Assessment of Yield and Agro-physiological Traits of Colocasia esculenta L. Cultivated under Elaeis guineensis jacq. Canopy

The dual challenges of climate change and global food insecurity have intensified interest in integrated land-use systems that combine tree plantations with food crops. This study evaluated agro-physiological attributes and yield of Colocasia esculenta under Elaeis guineensis plantations of different ages. The experiment employed a split-plot design with three replicates. These included canopy treatments assigned to main plots and sampling periods assigned to subplots. Canopy treatments included oil palm plantations established in 2008 (TC1) and 2013 (TC2) and an open-field plot as the control (C). Results indicated that C. esculenta grown under E. guineensis canopy exhibited enhanced vegetative performance as reflected in increased number of leaves, leaf area, chlorophyll content, and plant height following the order of TC1 > TC2 > C across both years. However, corm yield was significantly reduced under canopy, with reductions of 48.5% (TC1) and 75.6% (TC2) in 2020 and 52.7% (TC1) and 77.8% (TC2) in 2021, compared to the control. The age of the oil palm plantation positively influenced the agro-physiological traits of C. esculenta, suggesting that TC1 allows better light penetration and improved microclimatic conditions. Canopy treatments also led to increased soil moisture content and leaf area ratio (LAR), but decreased soil temperature and net assimilation rate (NAR), relative to the open field. The results suggest that C. esculenta can be integrated into mature oil palm systems as a shade-tolerant, understorey crop with increased vegetative properties; however, the yield penalties remain substantial. Therefore, targeted agronomic interventions are needed to enhance productivity under canopies.