Nutrient Deficiency We know that elements are essential for plant growth, especially during the vegetative period. Even so in the case of potassium needed in all stages of development. Fertiliser application and crop management are the practices we have to undertake for good plant health. Potash is one of the important nutrients in determining the size of leaf and the no of leaves at any given time during the plant growth period. There is an intensive uptake of potash by the plants at establishment stages. Older leaves of banana exhibit yellow chlorosis in very early stage. Apply 60 g/plant