The study examines the morpho-physiological differences in leaf characteristics between two species of C4 plants: sorghum and maize. The research was conducted in field conditions where plants were rainfed. Both species different varieties were cultivated at two distinct sites that exhibited variations in soil texture and drought stress incidence according to the vegetation condition index (VCI). Samples were collected during various growth stages to analyze the relative water content (RWC), proline levels, and stomatal density. Sorghum plants displayed higher RWC, proline levels, and stomatal density than maize plants. In sorghum, the biochemical traits, such as the proline content, may play a more critical role in withstanding water-limited conditions than in maize in our experiment. Under the same water restriction period, sorghum showed higher RWC levels. Sorghum plants reduced stomatal density under more water-limited conditions, which proves its plasticity. Additionally, early maturation played a crucial role in both species. The early sorghum variety KWS Kallisto and maize variety Walterinio KWS had a more stable yield at both sites. Nevertheless, the highest yields were found in the later varieties, KWS Hannibal and KWS Inteligens. The higher proline levels and the relative water content are drought-tolerant mechanisms and may be used to indicate drought intensity in field conditions. Our findings spotlight the influence of genetic diversity and genotype-environment interactions in determining crop responses to drought stress, providing valuable information for future breeding programs to enhance drought tolerance in crops.

We conducted a three-year field study to evaluate the above-ground biomass yield, plant height, and tillering capacity of eight Sorghum bicolor (L.) Moench varieties under two contrasting soil conditions (heavy clay soil and sandy soil) with different water retention. At the Field Experimental Station Žabčice of Mendel University in Brno, Czech Republic, we assessed yield performance and yield stability across years and environments. We applied standard agronomic practices and recorded detailed soil and climatic data. Significant differences were found among varieties and between locations in terms of plant height and tillering. KWS SOLE showed the most stable yield (11.80–15.63 t ha⁻¹), while LATTE, KWS TARZAN, and KWS HANNIBAL achieved the highest average yields (up to 20.16 t ha⁻¹). Plant height showed a strong positive correlation with biomass yield. This relationship underscores plant height as a valuable trait for selecting sorghum varieties with improved productivity and drought resilience. Variations in tillering capacity and environmental conditions also significantly influenced yield outcomes, highlighting the complex interaction between genotype and environment. These findings offer practical insights for cultivar selection and breeding strategies that aim to enhance the performance of sorghum varieties under the variable climatic conditions of Central Europe.

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, the scientific journal of the Mendel University in Brno, Czech Republic