The effect of allelopathic potential of barley and safflower crops on some growth traits of the accompanying weeds

The experiment and field operations were carried out in the fields of Nineveh city in two locations: the first in Rashidiya, Al-Hamdaniya. Local barley and safflower MUT-2 were planted on 11/26/2023 in the Rashidiya site, and on 12/2/2023 in the Al-Hamdaniya site. The experiment was carried out using the simple experiment system and the Randomized Complete Block Design RCBD, which used the combination method for intercropping. The experimental treatments were used including the following crop mixing ratios (100% barley, 100% safflower, 50% barley + 50% safflower, 40% barley + 60% safflower, 60% safflower + 40% barley). The results showed that the 100% barley cultivation treatment was significantly higher in the number of narrow-leaved weeds at a rate of (14.67 plants. m), followed by a significant difference in the 100% safflower cultivation treatment (13.00 plants. m) and a significant difference from all the study treatments, while the intercropping treatment (40% barley + 60% safflower) and (60% barley + 40%) was the lowest in the number of narrow-leaved weeds and a significant difference of (8.00 plants. m2). The intercropping treatment (50% barley + 50% safflower) was distinguished in achieving the lowest number of broadleaf weed plants, while for the weight of narrow-leaved weeds, the 100% barley treatment achieved the highest significant value in the weight of narrow-leaved weeds (46.00 g.m-2), followed by a significant difference from the 100% safflower treatment, also with a significant difference from the rest of the treatments, while the intercropping treatments (40% barley + 60% safflower) and (60% barley + 40% safflower) were the lowest in the weight of narrow-leaved weeds (21.00, 22.00) respectively. The results also showed that the 100% barley treatment continued to achieve the highest significant value in the weight of broadleaf weeds (76.33 g.m-2), followed by a significant difference from the 100% safflower treatment (66.67 g.m-2).