The influence of acaricides and potassium silicate on population density of Tetranychusurticae in hydroponic greenhouse

Tetranychus urticae koch. (Acari: Tetranychidae) is one of the important pests of strawberry greenhouses in Kermanprovince. Chemical control is one of the most common strategies for management of spider mites. Silicon in plantscan induce high mechanical stability and increase plant defense against pests. The present study was carried out toinvestigate the toxic effects of Spiromesifen 24% SC, Abamectin 1.8% EC and potassium silicate 2lit/ha against allmobile stages of pest on Paros cultivar of strawberry. Distilled water was used as a control. Treatments were sprayedon both surfaces of strawberry leaves. An experiment was conducted in a hydroponic greenhouse (temperature: 25 ±1˚C, RH: 50± 5% and photoperiod: 14L: 10D) based on a completely randomized design at 8 repetitions. OnesampleT-test was done for each treatment between pest density before and after spraying in SPSS v22 software.Also, data on density among treatments analyzed by the one-way ANOVA and the comparison of differencesbetween treatments was done using Student–Newman–Keuls test (P<0.05). T-test for each treatment showedsignificant differences (P≤0.001). Population density of pest revealed significant differences among the fourtreatments after spraying, whereas it wasn’t significantly different before spraying. The lowest and highest of mitedensity per plant was observed in treatments of potassium silicate (3.75 ± 0.71) and control (12.75 ± 1.51),respectively. Likewise, pest density per plant in oberon and abamectin treatments were estimated 7.75 ± 3.33 and8.00 ± 2.45, respectively. This research can provide valuable information for control of T. urticae.

Keywords:

oberon , abamectin , potassium silicate , strawberry