Ludhiana, Oct 8 (UNI) Leaf Colour Chart (LCC) is an ideal tool to optimise nitrogen use at reasonably high yield levels, irrespective of application of organic manures, crop residues and nitrogen carried over from the previous season.
To know when plants need nitrogen has been the major challenge for synchronising the fertilizer applications with plant need. In recent years LCC has been so developed that it allows measuring crop nitrogen demand simply by matching the leaf colour.
Green colour is an estimate of chlorophyll content of leaves, which is related to nitrogen content and can help in determining the time of nitrogen application to the crop. It gives instant result and there is no need for collecting plant samples for tissue testing in laboratories, according to researchers in the Department of Soils at the Punjab Agricultural University (PAU) Bijay Singh, Yadvinder Singh and Varinderpal Singh.
LCC is a high quality plastic strip (8''x 3'') with different shades of green colour and has been developed by the International Rice Research Institute (IRRI), Manila, after studies conducted in different Asian countries including India. It consists of six green colour shades, ranging from light yellowish green (Number 10) to dark green (Number 6).
Colour strips, fabricated with veins, resemble those of rice leaves and help while matching colour, the researchers said. It is a simple, easy-to-use and inexpensive tool that can even help farmers who are not highly trained in making nitrogen recommendations.
The LCC is avaliable at the PAU at a marginal cost of Rs 27 per piece.