Foliage sprays of magnesium nitrate at 10 pounds per 100 gallons of water– applied in citrus plots when the spring flush of growth was about two thirds expanded–substantially increased the magnesium concentrations in the leaves. After trees were sprayed, further development of magnesium deficiency symptoms was checked. Within six months, leaves with symptoms at the time of spraying had dropped and sprayed trees were then practically free of symptoms. Leaves which had shown no deficiency became deeper green than similar leaves on nonsprayed trees.

The above progress report is based on Research Project No. 1632.