Effect of Drought, Nitrogen Fertilization, Temperature, and Photoperiodicity on Quinoa Plant Growth and Development in the Sahel

Drought, heat stress, and unfavorable soil conditions are key abiotic factors affecting quinoa’s growth and development. The aim of this research was to examine the effect of progressive drought and N‐fertilization reduction on hort‐cycle varieties of quinoa (c.v. Titicaca) for different sowing dates during the dry season (from October to December). A two‐year experimentation (2017–2018 and 2018–2019) was carried out in Burkina Faso with four levels of irrigation (full irrigation—FI, progressive drought—PD, deficit irrigation—DI and extreme deficit irrigation—EDI) and four levels of N‐fertilization (100, 50, 25, and 0 kg N ha−1). Plant phenology and development, just like crop outputs in the form of yield, biomass, and quality of the seeds were evaluated for different sowing dates having different temperature ranges and photoperiodicity. Crop water productivity (CWP) function was used for examining plant’s water use efficiency under drought stress conditions. Emerging findings have shown that CWP was highest under DI and PD (0.683 and 0.576 kg m−3, respectively), while highest yields were observed in 2017–2018 under PD and its interaction with 25 to 50 kg N ha−1 (1356 and 1110 kg ha−1, respectively). Mean temperatures close to 25 °C were suitable for optimal plant growth, while extreme temperatures at anthesis limited the production of grains. Small changes in photoperiodicity from different sowing dates were not critical for plant growth.