Wintering of winter wheat in the Lublin region [Poland]
2007
Kolodziej, J. | Liniewicz, K. | Bednarek, H.,Akademia Rolnicza, Lublin (Poland). Katedra Agrometeorologii
Assessed in the paper were the conditions of wintering of winter wheat of the Grana variety, which was one of the longest cultivated varieties in Poland in the years 1970-1988. The experiment was carried out during 10 cold seasons at the Agrometeorological Observatory in Felin near Lublin on grey-brown soil (Orthic Luvisol), derived from silt formations, non-uniform, laying over chalk marl. In the statistical calculations considered were the wintering state of the winter wheat, as well as 11 climatic characteristics related to the air temperature, snow cover, and plant features. The analysis of the material was carried out using the correlation between the wintering state, being the dependent variable (y) and the independent variables (x1 - x11), and then the multiple regression. For calculation of the multiple regression with the selection of the best subset of independent variables used were 6 independent variables best correlated with the dependent variable. The regression equation which contained the 6 independent variables, described the wintering state with the accuracy of 92.15 percent. After the consecutive reductions, the equation with 3 independent variables was remained, which described the wintering state with the accuracy of 86.29 percent. This equation contained the following independent variables (listed according to their importance): number of days with snow cover, the growth of which improved the wintering; vegetation period starting date, the delay of which caused worsened the wintering condition, number of days with snowfall, the growth of which improved the wintering. The influence of air temperature was of moderate importance, because the most snowfall occurs at temperatures from 0 deg C to -5 deg C and the earlier start of the vegetation period in the spring depends also on the air temperature
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