Agriculture Reference
In-Depth Information
and twenty-four ounces per 100 square feet annually.
Magnesium deficiency will cause the spaces between the
veins of the leaves to look bleached-out at first, and then
some of the tissue will die and turn brown. In brassicas, the
bleached-out areas may include other pigments such as
orange or violet.
Manganese: Manganese is necessary for photosynthesis and
improves the yield of root crops. It is very rare to need
manganese unless your soil pH is naturally higher than 6.5,
which is also rare. Soils that are over-farmed can be deficient,
but this is unlikely to apply to your garden. If manganese
deficiency symptoms occur anyway, as manifested in a
uniform yellowing of new leaves,
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you can add manganese
sulfate at the rate of twelve ounces per 100 square feet. Only
add this once every three years as it tends to remain in the
soil. Slight manganese deficiency is hard to spot because it
looks like an extremely mild case of iron deficiency. In more
severe cases, leaves develop a definite grayish metallic sheen
and spots of dead tissue appear along the veins.
Molybdenum: Molybdenum is needed for practically every
cellular process in a plant. Most soils are deficient in
molybdenum. In excess, it is extremely toxic to plants.
Furthermore, a slight excess of molybdenum will exacerbate
any existing problems with manganese deficiency. Sufficient
levels of copper will mitigate the adverse effects from an
excess of molybdenum. For this reason, I recommend that if
molybdenum is added, it should be added in conjunction with
copper and manganese. If you add molybdenum, I
recommend using sodium molybdate or ammonium
molybdate. Ammonium molybdate or sodium molbdate
should be added at the rate of one-and-a-half ounces per 100
