The effect of sowing dates on a vegetation period of spring wheat varieties of different maturity groups

The purpose of the current work was to estimate the effect of sowing dates on a length of a vegetation period and the sowing qualities of spring wheat varieties of different maturity groups. The trials were carried out from 2018 to 2020. There have been studied such six varieties as middle-early varieties ‘Altaiskaya 70’, ‘Novosibirskaya 29’, ‘Tulunskaya 12’, Krasnoyarskaya 12, the middle-maturing variety ‘Kuraginskaya 2’, the middle-late variety ‘Svirel’. There have been studied such two sowing dates as optimal in May 15, and late in May 22. The sowing trials were carried out with a seeder SSFC – 7. Harvesting was carried out with the combine ‘Hege’. The grain was dried, cleaned on ‘Petkus’, and weighed. The germination was estimated according to GOST 12036-66. Grain crops were sown in weedfree fallow. The counting area of the plots was 10 m2, with three repetitions. When sown in late dates, the ‘sprouting-ear formation’ period reduced on 4 days for the middle-late wheat variety ‘Svirel’, on 2 days for the middle-maturing varieties ‘Kur aginskaya 2’ and ‘Krasnoyarskaya 12’, for the middle-early varieties ‘Altayskaya 70’, ‘Tulunskaya 12’, ‘Novosibirskaya 29’ this period did not change. The length of the period ‘ear formation-maturity’ period for middle-early wheat varieties was 34–36 days, for middle-maturing varieties it lasted 36 days, and for the middle-late variety ‘Svirel’ it was 40 days. The varieties ‘Tulunskaya 12’, ‘Novosibirskaya 29’ and ‘Altaiskaya 70’ increased their productivity on 0.2–0.6 t/ha at a late sowing date, the middle-maturing varieties ‘Kuraginskaya 2’, ‘Krasnoyarskaya 12’ and the middle-late variety ‘Svirel’ increased their productivity on 0.3–0.5 t/ha at an early sowing date. There should be noted that 1000-grain weight changed similarly to the productivity of varieties. This indicator of the middle-early varieties increased in the late sowing date, and that of middle- and late-maturing varieties in the early sowing date. The recommended period for sowing spring wheat in the conditions of the Krasnoyarsk Territory for middle-early varieties for seeds is the beginning of the third ten days of May with a sum of active temperatures of 190 °C; for middle- and late-maturing varieties it is the middle of the second ten days of May at a sum of active temperatures of 150 °C.