Growing media, water stress and re-watering effects on the growth and dry matter production of cocoa seedlings

Abstract

Cocoa (Theobroma cacao) seedlings are very sensitive to water stress during the nursery stage and early field establishment. Sawdust, carbonated rice husk, and compost in the following ratios (i) 60: 40: 0 – M1, (ii) 60: 30: 10 – M2, (iii) 60: 20: 20 – M3, (iv) 60: 10: 30 – M4, (v) 60: 0: 40 – M5, and (vi) topsoil – M6 as control were used to investigate the effect of growing media, water stress, and re-watering on the growth, dry matter production, and partitioning of cocoa seedlings. Each combination was subjected to water stress 6 weeks after sowing for a period of 4 weeks, after which they were rewatered. Plant height, stem girth, leaf number and area, and seedling biomass were significantly higher in soilless potting media as compared to topsoil. M4 and M5 significantly recorded the highest total dry weight, plant height, stem girth, leaf number, leaf area, and root volume before imposition of water stress. Following imposition of water stress, cocoa seedlings grown in M4 and M5 showed a recovery that was superior to the other growing media, indicating that higher proportions of compost together with sawdust and carbonated rice husk provide an alternative for growing cocoa seedlings.

Keywords

• cocoa
• water stress
• re-watering
• growing media
• carbonated rice husk