Document Type : Pest Management
Authors
Abstract
Amount of acaricidal used on apple mite pests (Tetranychus urticae Koch and Panonychus ulmi Koch) were recorded more than any other crops damaged by spider mite in Iran. Effects of three doses (0.4, 0.5, 0.6 per thousand) of new acaricides spirodiclofen SC 240, evaluated in comparison with two other registered acaricides i.e. fenazoquen 20% SC and clofentazine 50% SC on active stages, egg and two injury level of P. ulmi (ERM) and active stages of T. urticae (TSPM) on red and golden varieties of apple orchards in Tehran, Khorasan, West Azarbaijan, Ardebil and Esfahan provinces during 2003. The BCRD method was used to assign 4 replications of five treatments along with an untreated check plots. Mean mortality % recorded one day before and 3, 7, 14 and 25 days after treatments and mortality% calculated by Henderson-Tilton method. Analysis of variance on mean collected data carried out by SAS method and mean mortality% also grouped with DMRT method. Application of treatments initiated when mean observed of 3 and 5 active stages P. ulmi and T. urticae,respectively. Treatments effects on ERM active stages showed that, except Clofentazine and all treatments in Ardebil, reached to the mortality above 80%. Maximum control % recorded for doses of spirodiclofen 0.5 and 0.6 doses in Tehran and W. Azarbaijan provinces, respectively. Treatment effects at sampling interval found varied and except in Esfehan observed at increasing level up to 7 days after with 92.29% of spider mite inTehran. Decreasing mite mortality of those treatments also recorded 14 days onward with maximum 87.7% control at 25 days interval in Khorasan. Ovicidal effects of clofentazine was found weak against egg stage of ERM in comparison to other treatments.. Acaricidal effects on low number of ERM in late spring observed more effective than when mite population ranging between 5-10 mites/leaf during hot and dry condition in middle of summer months. Control measures on active stages of TSSM in apple orchard of Esfehan with mean of 10 to 12 mites/leaf was found more effective than in Tehran with mean of mite was ranging between 2.08-3.43 mites/ leaf.. Maximum mortality of TSSM among treatments recorded 96.15% and 86.14% for fenazoquen,n and spirodiclofen dose 0.6/liter water respectively in Tehran province. Side effects of Spirodiclofen on apple natural enemies observed with less hazardous to adult of Stethrous spp only fourteen days after treatments.
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