Ca formulations containing nitro-gen after the end of July or fruit quality may suffer. The desirable range for micronutrients is quite narrow. More damage is possible if micronutrients are applied in excess rather than from deficiencies. For this reason, do not apply micronutrients to fruit crops unless leaf analysis or visible symptoms confirm a deficiency. Only the nutrient that is deficient should be applied in sufficient quantities to correct the problem.
Boron deficiency can have an effect on growth and fruiting.
There is currently no accredited soil test for boron in Ontario. Use a petiole analysis to check for boron deficiencies. Boron levels should be 20-60 ppm. Where a boron deficiency has been confirmed, soil or foliar applications of boron may improve boron in plant tissues. There are several sources of boron, check the manufacturer's recommended rates and timing of applications.