Maize is an important crop grown on significant acreage around the world, and a major constraint for its growth is weed interference. Thus, field studies were conducted to examine johnsongrass interference, control, and recovery under different management practices and its effects on maize. Our results indicated that the most johnsongrass aboveground biomass was recorded in the nontreated and weed-infested for 55 days after sowing (DAS) treatments, while the lowest values were in nicosulfuron treatments (48 and 60 g a.i./ha). Among the various herbicide treatments, the greatest johnsongrass aboveground biomass was recorded in the isoxaflutole (applied pre-emergence at 99 g a.i./ha) + 1 hoeing treatment. Johnsongrass aboveground biomass at 78–85 DAS was 1.4- to 6.0-fold greater than that at 55 DAS, revealing johnsongrass recovery after nicosulfuron treatments. Johnsongrass competition had a significant impact on maize growth and grain yield. The main crop parameters, such as aboveground biomass, grain yield, and protein content, were lowest in the nontreated and weed-infested for 55 DAS treatments, while the greatest values of these parameters were recorded in the weed-free and nicosulfuron treatments. In conclusion, our results indicated that timely and effective chemical control of johnsongrass is essential for improving grain yield and quality of maize.

Wild mustard (Sinapis arvensis L.) and milk thistle (Silybum marianum (L.) Gaertn.) are two competitive broad-leaved weeds commonly found in cereals in Europe, while several weed species have developed resistance to the main herbicides that are applied on these crops. Thus, the implementation of integrated weed management (IWM) programs is of great importance. Field experiments were conducted based on a split-plot design with two factors (sowing date and herbicides). Our results showed that the density of wild mustard and milk thistle was higher in the early sowing compared to the late sowing, while the total weed density was up to 75% higher in early sowing. Moreover, the herbicides florasulam + 2.4-D and bromoxynil + 2.4-D exhibited high efficacy (>98%) against milk thistle and wild mustard, while tribenuron-methyl and florasulam + clopyralid provided greater efficacy in the late sowing compared to the early sowing. Among the four herbicides, the lowest dry biomass and grain yield of wheat were observed in tribenuron-methyl and florasulam + clopyralid, while in the weed-infested treatment, the highest values of both parameters were recorded in late sowing. Finally, the results showed that the sowing date is a cultural weed control method that should be implemented in IWM programs, since it can affect both weed density and herbicide efficacy.