Response of chilli pepper to different irrigation schedules and mulching technologies in semi-arid environments

The impacts of climate change on food security have increased interest in research and investments in irrigation technologies and agricultural water management. Agricultural practices such as mulching help to conserve soil moisture by reducing evaporation and mitigate the adverse effects of water stress on crops, especially in semi-arid environments. This study investigated the combined effects of irrigation schedules and different mulching technologies on the growth and yield of two varieties of chilli pepper – Legon 18 (Capsicum frutescens L.) and Kpakpo shito (Capsicum chinense) – in the Guinea Savannah agro-ecological zone of Ghana. Soil temperature and moisture content as well as plant growth parameters were collected over the growth period. The number of days taken for first and 50% flowering and fruiting were also recorded. Total fruit yield and crop water productivity were estimated after harvest. Results show that the combination of irrigation at 100% E T c r o p every three days and rice straw mulch ensured optimal soil temperature and moisture content that improved vegetative growth, shortened the number of days to flowering and fruiting, and significantly improved yield and water use efficiency compared to the other treatment combinations. Fruit yield for this treatment combination was up to 19,042.2 kg/ha and 19,074.6 kg/ha whereas crop water productivity was up to 6.08 kg/m3 and 6.09 kg/m3 for Legon 18 and Kpakpo shito, respectively. Plastic film mulch under each irrigation schedule produced higher growth and yield-related parameters than no mulch treatments. Although findings from this study cannot be directly generalized for the entire Guinea Savannah agro-ecological zone of Ghana due to spatial variability of soil and other climatic variables, the combination of irrigation schedule at 100% E T c r o p every three days and rice straw mulch is recommended for improved yield and water use efficiency in dry season chilli pepper production in semi-arid environments with sandy loam soils.