Effects of Contrasting Watering Regimes on Growth Dynamics and Chlorophyll Responses of Thirteen Corchorus olitorius Genotypes

Background: Limited water availability may restrict the vegetative development of Corchorus olitorius, but the responses of thirteen previously characterised Togolese genotypes to different watering schedules have not been established. Aims: Interruptions in water supply can constrain leafy vegetable production, yet the responses of thirteen previously characterised Togolese Corchorus olitorius genotypes to contrasting watering schedules remain insufficiently understood. This study evaluated their growth and relative chlorophyll responses to identify promising material for further evaluation and crop improvement under restricted water supply. Study Design: A completely randomised factorial experiment combining thirteen genotypes and three watering regimes, with two replications of five individually potted plants per combination. Place and Duration of Study: Screenhouse of the Laboratoire de Recherche sur les Agroressources et la Santé Environnementale, École Supérieure d’Agronomie, Université de Lomé, Togo, from December 2025 to March 2026. Methodology: Plants received daily watering, watering every seven days, or a single watering at treatment onset. Each application supplied 0.5 L per pot. Plant height, number of primary branches, number of green leaves and relative chlorophyll content were recorded on days 0, 7, 14 and 21; stem diameter measurements began on day 7. Changes from each replication’s day-0 mean were analysed using repeated-measures mixed models. Stem diameter was analysed as observed values. Results: Interactions between watering regime and recording day were significant for all five traits (P < 0.001). By day 21, mean height increases were 94.96, 34.12 and 12.19 cm under daily, weekly and single watering, respectively. Corresponding net changes from day 0 were +181.58, +71.46 and −7.62 green leaves per plant. Under single watering, no green leaves remained on day 21. Relative chlorophyll increases were greater under restricted watering at some assessments despite smaller growth increases. On day 14, G7 recorded the greatest numerical green-leaf increase under weekly watering, while G10 and G13 ranked highest under single watering. Conclusion: Weekly watering maintained vegetative development at lower levels than daily watering, whereas single watering resulted in complete leaf drying by day 21. Contrasting genotype responses identify material for further evaluation of leaf production and recovery under restricted water supply.