The Toothpick Project: commercialization of a virulence-selected fungal bioherbicide for Striga hermonthica (witchweed) biocontrol in Kenya

Abstract

The high-level view of global food systems identifies three all-encompassing barriers to the adoption of food systems solutions: knowledge, policy, and finance. These barriers, and the siloed characteristics of each of these, have hindered the development and adoption of microbial herbicides. How knowledge, policy, and finance are related to the Toothpick Project's path of commercializing a new bioherbicide, early in the scope of the industry, is discussed here. The Toothpick Project's innovation, developed over four decades and commercialized in 2021, uses strains of Fusarium oxysporum f.sp. strigae selected for overproduction and excretion of specific amino acids, killing the parasitic weed Striga hermonthica (Striga or witchweed), Africa's worst pest threat to food security. Historically, bioherbicides have not been a sufficient alternative to the dominant use of synthetic chemical herbicides. To be used safely as bioherbicides, plant pathogens need to be host specific, non-toxic, and yet sufficiently virulent to control a specific weed. For commercialization, bioherbicides must be affordable and require a sufficient shelf life for distribution. Given the current triple storm encountered by the chemical herbicide industry (herbicide-resistant weeds, lawsuits, and consumer pushback), there exists an opportunity to use certain plant pathogens as bioherbicides by enhancing their virulence. By discussing barriers in the scope of knowledge, policy, and finance in the development of the Toothpick Project's new microbial bioherbicide, we hope to help others to anticipate the challenges and provide change-leaders, particularly in policy and finance, a ground level perspective of bioherbicide development. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.