In the period 2014-2016 a filed experiment with sunflower was conducted. The trial included 9 variants, of which two controls (zero and economic) and 7 variants with herbicide application (soil and foliar). The experimental field was stated in the region of the city of Pazardzhik. A number of principal and concomitantindicators relevant to the formation of the quantity and quality of the yield were studied.
The results presented in the current paper indicate that the herbicide combinations as required by the Conventional Sunflower Technology had a beneficial effect on plant height, which at the end of the vegetation period was 3 to 11 cm greater, and the mass of the sunflower seed from one sunflower head was 1 to 11 g larger for the variants after herbicide application in comparison with the control group earthed up once. In the latter, the yield increased by 26%, and for the variants treated with herbicides an increase in yield from 122.3 to 144.5% was achieved as compared to the zero control group.
The results obtained from our experiment confirm that the highest yield increase is observed in the following treatment combinations: Wing-P + Stratos Ultra, Stomp Aqua + Stratos Ultra and Gardoprim Plus Gold 500 SC + Fusilade Forte.
Keywords: sunflower, height, a mass of the grain, herbicides, yield