Chlorosis: Chlorosis in grapes is usually caused by iron deficiency. American varieties are particularly prone to have this problem. The leaves turn yellow, but the veins remain green. If not remedied, chlorosis will decrease the yield, reduce sugar content of the fruit, and eventually kill the vine. Two applications of iron sulfate or iron chelate during the growing season should control chlorosis. In high pH soils, iron sulfate and some iron chelate may become tied up and unavailable to the plant. Foliar applications can be made, or a chelate especially for alkaline and calcareous soils, such as Sequestrene 138Fe, can be used.

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