In
order to have optimum plant growth and production, it is essential that
all the essential major nutrients (nitrogen, phosphorus, potassium,
calcium, magnesium and sulphur) and micro nutrients (iron, manganese,
zinc, copper, molybdenum, cobalt and chlorine) are available to the
plants in required quantity. The availability of plant nutrients depends
on the type of soil and also biotic and abiotic stresses. In addition
different enzymes like Gibberellins, Cytokinins, Oxyzines also contribute to plant growth and yield.