Protecting cassava, a neglected crop, from pests and diseases

Abstract

Cassava (Manihot esculenta Crantz) is the fifth most produced staple food crop in the world, being a basic source of staple food for an estimated 800 million people worldwide. Cassava is an increasingly popular crop. Cassava is grown by smallholder farmers in more than 100 tropical and subtropical countries of Africa, Asia and Latin America. Thanks to its efficient use of water and soil nutrients and tolerance to drought, cassava can produce reasonable yields using limited or no inputs, even in areas with poor soils and unpredictable rainfall. Like other crops, cassava is vulnerable to pests and diseases that can cause heavy yield losses. Insect pests such as white flies and mealybugs, and diseases caused by viruses and phytoplasma, affect the production of cassava worldwide. Of the viral diseases, Cassava mosaic disease (CMD) and Cassava brown streak disease (CBSD) are the most widespread, severely affecting at least 50 percent of cassava crops in Africa. CMD and CBSD pose a serious threat to the food security of 135 million people in Central and East Africa alone. At least half of all plantings in Africa are affected by one of these diseases. Scientists estimate that annually, 15–24 percent (equivalent to approximately 12–23 million tonnes) of the crop is lost due only to CMD in Africa.