Plant pathologists are keenly focused on what they study and how they study it – the details of a plant pathogen and how it infects a plant, causing disease. This review by Fran Robson and colleagues reminds us why.
Plant disease has a devastating impact on farmers, families, communities, ecosystems and economies. The review focuses on one of the most serious disease threats to global food security – cassava brown streak disease (CBSD). Cassava is a staple crop that feeds around 800 million people worldwide. It is grown by smallholder farmers in over 100 countries for home consumption and sale, and by commercial producers on an industrial scale. The starchy roots are eaten and used to make culinary, industrial, and pharmaceutical products. In 2019 the global cassava market was estimated to be worth $164 billion.
CBSD first emerged in East Africa in 1935. It is now spreading westwards, causing huge losses and jeopardising food security in countries across Africa and threatening the large scale cassava production of West Africa. CBSD is caused by an RNA virus, cassava brown streak virus (CBSV). The full genome sequence was published in 2001. CBSD is spread by the movement of infected cassava planting material and by insect transmission.
Once a plant has a virus there is no cure. Disease management through prevention and mitigation measures is key. This includes improved agronomic practices, the development of resistant cassava varieties, providing virus-free cassava planting material, improved disease surveillance, better diagnostics, and the controlled movement of planting material.
In writing this review the authors talked with several senior researchers who contributed their unique perspectives on the international initiatives and development programmes, the biological and technological advances, and the community-focused efforts that will help mitigate and manage CBSD.
Plant pathology research is published in journals, to be read and cited by others. The more often papers are cited the higher the ‘impact factor’ of the journal and the more prestige is associated with it. Researchers are under pressure to publish, with promotion and research funding resting on high-impact factor publications. That’s the what and the how. But Stephan Winter, who has spent much of his life in cassava research, reminds us that ‘an impact factor is a measure of how much food is on the table’. That’s the why.
Image: A farmer reveals extensive storage root rot caused by cassava brown streak disease [Photo credit James Legg].
Fran Robson, Diane Hird and Eric Boa published this study in Plant Pathology:
Cassava brown streak: A deadly virus on the move
TITLE IMAGE: Food products containing cassava (image from a CONNECTED animation created by Eve Bannister and Charlotte May; https:// vimeo. com/ manage/ videos/ 34943 4012; Bannister & May, 2019).
