Mars and SwissDeCode team up to detect cocoa tree virus and boost sustainable cocoa farming

27 Sep 2021 --- A test that pinpoints the potentially devastating virus in cocoa trees before they show any symptoms has been developed by Mars Wrigley and agri-food testing company SwissDeCode.

Hailed as being fast and straightforward, the new test is a major improvement for the cocoa industry because it helps to protect cocoa yields and farmers' income by detecting Cocoa Swollen Shoot Disease (CSSD) in asymptomatic trees in less than 60 minutes.

It has been a long time coming, as SwissDeCode says it has been searching for a solution to help combat CSSD for decades.

For decades, cocoa trees have been infected. The virus is an acute problem for the cocoa and chocolate industry as it can reduce cocoa yield by up to 70%. 

Until now, no efficient methods to quickly detect the presence of the virus in fields in asymptomatic plants have been found.

The new method has been adapted to the needs of the cocoa industry.

Cocoa Swollen Shoot Disease is an acute problem for the cocoa and chocolate industry as it can reduce cocoa yield by up to 70%.

Technology & research 
The new solution is an easy-to-perform testing kit that would enable field personnel to test cocoa trees, using their leaves as samples quickly. 

It is built on SwissDeCode's DNAFoil proprietary technology and incorporates underlying research from Mars Wrigley.

It means that farmers can take immediate action to prevent the spread of the virus to healthy trees, thus safeguarding the yields. Cocoa tree nurseries also welcome the fast detection because it allows monitoring of tree health regularly and the release of planting materials only when they are substantially free of the virus. 

Replanting infected areas and regenerating old farms can be conducted with greater peace of mind, helping farmers increase yields and income while preventing deforestation.

Collaboration is key for crop science 
Mars Wrigley has a long history of advancing crop science to improve cocoa production worldwide. 

This collaboration has allowed SwissDeCode to understand end-users' specific issues and requirements, from cocoa farmers to trading organizations. 

Once field validations have been completed, the kit will be ready for large-scale use.

"We are making cocoa farming more sustainable by preventing large-scale deforestation caused by recurring infections," says Brij Sahi, CEO & co-founder, SwissDeCode

"We have been looking for reliable preventive solutions against CSSD since the 1940s, as each year cocoa farms are being increasingly affected by this virus. Joining forces with SwissDeCode, we have finally found a rapid and reliable on-site diagnostic," adds Jean-Philippe Marelli, senior director, integrated pest management, Mars Wrigley.

Most of the world's cocoa comes from West Africa, with the two largest producers, Cote d'Ivoire and Ghana, accounting for nearly 60% of global cocoa production. 

Cocoa exports play a considerable role in their economies and are an essential source of income for millions of smallholder farmers.

What is Cocoa Swollen Shoot Disease?
The disease is caused by plant viruses and transmitted by mealybugs from infected to healthy cocoa trees. West Africa is particularly affected, especially Ghana and Ivory Coast, where over 780,000 hectares of cocoa trees are believed to be infected.

Cocoa trees affected by CSSD can be asymptomatic for up to two years, but then they start to show symptoms such as red leaf veins or swollen stems and roots and typically die within three to four years of symptom development. 

Several strains of the virus have been identified, and the only known cure is cutting and destroying infected trees. The virus has already infected about 17% of Ghana's cocoa areas (more than 300,000 ha) and more than 100,00 ha in Côte d'Ivoire. 

Infected trees cannot be cured, and the disease can only be managed by preventing further spread to healthy trees by planting barrier crops or cutting out infected trees entirely.

Targeted intervention 
These measures can significantly impact the sustainability of cacao production since they are responsible for the loss of thousands of hectares every year, and millions of dollars are spent in replanting cocoa trees, which is considered the best solution to stop the spread of the disease. 

This new technology enables early detection, which allows for targeted intervention and helps decrease the need to cut down adult trees to mitigate the spread of the disease. 

Edited by Gaynor Selby