Dependence of hulless oat yield on weed infestation degree

Abstract

The dependence of hulless oat yield of the Sibirskiy golozernyy variety on the level of weed infestation was studied in the field of the Training and Experimental Farm of the Omsk State Agricultural University located in the southern forest-steppe of the Omsk Region on meadow-chernozem medium-deep low-humus and medium-loamy soil. The experiment was conducted over four years with different crop chemicalization (no chemicals, treatment with the herbicide Agritox against unfertilized background, and against the background of ammonium nitrate application); seeding dates (May 15, May 25, June 5) and seeding rates (3.5, 4.5 and 5.5 million viable grains per hectare). The dispersion analysis revealed that the main contribution to the variation of the overall level of weed infestation was made by the conditions of chemicalization (65.2%) followed by the seeding coefficient (19.4%) and seeding dates (9.4%). For the level of infestation by Poaceae species, the dominant factor was also the chemical background (52.1%), the percentage of influence of seeding dates was 23.9%, and the seeding rate - 19.8%. The analysis of yield data confirmed the decisive importance of the chemicalization background which influence accounted for more than 83% of the yield variance. The seeding dates also had significant impact on yield formation; the studied seeding rates had virtually no effect on crop productivity. Under almost all the conditions studied, a strong negative correlation was found between the total weed infestation or the infestation by Poaceae weeds and crop yields. One percent increase of weed infestation reduced oat yield by 0.04 to 0.08 tons per hectare. The decrease of hulless oat yield depends on the degree of weed infestation by 45…83%.