PRODUCTIVITY AND YIELD STRUCTURE ELEMENTS IN SAMPLES OF SOFT WINTER WHEAT
The studies were conducted in 2017 - 2018 at the experimental fields of the FSBSI “Agricultural Research Center «Donskoy»” to evaluate productivity and elements of the structure of winter wheat samples participated in the competitive variety testing, and to find the optimal values of the traits which promote maximum yield formation. 75 samples of winter soft wheat developed in the FSBSI “Agricultural Research Center «Donskoy»” have been studied. The variety ‘Ermak’ was used as the standard one. The wheat samples’ yields varied from 9.53 to 12.20 t/ha. According to the productivity, 8 winter soft wheat samples have been identified: ‘1765/13’ (10.97 t/ha), ‘Donskaya Step’ (10.98 t/ha), ‘1334/15’ (11.02 t/ha), ‘1001/15’ (11. 08 t/ha), ‘Univer’ (11.13 t/ha), ‘1488/15’ (11.27 t/ha), ‘1005/14’ (11.41 t/ha), ‘1166/15’ (12.20 t/ha). Their productivity increase to the standard variety ‘Ermak’ ranged from 0.39 to 1.63 t/ha (least significant difference<sub>05</sub> = 0.39 t/ha). The plant height ranged from 80 to 120 cm; the standard variety ‘Ermak’ is 103 cm. The highest yield during two years formed plants with the height from 105 to 110 cm. The number of productive stems varied from 400 to 700 pieces/m<sup>2</sup>; the maximum yield was when the number of productive stems ranged from 650 to 700 pieces/m<sup>2</sup>. The highest yield formed samples with 42 to 46 kernels per head. When the length of the ear was from 7.5 to 8.0 cm, the yield increased to 10.8 t/ha. Grain weight per ear varied from 1.3 to 2.4 g; the largest productivity formed samples with 1.4-1.6 g of grains per ear. All studied wheat samples formed large kernels (more than 40 g). When 1000-grain weight increases from 40 to 44 g, the productivity reduces and then was at the same level.