The iSPARK project, commissioned by the UK-CGIAR Centre, is supporting research designed to improve cowpea yields for smallholder farmers in Western Kenya.
Smallholder farmers are the backbone of Kenya’s agriculture, contributing up to 78% of total agricultural production and approximately 23.5% of the nation’s GDP. Despite being the cornerstone of the country’s economy, they continue to face several challenges to production. These challenges include pest infestations, declining soil fertility, high input costs, limited access to markets and information, and the impacts of climate change.
In Western Kenya, a predominantly rural region, smallholder farmers rely on small plots that are typically under five acres for subsistence farming. The key crops grown include maize, beans, cassava, sweet potatoes, vegetables, sugarcane, and bananas. The characterization of small plots of land in Western Kenya has necessitated nearly every household in the region to grow vegetables for food and nutrition security, such as cowpea leaf, Kales and other vegetables indigenous to Africa. Pests and diseases are identified as major hindrances to increased vegetable production.
To better understand smallholder farming systems and the adoption of climate-smart agricultural practices, researchers at the Innovation in Sustainability, Policy, Adaptation and Resilience in Kenya (iSPARK) project conducted a series of farmer focus groups and a household survey in Kisumu County between July and November 2024. One of the key practices explored was vegetable integrated push-pull technology (VIPPT).
VIPPT is an innovation that builds upon a well-established push-pull technology. Push-pull technology is an approach which involves using repellant plants (silver leaf desmodium) to push pests away from the main crop and attractant plants (brachiaria grass) and pull them towards a trap crop. This method was originally developed to control maize stemborers and suppress Striga weed infestations. The integrated approach now intensifies this system by incorporating vegetables and legumes, making it more relevant for diversified smallholder production systems. The main objective of this upscaling is to bridge the yield gap in vegetable farming, while maintaining ecological control over key vegetable pests, including aphids, flea beetles, adult thrips, and spider mites.
“Past studies have focused on nutrition sensitivity of VIPPT, smallholders’ perception of this technology and its gender aspect while providing limited evidence on the adoption, intensity of use and possible impacts on vegetable yield outcomes” says Eliud Koech, a masters student at the University of Nairobi. The iSPARK project is backing this research to bridge the current knowledge gaps not only in VIPPT but also in other innovations and interventions across Western Kenya. Dr.Rebecca Sarku, a Research Fellow at University of Leeds, added, “this is not just about one crop or county but about creating empirical evidence that policymakers can use to scale these locally-led innovations at national levels.”
Women’s group engaged in group ranking and score of interventions adopted by farmers in the area. Image credit: iSPARK
Why VIPPT and Cowpea Matter
VIPPT, a farmer-led climate resilient technology, is transforming vegetable production in Kisumu County. There is clear evidence that many farmers are not only adopting the technology but also recognizing it as a driver of resilience and equity.
“Before the introduction of this technology, I only used push-pull on my maize plot, while growing other crops outside it. Vegetable pests were a nightmare for my cowpea leaves, the main vegetable crop on my farm. Yields were very low, despite heavy use of pesticides to control them. But now I’ve integrated cowpea leaves into the push-pull system on my farm, and they’re highly productive. Interestingly, I no longer rely on harmful pesticides,” says Christopher Ongiyo, a smallholder farmer in Kisumu West.
This, among other success stories shared by farmers, has attracted the attention of researchers, prompting them to delve deeper into the technology and build evidence around it. “We draw evidence from cowpea leaf yields because of their nutritional value and importance as a key source of income, while also enhancing soil fertility through nitrogen fixation. Furthermore, most farmers who have adopted the technology in Kisumu County have integrated it with cowpeas,” says Koech.
Evidence For policymaking
The preliminary evidence from household survey data collected from 369 smallholder cowpea farmers in Kisumu suggests that the dissemination of VIPPT has an upward trajectory. Notably, 61% of the farmers reported avoiding pesticide use, while 98% of the adopters identified VIPPT as an effective method for increasing yields through improved control of vegetable pests.
As Koech explained, “These findings, along with other evidence, will help us to identify the factors influencing the adoption and the intensity of the technology’s use. Education level, access to extension services, group membership, perceived benefits, access to credit, training, and market access are among the key variables of interest.” These empirical findings could be critical for policy makers looking to inform and guide large-scale implementation.
Key emerging insights
- Reduction of pesticide use: VIPPT is providing an effective alternative to chemical pest control by promoting biological and ecological approaches. This has led to a significant reduction in pesticide use, lowering production costs and improving human health through the provision of safer food.
- High adopter satisfaction rate: Those adopting the technology reported that it was highly effective and expressed strong support for its continued dissemination.
- Community influence is key to dissemination: Many farmers adopted VIPPT after learning about it from their neighbours. Community-based knowledge sharing has proven to be a powerful tool for scaling innovations.
- Increased cowpea leaf yields among adopters: Most farmers reported a substantial improvement in cowpea leaf productivity, which they attributed to the benefits of VIPPT. The integrated approach has enhanced pest control and soil health, leading to higher yields and greater consistency in production. Training is Key to Adoption: Farmers reported that the training and support from development partners, including the UPSCALE project, have been instrumental in the successful dissemination of VIPPT.
Looking ahead
One of the UK-CGIAR Centre’s research areas is confronting climate change and environmental degradation by promoting sustainable crop management and climate-smart agronomic practices. This research for the iSPARK project directly supports that objective, particularly within the African context, where many innovations have been implemented but remain insufficiently assessed or documented.
As this study contributes to the broader agenda of scaling existing innovations, the next critical step is to use the evidence to expand these technologies into new regions. This involves integrating them into national strategies, empowering youth- and women-led agribusinesses to build resilience as well as shaping inclusive policies that reflect the needs and realities of smallholder farmers. Evidence from this research will be crucial to promoting sustainable and resilient agricultural innovations.
Acknowledgements
The funding provided for this research by the UK-CGIAR Centre. The Centre is funded by UK International Development.
Image by CGIAR Climate Change, Agriculture and Food Security/Flickr.