Results concerning testing of the spirotetramat active ingredient for controlling of two spotted spider mite (Tetranychus urticae Koch) at soybean crop in South-East of the Romania

Abstract

Two spotted spider mite (Tetranychus urticae Koch) is one of the most dangerous pest of soybean crops in Romania. In case of lack of the control measures, damages produced by this pest can arrive at 70% or, in some cases, at 100%. High temperatures and, especially, drought from summer period represent favorable conditions for two spotted spider mite. Chemical control is the most effective method to control T. urticae at soybean crop. However in Romania there are low numbers of registered active ingredients for control of this pest. In period 2014-2016, at NARDI Fundulea there were tested three doses of spirotetramat active ingredients for two spotted spider mite control in soybean crop. Average air temperatures registered in July and August, between 2014 and 2016, was higher then multiyear average. Also, rainfalls amount registered in July was below multiyear average while rainfalls amount registered in August 2014 were lower then multiyear average, higher in August 2015 and close to normal in August 2016. Result of this experiment show that in the climatic conditions from NARDI Fundulea, spirotetramat active ingredient, applied like vegetation treatment, in dose of 0.75 p.c./ha have effectiveness higher then 99 % in control of two spotted spider mite at soybean crops, between 2014 and 2016, while spirotetramat in dose of 0.60 p.c./ha have effectiveness higher then 98 %. This doses of spirotetramat have similar effectiveness with hexithiazox active ingredient, applied in dose of 0.40 kg/ha. In last years, climatic conditions from summer period, in south-east of the Romania were favorable for two spotted spider mite attack