Tropentag, September 16 - 18, 2026, Göttingen "Towards multi-functional agro-ecosystems promoting climate-resilient futures"

Shade effects on okra and eggplant growth and productivity in fruit-tree agroforestry systems, Kenya

¹Pwani University, Dept. of Crop Sciences, Kenya
²Pwani University, Dept. of Biological Sciences, Kenya
³Pwani University, Community Development, Kenya
⁴Gaston Berger University, Faculty of agricultural sciences, Senegal
⁵Humboldt Universität zu Berlin, Center for Rural Development (SLE), Germany

Abstract

Smallholder vegetable production in coastal Kenya faces growing climate pressure from elevated temperatures and high evapotranspiration, threatening crop productivity and food security. Fruit tree–based agroforestry systems offer a promising pathway toward multi-functional agro-ecosystems buffering climatic stresses through shade-induced microclimate regulation while diversifying farm output. Yet crop-specific responses to shade remain poorly understood, limiting evidence-based design of climate-resilient agroforestry arrangements. This study evaluated growth and yield of okra (Abelmoschus esculentus L.) and eggplant (Solanum melongena L.) under four shade levels (full light, partial, intermediate, and full shade) in mango (Mangifera indica L.)- and baobab (Adansonia digitata L.)-based systems in Kilifi County, Kenya. A factorial randomised complete block design was implemented across three sites with three replications. Plant height (PH), total fruit number (TF), and summed-up fruit weight (FW) were recorded from eight plants at crop maturity and analysed using ANOVA with Tukey HSD tests. Shade significantly affected all parameters (p ≤ 0.05), with responses varying by crop and tree system. In the mango-based system, okra PH was greater under full light than shaded conditions (46 vs. ~32 cm; p = 0.002), while TF and FW were higher under full light and partial shade than full shade (3.5–3.6 vs. 1.3–1.8 and 55–60 vs. 10–24 g, respectively; p < 0.001). Eggplant yielded higher TF and FW under full light than shaded treatments (4.2 vs. 1.1–2.2 and 145 vs. 24–64 g, respectively; p < 0.001). Under baobab, okra showed highest FW under partial and lowest under full shade (90 vs. 38 g; p < 0.001). Eggplant remained shade-sensitive with higher TF and FW under full light than shaded conditions (8.1 vs. 1.9–3.5 and 506 vs. 128–167 g, respectively; p < 0.001). These findings confirm that tree–crop interactions in agroforestry systems are crop- and system-specific. Eggplant requires full light for optimal productivity, while okra benefits from partial shade under baobab. Strategic matching of vegetables and fruit trees based on crops’ shade tolerance can enhance agro-ecosystem functionality and sustainability, support smallholder livelihoods, and may strengthen climate resilience of horticultural farms in Kilifi County and beyond.

Keywords: Agro-ecosystem, climate resilience, horticulture, shade tolerance, vegetables

Contact Address: Mathew Mumo, Pwani University, Dept. of Crop Sciences, 195-80108, 00200 Kilifi, Kenya, e-mail: mattmumoyahoo.com