INFLUENCE OF AGRO METEOROLOGICAL CONDITIONS IN THE AUTUMN PERIOD ON THE INITIAL GROWTH, DEVELOPMENT AND YIELDS OF WINTER WHEAT GROWN AFTER DIFFERENT PREDECESSORS IN THE ARID ZONE OF STAVROPOL
In connection with the decisive role of weather conditions in the grain harvest, the establishment of real links between the nature of agro meteorological phenomena and the stages of vegetation of winter wheat is relevant. The experiment was carried out at the Prikumskаyа experimental selection station in 1972-2017 in the arid zone of the Stavropol Territory. The purpose of the research was to identify the influence of individual agro meteorological factors on the onset of average dates and the duration of the initial phases of plant growth and development for various predecessors and their relationship to the yield of winter wheat. The average sowing time was at the end of September (09.28-29.09). The phase of shoots on a clean pair came on average after 12 days (10.10), on a busy pair after 17 days (16.10) and half a pair after 21 days (20.10) and accounted for the end of September - October, respectively, at 100, 89 and 72% of years. The duration of emergence of shoots reliably depended on the amount of precipitation in September-October and the temperature regime of autumn. The more precipitation fell, the autumn was warmer and the better the predecessor, the faster shoots appeared. The tillering came in the autumn period on a clean pair of 89%, on a busy pair - 67% and a semi-pair - 59% of years, and the average term was, respectively, at 31.10, 5.11 and 12.11. The duration of the seedling-tillering period for a clean pair was 23, for a couple of 25 and a semi-pair for 29 days, and from tillering until the end of the autumn growing season, 32, 30 and 23 days, respectively. The yield of winter wheat reliably depended on the duration of the initial period of growth and development of plants. The shorter the sowing period - shoots and shoots - tillering, the higher the productivity of sowing. And these periods are shorter, the more favorable the weather conditions and the longer autumn vegetation.