Study on efficiency of various spraying techniques for controlling two-spotted spider mite, Tetranychus urticae Koch., on common bean (Phaseolus vulgaris L.)

عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران

Two-spotted spider mite, Tetranychus urticae Koch., is a destructive pest on common bean (Phaseolus vulgaris L.) which affects seriously its quantity and quality. As T. urticae feeds mainly on the undersides of the leaves, many of the prevalent spraying techniques have been found ineffective in controlling this pest. In this study, efficiency of six sprayer machines were investigated in controlling T. urticae on common bean var. Akhtar. The Nissoron was used as acaricide. This experiment was performed in factorial based on randomized complete block design with four replications. Experimental factors were sprayer machines with six levels including Hydraulic Motorized Sprayer on Trolley (100 litters sprayer), Motorized Knapsack Mist Blowers Sprayer with common head, Motorized Knapsack Mist Blowers Sprayer with electrostatic head, Motorized Knapsack Mist Blowers Sprayer with Micronear head, Knapsack Micronear Sprayers and Book Knapsack Sprayer with pump side and Nissoron with two levels (0.3 and 0.5 liter/ha). To do so, density of the two-spotted spider mite was identified at 1 day before and 1, 3, 5, 7, 14, 21 and 28 days after spraying. For sampling, 12 bean plants were selected in each plot and three leaves were detached from each plant and finally mite density (number of adults and nymphs) was identified on 2cm² of each leaf. Accordingly, mortality percentage of the pest was calculated. The results showed that there was significant difference among different kinds of sprayers and between Nissoron dosages in mortality rates of two-spotted spider mite (F5, 32 =33.250; P<0.01). The most mortality was observed in 0.5 liter/ha of Nissoron for all types of sprayers. The mortality rates for Motorized Knapsack Mist Blowers Sprayer with electrostatic head, Hydraulic Motorized Sprayer on Trolley, Motorized Knapsack Mist Blowers Sprayer with Micronear head, Motorized Knapsack Mist Blowers Sprayer with common head, Book Knapsack Sprayer with pump side and Knapsack Micronear Sprayers were 83.7, 76.5, 57.4, 43.2, 36.8 and 23.4%, respectively. Accordingly, the best sprayer machine for controlling two-spotted spider mite on common bean was Motorized Knapsack Mist Blowers Sprayer with electrostatic head.

Common bean؛ Two-spotted spider mite؛ Chemical control؛ Different spraying methods