Virus destroying cassava in Malawi

Malawi Government is struggling to contain two flesh-eating viruses that have for a long time devastated cassava plantations in the South and lake shore districts.
The two diseases, cassava mosaic and cassava brown streak, have the potential to wipe out entire harvests with sheer rapidity.
Speaking during the launch of the cassava virus project, which seeks to reduce the incidences of the diseases, the Minister of Agriculture, Irrigation and Water Development Allan Chiyembekeza conceded that cassava crop is under threat.

“Once they attack there is no productivity. However, through the cassava virus project, we have found a way of cleaning up the materials so that farmers plant clean cassava. Breeders are also developing some varieties that are resistant to these diseases.
“Through the project, we have even mapped the country so that we know particular districts that have been severely hit by the viruses and we have discovered that Cassava Brown Streak is severe along to the lake shore districts, especially in Nkhotakota and Karonga while Mosaic is across the country, more especially in the South,” he said.
In his remarks cassava virus project coordinator Joseph Ndunguru said the initiative is having a huge impact in reducing incidences of the diseases.
“Before this project, we had limited capacity to address these diseases, especially in terms of diagnosis. We are using the information to decide on four things, namely where to multiply clean planting materials; where to screen planting materials; strengthen our regulations to inform farmers not to move materials randomly and categorising these viruses into strain levels.
“We advise farmers and stakeholders to decide on strategic deployment so that planting materials are deployed to correct areas to have durable resistance. We have also trained a lot of scientists to diagnose the diseases,” he said.
The two cassava diseases are spread by a whitefly, an insect which carries the pathogen and infect the plant while feeding on the sap, phloem and leaves.
Cassava brown streak renders the root inedible by giving it blighted and brown blotches that give the disease its name while Cassava mosaic is more severe and has a variety of foliar symptoms that include misshapen and twisted leaves and overall reduction of plants and tubers.