Effects of water volume rates on spray deposition and control of tarnishedplant bug [Hemiptera : Miridae] in strawberry crops

Field experiments were performed on the effect of three volumes of applicat ion on spray deposition and insecticidal efficacy against the tarnished pla nt bug (Lygus lineolaris) in two strawberry (Fragaria ananassa) cultivars, Kent and Chambly. The rate of application of malathion was kept constant at 4.5 kg a.i. ha(-1) for volumes of application of 500 and 1500 L ha(-1). Pl ant coverage was measured using a fluorescent tracer applied at volumes of application of 500, 1000 and 1500 L ha(-1). The tracer was recovered from s amples taken from different plant locations and on the ground. Tarnished pl ant bug populations were evaluated 24 hours before and after insecticidal t reatment. When coverage data were normalized for a fixed active ingredient rate, an increase in the volume of application from 500 to 1500 L ha(-1) fr equently had no effect on the amount of tracer recovered at the various loc ations. On some occasions, an increase in volume of application resulted in a decrease in the amount of tracer recovered, i.e. leaves at the top and b ottom of the canopy (Kent), sepals (Kent). Tarnished plant bug population c ontrol was commercially acceptable at 500 and 1500 L ha(-1).