UMass Healthy Fruit Volume 7, No. Foliar Boron Boron is essential for many plant processes.
Deficiencies result directly in apple fruit disorders, but also reduce calcium uptake.
Proper boron management is essential to your calcium-management program. Boron can either be applied to the soil annually at a rate of 2-3 lbs of actual boron per acre. Concentrations should not exceed 6X, and take care to dissolve soluble pesticide bags in the tank before adding the soluble boron. Do not apply boron to peaches unless they are known to be deficient, and if they are, do not exceed 1 lb of actual boron per acre. Magnesium Sprays Can Be Useful Magnesium is commonly deficient in Massachusetts apple orchards.