It is part of the chlorophyll molecule and is necessary for the activation of carbohydrate metabolism enzymes.
Deficiency – The first symptoms of deficiency appear in the older leaves, the characteristic symptom being chlorosis or interveinal yellowing of the old leaves, with the veins remaining green.
Magnesium deficiency also promotes a reduction in the sugar content in the must and can cause the rachis to desiccate, due to the imbalance in the K/Mg ratio, with greater potassium absorption.
