Environmental impact on grain quality in Ethiopian sorghum landraces

Sorghum is an important staple crop for food security, providing a resilient source of nutrition in drought-prone regions. However, variation in sorghum grain quality content across diverse environments and the impact of drought stress pose significant challenges in identifying stable, high-nutrient genotypes for improved food security and resilience. This study aimed to evaluate the effects of drought and environmental conditions on sorghum grain quality content. This study evaluated 358 sorghum landraces under three conditions: optimal (Melkassa), wet intermediate (Jimma), and natural drought (Miesso) over two seasons (2020–2021), assessed sorghum grain quality content using Near-Infrared Spectroscopy (NIRS) method. Starch content was highest at Melkassa in 2021 (71.6 %) and lowest at Miesso in 2021 (66.5 %). Protein content was highest at Miesso in 2020 (11.6 %) and lowest at Melkassa in 2021 (7.7 %). The highest mean values for iron (Fe) (44.2 ppm) and zinc (Zn) (38.5 ppm) were recorded at Jimma in 2020. Starch ranged from 64.94 % to 72.71 %, protein from 7 % to 12 %, Zn from 19.3 to 95.7 ppm, and Fe from 3.75 to 93.1 ppm across environments. Genotypes G246, G84, G4, and G175 exhibited high and stable starch content, G358 for protein, G264 for Zn, and G142 and G137 for Fe across environments. Starch content was 5 % higher in wet intermediate environment compared to stress environment, while protein content was about 21 % higher in stress environment than in wet intermediate environment. Drought stress reduced starch and mineral content but increased protein levels, highlighting its significant impact on sorghum grain quality content across environments. • Comprehensive analysis of 354 Ethiopian sorghum landraces and four commercial checks under diverse environmental conditions. • Environmental conditions studied include well-watered, wet intermediate, and natural drought environments over two growing seasons. • Significant variation observed in kernel composition traits across different environmental conditions. • Potential applications of findings in improving drought tolerance and nutritional quality of sorghum.