Quick indexing of huanglongbing on the basis of symptomology and iodo-starch test in relation to environmental factors

Huanglongbing (hlb) is one of the devastating diseases in major citrus growing areas of the world. the disease has posed a threat for citrus industry with a considerable loss in production. a survey was carried out for monitoring of hlb in citrus growing areas of sargodha district. symptomology and iodo-starch test were two parameters for quick indexing of disease in the field. the disease incidence was in the range of 8.2 to 11.4%. characteristic symptoms such as mottling and zn-deficiency like symptoms were observed in the leaves suspected to be infected of citrus samples. iodo-starch test was found to be reliable for starch accumulation in hlb infected samples in the field. the correlation of maximum,minimum temperature and relative humidity with symptomatic expression was found significant while the rainfall had negative impact on progression of disease. © 2015,university of agriculture. all rights reserved.