Initial defoliation as predictor of topkill in brush-control spraying
Data from 15 foliar spraying studies comprising numerous herbicidal formulations and a variety of woody species yielded no relationship that would permit topkill to be accurately predicted from defoliation measurements. Defoliation does, however, define the upper limit of expectable topkill. Thus if defoliation is unsatisfactory, topkills will be no better and retreatment can be planned. When defoliation was satisfactory acceptable topkills were obtained in about 60 percent of the comparisons, but there was no way to predict which treatments would recover.