Testing pearl millet and cowpea intercropping systems under high temperatures

Results showed that intercropping pearl millet led to a significantly lower total grain yield in comparison to the sole equivalent. Pearl millet's highest yields were 1350 kg ha−1 when intercropped and 2970 kg ha−1 when grown as a sole crop; for cowpea, 990 kg ha−1 when intercropped, and 1150 kg ha−1 as a sole crop. Interestingly, even when maximum daily temperatures reached up to 42.2 °C (on Julian day 112 in 2016), well-watered, pearl millet produced reasonable yields. Cowpea yields were often lower than 1000 kg ha−1. Only under the highest irrigation treatment (well-watered) sole cropped, low density were yields of 1150 and 1110 kg ha−1 achieved in 2015 and 2016, respectively. We conclude that successful intercropping systems must be highly specific to conditions and demands. More research would be needed to identify suitable cowpea genotypes and planting densities that could allow for higher intercropped pearl millet yields.