Meteorological factors influence on the yield and duration of the buckwheat varieties growing season in the Yuzhno-Minusinsk forest-steppe zone

The purpose of research is to study the influence of meteorological conditions on the productivity and duration of the growing season of buckwheat varieties. In the forest-steppe zone of the South-Minusinsk District, field research was carried out on the fields of the Kuraginskoye OPH in 2019-2021 with two varieties of buckwheat: Zemlyachka and Zhdanka. It has been established that meteorological factors have an unequal effect on the formation of the level of grain yield of the studied buckwheat varieties, which differ in the duration of the growing season. The yield of the variety Zhdanka reacts significantly to precipitation in all ten days of June (r = 0.538-0.816), the second ten days of August (r = 0.798). In the second ten days of August, favorable conditions for grain filling were formed in terms of moisture availability, relative humidity (r = 0.563) and average daily air temperature (r = 0.813), HTC indicator (r = 0.669). Low moisture content in the second decade of July had a negative impact on the realization of the potential productivity of the variety Zhdanka (r = -0.683). The yield of the Zemlyachka variety did not have a significant correlation with any of the weather indicators (r = -0.273-0.274), which indicates the genotypic features of the varieties in response to the variability of vegetation conditions and different dependence on them in the process of ontogenesis. A significant influence of meteorological factors on the duration of the growing season and its main interphase periods has been revealed. An identical reaction of varieties Zhdanki and Zemlyachka to the effect of weather conditions on the passage of phenological phases was established. A strong positive correlation was obtained between the duration of the growing season and the hydrothermal coefficient in the first (r = 0.942-0.954) and third decade of July (r = 0.854-0.859), the first (r = 0.837-0.851) and the third decade of August (r = 0.934-0.946), weak in the first decade of June (r = 0.420-0.434) and the second decade of August (r = 0.460-0.474). Good moisture supply and elevated average daily air temperatures lead to a lengthening of the growing season and, above all, the interfacial: flowering - maturation.