TO THE QUESTION ON TIMES OF SOWING OF THE WINTER WHEAT
In article results of studying of efficiency of 30 breeds of a winter wheat depending on time of crop, degree of defeat by diseases and colonisations by cereal flies in autumn vegetation for the purpose of specification of times of sowing of culture are resulted. Breeds have the longest vegetative period at early, and the shortest - late crop times. Efficiency of plants of a winter wheat has difficult polynom dependence on duration of autumn vegetation, and is defined both physiological features of culture, and weather conditions of years of research. At wheat as on indicators real (a grain yield from metre square, mass of grain from a plant, quantity of grains on a plant), and potential (quantity of productive stalks on a plant, quantity of cones on a plant) efficiency advantage has the second time of sowing (on September, 30th). Plants of wheat of the first time of sowing (on September, 10th) concede to plants of the second time of sowing on the indicators set forth above because they are surprised diseases in the autumn and are colonized by cereal flies, as leads to decrease both real, and potential efficiency. Efficiency of plants of a winter wheat decreases proportionally to increase in prevalence of mealy dew or a brown rust in autumn vegetation. Plants of wheat of the third time of sowing (on October, 20th) concede to plants of the second time of sowing on the indicators set forth above because they do not have not enough duration of autumn vegetation and they enter a tillering stage with the beginning of vernal vegetation. Observed thereof decrease in indicators of potential efficiency leads to decrease in indicators of real efficiency. Authors consider that the data obtained by them testifies to desirable carrying over before target dates of sowing of a winter wheat in Stavropol Territory on 8 - 10 days later.