The influence of weather and climatic conditions on the phenological indicators and productivity of winter wheat cultivated by direct seeding technology in the arid zone of the Stavropol Territory

Abstract

The studies were conducted in the arid zone of Stavropol region to determine the productivity of winter wheat cultivated by direct seeding technology, based on phenological observations and NDVI. The work was carried out on the basis of the agro-enterprise JSC Agrohleboprodukt for 2018-2020. The predecessors are sunflower, chickpeas, winter wheat varieties (Zustrich (St.), Bagheera and Bagrat). Plant samples were selected according to the generally accepted method. Satellite mapping data of vegetation cover is obtained on the basis of the service VEGA-Science . It was found that the growth, development and productivity of winter wheat depended on the prevailing weather and climatic conditions. Studies of the dynamics of the average annual indicators showed that precipitation tended to decrease (37.6-14.4 mm), and the temperature and vegetation index NDVI-to increase (9.6-12.3 °C and 0.456-0.491, respectively). The analysis showed the absence of a reliable level of significance of the combined application of these factors for predicting the productivity of winter wheat. The terms of sowing the crop were determined by external conditions and shifted to a later period. The largest average linear deviation of the indicator was revealed in 2020 (6.4444). On average, the variation of seedlings for different varieties and predecessors was 9 % (the lowest for chickpeas – 7.5 %). Seedlings of grain crops appeared 19-20 days after sowing. The coefficient of variation showed a high heterogeneity of the phenological index for all phases, except for tillering (8.6-9.0 %). The average density of plant seedlings was 379 pcs./m2. The coefficient of variation of the indicator is uniform for all varieties and precursors (3.65 %). A decrease in plant density was observed from the germination phase to earing and for all the predecessors (the largest for the Zustrich variety – 7.3 % and 10.2 % for sunflower and chickpeas, respectively). From 2018 to 2020, the yield of winter wheat when sowing for sunflower was 301-450 t/ha, for chickpeas – 326-468 t/ha. \n\xa0