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“Manganese
General Information
Cannabis uses manganese (Mn) throughout its life cycle and it must be present in all stages of growth. Manganese is present in all professional-quality fertilizers. When combined with other elements, manganese contributes to plant photosynthesis and in the facilitation and utilization of nitrogen. Manganese and iron are both essential elements for chlorophyll production.
Deficiency
Manganese deficiency is quite prevalent in indoor and hydroponic situations. Younger tissue leaves express symptoms first, becoming yellow between veins, a condition known as interveinal chlorosis, while the veins themselves remain green. When severe deficiency occurs, symptoms rapidly migrate from younger tissue to old, and necrotic spots will appear on the leaves, which will eventually die and drop off. Plants will be stunted and new leaves can be misshapen. Manganese deficiency can also extend the ripening of buds, and severe deficiency can mimic a magnesium deficiency.