Phosphorus is the second nutrient element and an essential constituent of every living cell. It is involved in all types of metabolic activities and is an essential constituent of majority of enzymes. It is also a structural component of membrane system of cell, chloroplasts and mitochondria.
Phosphorus stimulates root development and growth in seedling stage.
It stimulates flowering, fruit setting and seed formation and the development of roots.
It hastens leaf development and encourages greater growth of shoots and roots.
It enhances the development of reproductive parts and thus bringing about early maturity of crops particularly in cereals and counteracts the effect of excess Nitrogen.
It develops resistance to certain diseases.
It increases the number of tillers in cereal crops and also improves the ratio of grain to straw.
It strengthens the straw of cereal crops preventing lodging.
Root and shoot growth is restricted and plants become thin, erect and spindly.
The foliage is sparse and restricted, the development of lateral buds is suppressed.
Under severe deficiency, the apical parts of the leaves turn brown and then margin of the leaves may roll.
The leaves of cereal crops become dull grayish green in colour.
The deficiency is characterized by slow growth and low yields.
Leaves may shed prematurely and flowering and fruiting may be delayed considerably.
Growth is stunted even under abundant supply of Nitrogen and Potassium.
Premature ripening of crop is seen.
In cereal crops, the foliage turns bluish green and then strong reddish purple tints develop on the nodes, internodes, leaves and even heads.
The heads are poorly formed
Tillering decreases and results in low yields.
Apply Phosphorus containing fertilizers like SSP or DAP, before planting as per recommendation.
Two to three soil applications @ 25 - 30 kg/ acre depending on the crop and stage helps in managing the deficiency,
Spray MAP (12:61:00) @ 10 gm/ltr two to three times at intervals of 15 days to reduce crop loss.