AGROBIOLOGICAL CHARACTERISTICS OF HULLESS BARLEY CULTIVARS DEVELOPED AT OMSK AGRARIAN SCIENTIFIC CENTER
Background. An extremely important task today is to develop new hulless barley cultivars, capable of yielding large and high-quality grain harvests, and introduce them into agricultural production. Objective. The purpose was to study three hulless barley cultivars ‘Omsky golozerny 2', ‘Omsky golozerny 4' and ‘Maysky', developed at Omsk Agrarian Scientific Center, in order to describe their agrobiological characteristics. Materials and methods. The experimental part of the work was carried out in 2015-2017 on the experimental fields of Omsk ASC in the southern forest steppe (third crop rotation after the wheat predecessor; fourth crop after fallow). There were 4 replications on the plot of 10 m<sup>2</sup>. The seeding rate was 4 million viable seeds per 1 ha. Agricultural practice used in the experiments was conventional for West Siberia. Parameters of stability and plasticity were calculated according to Eberhart and Russell, Wricke; adaptability, according to Zhivotkov; homeostasis, according to Khangildin; stress tolerance and compensatory ability, according to Rossielle and Hemblin. Results. Many years of breeding work at Omsk ASC resulted in the development of three hulless barley cultivars: ‘Omsky golozerny 2' (listed in the State Register of the Russian Federation for regions 9, 10 and 11), ‘Omsky golozerny 4' (submitted for the State Crop Variety Trials in 2017), and ‘Maysky' (not included in the State Register). The new hulless barley cultivar ‘Omsky golozerny 4', considering its higher productivity (+1.36 g to the reference in 1000 grain weight, and +0.73 t/ha to cv. ‘Maysky'), in the yield of nutrients per area unit equaled the reference ‘Omsky golozerny 2', but exceeded ‘Maysky' (+47.2 kg/ha of protein, +390 kg/ha of starch, and +42.4 kg/ha of crude fat). ‘Omsky golozerny 4' was also characterized by stability (stability = 4.8), increased compensatory ability (3.29) and adaptability (103%). There was an increase in productivity with improved growing conditions (ecological plasticity = 1.25). ‘Maysky' had higher stress tolerance (-1.35), while the reference ‘Omsky golozerny 2' showed increased homeostasis (0.118). Thus, ‘Omsky golozerny 4' exceeded the previous two cultivars in adaptability and stability.