Population Dynamics and Epidemiology of Diaphorina citri in Relation to Yield Losses Caused by Citrus Greening

Abstract

| Citrus greening (CG) or huanglongbing (HLB) is the major cause of citrus decline. The disease is currently prevailing in all districts of Punjab and posing severe threat to citrus production and export. The current research was designed with two objectives; (1) to study the population dynamics of Diaphorina citri, the vector of CG, and (2) to record the incidence of CG in different citrus growing areas of Punjab and estimation of losses caused by this disease.To study the dynamics of Asian citrus psyllid (ACP), a comprehensive survey of kinnow (Citrus reticulate cv. kinnow), musambi (Citrus sinensis cv. musambi) and feutrell's early (Citrus reticulate cv. feutrell's early) orchards was conducted in tehsil Sargodha during 2017 and 2018. Correlation and regression analysis were used to determine the relationship of ACP with CG, and the relationship of environmental factors with ACP. Surveys were conducted to record the incidence of CG and estimate the yield losses caused by it. The study of population dynamics of ACP revealed that ACP population was higher between 7 th to 14 th April and 11 th to 18 th September, during 2017 and 2018. While, there was less ACP population between February 10 th to 2 nd March and 10 th July to 30 th July, during 2017 and 2018, respectively. There was significant and positive correlation between ACP population and CG on kinnow, musambi and feutrell's early cultivars. Maximum and minimum temperatures and rainfall also showed positive and significant correlation with CG, while relative humidity showed not significant correlation with CG. During current study, maximum temperature, minimum temperature and rainfall explained maximum, i.e., 79, 76 and 83% variability in ACP population, respectively. The incidence of CG was observed higher (45%) in Faisalabad while lower (21.67%) in Multan. Similarly, yield losses due to CG were recorded maximum (33.5%) in Faisalabad and lowest (15.5%) in Multan districts. The current findings will help in the effective control of CG in Punjab by the in time management of its vector. NoveltyStatement | The epidemiology of D. citri and yield losses caused by CG have been studied first time in citrus belt of Punjab, Pakistan, during this research.