Investigation on the Thiodicarb (Larvin 80%-DF) Efficiency on the Beet Armyworm in Comparison With Current Insecticides.
2001
Rastegari, Nuzar | Ashraf Mansuri, Gholam Reza | Tavakkoloi, Bahram | Ravanbod, Asghar
During a 2-year research, 1998- 1999, the efficacy of 3 different insecticides, including thiodicarb, carbaryl and phozolone were compared to control the beet armyworm larvae population on sugarbeet in Fars province (Darab station) using a Completely Randomized Block Design (CRBD) with 5 treatments and 4 replications. The treatments were thiodicarb (Larvin 80% DF) at the rates of 0.75 and 1.0 kg/ha, carbaryl (Sevin WP 85%) 3 kg/ha, phozolone (Zolone EC 35%) 2L/ha and control. The threshold for economic injury level (EIL) was considered as 2-larvae/ plant. Spraying was done a few days after reaching EIL with an atomizer sprayer and larvae (third instars onwards) were counted 1 day before and 1,3,5,7,10 and 15 days after spraying on 20 randomly selected plants in each plot (6 rows × 10 m length). Based on the larvae populations on 1 day before spraying the percentage mortality within each plot (replication) were calculated using Schneider and Orelli&rsquos formulation. The obtained data were transformed to Arcsin and were subjected to analysis of variance. The means were compared by Duncan,s Multiple Range Test. The results in both years showed that although all the treatments compared with control produced satisfactory mortality in pest population, but the effect of thiodicarb (both concentrations) is more sever and prolonged compared with 2 other treatments till 15 days after spraying. The mean percentage mortality in both years, for all 4 treatments and in all the days of sampling show more than 84% mortality for larvae. Two-factor analysis variance of data (insecticide and time interaction) showed that the best result is due to Larvin 1 kg/ha in 15th day after treatment.
Показать больше [+] Меньше [-]