White or gray specks may appear on leaves. Older leaves are affected first. Excess manganese may cause iron deficiency and may cause symptoms similar to manganese deficiency. Boron, B, is necessary for the movement of sugars, for reproduction, and for water intake by cells. It also tends to keep calcium in a soluble form.
Boron deficiency causes distorted and dead growing tips, hollow stems and deformed fruit.
Leaves are often scorched and curled and sometimes mottled and discolored. Young leaves are affected first. Excess boron may cause scorched leaf edges similar to potassium or magnesium deficiencies. Zinc, Zn, is necessary for the production of proteins and affects plant size and maturity. Zinc deficiency causes leaf yellowing between the veins, usually with purple or dead spots starting with the older leaves.