Phosphorous Nutrient Deficiency in Plants

Form

Taken up as both Phosphate, HPO₄^– and Phosphite, H₂PO₃^–, Phosphorus is essential for energy transfer, cell division and the development of root and shoot systems.

Function

Phosphorus promotes root activity, affecting the uptake of nutrients and water, the formation of sugars and the development of both flowers and fruit. In addition, Phosphorus plays a central role in maintaining plant health and in stimulating the activity of beneficial microbes in the root zone. Phosphorus deficiency can result in slow growth rates, poor fruit set and low Brix levels.

Symptoms

Phosphorus nutrient deficiency is typically seen in younger stem and leaf tissue as a distinct purple or bronze chlorosis. Plants tend to be slow growing, stunted, with poor root mass, flower set and fruit development.

Significance

Phosphorus stress affects the early stages of development, during which the plant is setting genetic yield potential. In addition, tolerance to biotic and abiotic factors will be poor, increasing risk of drought/heat stress and reducing disease resistance mechanisms. Phosphorus nutrient deficiency is often worse in alkaline soils and P-fixing soils rich in Calcium, Magnesium, Iron or Aluminium.

Actions

Check soil status and correct if necessary. Place and protect phosphorus fertilizers. Foliar fertilizer treatment at the onset of active growth can be very effective. Routine foliar Phosphite can have a major impact on promoting plant health.