طراحی، ساخت و ارزیابی دستگاه جمع آوری آفات Bio-Collector) )در مبارزه با آفت سرخرطومی برگ یونجه

Alfalfa weevil is considered to be the most destructive insect pest on alfalfa worldwide. Large amounts of chemical insecticides are sprayed in alfalfa farms to reduce the damage every year. As alfalfa is a main source of fodder for livestock, some of these chemicals can flow in meat as well as dairy products which are finally used as human food. Moreover, there are many side effects on beneficial insects and honeybees in alfalfa farms. Current research was undertaken to design, build and test a mechanical device as an exclusive bio-collector to help reducing alfalfa weevil population after cutting operation by physical removing of remaining insects in all living stages. During the first year of a 2-year project, designing and building of machine was completed. Field studies on performance and evaluation of the efficacy was conducted in second year in an alfalfa farm near to the Kheirabad agricultural research station in Zanjan province. The experiment was laid out in factorial design as completely randomized design. Two main factors including suction pressure and moving speed were tested for evaluation of machine efficacy. Performance efficacy was measured and evaluated in terms of percentage of control on 3rd and 4th instar larvae, percentage of control on adult weevils, percentage of control on other insects and percentage of control on weed seeds. Treatments were considered as a combination of two moving speeds (2km/h and 5 km/h) with three suction pressures (Low: 0.34mb, Medium: 0.90mb, and High: 1.68mb). 3 replications were considered for each treatment (including control) and so, there was total of 18 experimental units (plots). Analysis of results was conducted by using MSTAT and SPSS statistical softwares with Duncan Multiple Range Test. The mean value of suction pressure at the head of device in low, medium, and high levels were 0.34, 0.90, and 1.68mb respectively and the mean value of exhausting wind speeds at fan chamber also were 12.36, 21.26, and 26.98m/s in low , medium, and high motor speed. Result indicated that the effects if moving speed on control and collection of 3rd instar larvae at p<0.05, effects of suction pressure on control and collection of adult weevils at p<0.05 and effects of suction pressure on control and collection of 3rd and 4th instar larvae at p<0.01 were significant. Results from the comparison of mean values showed that the maximum percentage of control ( درصد40.7) achieved on 3rd instar larvae at the moving speed of 2km/hr. The maximum percentage of control on adult weevils equal to درصد35.2 is that corresponding to rotation speed of 4198rpm (high suction pressure, 1.68mb) Key Words: alfalfa, alfalfa weevil, Bio-collector, IPM, pneumatic control