For Fraction Mukhori, 45, cassava was more than a crop — it was the backbone of his family’s survival. Since 1999, the father of six from Maida Village in Traditional Authority (T/A) Kapichi’s area in Thyolo District, southern Malawi, relied on his half-hectare cassava field to feed his family, pay school fees, and cover essential expenses.

In a region where maize, the country’s staple grain, struggles to grow, cassava flourished. Last year alone, Mukhori earned up to K600,000 (about $343) from his harvest. His farm, located in Khonjeni Extension Planning Area (EPA), became a symbol of cassava’s promise in Thyolo.

To outsiders, Mukhori’s modest grocery shop at Mphanje market might seem like his main source of income. Few would guess that cassava farming was his true economic engine.

But this year, everything changed. His once-reliable crop is withering in the fields.

What Went Wrong?

A wave of Cassava Brown Streak Disease (CBSD) has swept through the district, turning hunger from a distant fear into a reality for farmers like Mukhori.

The story is similar for Norbert Msuza, another seasoned cassava farmer. At 45, Msuza has spent nearly two decades cultivating cassava in Group Village Headman Mulonda’s area under Thekerani EPA. Late last year, he noticed yellowing leaves and dark brown rot in his tubers — typical signs of CBSD.

Msuza traditionally consumes fresh cassava and processes it into dried flour known locally as makaka and makanya. From his one-hectare field, he typically earns over K300,000 ($172) annually. But this year, he is devastated. Despite the outbreak, he says no advisory support has reached him.

An study conducted in July 2025 by the Thyolo agriculture office and Bvumbwe Research Station confirmed an outbreak. Over 288.1 hectares of cassava have been affected, with Thekerani and Dwale EPAs being the hardest hit.

Thyolo District Commissioner Hudson Kuphanga calls the situation “alarming.”

“We’re looking at a potential cassava disaster. Thekerani alone has 844 farmers affected, and Dwale has 746. If we don’t act swiftly, the disease could wipe out cassava fields across the entire district,” he warns.

Kuphanga urges farmers to uproot infected crops, use clean planting materials, and adopt Integrated Pest Management (IPM) to control whiteflies — the insects that transmit the disease.

What Is Cassava Brown Streak Disease?

CBSD is caused by two viruses: Cassava Brown Streak Virus (CBSV) and Ugandan Cassava Brown Streak Virus (UCBSV). These viruses are transmitted primarily by whiteflies (Bemisia tabaci) and through infected planting materials.

Its symptoms include: yellowing of leaves; brown streaks on stem; dieback of branches; and dry, cork-like necrosis in tubers, making them inedible.

CBSD can cause yield losses of up to 100%, especially in susceptible varieties. It severely impacts food security and the income of smallholder farmers.

George Matiya, Chairperson of Thyolo District Council’s Agriculture Services Committee, confirms that CBSD is “significantly reducing both the yield and quality of cassava roots.”

Signs of CBSD have also emerged in neighboring Mulanje District, raising fears of a regional outbreak.

Blessings Fadwick Khajawu, 61, from Chigwembere Village in T/A Chikumbu, has farmed cassava since 2004. He depends on local varieties like gado, manyokola, akazimwawapeza, and pwapwa to support his household.

“We used to sell cassava and buy maize, our staple food,” he explains. “In Mulanje, most families can’t grow enough maize due to limited land, so cassava was our safety net.

“We need the government to act quickly,” Khajawu pleads. “There should be extensive research and immediate pesticide interventions to save us before it’s too late,” he says.

Mulanje’s Director of Agriculture, Osmund Chapotoka, confirms CBSD presence in Milonde, Msikawanjala, and Boma EPAs. He suspects the disease may have spread from Mozambique, given the proximity of affected areas to the border.

Extension Services Key to Short-term Containment

Agricultural analyst Gresham Kamnyamata says the outbreak should be a wake-up call, suggesting the need for farmers to adopt interim solutions as they wait permanent answers to the challenge.

“We urge all cassava growers to embrace better crop husbandry and seek guidance from extension officers. Prevention and early intervention are critical.”

Food and agriculture expert Ronald Chilumpha adds: “Using infected cuttings only fuels the spread. Farmers must prioritize clean planting materials to protect future harvests.”

Could Biotech Provide a Quick Solution?

Agricultural biotechnology (agribiotech) uses scientific tools to improve crops through genetic engineering, tissue culture, and molecular diagnostics. Using biotech, scientists can develop disease-resistant varieties, improve yield and nutritional value, and reduce reliance on chemical inputs.

Yohane Chimbalanga, Senior Research Officer at the National Commission for Science and Technology (NCST), says the commission supports science-based solutions.

He also highlights the potential of genetically modified (GM) cassava to resist both CBSD and Cassava Mosaic Disease (CMD), improving yield, root quality, and climate resilience.

Chimbalanga says, while there is no one working on CBSD-resistant cassava in the country at the moment, the commission is willing to support those interested.

“Biotechnology offers sustainable tools like CRISPR-Cas9, marker-assisted selection, LAMP diagnostics, and tissue culture to combat CBSD,” he explains, “When combined with traditional breeding and integrated pest management, it could offer a sustainable, science-driven approach to protecting cassava.”

Success Stories from Other Countries

Countries like Nigeria, Tanzania, and Uganda have made strides in biotech cassava. For example, according to a Pros.Org journal, transgenic cassava lines in Nigeria showed complete immunity to CBSV and UCBSV; yield improvements of up to 70% have been reported in resistant varieties.

On the other hand, the Great Lakes Cassava Initiative distributed clean planting materials to over 1.15 million farmers across six countries in Africa.

Dr. Kingdom Kwapata, Lecturer in Plant Breeding and Biotechnology at Lilongwe University of Agriculture and Natural Resources, says Malawi is lagging behind.

“RNA interference (RNAi) technology has been used elsewhere to silence CBSD virus genes. We need to invest in similar trials here,” says Dr Kwapata, one of the scientists behind Malawi’s adoption of GM cotton.

A Looming National Crisis

Unless immediate and coordinated efforts are made, Malawi risks losing a critical food source. CBSD has already been detected in other cassava-growing districts including Nkhotakota, Nkhatabay, Rumphi, and Karonga, raising alarms of a nationwide outbreak.

Thyolo District Commissioner Hudson Kuphanga paints a grim picture:

“This is more than just a farming issue; it’s a community crisis in the making. People in Thyolo didn’t harvest enough maize this year, so many were relying on cassava. But with this disease outbreak, the cassava harvest will also be lower—it’s going to be a terrible situation.”

The parallels with the Banana Bunchy Top Virus (BBTV) are striking. In Thyolo alone, BBTV devastated over 4,031 hectares of banana plantations. The lessons from that crisis must inform today’s response.

Need for Swift Action

As CBSD threatens cassava farming in southern Malawi, farmers like Mukhori, Msuza, and Khajawu are calling for urgent action.

On the other hand, with thousands of livelihoods on the line, experts and authorities are urging a multi-pronged strategy to combat the cassava crisis, including deployment of rapid response teams to identify and destroy infected crops; public awareness campaigns to educate farmers on disease symptoms and prevention; increased distribution of clean cassava planting materials, and investment in disease-resistant cassava varieties through biotechnology.

Agricultural experts warn that viral diseases are becoming increasingly common, driven in part by climate change. Malawi’s experience with bananas offers a cautionary story.

Over the past two decades, banana production in Malawi has plummeted due to widespread outbreaks of pests and diseases, poor agronomic practices, and limited access to clean planting material. This collapse has disrupted the entire banana value chain.

Since 2017, the Food and Agriculture Organization (FAO) has supported Malawi’s efforts to revitalize the banana industry. The interventions include: preserving local germplasm and genetic diversity; promoting agroecologically adapted banana varieties; establishing over macropropagation chambers and distributing clean banana suckers across 10 districts.

Despite these efforts, the damage was already done. According to Dr. Abel Sefasi, a biotechnology lecturer at LUANAR, Malawi now imports over 20,000 metric tons of bananas annually—a situation he says could have been avoided with earlier adoption of biotechnology.

Biotech has already transformed Malawi’s cotton sector.

According to farmers who have been speaking with Zodiak, the introduction of Bt cotton, which resists bollworm infestation, has doubled yields from 400 kg/ha to 800 kg/ha for many farmers; reduced pesticide use, lowering costs and health risks and enabled some farmers to reach 2,000–5,000 kg/ha under optimal conditions.

Experts believe this success could be replicated in cassava — if the country acts swiftly.