Magnesium deficiency

Magnesium (Mg) deficiency is a plant disorder. Magnesium can be easily washed out of light soils in wet seasons. Excessive potassium fertiliser usage can cause also Mg to become unavailable to the growing plant.This disorder particularly affects potatoes, tomatoes, apples, currants and gooseberries, and chrysanthemums.Symptoms include, yellowing between leaf veins, which stay green, giving a marbled appearance. This begins with older leaves from late June, but spreads to younger growth. Can be confused with virus, or natural aging in the case of tomato plants. Fruits are small and woody.
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Magnesium deficiency Hypomagnesemia, low magnesium A clinical situation due to inadequate intake or impaired intestinal absorption of magnesium, [more]Magnesium deficiency - Community and Resources

Can occur due to inadequate intake or impaired intestinal absorption of magnesium. Low magnesium (hypomagnesemia) is often associated with low calcium (hypocalcemia) and low potassium (hypokalemia). Deficiency of magnesium causes increased irritability of the nervous system with tetany (spasms of the hands and feet, muscular twitching and cramps, spasm of the larynx, etc.). According to the National Academy of Sciences, the Recommended Dietary Allowances of magnesium are 420 milligrams per day for men and 320 milligrams per day for women. The upper limit of magnesium as supplements is 350 milligrams daily, in addition to the magnesium from food and water.