Leaf analysis in citrus: Interpretation tools

Abstract

Occurrence of nutrient constraints is as old as history of citrus cultivation. Identifying multiple nutrient constraints has always perplexed the nutritionists due to lack of consistency in response to fertilization when executed in field. Such a discrepancy in diagnostic interpretation has emerged on account of a variety of interpretation tools made under usage. For example, when a leaf analysis dataset is subjected to different interpretation tools, highly overlapping diagnoses are obtained. Analysis of different tools used in leaf analysis data interpretation further warranted the necessity of working out the cultivar-specific nutrient diagnostic norms. Large number of interpretation tools have been put forward to interpret the leaf analysis data. Late DRIS (Diagnosis and Recommendation Integrated System), initially developed for rubber crop, found its great utility to many of the annual and perennial crops, citrus being one of them. Work done in India with reference to different citrus cultivars suggested a strong cultivar-specific dependence of the diagnoses that agreed with field diagnoses. Use of DRIS-based diagnoses provided replicating outcome under diverse soil types. The detailed account of different leaf analysis interpretation tools is further discussed.