PlantwisePlus Blog

In Makueni County, Kenya, young spray service providers are transforming how smallholder farmers manage pests.   The Crop Sprayer app, developed by CABI PlantwisePlus, is helping agripreneurs reduce pesticide risks through accurate dosage calculations, protecting farmer budgets, human health and the environment. 

Spray service providers are trained professionals who offer pesticide application services to farmers. In Makueni County, three young agripreneurs, Wanza Simon, Wilfred Kyalo, and Kelvin Musyoki Mutinda, are using the Crop Sprayer app to build sustainable agribusinesses while promoting safer pest management practices.  

The challenge of calculating pesticide doses 

Wanza Simon, a 28-year-old plant doctor who trains and advises spray service providers, is familiar with the difficulties of pesticide calculations. Her training used standard 20-litre pumps, which meant she struggled to calculate for different sprayer sizes when advising the 8 young men she mentors. As a result, Wanza often doubted whether she was giving the right advice or recommending over-application that could harm crops or the environment. This uncertainty affected her confidence, and some farmers questioned her recommendations. 

Wilfred Kyalo, also 28, with a degree in Dryland Agriculture, faced the same problem working with large-scale mango farmers. “I was relying on guesswork and crude tools,” he recalls. “Sometimes I underused the chemical, and farmers complained of pest resurgence. Other times, I overused, and the excess went to waste. This is money literally down the drain.” The lack of precision limited him to serving just two farmers per day. 

Kelvin Musyoki Mutinda, 30, knows this challenge well. Most agro-dealers gave dosage instructions for 20-litre knapsack sprayers, but many smallholder farmers used smaller 16- or 18-litre pumps. Without a precise conversion method, Kelvin often applied the same dose intended for larger sprayers on smaller ones, unintentionally overusing pesticides. Sometimes the result was plant scorching, fruit loss, or poor pest control. “As a service provider, you feel guilty when that happens,” he said. Before using the app, he “operated on assumption rather than facts.” 

An easy-to-use tool 

The Crop Sprayer app provides an easy way to calculate exact pesticide quantities for any sprayer capacity and farm size. For Wilfred, introduced to the app during the primary mango-spraying season, the impact was immediate. “With one click, the app calculates the exact pesticide and water amounts I need for each farm and each sprayer size,” he says. “For me, that meant no more wastage, no more back-and-forth for extra water.” 

He went from serving two to four farmers per day. In his first month using the app, he completed over 30 farm jobs, more than he had ever managed in such a short time. “The Crop Sprayer App has made my work easier, faster, and more professional. I now make informed decisions, use fewer chemicals, and earn more.” 

Wanza incorporated the app in her work within six months. As a result, she has upgraded to motorized pumps, doubled her productivity, and increased her service charges. Farmers trust her more than ever, appreciating her evidence-based recommendations and timely services. 

Growing businesses through better service 

The precision has translated directly into business growth. Kelvin currently supports about 75 farmers, including clients from neighbouring Machakos County. One client used to over-apply pesticides on his large farm, using nearly 50 pumps instead of 30. After Kelvin demonstrated the app and recalibrated his spray plan, the farmer realized he had been wasting pesticide. Since then, he has bought exactly what he needs and has referred Kelvin to more clients. “If you do your work well, you get referrals,” explains Kelvin. 

Spreading the word 

These young agripreneurs are now sharing what they have learned. Wanza has introduced the app to 12 farmers and trains 8 young men who provide spraying services. Kelvin has introduced the app to other farmers and spray service providers. Wilfred shared the app with more than 130 organized farmers and is mentoring 54 young people on agribusiness skills and digital tools. “Looking back, the app has done more than help me. It’s teaching the next generation to work smarter, safer, and with purpose.” 

Environmental and economic benefits 

In this way, Wanza, Kelvin and Wilfred are reducing pesticide misuse and wastage. By helping farmers purchase only what they need, they are addressing the unsafe practice of sharing leftover pesticides. This hazardous practice can lead to farmers applying the wrong chemicals to crops or pests. 

As Wilfred observes, “The App has brought a mathematical certainty to farming, aligning economic value with ecological responsibility.” 

Wanza is now actively promoting nature-based pest control methods. As such, she is helping spread climate-smart agriculture that supports livelihoods while protecting the environment. 

Kelvin summed it up: “The Crop Sprayer App gives me confidence and gives farmers peace of mind. They know they are getting value and safety at the same time.” His philosophy, “Safety starts with me,” captures how this generation understands that their success depends on the health of their communities and environment. 

The way forward 

 Wanza, Wilfred, and Kelvin show what can happen when people have access to practical digital tools. They help spread change, building more sustainable, profitable, and environmentally responsible plant health systems. Through tools like the Crop Sprayer App, CABI’s PlantwisePlus programme is demonstrating that precision agriculture works in smallholder communities. 

PlantwisePlus

PlantwisePlus gratefully acknowledges the financial support of the Directorate-General for International Cooperation, Netherlands (DGIS); European Commission Directorate General for International Partnerships (INTPA); UK International Development from the UK government; and the Swiss Agency for Development and Cooperation (SDC). 

Further reading

Meet Shahadul Islam: the rice farmer using digital tools to improve yield and quality

Youth leading Africa’s food future: Meet Mary Mueni, a young Kenyan at the forefront of agribusiness innovation

From field to farm: How digital innovation is transforming precision agriculture in Uganda