Accurate and timely assessment of nutritional need of crops is an important decision making tool which a farmer can use to plant balanced and efficient crop nutrition. Crops are often fertilized by the growers, on the basis of soil fertility, experience of successful growers, product promotion and speculation or even hearsay. However, for scientific nutrient management, reliable information is needed to decide the quantity and type of manures and fertilizers required and also their most effective application strategy.
Among several diagnostic methods, analysis of growing plants seems to be the most efficient in arriving at the need – based nutrient application for various crops. Information and advice on their use must be made available prior to bud differentiation, expression of the potential yield and before crop load is know. The need of fruit plants and other perennial crops for nutrients and their management differs from that of annual crops in a number of ways, many of which are related to the perennial nature of tree crops. In these crops, there is a need to supply nutrients both for repeated production and harvesting and to nourish the vegetative and fruiting organs from year to year.
Knowledge of nutrient concentration in growing plants can serve as a tool for correcting any deficiencies if carried out early enough to safeguard yield. It can also be used evaluate the efficacy of a recent application. The information it provides can help to plan nutrients application only in subsequent years on that field or to compute nutrient removals in relation to productivity and nutrient balance sheet.
Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur, Sodium, Manganese, Zinc, Copper, Ferrous, Boron, Molybdenum.
|Crop||Index tissue||Growth Stage / Time||Sample Size|
|Sugarcane||3rd leaf from top||3-5 month after planting||15|
|Tobacco||3rd leaf from top||45-60 days old||15|
|Wheat||Flag leaf||Before head emergence||50|
|Maize||Ear leaf||Before tasseling||15|
|Tomato||Leaves adjacent to inflorescence||Mid Bloom||15|
|Brinjal||Leaf blades with midribs minus petioles from most recent fully developed leaves||-||12|
|Grapes||5th petiole from base||45 Days after pruning march or October||200|
|Pomegranate||8th leaf from apex||Bud differentiation. In April for Feb. crop and august for June crop||50|
|Banana||Petiole of 3rd open leaf from apex||Bud differentiation 4 months after planting||15|
|Mango||Leaves + Petiole||4-7 months old leaves from middle of shoot||15|
|Guava||3rd pair of recently matured leaves||Bloom stage (Aug. or Dec)||25|
|Sapota||10th leaf from apex||September month||30|
|Groundnut||Recently matured leaflets||Maximum tillerning||25|
|Sunflower||Youngest matured leaf blade||Initiation of flowering||20|
|Soybean||3rd leaf from top||2 months after planting||25|