Micro Nutrients

Micro nutrients are those absorbed in small to minute quantities. They are generally less well known than the previsouly listed Macro nutrients since most plant foods don't contain them. Here's the list of what they are and the effects they have on plants.

Required for cell wall formation.

Deficiency: Calcium deficiency causes stunting and crinkling leaves. Young shoots die and blooms fall from the plant. Calcium deficient tomatoes will develop brown spots on the bottom of the fruit which will cause decay especially with the onset of high temperatures. This is called blossom end rot or BER. Toxicity: Excessive Calcium is difficult to spot.

Protein synthesis, water uptake , fruiting and seeding, a natural fungicide.

Deficiency: Sulfur deficiency is uncommon but can cause young leaves to turn yellow with purple bases.

Toxicity: Excessive sulfur slows growth, leaves are smaller.

Chlorophyll formation, helps in respiration of sugars to provide growth energy.

Deficiency: Iron deficiency is common and causes new growth to become pale and blossoms to drop from the plant. Yellowing is initially observed between the veins and leaves may die along their margins.

Toxicity: Excessive Iron is difficult to spot and is quite rare.

(Mg) Magnesium:

Utilized in chlorophyll production and enzyme manufacture.

Deficiency: Magnesium deficiency causes older leaves to curl and yellow areas to appear between leaf veins. Only the newest growth will remain green as Magnesium is transported from the older leaves to feed the newer ones.

Toxicity: Excessive Magnesium symptoms are rare. (B) Boron:

Necessary for the formation of cell walls in combination with calcium.

Deficiency: Boron deficiency results in brittle stems and poor growth. Stems may twist and split. Toxicity: Excessive Boron will cause leaf tips to become yellow and die off.

(Mn) Manganese:

A catalyst in the growth process, formation of oxygen in photosynthesis.

Deficiency: Manganese deficiency causes yellowing of leaves between the veins and failed blooms. Toxicity: Excessive Manganese can reduce the availability of Iron.

Utilized in chlorophyll production, respiration and nitrogen metabolism. Deficiency: Zinc deficiency results in small leaves with crinkled margins. Toxicity: Excessive Zinc may also reduce the availability of Iron.

(Mo) Molybdenum:

Nitrogen metabolism and fixation.

Deficiency: Signs of deficiency are small, yellow leaves.

Toxicity: Excessive Molybdenum can cause tomato leaves to turn bright yellow in rare instances. (Cu) Copper:

Activates enzymes, necessary for photosynthesis and respiration. Deficiency: Copper deficiency causes pale, yellow-spotted leaves. Toxicity: excessive Copper may reduce the availability of Iron.

While Cobalt is not known to be directly required by plants, Nitrogen fixing organisms that help legumes like beans and alfalfa feed require Cobalt in trace amounts. Cobalt is also contained in vitamin B-12, which is vital to all forms of life, so there may be more to come on the subject as additional research is performed. Deficiency: N/A Toxicity: N/A

Growth Room

Indoor basil grow room - note the 6" PVC tubes - photo courtesy Sunlight Supplies, Vancouver, WA Close-up shot of the author's favorite tomato strain which has an unusually high Brix, or 'sweetness"

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  • URHO
    Why do tomato flowers fall off?
    8 years ago

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