Effect of the Interaction Between Genotype and Weed Control Treatments on Weed traits and Vegetative Growth of Sorghum bicolor L.

• Lizan Dara Yara Muhammad, Zakaria Mahmoud Muhammad

  Author

This study was conducted during a field experiment carried out during the autumn growing season (2025) in the Forestry and Rangeland Directorate in Sulaymaniyah, located at longitude 45.43° East and latitude 35.55° North of the equator, to determine the effect of different weed management methods on the yield of four sorghum cultivars. These included (buhouth, Rabeh, Inkath, and Giza). In addition to weed control treatments (four treatments), the study included a control treatment (no control), a weed-free treatment (manual weed removal), weed control by tillage, and chemical control using the herbicide Castran after germination. The results of the study showed a clear and significant effect of weed control treatments on all weed characteristics and vegetative growth The chemical control treatment achieved the lowest values after manual weeding in weed density, recording 4.83 and 0.83 weeds.m² for narrow- and broad-leaved weeds, respectively. The dry weight of weeds reached 20.17 and 2.85 g.m² for narrow- and broad-leaved weeds, respectively. It also recorded the highest weed control efficiency, reaching 88.34% and 81.42% for narrow- and broad-leaved weeds, respectively. In contrast, the inhibition percentage reached 91.81% and 80.65% for narrow- and broad-leaved weeds, respectively, whereas the control treatment recorded the lowest inhibition percentage of 0.0%. As for the cultivars, they showed limited differences.  In contrast, as the control treatment (no control) was in recording the highest density and biomass of weeds, with the number of narrow-leaved weeds reaching 19.25 weeds.m² and broad-leaved weeds reaching 3.25 weeds.m², while the dry weight recorded 263.30 and 22.24 g.m² respectively. No significant differences were found between the cultivars in some weed traits, indicating a similarity in their competitive ability. The interaction between control treatments and cultivars showed a clear significant effect. Buhouth cultivar excelled in the number of fine weeds (9.08 weeds.m2) and the highest inhibition rate (66.18%), while the Giza cultivar had the highest control rate (66.18%). Rabeh cultivar recorded the lowest values ​​in some traits, while the Inkath cultivar excelled in plant height (115.81 cm). The control treatment with some cultivars recorded the highest weed density and weight (91.0 weeds.m2) for fine weeds, while the interaction between manual weeding and all cultivars achieved the lowest values. (0.0) and the highest control and inhibition rates reached 100%. Chemical treatment approached the efficiency of manual weeding for some cultivars, recording control rates of 89.70–91.20%. This was reflected in vegetative growth characteristics, as the manual weeding treatment resulted in a plant height of 126.88 cm and a leaf area of ​​3743.13 cm² plant^-1, compared to the control treatment (91.00 cm and 2007.66 cm² plant^-1 , respectively). Furthermore, the combination of manual weeding with the Inkath cultivar achieved the highest plant height of 132.00 cm, while the combination of manual weeding with Rabeh cultivar resulted in the highest leaf area of ​​4150.12 cm² plant^-1.

• pdf