If the deficiency becomes sever, the fruit may be misshapen with sunken corky areas. Boron may be supplied as a foliar spray or in a soil application. Rates of application to the soil are generally 1.5-2.5 pounds of actual boron per acre per year. Soil and leaf analyses should be used to determine optimum rates and methods of application. Pears can be sprayed with Solubor at the same rate as apples.
Excessive boron can kill young apple and pear trees.
Recommended Rates and Materials for Nutrient Sprays. Solubor or Soil applied B 3 to 4 1.5-7.5 actual B Petal fall and first cover.