Efficacy of Insect-Proof Screen in Reducing Infestation of Strawberry by three Important Pests and Effects of Some Biorational Compounds on the two-Spotted Spider Mite Tetranychus urticae K., Under Greenhouse Conditions

Amongst the temperate fruits, the strawberry is an unparalleled crop, and suitable climatic conditions and organic production would make it possible that Iran could be rise as an important producer and exporter. In this study, possibility of using insect-proof screen was evaluated against the two-spotted spider mite (Tetranychus urticae), the western flower thrips (Frankliniella occidentalis), and the strawberry aphid (Chaetosiphon fragaefolii). Infestation of both organic and control greenhouses to the pests, as well as Plant measures (yield and quality average weight per fruit) were compared in organic, control, and commercial greenhouses as CRD. Effects of biorational compounds on the spider mite were evaluated as CRD by the Taguchi’s method. In the organic greenhouse, infestation levels of the leaves to the spider mite and population abundance of the thrips during one-month sampling interval were always below the economic injury level (EIL) (25% of leaflets infested by mite and 5 thrips/flower, respectively), whereas in the control greenhouse they were always above the EIL. In addition, population abundance of the aphid in control greenhouse was always greater than that of the organic greenhouse (0), but in both greenhouses, population abundance was below EIL (30 aphids/bush). Crop yield in commercial greenhouse (317.4 g/bush) was higher than that of the organic one (216.9 g/bush), No significant difference was preset the fruit weight the in between two greenhouses (12.10 and 11.91 g, respectively). Twice application of at a two-day interval NeemAzal® (12000 ppm) 40 ml/pot controlled the mite properly. Results suggest that, insect-proof screens of appropriate mesh may prevent entrance of these pests into greenhouses. Futher more the azadirachtin-containing biorational formulations are recommended for use in organic production of strawberry.