CEPHUS PYGMAEUS INFLUENCE FOR SOFT WINTER WHEAT ELEMENTS YIELD IN THE FOREST SAMARA REGION

The purpose of the study is to reduce yield loss of winter wheat crops infested with stem borer. The studies were conducted in the forest of the Samara region in the vicinity of st. Ust-Kinelsky in 2011, 2012 and 2014. in the fields of the Povolzsje Science Research Institute of selection and seeds production of P. N. Konstantinov with the meso form of the relief at the landscape profile length of about 8 m to 4 varieties of soft winter wheat: Povolgskaya 86, Kinelskay 8, Kinelskay 4 and Konstantinovskaya (Erythrospermum). The damage of productive stalks of wheat sawfly larvae was 0.5-1.2%, peaking at an average of weather conditions in 2012, the minimum – in a relatively arid 2014 and depended on the plant population, sawflies favored more sparse crops with a correlation coefficient In 2011, 2012 –0,472- –0.480, –0.734 – in 2014. Under the influence of the sawfly larvae damaged ear stem length was reduced by no more than 5.2, the number of grains per ear – 14.4, the weight of grain in the ear – 14.4, weight of 1000 seeds – 15,2%. The largest decrease in the length of the spike observed in average weather conditions for 2012, the number and grains weight per ear – in a wet 2011, the mass of 1000 grains – in the dry 2014 from wet to dry years, the harmfulness of the sawfly increased from an average to the bottom of the slope. The smallest decrease in all indicators of productivity observed in the upper part of the slope. The number of adults cephus pygmaeus in all parts of the slopes were almost equally low (0.2-0.4 ind./100 net sweeps). The cephus pygmaeus loss of of wheat grain productivity were minor and were 3-35 kg/h.

winter, wheat, plain, stem, pygmaes, elements, yield