Weed infestation of winter wheat (Triticum aestivum L.) under the conditions of application of some retardants

摘要

A field study was conducted in the period 2004–2007 on grey-brown podzolic soil (sandy). This study analysed the relationship between the use of stem shortening in cereals by means of retardants with the following active substances: chlormequat chloride (Antywylegacz P?ynny 675 SL), trinexapac-ethyl (Moddus 250 EC), chlormequat chloride + ethephon (Cecefon 465 SL), and weed infestation. The retardants were applied at the 1st node stage (BBCH 31 – Antywylegacz P?ynny 675 SL) and the 2nd node stage of winter wheat (BBCH 32 – Moddus 250 EC and Cecefon 465 SL), together with the adjuvant Atpolan 80 EC (75% of SN 200 mineral oil) or without the adjuvant. Winter wheat, cv. 'Muza', was grown after vetch grown for seed. The whole experiment was sprayed with the herbicides Apyros 75 WG and Starane 250 EC at the full tillering stage (BBCH 29–30). Plots where no growth regulators were used were the control treatment. Weed density and biomass showed great variation between years. In the winter wheat crop, Veronica persica, Viola arvensis, Veronica arvensis, Capsella bursa-pastoris ,and Chenopodium album dominated in the dicotyledonous class, whereas Apera spica-venti , Echinochloa crus-galli ,and Elymus repens were predominant among monocotyledonous plants . The level of weed infestation of the winter wheat crop, as measured by the number and air-dry weight of weeds, was significantly differentiated by years and retardants used as well as by interactions of these factors. The adjuvant Atpolan 80 EC did not have a significant effect on the above-mentioned weed infestation parameters. .