Nutrient imbalance in soils is an emerging threat to sustainable agriculture: intensive cultivation, use of poor quality groundwater, depletion of soil organic matter and excessive use of fertilizers are major reasons for poor soil fertility worldwide. This necessitates correct diagnosis of plant nutrient deficiencies to avoid further use of pesticides in cases where pests or pathogens that are not in fact the cause of poor crop health. Richly illustrated with 600 colour photographs, this book is a visual field identification guide for symptoms of most common nutrient deficiencies in field crops, covering all their stages of occurrence. Detailed descriptions and suggested for management practices are given with each entry.

Senescence and abscission both are genetically controlled phenomenon yet reports of environmental, nutritional and chemical controls are not unknown.Gibberellic acid play vital role in controlling of senescence and abscission. Gibberellic acid delay the senescence by delay the synthesis of hydrolytic enzymes.Recent studies show that Gibberellic acid control the genetical characters. Hydrolytic enzymes promote the degradation of not only macromolecules like starch, proteins, lipids, nucleic acid etc., but also degrade the cell organelle like chloroplast, mitochondria, nucleus etc., Chloroplast is the first cell organelle affected by the activity of hydrolytic enzymes. It is also proved by the yellowing of the leaves. The untreated leaves show yellowing earlier as compared to the gibberellic acid