INFLUENCE OF ADDITIVES IN THE END-USE MIXES OF TEBUFENOZIDE ON DEPOSITION, ADHESION AND PERSISTENCE IN SPRUCE FOLIAGE

A commercial flowable formulation of tebufenozide, RH-5992 2F -butyl-N '-(3,5-dimethylbenzoyl)-N-(4-ethylbenzoyl) hydrazine], was diluted wit h water, water and canola oil, and water and the methyl ester of canol a oil, to provide six end-use mixes with concentrations of 35 and 70 g of active ingredient (Al) litre(-1). The mixes were applied at 70 and 140 g Al ha(-1) over white spruce [Picea glauca (Moench) Voss] seedli ngs in a laboratory spray chamber and foliar concentrations of tebufen ozide were determined over a 60-d period. At intervals of time post-sp ray, seedlings were sprayed with monosized droplets of Sunspray(R)11N as rainfall, and the amount of tebufenozide knocked off from foliage w as determined. The potential energy of adhesion (PEA) of the Ai partic les on the foliage increased with time and varied according to the typ e of end-use mix, its viscosity and the dosage sprayed. The end-use mi xes were applied over while spruce trees under field conditions and pe rsistence of tebufenozide was investigated. DT50 Values were influence d by the type of mix and dosage sprayed. Oil-containing mixes and high er dosages increased the PEA of tebufenozide particles.