Some effects of continuous use of herbicides in sultanas in the Sunraysia area.

As an alternative to cultivation, repeated yearly applications from 1964 to 1968 of simazine plus or minus amitrole gave satisfactory weed control in sultanas at two sites in the Sunraysia area. The minimum rates needed of simazine per year were 1.3 and 3.3 lb an acre at the lighter and heavier soil sites respectively. There were no differences in residual weed control if amitrole was added to these amounts. Sultana maturity and yield, leaf nitrogen, phosphorus and potassium, and soil organic matter, pH and cation exchange capacity were all unaffected by the herbicide applications.