Contribution of yield structure elements to the winter wheat productivity formation at different moisture availability

The current paper has presented the experimental results of estimating the influence of moisture availability on productivity and yield structure elements of the winter wheat varieties. There have been studied 11 winter common wheat varieties of a semi-intensive type developed in the FSBSI “ARC “Donskoy”. The purpose of the study was to determine the influence of different soil moisture levels on the yield and its structural elements of winter wheat. The varieties were tested in laboratory conditions by simulating soil drought (sucrose solution was with an osmotic pressure of 16 atmospheres), as well as on a vegetation plot “zasushnik” with optimal and insufficient moisture. When determining potential drought resistance based on the ‘seed germination’ indicator, the studied varieties were divided into three resistance groups. The varieties ‘Ayuta’ (83.3 %) and ‘Volnitsa’ (82.1 %) were highly drought-resistant, which significantly exceeded the standard variety ‘Don 107’ (70.3 %) (НСР05 ± 6.0 %). The estimation of varieties in contrasting moisture conditions made it possible to identify stable yield traits, such as ‘length of a head’, ‘number of grains per main head’ and ‘grain weight per main head’, and ‘1000-grain weight’. High depression values under drought conditions were established according to ‘number of productive stems’, ‘length of a head’ and ‘1000-grain weight’ (6.5; 7.0; 12.0 %, respectively). There has been found a correlation between the laboratory and vegetation estimation of the trial. The correlation coefficient between resistance to lack of moisture in soil (number of viable seeds) and a depression degree of yield indicators (‘number of productive stems’, ‘length of a head’, ‘number of grains per main head’, ‘grain weight per main head’, ‘1000-grain weight’) ranged from 0.32 to 0.98. There have been identified the varieties ‘Zhavoronok’, ‘Polina’, ‘Premiera’ and ‘Podarok Krymu’, combining laboratory drought resistance with a complex of productivity traits.