Citrus greening disease

Abstract

Citrus greening disease is a major cause of crop and tree loss in many parts of Asia and Africa. Brief comments are made on geographical distribution, economic significance and symptoms (infected trees or branches suffering damaged fruit, poorly developed roots, and heavy leaf drop followed by out-of-season flushing and blossoming, with dieback occurring in severe cases). Differential varietal susceptibility is noted. Viral transmission usually involves an insect vector, eg the psyllids Trioza erytreae and Diaphorina citri, but dodder Cuscuta species have also been implicated. Thermal control, chemical control and breeding of resistant stock are described, directed against the virus or, more commonly using insecticides or biological control, against the vector. -P.J.Jarvis