Pseudocercospora leaf and fruit spot disease of citrus: Achievements and challenges in the citrus industry: A review

Citruses are the worlds’ second fruit crops by volume next to banana. It is one of the most important commodity in tropical Africa as source of foreign currency, raw material for agro-industries and source of employment. The production and productivity of citrus in tropical Africa including Ethiopia are critically threatened by a number of diseases. Among others, pseudocercospora leaf and fruit spot of citrus caused by a fungus Pseudocercospora angolensis is the most destructive disease of citrus. Literature reviews have been made by searching the available information on leaf and fruit spot of citrus. Journal articles, research papers, workshop proceedings, Thesis research, manuals, and quarantine regulations were among the information sources of the review. The disease is widespread in 22 African countries including Ethiopia with a single report around Yemen in the Arabian Peninsula. Scattered research efforts have been made by different researchers in Africa mainly dealing with its geographic distribution, biology, and management practices. Fungicides, plant extracts/essential oils, and host resistance are among the research efforts made for the control of P. angolensis. Even though the disease is not yet reported to the rest of the world, it becomes a serious concern as an important quarantine pest thereby critically affecting the world trade and germplasm exchange of the citrus industry. Therefore, the purpose of this paper is to compile the scattered information on various aspects of leaf and fruit spot of citrus mainly to avail the information for researchers, development workers and policy people. Moreover, this review will suggest future research and development direction towards better understanding and sustainable management practices of the disease.