Molybdenum (Mo) is a trace element but it has a big job. A good, albeit small, supply of molybdenum improves nitrogen uptake and conversion in plants.
Molybdenum is a co-factor in the enzyme nitrate reductase (the enzyme which catalyzes the first reaction in the formation of organic nitrogen compounds to inorganic). It helps plants utilize nitrate N, and aids in converting nitrates to ammonium – the initial stage of protein synthesis. In legumes, which are especially sensitive to a molybdenum deficiency, Mo is essential to the process of atmospheric nitrogen fixation by rhizobia in root nodules.
Besides legumes, brassicas and cucurbits (squash, gourds, melons) can be sensitive to molybdenum deficiency.
As it is so closely related to nitrogen use, the signs of a molybdenum deficiency are similar to a nitrogen deficiency. Symptoms begin in older leaves first – watch for pale and yellowed leaves, with necrotic margins and tips, and cupping or rolling. Plant growth is often stunted, and flowers will be suppressed or will wither.
Soils low in potassium or acidic (low pH) – especially when high in iron or aluminum oxides – can have low molybdenum availability. As well, high levels of copper or sulfur in the soil can interfere with molybdenum uptake and translocation.
A plant’s needs for molybdenum are relatively small, but it is essential for optimizing growth and development.
A starter fertilizer is your first step to ensure adequate Mo. OMEX Moly is a water-soluble solution with a guaranteed analysis of 1.5% or 3% molybdenum. It is recommended for the prevention and correction of molybdenum deficiency in crops to encourage nodulation in pulses, especially in low pH soils.
Talk to your retailer or OMEX sales representative for more information on how to make sure your crop lives up to its full potential.
In our next post: Iron – an important micronutrient for keeping plants green and healthy.