Physiological and Agronomic Characteristics of Alternative Black Barley Genotypes ( Hordeum vulgare var. nigricans and H . v . var. rimpaui ) under Different Hydrothermal Conditions of the Growing Seasons

Black-seeded barley can be a valuable raw material for functional food. However, its restoration to cropping should be preceded by the identification of the characteristics determining productivity. The field study was conducted to identify specific parameters of the black-seeded barley genotypes ( Hordeum vulgare var. nigricans and H. v. var. rimpaui ) and compare them with common barley ( H. vulgare ) under the different hydrothermal conditions of the two growing seasons of 2021 and 2022. Our research has shown that each genotype has a set of specific characteristics that best describe it at a given developmental stage. H. v . rimpaui was well characterized by chlorophyll fluorescence parameters such as F V /F M , F V /F 0 , and PI ABS at the seedling stage and H. v . nigricans by F V /F M and F V /F 0 at the flag leaf stage. Moreover, H. v. var. rimpaui was distinguished by a high biomass of shoot (726 g m −2 ) and straw yield (5.04 t ha −1 ) but H . v. var. nigricans by a high number of sterile generative tillers (103 m −2 in the dry year 2022). Further research should focus on the response of black-seeded barley genotypes to abiotic stresses, while in agronomic practice, efforts should be made to increase the number of grains per ear and 1000-grain weight.