Phosphorus

A dull, dark green color will appear on the leaves.

This symptom often has been characterized as black leaf of grapes Marginal chlorosis, browning, and drying may      occur as the deficiency becomes more severe.

Potassium

Severe potassium deficiency greatly reduces vine vigor, berry size, and crop yield.

Symptoms of potassium deficiency generally develop in mid-shoot leaves followed by older basal leaves.

Calcium

Growth of the plant is reduced.

Symptoms are first seen at the growing points of the plant, which may become necrotic and die.

Magnesium

Symptoms of Mg deficiency develop on the older leaves first.

Chlorosis (yellowing) appears between the veins of the leaves while the veins remain green.

Sulphur

Whole orchard or spot-wise stunted growth of pale-green plants.

Boron

Poor fruit set clusters will tend to be small, and berries will not fully develop on the rachis.

Terminal buds may not break in the spring, and ends of shoots sometimes are distorted.

Iron

Leaf veins remain green interveinal portion turns yellow young leaves small but not deformed.

Manganese

Symptoms first appear as interveinal chlorosis, or yellowing of the younger terminal leaves.

Zinc

Poor fruit set and stunted shots with small, misshapen leaves foliar application of zinc is the most effective      method for treating Zn deficiency.