Trees That Feed, Trees That Earn

In 2019, when Merry Lukosi enrolled in our tree trial, she could not have imagined what would grow from it. What began with a handful of grevillea seeds soon expanded to include avocado trees, and within just a few years, her farm has grown into a thriving mini-forest. Today, nearly 90 trees rise above her farm in Tanzania's Kilolo District, their leaves casting shade and their promise reaching far beyond firewood: they now feed her household, generate income, and serve as an investment in her family's future.

"I have around 37 avocado trees. I can improve my diet by eating avocados with my meals. Also, I sell surplus and get money to buy soap and other consumables at home," Merry says.

Merry's journey is part of a broader trend across Africa, where millions of smallholder farmers are planting fruit trees as part of a shift toward agroforestry and diversified farming. These practices not only improve household nutrition and stabilise income but also make farms more resilient to unpredictable weather.

For many years, One Acre Fund's agroforestry offering was dominated by grevillea and other timber trees. Over time, however, farmers increasingly expressed interest in fruit trees. Their reasons were clear:

• Nutrition and dietary diversity: Farmers wanted lifelong access to fruit that provide vital nutrients often unavailable in local markets or prohibitively expensive.
• Resilience : Fruit trees provide consistent nutrition for families, particularly children, and strengthen household resilience against food insecurity.
• Market opportunity: Fruits often fetch high prices in local markets. Some, like avocado and macadamia, are considered cash crops with export potential, offering farmers access to lucrative new markets.

By listening closely to farmers and prioritising their resilience, we have expanded our fruit tree offerings. Over the past four years, we have increased our portfolio from 2 species to 10 varieties. In 2025 alone, we distributed over 3.6 million seedlings of avocado, papaya, coffee, macadamia, guava, lemon, banana, cloves, parkia, and Japanese plum, across the countries we serve.

Why measure impact if farmers already know?

The farmers we serve consistently tell us that fruit trees make a real difference in their lives. We agree, but also believe in quantifying that impact. Measuring helps us understand not just that fruit trees make a difference, but how much each species contributes. This matters for three reasons:

1. Scaling decisions: Knowing which species provide the highest impact guides where we invest in production and distribution.
2. Social Return on Investment (SROI) : Both at the organisational and farmer level, we weigh the costs (seedlings, planting, maintenance) against the benefits (nutrition, income) to ensure the return justifies the effort.
3. Rigour and transparency: Quantification ensures impact metrics are evidence-based and defensible, strengthening our accountability.

Fruit trees don't just feed families, they create pathways to income, resilience, and opportunity. Farmers have always understood their value. By quantifying their impact, we ensure every decision we take, from what trees to produce to determining how we scale them, is grounded in evidence and driven by farmer demand. At the end of the day, this isn't just about numbers. It's about ensuring farmers get the greatest possible return from every tree they plant.

Over the last two years, we have built a robust framework to measure fruit tree impact. This framework has been reviewed by Innovations for Poverty Action (IPA), a research organization dedicated to discovering and advancing what works to improve the lives of people living in poverty. We then refined our approach based on their feedback to ensure alignment with best practice.

How we quantify fruit tree impact

To assess the full value of fruit trees, we build Net Present Value (NPV) models that capture a tree's benefits over its lifetime. Here's how it works:

• Life cycle mapping: Our enumerators survey farmers who own trees of different ages. Farmers describe the non-productive years, when yields begin, peak, and when they taper off.
• Quantifying harvests: Farmers estimate the quantity of fruit harvested at each stage. We measure this in kilograms for consistency.
• Market prices: We conduct simultaneous price surveys to establish fair market value for each fruit type.
• Costs: We capture the full range of farmer costs (e.g. planting, maintenance, harvesting, transportation, and even opportunity costs for land use).
• The value that each tree will bring to an owner: We apply a discount rate to future values, producing a single, present-day estimate of lifetime value per tree.

What we found through fruit tree impact measurement

When we started measuring the impact of fruit trees, it became apparent that they differ and provide different values. Some mature faster, others produce higher yields, some have better market prices, and some perform better in some agro-ecological zones than others. With clearer evidence of the performance and potential value of the fruits, we were able to make informed decisions about which trees to provide and how to scale distribution. This evidence also contributed to a broader shift across the organization towards prioritizing fruit trees within the tree portfolio, helping drive the expansion from just 2 fruit varieties in 2021 to 10 in 2025.

Why the evidence matters

Measuring impact also helps farmers understand the short-term and long-term benefits of their investment in fruit trees.

For example, our cross-country analysis showed that improved avocado varieties yield among the highest lifetime returns. Using a 20-year Net Present Value (NPV) model, we found that a single (improved) avocado tree can generate approximately $100 in Rwanda, $110 in Tanzania, and $80 in Burundi. These differences are expected due to variations in growth patterns, climate, quantities harvested, and market prices. However, they point to the same conclusion - fruit trees are beneficial and worthwhile long term assets for farmers to invest in.

By grounding our decisions in data-driven evidence, we are empowering farmers with the information they need to choose the species that will best strengthen their income and resilience, allowing them to dream bigger and plan for their future.