The document presents research on improved vegetable technologies in Babati District, Tanzania, highlighting enhanced yields and incomes from elite cultivars under integrated management practices. It discusses the development of an Extrapolation Suitability Index (ESI) to identify optimal areas for scaling these technologies, utilizing geo-spatial technology and digital agronomy. Future plans include creating a mobile tool for farmers to access suitability maps and agronomic advice.

1. Extrapolation suitability for improved vegetable
technologies in Babati District, Tanzania
Francis Muthoni1, Justus Ochieng2, Jean-Marc Delore1 & 3, Phillipo J. Lukumay2, and Inviolate Dominic2
1International Institute of Tropical Agriculture, 2WorldVeg Centre, 3Wageningen University & Research
Power on Your Plate Summit
25-28 January 2021, Virtual and In-person, Gran Meliá Arusha, Tanzania

2. Outline
• Introduction
• Experimental trials of elite vegetable cultivars
• Generating Extrapolation Suitability Index (ESI)
• Relevance of ESI maps in scaling programs
• Future plans

3. Introduction
• Vegetables are important dietary component rich in essential micro-
nutrients & source of income.
• Investment on sustainable vegetable production technologies enhance
societal benefits & environmental sustainability.
• Two improved vegetable cultivars grown under integrated management
practices (IMP’s) in Babati district of Tanzania produced double the yield
and net income compared to standard farmer’s practice.

4. • Where to scale-out high yielding cultivars + IMP’s with minimal risk of
failure?
• Solution: Leverage geo-spatial technology & digital agronomy.
• Generate maps on risk of extrapolating to new areas.

5. Study area in Babati, Tanzania
• On-farms trials of tomato (Tengeru-10) and African Eggplant (Tengeru
white).
• Four villages representing agro-ecological zones since 2013.

6. Validation of improved vegetable technologies
• On-farm trials compared cultivars produced under integrated
management practices (IMP) & standard farmers’ practice (control).

7. Yield & income from on-farm trials
• Yield & income of tomato (Tengeru10) and African eggplant (Tengeru-
white) under integrated management practices (IMP) double compared
to farmers practice.
IMP had >double yield
& income compared
to farmer practice
(control).
Where else to scale
out two cultivars with
IMP to replicate
success?

8. Input data for developing ESI
• Integrate on-farm trials (reference) & gridded remote sensing
(projection) data.

9. Characterizing reference environments
• Homogeneity of environmental conditions in field trials examined with
HPCA.
• Discriminated 3 clusters representing population of target environments.
Magug
u
Galapo
Bermi
Seloto

10. Selection of reference target environments
• Yield & income from different environmental clusters compared to select
the best-bet reference trial sites for extrapolation of vegetable cultivars.

11. Mapping ESI for Vegetable cultivars
• ESI ranges from 0 to negative infinity with 0 being the most suitable
• Tengeru 10 widely adapted but African eggplant unsuitable in southwest
Babati.

12. Most important covariates (MIC)
• Tengeru 10 largely limited by Evapo-transpiration (ETP) and elevation
(DEM).
• Tengeru-white mainly limited by precipitation (PPT) and market access.
• Soil water conservations measures & supplemental irrigation
recommended.

13. Significance of ESI maps
• Extrapolation suitability (ESI) maps produced to guide extension &
development partners on priority sites for targeting scaling intervention.
Application of ESI maps expected to:
• Reduce the risk of failure,
• Prioritize allocation of scarce resources for maximum impact, and
• Possibly enhance adoption at scale.

14. Future developments
• Design of a simple & user-friendly mobile-based tool for farmers and
extension staff with basic phones.
• Integrate suitability maps with Mwanga Platform for digital agronomic
advisory.

15. Africa Research in Sustainable Intensification for the Next Generation
africa-rising.net
This presentation is licensed for use under the Creative Commons Attribution 4.0 International Licence.
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