Evaluation of the Efficacy of the Acaricide bifenazate (SC 24%) against Tetranychus urticae Koch in Greenhouse Crops

Spider mite is the most acaricide resistant pest of the greenhouses in the world. Improper acaricide management caused reduction in the effectiveness of the pesticide in a short period of time in a few greenhouses in the country. To increase the diversity and the impact of the acaricidal efficacy, an investigation was carried out to compare the efficacy of the new acaricide biofenzite (Floramite® SC 24%), at the doses of 0.3, 0.4 and 0.5 ml/1000L with the registered doses of hexythiazox (Nissorun® EC 10%), abamectin (Vertimec® EC 1.8%) and etoxazole (Baroque® SC 10%) respectively. Treatments included application of these acaricides against Tetranychus urticae infested strawberry, cucumber and rose plant leaves in Tehran and Esfahan provinces with a control (water spray). The complete randomized block design with three replications was used and with each replicate consisting of crops planted in 30 meter long rows. Samplings were done randomly at intervals of one day before and 3, 7, 14 days after spraying for strawberry and cucumber and this period extended up to 21 days for rose in Esfahan. The effect of each treatment was evaluated by counting the active mite stages on the lower side of 30 randomly collected leaves of strawberry, cucumber and roses. Percent mortality was calculated by Henderson- Tilton formula and statistical analysis was done with SAS software. Acaricidal treatments were compared with Duncan Multiple Rang Test Method. Results showed that all Floramite doses caused higher percent mortality (81.68-85.24%) up to 14 days on cucumber leaves. Maximum rose spider mite percent mortality was observed by 0.5 ml/1000L Floramite dose (61.14%) up to 21 days after treatment in Esfahan. The results show that, 0.4 and 0.5 ml/1000L of Floramite doses could be used in greenhouses with previous records of chemical control measures against spider mite infestation.