Scientists banking on GM crop varieties to lift cassava industry
Monday, October 17, 2022
Workers sorting new cassava varieties that were multiplied at RAB station in Huye. Photo: Courtesy.

When Francois Hitimana invested Rwf12 million in cassava farming, he was expecting to harvest enough and make profits.

In 2012, he planted cassava on 17 hectares in Kinazi Sector, Ruhango District, but the entire plantation was ravaged by cassava brown streak disease (CBSD), locally known as Kabore, leaving all his ventures in ruins.

The farmer is among many who have been struggling to access improved cassava varieties resistant to the two major destructive diseases – Cassava Brown Streak Disease and Cassava Mosaic Disease (CMD) known as Ububembe which threaten cassava production in the country.

Kabore, a cassava virus disease which spread in Rwanda, in 2013, causes root rot rendering cassava inedible. The devastating disease also harms cassava root (tuber) production, and it is said to be the major cassava threat in East Africa.

Workers sorting new cassava varieties that were multiplied at RAB station in Huye. Photo: Courtesy.

The diseases affected the incomes and food security of many people in Rwanda, considering that more than 700,000 families grow cassava in 3,980 villages of Eastern, Western and Southern Provinces, which can produce up to 1.7 million tonnes.

About 200,000 hectares are used for cassava growing in Rwanda where cassava is the third most important crop after bananas and sweet potatoes.

National cassava production dropped from 3.3 million tonnes to 656,924 tonnes in 2013 and 900, 000 tonnes in 2014 due to Kabore.

Cassava productivity still remains below its yield potential due to constraints including viral diseases such as Kabore, according to surveys.

A survey carried out by a team of 16 researchers in 13 cassava-growing Districts of Rwanda indicates that the disease is still a threat.

The highest field incidence of the disease was recorded in Nyanza district followed by Bugesera and Gisagara districts, respectively. Studies indicated the presence of CBSD at the rate of 35.3 percent due to dominance of the informal cassava seed system.

Cassava mosaic disease and cassava brown streak disease reportedly cause yield losses of more than $1 billion yearly, globally, according to the East African Agriculture and Forestry journal.

Athanase Nduwumuremyi, a Senior Scientist and Cassava breeder at Rwanda Agriculture and Animal Resources Development Board (RAB), told Doing Business that they got approval from Rwanda Environment Management Authority (REMA) to use agriculture biotechnology to carry out confined field trials for a Genetically Modified (GM) cassava variety that is resistant to the two destructive diseases.

Nduwumuremyi said the approval was needed because the law on bio-safety that regulates the production and use of GM crop products is yet to be enacted.

Genetically modified crops produced through the use of biotechnology have much to offer in line with addressing food insecurity and the increasing production costs incurred by farmers, agricultural experts said.

REMA was designated as the authority to regulate the use of agriculture biotechnology products including GM crops after Rwanda ratified the Cartagena Protocol on biosafety to the convention on biological diversity. The latter is an international agreement which aims to ensure the safe handling, transport and use of living modified organisms resulting from modern biotechnology that may have adverse effects on biological diversity, taking also into account risks to human health.

REMA is collaborating with the Rwanda Agriculture and Animal Resources Development Board (RAB) to ensure that any biotechnology that is used is safe.

"We are establishing laboratories and raising awareness to be able to know what we are doing on the market especially when it comes to genetically modified organisms,” Juliet Kabera, the Director General of REMA, recently said.

According to Nduwumuremyi, biotechnology is already being used in plant disease diagnostics, mass propagation of clean planting material through tissue culture technique, biological control, animal biotechnology, crop improvement, medicine and others. He said that agriculture biotechnology products, including GM crops, are needed in Rwanda to increase agriculture production and improve nutrition.

"The technology could help strengthen crops against extreme temperatures, drought, poor soil conditions, pests and diseases, and weeds,” he said.

After trials using agriculture biotechnology, "Cassava Brown Streak Disease (CBSD) resistance has been confirmed in the greenhouse.”

"The cassava variety will be released for use after enacting a biosafety law,” Nduwumuremyi said.

Besides research into GM cassava, Rwanda is also conducting trials for GM potato variety resistant to potato late blight disease that will not require the use of agro-chemicals.

"So far there has been no victim of GM crops. They are really needed to address food insecurity,” Nduwumuremyi said.

Pacifique Nshimyimana, a Rwandan agricultural researcher, said: "Biotechnology has been fruitful on other crops. South Africa has had access to GMO maize since 1994 with varieties ranging from fall army-worm resistant BT Maize to drought-tolerant TELA Maize.

In Nigeria, the adoption of BT Cowpea reduced 70 per cent cost of spraying pesticides. In the Philippines the case of GM Golden Rice with Vitamin A is making it easier,” he said, noting that Uganda also developed a similar GM product on bananas, which once commercialized will offer vitamin A to consumers.

Kenya lifts the ban genetically modified crops

In early October, Kenyan President William Ruto lifted the ban on open cultivation of genetically modified crops after 10 years. This was after the recommendation by a task force put in place to review matters relating to GMOs and food safety.

South Africa, Sudan, Egypt, and Burkina Faso lead in the commercialization of GM crops.

Crops under research for use in Africa include cotton, maize, cassava, cowpea, sorghum, potato, banana, sweet potato, sugar cane, coconut, squash and grape among others.

Nigeria approved commercial planting of Pod Borer-Resistant (PBR) GM cowpea.

Today, more than 17 million farmers are planting GM crops in 29 countries and are reaping higher yields with reduced use of pesticides and better management of weeds, among other benefits, according to the Food and Agriculture Organization (FAO).