EFFECT OF SUNLIGHT AND STORAGE TIME ON STAIN SIZE OF A DYED SPRAY DILUENT

In research on pesticide application technology, dyes and/or tracers a re often added to the spray mixture. Dyes are used to enhance the cont rast between stains made by droplets impinging on various surfaces whi le tracers allow for the measurement of the mass of liquid collected. This article quantifies that light and time stability of stains made b y droplets of a spray mixture on Kromekote(R) cards. The spray mixture was insecticide diluent ID585, 2% by volume Automate Red B dye, and 1 % by volume tris (2-ethyl hexyl) phosphate (TEHP). The red dye provide s a good contrast on white Kromekote cards. Using image analysis, the size of the stains of various initial diameters was monitored after so lar exposure levels up to 2277 kJ/m and after storing the samples away from light under laboratory conditions (approximately 21-degrees-C, u ncontrolled relative humidity) for up to two months. Results showed th at stain size was stable under all these conditions. The spray mixture is therefore well suited for research on physical aspects of pesticid e application technology.