Effect of Different Fertilizer Regimes on Life Table Parameters of Tetranychus urticae (Acari: Tetranychidae) on Resistant Bean Cultivar

Cultural methods such as crop fertilization can affect susceptibility of plants to herbivores by altering plant tissue nutrient. In this study, the life table parameters of the two-spotted spider mite (TSSM), Tetranychus urticae Koch were determined under different chemical fertilizer regimes on resistant bean cultivar (var. Parastoo) under laboratory conditions at ۲۵±۱°C, ۶۰±۵% RH and a photoperiod of ۱۶:۸ (L:D) hour. Treatments included ۳۰, ۶۰, and ۱۰۰% of the recommended level of urea, ammonium nitrate, and potassium sulfate fertilizers. According to the obtained results, the longest preadult development time was related to individuals reared on the fertilized bean with potassium sulfate ۶۰%, while the shortest period was related to those on ۳۰% ammonium nitrate and ۶۰%urea. The mean fecundity of the individuals reared on fertilized beans with different concentrations of ammonium nitrate (especially ۶۰% ammonium nitrate) were significantly higher than the other fertilizers. The highest and lowest values of intrinsic rate of increase (r) were obtained on beans fertilized with ۶۰% ammonium nitrate and ۱۰۰%potassium sulfate, respectively. In addition, the values of net Reproductive rate (R۰) and the Gross Reproductive Rate (GRR) of TSSM reared on bean fertilized with ۶۰% ammonium nitrate were significantly higher than the other fertilizer treatments. Our findings may provide important information in the design of a comprehensive program for integrated soil fertility management and subsequently integrated management of TSSM in bean fields.

Keywords:

Nitrogen fertilizer , Potassium fertilizer , Two-spotted spider mite , Urea fertilizer.