Abstract
Citrus is an important fruit crop in Pakistan that requires proper crop nutrition and disease management strategies as it is a
tree crop and withstands harsh seasonal conditions for decades. Huanglongbing (HLB) is a century old, devastating disease of
citrus caused by phloem limiting bacteria of the α-proteobacteria subdivision. As disease has no known cure, so, effective
prevention methods are useful in crop management. Improper crop nutrition impairs plant genetic resistance to invasive
pathogens, decreases yield and reduces productive life of the plant. In this study we selected 116 citrus trees from 43 orchards
of Punjab for a nutritional assessment. All the trees were showing HLB symptoms and were subjected to NPK and Zn
analysis as well as molecular detection of Candidatus L. asiaticus, the pathogen associated with HLB. Nitrogen and Zn were
significantly higher (P≤0.05) in HLB infected trees. Out of 48 diseased trees, 19, 43 and 27 were deficient in nitrogen,
phosphorous and potash, respectively. Our study concludes that there is no relationship between nutritional deficiency status
and HLB incidence in citrus; however, nutritional treatments may help in stress relief to infected plants.
