Nutrients » Phosphorous


Phosphorus (P) is essential to plant growth. It is involved in several key plant functions, such as energy transfer, transformation of sugars, photosynthesis, and transfer of genetic characteristics from one generation to the next.

P is classified as a major nutrient, meaning that it is required by crops in relatively large amounts. Its functions cannot be performed by any other nutrient, and an adequate supply of P is required for an optimal growth, development and reproduction.

P plays a vital role in almost each plant process that involves energy transfer. High-energy phosphate is the energy source that drives the multitude of chemical reactions within the plant.

P is a vital component of the substances that are building blocks of genes and chromosomes. So, it takes part in the process of carrying the genetic code from one generation to the next.

Text to write in balls: root development, flowering, vigor, energy transfer, Photosynthesis, genetic code, Transformation of assimilates 

P-fertilizers are not routinely applied to fruit trees as they are in herbaceous crop plants, such as tomato and cucumber. Routine application is required in very poor soils or soils that readily fix P rendering it unavailable.

P-deficiency rectification in applying P-fertilizer to the soil surface under established fruit trees is not immediate, and is generally protracted. Application through drippers is more effective in this regard if root growth is concentrated at the points of water emission. Concentration can occur in regions of low rainfall. Root systems having developed in this way have an enhanced dependence on applied phosphorus due to restricted spread. P-fertilization, whether carried out or not during a particular season, should be based on the results of leaf analysis, irrespective of the nature of root development.

Images from the book Symptons of Nutrient Imbalances in fruit trees, Bruno Razeto.

Symptoms of P-deficiency in blueberry.