The Effect of some Herbicides and Spraying Periods on the Growth and Weeds of a Soybean Crop (Glycin max L.)

Abstract

A field experiment was conducted in the Kurdistan Region of Iraq for the 2022-2023 agricultural season in the fields of the Agricultural Research Station in Erbil / Ain Kawa Governorate on 5/28/2022. With the aim of knowing the effect of the herbicides (imazethapyr and the mixture of bentazone + Calant Super) and the recommended quantities for each of these pesticides and the spraying periods of these pesticides, which included four periods (two weeks, four weeks, six weeks and eight weeks) after the germination of the soybean crop of the Shaima variety). The experiment was applied according to a randomized complete block design (R.C.B.D.) as a global experiment with three replications, and the results showed that the weed-free treatment was superior to the rest of the pesticide treatments because control was used throughout the growing season and for all the studied weed characteristics, which included the percentage of control, the dry weight of the bush, and the weed index. As for the periods, Spraying: The two spraying periods were superior, two weeks after germination and four weeks. As for the dry weight characteristic of the bush, the two spraying periods were superior after four weeks and six weeks. As for the bush index characteristic, the two spraying periods were superior after six weeks and four weeks after germination. As for the effect of herbicide treatments on the characteristics of vegetative growth (plant height, number of branches, plant-1, leaf area), the treatment without weeds was superior in the characteristics of plant height and number of branches. Plant-1. As for the protective area characteristic, the pesticide mixture treatment (pentazone) was superior. + Callant Super. As for the effect of spraying periods on the characteristics of vegetative growth, the spray treatment after six weeks was superior in terms of plant height. As for the characteristics of leaf area and number of branches. Plant-1, the spray treatment after four weeks was superior and achieved the highest average.