Evaluation of Herbicides on the Content and Yield of Raw Protein in Wheat (Triticum Aestivum L.)

Abstract

The investigation was carried out at Dobrudzha Agricultural Institute – General Toshevo during 2012 – 2014 in four-field crop rotation (wheat-maize-wheat-sunflower). Cultivars Aglika and Enola were sown at two dates – optimal (1st – 15th October) and late (after 20th November). The following set of herbicides was tested: Derby super VG – 3,3 g/da; Palace 75WG + oil – 25+100 g/ml/da; Granstar 75DF – 1,5 g/da; Lintur 70VG – 15 g/da; Husar Max ОD – 100 ml/da; Secator ОD – 10 ml/da and Mustang 306,25СК – 80 ml/da. The herbicides were applied at three dates: 1st date А – stage 29 according to Zadoks (Tillering stage); 2nd date B – stage 32 according to Zadoks (Stem elongation) and 3rd date С – stage 37 according to Zadoks (Emergence of flag leave). The experiment included two control variants К1 – weed-free control (manually weeded from the emergence of the first weeds till heading of wheat), and К2 (nil) – a control variant infested till harvesting of the crop. A high level of significance of the tested herbicides on the values of raw protein in grain and protein yield from the investigated cultivars was determined under the conditions of the experiment. The years of investigation had highest effect on the values of the tested characteristics. Best results were obtained in 2012. The two cultivars formed grain with the highest raw protein content in 2014. Regardless the sowing data the grain of cultivar Enola reached the maximum content of raw protein at the tillering stage of herbicides application, on the contrary of cultivar Aglika. The grain of cultivar Enola contained raw protein 9.33% more then cultivar Aglika average for the trail. The auxin type herbicide Lintur 70 VG cased the increasing the raw protein content in maximum degree in comparison the other herbicides. The exceeding to the weed-free control was 16.67% average for the years. At the late date of herbicide application, the amount of protein decreased in both cultivars. Averaged for the investigated period, the size of protein yield of cultivar Enola was with 18.7 % higher than the yield of cultivar Aglika. Cultivar Aglika has well expressed tolerance to the stages of herbicide application in comparison with cultivar Enola. Aglika’s raw protein yield was higher at the stem elongation stage (32 Zadoks) of herbicides applicaton. Cultivar Enola differ from cultivar Aglika with the greatest raw protein yield at the tillering stage (29 Zadoks) of herbicides application. In all three years of the investigation, highest yield of raw protein was obtained from the manually weed-free control (К1) and lowest – from the infested control (К2). Averaged for the tested variants of the trial, only after the application of the herbicides Derby super VG and Secator OD the raw protein yield remained at the level of the weed-free control (К1). There was a strong positive correlation of grain yield with raw protein yield. Averaged for the period of investigation, the sowing date of cultivar Aglika did not show significant effect on the values of the correlation coefficients. In cultivar Enola, the late sowing date lead to high increase of the correlation. This tendency was best expressed in harvest year 2014 (r=,875**). The regression models obtained for the investigated years once again confirmed the high proportional correlation of grain yield with protein.