in a row to row spacing of 30 cm during the month of May, 1999 using RCBD to see the performance of various insecticidal treatment. There were six treatments consisting five insecticides namely Thiodan-35 EC at 600 ml/ac, Azodrin-40 EC at 500 ml/ac, karate 2.5 EC at 250 ml/ac, Lorsban 40 EC at 250 ml/ac, Lorsban EC at 400 ml/ac and Deltapine 400 EC at 400 ml/ac and a control, each treatment was replicated four times. As such there were 24 plots. All insecticides were applied at economic thresh hold level. Pre-treatment population of white back plant hopper was recorded one day before treatment, while post treatment population was recorded at 24, 48 and, one week after spray. 24 hours of post treatment Karate 2.5 EC caused greater mortality of pest (81.13.) , followed by Azodrin 40 EC. (75.28%). After 48 hours the trend of effectiveness of various insecticides remained same. Karate reduced more pest population (89.31 %) followed by Azodrin (82.24%). One wee}c of post treatment pest population affected significantly by the insecticides as earlier during 24 and 48 flours of after spray. Karate had the greater mortality (85.30 %) over all other products tried. Grain yield recorded varied significantly by the insecticide treatments. Plots treated with karate 2.5 EC and Azodrin 40 EC resulted in Maximum grain yield 16.62 and 15.53 kg/plot) however, other treatment also gave more yields over control but remained at par with karate and Azodrine. On the basis of present studies it may be concluded that Karate and Azodrine were the effective insecticides in controlling white back plant hopper on rice crop as these products have longer toxicity when compared to other insecticides. The greater reduction of pest resulting in more rice yield. It may therefore be recommended that Karate 2.5 EC at 250 ml and Azodrine 40 EC at 500 ml may be sprayed against white back plant hopper in rice crop.