An experiment was implemented in the experimental field of the Department of Field Crops, College of Agricultural Engineering Sciences, University of Baghdad, Jadriya during the year 2020-2021. The study aimed to investigate the effect of some herbicides (Crash + U46-Combifiluid) combination and Axial, Weed Free and Weedy, on the companion weeds and growth indicators for three cultivars of wheat (Shame6, Samur, and GRAIME). The experiment was conducted according to a RCBD (in a split-plot arrangement with three replicates), while the cultivars represent the main treatments and herbicide treatments. The results showed the superiority of cultivar GRAIME in the trait of the number of tiller. meters 2 and the flag leaf area (centimeter2), as it recorded averages of 469.90 meters2 and 22.61 centimeter2 respectively. The cultivars did not differ significantly between them in terms of the dry weight of plants. In comparison, the cultivar Samur recorded the highest plant height of 135.12 centimeter and the lowest weed dry weight was 40.44 gram. meters-2, recording the highest inhibition ratio in the weed dry weight amounted to 62.60%. The combination treatment (Crash + U46-Combifiluid) for all traits was superior to the weedy treatment, which recorded the lowest averages, as it recorded 459.9 tiller.meters2, 124.89 centimeter, 22.70 centimeter 2, and 1344 gram. meters -2 for the number of tillers, plant height, flag leaf area, and the dry weight of wheat plants, respectively. Besides, the lowest average weed dry weight was 6.55 gram. meters -2 and the highest inhibition ratio in the weed dry weight was 93.97%, it was close to the results of the weed-free treatment. The treatment of cultivar GRAIME with (Crash + U46-Combifiluid) combination achieved the highest mean for the number of tillers, flag leaf area, and dry weight of wheat plants reaching 515.70 tiller. meters 2 and 25.20 centimeter 2 and 1371.20 gram. meters-2 respectively, In comparison, the lowest weed dry weight was achieved in the treatment of cultivar Samur and Shame6 with the combination of (Crash + U46-Combifiluid) reached 0.00 and 5.80 gram. meters-2 respectively and recorded the highest inhibition ratio of weed dry weight reached 100% and 94.44% respectively.

A field experiment was carried out during the winter season for the year 2021-2022 at the Agricultural Research Station A of the Field Crops Department - College of Agricultural Engineering Sciences- University of Baghdad/ Al-Jadriya. To determine which of the plant densities has the most influence on the weeds associated with the flax crop (Syrian local variety). And to determine the best effect of the Johnson grass (sorghum halepance L.) weed extract, whether alone or in combination with the used Quizalofop- p- Tefuryl herbicide, and to use it in integratTed weed control programs to reduce dependence on herbicides in weed control, Reduce environmental pollution by these herbicides, According to the design of the Randomized Complete Block Design (RCBD). In the order of split plot and with three replications, Such as the first factor, the distance between the row (20, 25, and 30) cm that represents the main plots. Then, the second factor is Control treatments which represent the subplots, (weed free (T1), application Quizalofop-p-Tefuryl at a rate of 2 mL commercial substance (T2), Recommended application rate, Johnson grass extract (stem and leaves) at a rate of 18 L (T3), half the amount of herbicide + half the amount of extract (T4), weedy (T5)). The results showed the following: The distance of 20 cm achieved the lowest dry weight of the weed and the highest average inhibition of 134.57 g/m2 and 49.91%, respectively. While the distance of 30 cm achieved the highest plant height of 78.63 cm, the highest number of main branches in the plant amounted to 5.162 branch/ plant. The highest weight Dry flax plants amounted to 355.21 g/m2. Moreover, the highest percentage of oil was 38.524%. The treatment (T2) achieved the lowest dry weight of the weed and the highest percentage of inhibition amounting to 138.87 g/m2 and 49.91%, respectively. The highest plant height reached 76.92 cm, the highest number of main branches in the plant amounted to 5.158 branch/ plant, and the highest dry weight of flax plants reached 5.158 branch/ plant. 398.61 g/m2 and the highest percentage of oil was 37.35%. The effect of the interaction between the two study factors was significant in most of the traits under study. As the distance of 20 cm with the T2 treatment achieved the lowest dry weight of the weed amounted to 124.53 g/m2 and the highest inhibition rate of 52.35%. While the interaction between the distance of 30 cm and T2 achieved the highest plant height of 80.04 cm, the highest average number of main branches reached 5.833 branch/ plant, and the highest dry weight of flax plants reached 398.61 g/m2 and achieved the highest percentage of oil amounted to 39.847%.

A field experiment was carried out to find out the effect of selected chemical herbicides (Crash+ U46-Combifiluid) and Datura leaf extract (4 leaf age) on companion weeds of two barley cultivars (IPA99 and IPA 265), coupled with certain growth indicators of these two cultivars. The results showed the superiority of the two treatments of spraying weed herbicides (T1) and Datura leaf extract (T2), as they recorded the lowest weed dry weight amounted to 4.75 and 17.18 grams/meters-2. Along with, the highest inhibition ratio in dry weight was 96.14% and 86.09%, the highest number of tillers was 522.00 and 428.00 tiller. meters -2, the highest plant height of 104.34 and 98.28 cm, the highest flag leaf area was 13.28 and 10.34 cm2. Besides, the highest dry weight of 1343.80 and 1207.50 grams/meters-2 for the two treatments respectively, compared with the control treatment (Weedy) T3, which recorded the highest weed dry weight of 122.16 grams/meters-2. In the same role, the lowest inhibition ratio of 0.00%, and the lowest number of tillers was 322.50 tillers. meters-2, the lowest plant height, the lowest flag leaf area, and the lowest dry weight were 86.98 cm and 7.35 cm2, and 906.90 grams/meters-2, respectively. Furthermore, the IPA 99 cultivar was significantly superior by giving the lowest weed dry weight of 42.90 grams/meters-2, the highest inhibition ratio of 64.24%, the highest plant height of 103.25 cm, and the highest dry weight of 1175.80 grams/meters-2. In comparison, the above cultivar exceeded the IPA 265 cultivar, which recorded the highest dry weight of weed of 53.16 grams/meters-2 and lowest averages for plant height and plant dry weight of 89.93 cm and 1129.80 cm2 respectively. The two cultivars did not differ significantly in the number of tillers. meters-2 and leaf area cm2. It was observed that the cultivars could reduce the weed’s dry weights and thus inhibit its growth, meaning that it had the ability to compete with the companion weeds. The two treatments T1 and T2 were superior with IPA 99 & IPA 265 by giving the best combination in reducing the weed dry weight by 88 and 5.61 grams/meters-2, the inhibition ratio was 96.79% and 95.50%, the number of tillers was 531.70 and 512.30 tiller. meters-2. In addition to the dry weight of the crop plants was 1360.00 and 1327.70 grams/meters-2 for the two treatments and the two cultivars respectively, compared with the treatment T3, which recorded with IPA 99 and IPA 265 the highest dry weight of weed of 119.95 and 124.36 grams/meters-2. On the other hand, the lowest inhibition ratio of 0.00% for both cultivars, the number of tillers was 281.70 and 363.30 tiller. meters-2, and the dry weight of the crop plants were 910.50 and 903.40 grams/meters-2 for the two cultivars respectively.