By Special Correspondent
In the cool, mist-shrouded uplands of Njombe and Iringa, a quiet agricultural revolution has rewritten the economic destiny of thousands of smallholder farmers. A decade ago, the Irish potato was merely a subsistence crop in Tanzania’s Southern Highlands—plagued by diseased seeds, anemic yields, and exploitative middlemen. Today, cooperatives from these same hills are not only smashing productivity records but shipping containers directly to Nairobi and Stone Town.
This transformation was no accident. It is the product of a decade-long, meticulously orchestrated partnership strategy led by the Southern Agricultural Growth Corridor of Tanzania (SAGCOT)—a public-private alliance that has elevated the potato from survival crop to commercial powerhouse. For agribusiness stakeholders across East Africa, Tanzania’s potato story offers masterclasses in coalition-building, policy consistency, and integrated value chain development.
The Coalition Takes Shape (2014–2016)
The transformation began in 2014, when SAGCOT Centre identified potatoes as a strategic crop for the Ihemi Cluster covering Iringa and Njombe. The sector was chaotic. Farmers recycled seeds season after season, guaranteeing disease spread and yields that averaged a dismal 7 tonnes per hectare—less than a third of what modern agronomics promised.
In 2015, SAGCOT assembled what would become a flagship Potato Partnership. This was no government diktat, but a carefully constructed coalition: Mtanga Foods brought seed multiplication capacity; AGRA provided catalytic funding; technology partners Grimme and Lemken delivered mechanization; CRDB Bank opened financial access. The target was ambitious—reach 11,500 farmers and build a commercially viable value chain from scratch.
The initiative gained international heft in June 2016 when SAGCOT, working with Tanzania’s Ministry of Agriculture, facilitated a landmark trade mission led by the Dutch Minister for Agriculture. The visit culminated in a bilateral MoU between Tanzania and the Netherlands to co-develop the potato sector—a partnership that would channel world-class Dutch seed genetics and agronomic knowledge to Tanzanian soil.
The Productivity Explosion (2017–2019)
The impact was swift and dramatic. By 2017, just two years into intensive intervention, productivity among participating Njombe smallholders had exploded from 7 tonnes per hectare to 31 tonnes per hectare—a 340% increase.
Certified seed was the unlock. Farmers accessed 2,325 metric tonnes of improved seed potato in 2017 alone. New investors arrived, including TanzaNice, which established operations producing both seed potatoes and avocados, directly addressing the critical shortage of quality inputs.
In 2018, the partnership established a Potato Centre of Excellence in the cluster, operated by STAWISHA. This center became a living laboratory for best practices, ultimately recording a staggering 59 metric tonnes per hectare—the highest potato yield ever documented in Tanzania. The demonstration was unequivocal: with proper inputs, modern agronomy, and mechanization, Tanzanian highland soil could compete with any potato-growing region in the world.
The technological transformation extended beyond genetics. Farmers began treating the region’s acidic soils with lime application—a simple but revolutionary practice. Field testimonials from Njombe documented how lime alone doubled yields from 6 to 12 tonnes per acre, transforming marginal plots into profitable enterprises.
Building Resilience Through Institutions (2020–2023)
The journey encountered turbulence. In July 2020, STAWISHA—a cornerstone partner—ceased operations. But the SAGCOT model’s resilience lay precisely in its diversity. The Centre swiftly pivoted, focusing resources on developing medium-scale commercial seed multipliers to fill the vacuum.
This period witnessed the emergence of robust farmer institutions. The Isowelu Agricultural Marketing Cooperative Society (AMCOS) in Njombe became an exemplar. By rigorously adopting Good Agricultural Practices (GAP) and maintaining strict quality standards, Isowelu AMCOS scaled production to 2,500 metric tonnes in 2021.
Most significantly, Isowelu AMCOS circumvented traditional middlemen to secure direct markets in Kenya and Zanzibar. In the 2021 season, the cooperative harvested approximately 186.4 tonnes from just 15 acres, competing head-to-head with Kenyan varieties in Nairobi’s wholesale markets.
Institutional maturation accelerated. In 2022, SAGCOT facilitated creation of the Potato Council of Tanzania (PCT), establishing national-level governance for the subsector. This dovetailed with regional integration efforts as SAGCOT joined the East African Community (EAC) Potato Seed Platform, launched in Kampala to harmonize cross-border seed trade and phytosanitary standards.
Measuring the Impact
The economic transformation tells its own story:
Productivity Gains
From a baseline of 7 tonnes/ha in 2015 to an average of 28 tonnes/ha in 2021—a fourfold increase. Elite farmers now routinely exceed 50 tonnes/ha.
Knowledge Diffusion
In 2016, 1,852 farmers received formal GAP training. By 2021, farmer-to-farmer training models like “Tajirika na Lusitu” (Get Rich with Potatoes) had cascaded knowledge from Njombe across Mbeya and Ruvuma regions.
Investment Climate
The clarity and stability of the value chain attracted diverse private capital—from cold chain logistics providers to HZPC, one of the world’s premier potato breeding companies.
Lessons for Regional Agribusiness
The SAGCOT potato success validates the “cluster approach”—concentrating infrastructure, finance, and extension services in specific high-potential zones like Ihemi and Mbarali. This spatial concentration allowed stakeholders to solve systemic constraints that no single actor could address independently.
The model depended on three pillars: partnership diversity (public, private, NGO, and farmer organizations sharing risk); technology transfer (not just seeds, but agronomic knowledge and mechanization); and market linkages (connecting production zones directly to demand centers).
As SAGCOT evolves into the Agricultural Growth Corridors of Tanzania (AGCOT), expanding the model across Northern, Central, and Mtwara corridors, the potato blueprint becomes instructive. It demonstrates that African smallholders, when systematically linked to technology, finance, and markets through credible intermediation, can feed not merely their families but entire regions.
For the Kenyan traders who now watch trucks loaded with Njombe potatoes roll into Nairobi and Mombasa, these shipments represent more than produce. They are the tangible dividends of a decade-long commitment to building agricultural value chains that work, evidence that patient partnership can transform subsistence into prosperity, one hectare at a time.