Deptt. of Entomology, C.S.A. University of Agri. & Technology, KANPUR (U.P.)
Online published on 6 September, 2012.
Most of the world's rice production comes from irrigated and low land rice fields where insect pest are serious constraints. Diversity in rice ecosystem and climate widely influence rice field and its growth rates over 90 per cent of the world rice grown in Asia where more than 100 insect species attack the crop (1). Amongst more than 80 species of insects infesting rich in India, about 20, including rice, Rice leaf Roller-Cnaphalocrosis medinalis Gn is of major economic importantce in Uttar Pradesh, particularly central region of this state. The experiment was conducted at new dairy farm Kalyanpur, (Kanpur). The soil of experimental field plot was light clay loam. In selecting the field for the experiment, homogeneity of soil fertility was also taken in to consideration. The trial was laid in Randomized Block Design having nine treatments and four replications. The plot size was 5 x 5 m and distance between plot to plot and replication kept at 1 meter, respectively. Eight insecticides, in which 2 granules (Thimet, Carbofuran), 2 emulsified concentrates (Chlorpyriphos, Hostathion), three dusts (Endosulfan, Methyl perathion, Malathion) and one indigenous plant products: Neem oil. was used as soil and foliar spray application in the present study. Surprisingly identical responses were recorded on leaf roller population against all the treatments excluding control after 72 hours of the insecticide application. Almost similar response and trends were recorded after 5 days of treatments. Granular insecticide reponded the best and order of pesticides change at 15 days after treatment to that of earlier two observation intervals and a similar propensity was illustrated after 25 days after treatment in jassid reduction.
