University of GuilanCaspian Journal of Environmental Sciences1735-303320220220401Effects of chemical herbicides and Datura leaves extract on the companion weed of two barley cultivars Hordeum vulgare L., the yield and its components351357556710.22124/cjes.2022.5567ENRafid Ahmed AbbasAl-khaldyCollege of Agriculture, Al-Qasim Green University, Babylon, IraqWatheq FalhiHammoodCollege of Agricultural Engineering Sciences, University of Baghdad, Baghdad, IraqSuhad MathkoorA. SafiCollege of Agricultural Engineering Sciences, University of Baghdad, Baghdad, IraqJournal Article20220519A field experiment was carried out to find out the effect of some chemical herbicides (Crash and U46), and Datura leaves extract (4 leaf age) on the companion weed of two barley cultivars (IPA 265 and IPA 99) and the yield and components of these two cultivars. The results showed the superiority of the two weed spraying (T<sub>1</sub>) and the extract (T<sub>2</sub>) treatments by giving the best results, as they recorded the lowest number of weeds after 30 days of spraying with 2.83 and 10.17 plants m<sup>-2</sup>. Besides, the highest control percentage was 96.11% and 86.27% for the two treatments, respectively, compared to the control treatment (T<sub>3</sub>; weedy), which gave the highest number of weeds after spraying 73.50 plants m<sup>-2</sup>, while the lowest control percentage of 0.00%. Moreover, T<sub>1</sub> was superior by giving the best grain yield of 1.99 ton ha<sup>-1</sup> and the highest weight of 1000 grains (48.88 g) as well as the highest number of grains per spike (43.57 grain spike<sup>-1</sup>). T<sub>1 </sub>exhibited a significant difference with T<sub>2</sub>, which recorded a lower yield of 1.34 ton ha<sup>-1</sup> and weight of 1000 grains (46.78 g), as well as the number of grains (33.17 grain spike<sup>-1</sup>) and a number of spikes (313.3 spike per m<sup>2</sup>). In comparison, the control treatment (T<sub>3</sub>) recorded the lowest grain yield and the lowest weight of 1000 grains along with the lowest grain per spike, and the lowest number of spikes (1.00 ton ha<sup>-1</sup>) as well as 36.72 g, 25.60 grain spike<sup>-1</sup> and 269.7 spikes m<sup>-2</sup>, respectively. The two cultivars called IPA 99 and IPA 265, recorded a control percentage of 64.07% and 57.52%, respectively. There was a significant interaction in specific traits understudy for the two factors of the study, so that, T<sub>1</sub> and T<sub>2</sub> were superior with cultivars IPA 265 and IPA 99 by giving the best interaction in reducing the number of weeds after 30 days of spraying plant m<sup>-2</sup>, coupled with the control percentage. Since, the cultivar IPA 99 and T<sub>1 </sub>achieved the lowest number of weeds, i.e., 2.33 plant m<sup>-2</sup> and the best control percentage reached 96.79%. However, the cultivar IPA 265 and T<sub>1</sub> achieved the best grain yield of 2.113 ton ha<sup>-1</sup>. It can be concluded from this that spraying barley weeds with Datura leaves extract eliminated the weed, gave good control percentages, and increased the yield of barley grains and their components, with results close to what was achieved by the addition of the two herbicides.https://cjes.guilan.ac.ir/article_5567_af2160f6b44ff0f658682452f0f9ffc5.pdf