Purple witchweed infests over 50 million hectares of croplands in Africa, causing annual crop losses exceeding US$9 billion. At the same time, the conventional use of synthetic chemical herbicides has faced challenges like herbicide-resistant weeds, lawsuits, and consumer pushback.
This has created an opportunity for bio-herbicides, provided they meet key criteria: host specificity, non-toxicity, affordability and sufficient shelf life for distribution. With all this in mind, the Toothpick Project initiated a pilot in western Kenya in 2018, addressing approximately 340,000 hectares affected by purple witchweed that caused annual crop losses of US$53 million.
Strategy for security
Since then, it has strategically developed a bio-herbicide, named Kichawi Kill™, using strains of the fungus Fusarium oxysporum f.sp. strigae. These strains were selected for over-production and excretion of specific amino acids, ensuring efficacy against purple witchweed without resorting to harsh chemicals that might harm the environment or other crops.
The innovation is designed to be a sustainable solution and a game-changer for crop yields. By protecting crops from the purple witchweed invasion, the Toothpick Project aims to contribute to food security in Africa via a ripple effect. The protective effects of the innovation will result in more viable crops, which mean more food. This, in turn, can boost the economy and improve the overall quality of life in Africa.
The project initially faced regulatory hurdles and challenges in adapting the strains that delayed its progress, as regulations around bio-herbicides were less defined compared to those around chemical herbicides. Kichawi Kill™ eventually received commercial approval in Kenya after a prolonged registration process. Now, the project aims to expand its impact to other countries, facing regulatory barriers and exploring trade agreements.
Three pillars of success
According to a recent article published by the Toothpick Project (in conjunction with Montana State University and the Kenya Agricultural and Livestock Research Organization), its success lies in overcoming barriers in knowledge, policy and finance.
Agricultural research has historically prioritised yield-focused plant-breeding and synthetic or chemical herbicides. The Toothpick Project challenges this trend, emphasising the need for diversified research into bio-herbicides. The development of Fusarium oxysporum f.sp. strigae involves a unique virulence enhancement technology, ensuring its effectiveness against purple witchweed.
At the same time, regulatory protocols and goals for reducing greenhouse gas (GHG) emissions and improving food security play a crucial role. The Toothpick Project has actively engaged with policy considerations, aligning its bio-herbicide development with broader agricultural and environmental objectives.
Additionally, the Toothpick Project understands that funding is essential for research, intellectual property, regulatory trials, marketing, and commercial scale-up. So far, it has had considerable success in securing funding for its innovative approach, showcasing the importance of financial backing in the bio-herbicide development landscape.
Despite its success, however, funding challenges remain. The Toothpick Project has highlighted the need for transformational financial support for agricultural innovations. Current funding trends, favouring quick returns from digital solutions and overlooking longer-term biological innovations, pose challenges for projects like the bio-herbicide research.
Fund owners emphasise long-term financial sustainability with a focus on commercial products, creating a funding gap for projects in the intermediate stages. The project underscores the importance of funding components such as longevity, flexibility and a farmer-driven approach to ensure transformative change.
Global initiatives
Recent international events — including COP27, the Paris Agreement, the 2021 UN Food Systems Summit and the Bonn Climate Change Conference — have set ambitious goals to tackle issues related to food security, agriculture and climate change. Notably, COP27 introduced a draft decision titled 'Joint work on implementation of climate action on agriculture and food security,' emphasising the need for concrete action plans involving multiple stakeholders.
However, concerns have arisen as discussions have shifted from pledges to implementation. Critics have pointed out the lack of dedicated funding to meet R&D needs, hindering the realisation of policy goals. While COP27 addressed the previous omission of food-related issues, the focus on food security overshadowed the fact that food systems contribute significantly to global GHG emissions.
Comparisons have been drawn with the 2021 UN Food Systems Summit, where financial pledges and representation from farmers marked a more productive approach. Yet, the effectiveness of these commitments in driving on-the-ground changes remains uncertain.
Optimistic outlook
Despite the aforementioned obstacles, the Toothpick Project presents an optimistic narrative of successfully developing and commercialising a microbial bio-herbicide. The project's success raises questions about the alignment of finances and supportive policies to foster future bio-herbicide research and commercialisation. As global conversations about agricultural priorities become more inclusive, the project anticipates increased investments in bio-herbicide research and ventures.
Kichawi Kill™ has navigated challenges in knowledge, policy and finance to become a model for bio-herbicide expansion across sub-Saharan Africa. However, challenges remain, including the need to enhance virulence, ensure the effective delivery of secondary inoculum and address shelf life limitations.
The project's innovative approaches, such as the ‘toothpick method’ and the development of a seed coating product, offer promising solutions. The latter received expedited regulatory approval in June 2023, providing farmers with increased flexibility in planting.
As the Toothpick Project continues to pave the way for bio-herbicide development, its success underscores the importance of inter-disciplinary collaboration and a holistic approach that considers the needs of farmers, scientists, policymakers and funds. The bio-herbicide's potential to transform weed control in Africa offers promising potential and a positive outlook in the face of agricultural challenges.
Source: Pest Management Science
“The Toothpick Project: commercialization of a virulence-selected fungal bioherbicide for Striga hermonthica (witchweed) biocontrol in Kenya”
https://doi.org/10.1002/ps.7761
Authors: Claire S. Baker, et al.
