Researchers developing potatoes resistant to late blight disease

A group of international and national researchers are developing a genetically modified biotech potato variety that is free from the destructive late blight disease.

The researchers are currently evaluating the prospects of four genetically modified biotech potato varieties through Confined Field Trials (CFTs) in Muguga, Njabini and Molo.

Dr Catherine Taracha, the Kenya Agricultural and Livestock Research Organisation (KALRO) principal investigator to the project, said data collected from the CFTs will be evaluated to guide on the best varieties to proceed to National Performance Trials (NPTs).

She said the potato sector is plagued by many problems, among them the potato late blight whose management still poses a great challenge, particularly among smallholder farmers in the potato growing areas in Kenya.

Taracha spoke during the harvesting of the crop at Muguga CFT in Kiambu county.

According to the National Potato Council of Kenya, the late blight potato disease is caused by a water mold that damages leaves, stems and tubers.

Symptoms on the stem are dry, dark brown elongated blotches that cause wilting and drying, while the tuber has light brown blotches that are slightly sunken on the surface.

The disease leads to high yield losses both in the field and during storage. Losses in potato yield can go as high as 80 per cent annually.

Taracha said in order to obtain a good harvest, farmers must spray up to 20 times of chemicals to control late blight.

“Potato is a key food as well as cash crop in the highlands of Kenya and is extensively produced by smallholder farmers. It is the second most significant food crop in Kenya after maize employing more than 2.5 million persons. It plays a key role in Kenya's food security and contributes to alleviation of poverty,” she said.

Taracha said Kenya loses about 30 to 60 per cent of the potato crop to late blight yearly.

“The inability of resource-strained farmers to control late blight, the optimum management of the disease in Kenya is likely to be achieved through development of biotech varieties and this is currently being conducted in the country in a project termed the Global Biotech Potato Partnership,” she pointed out.

Erick Korir, principal biosafety officer at the National Biosafety Authority (NBA), said the agency approved the CFTs for the biotech potato for KALRO and other project partners.

This will allow the researchers to carry out trials on the late blight disease for three seasons, and collect enough data to inform the next phase of the project under multi-location CFTs (ML-CFTs) in the country.

He explained that since biotech crops contain foreign genes, their field-testing is carried out under regulated conditions, hence the tested biotech varieties must remain within the CFT trial site until they have been approved for environmental release by NBA.

The research project is being led by KALRO under the Feed the Future Global Biotech Potato Partnership project.

It seeks to resolve the lingering challenge of late blight disease, by developing and releasing potato varieties that are resistant to the disease. 

Taracha said the harvest from the second round of ML-CFTs shows that the biotech potatoes have a yield advantage and do not require a single chemical spray, when compared to the conventional varieties that have severely suffered from late blight.

Taracha said the project hopes to release late blight resistant potato varieties to farmers within two years. She said they would expedite the release of the new varieties to boost harvests and income for farmers from sale of surplus produce.

The Feed the Future Global Biotech Potato Partnership project is implemented in four countries including Kenya, Nigeria, Bangladesh, and Indonesia.

It is led by Michigan State University, and involves various partners including KALRO, AATF, and International Potato Centre (CIP) in Africa.

Dr Eric Magembe, the project lead in Kenya and from CIP, observed that as a biotechnologist, he knows firsthand the losses that farmers are going through.

“Data from the ongoing ML-CFTs will lead to the selection of the best varieties to be released to farmers and will eventually increase potato production for food and nutritional security as well as incomes," Magembe said.

"These biotech potatoes will also see less use of chemicals to control the disease, and this will have a positive impact on the overall health of farmers and the environment.”