Influence of hydrothermal conditions on species of weeds in sunflower seeds

Abstract

Studies have found that the dynamics of stocks of weed seeds in the soil and on the basis of predicting the actual contamination of crops is one of the main criteria for scientific planning of measures and means of its destruction. In experiments, not always a large number of potential seed stocks was answered by a higher number of weed shoots during the growing season. These differences are due to the combination of many factors, the main of which are the processing methods and weather conditions of the growing season. These differences are due to the combination of many factors, the main of which are the processing methods and weather conditions of the growing season. In years, with an increase in the hydrothermal coefficient (1.5-1.6), there was an increase in the number of dicotyledonous weeds, and a decrease in the value of this indicator (0.82-1.0) increased the proportion of single-cotyledonous weeds in sunflower crops, especially during non-leaf cultivations (h = 0.71 ± 0.19). When comparing the meteorological conditions and the average annual balance of weed seeds in the cultivating soil layer, there is a tendency to greater loss of germination in years with high hydrothermal coefficients and vice versa, under conditions of a reduced hydrothermal regime of seeds in the soil, germination is better preserved (h = 0.85 ± 0.14). Wet and cool winters with sharp temperature fluctuations on the soil surface contribute to a significant reduction in the potential weediness of fields by physically full weed seeds. Conditions that contribute to the maintenance of weed seeds in the soil are moderately cool and dry winters.