Managing itchgrass and morningglory in plant cane: a strong decision on associating herbicides for pre-emergence control

Abstract To enhance weed control in sugarcane systems, the application of herbicide association is widely practiced. This approach broadens the spectrum of weed control and ensures a successful sugarcane yield. Therefore, this study aimed to assess the efficacy of herbicide combinations in controlling Rottboellia exaltata (itchgrass) and Ipomoea quamoclit (morningglory) during pre-emergence while also evaluating the potential impact on the sugarcane variety RB85 5156. The experimental design employed a randomized block structure with seven treatments and four replications. The treatments were as follows: 1 - no herbicide application; 2 - indaziflam + sulfentrazone (120 + 750 g i.a ha − 1 ); 3 - indaziflam + diclosulam (120 + 110 g i.a ha − 1 ); 4 - indaziflam + tebuthiuron (120 + 900 g i.a ha − 1 ); 5 - flumioxazin + diclosulam (150 + 110 g i.a ha − 1 ), 6 - flumioxazin + pyroxasulfone (200 + 200 g i.a ha − 1 ) and 7 - clomazone + sulfentrazone (1,080 + 750 g i.a ha − 1 ). The following parameters were evaluated: percentage of itchgrass and morningglory control, green coverage percentage (Canopeo® system), weed biomass (g m − 2 ), and itchgrass height. Tiller counts were also assessed to characterize the effects of the herbicides on sugarcane plants. Several herbicide associations have been proven effective alternatives for managing itchgrass and morningglory. The most successful treatments for itchgrass control were indaziflam + tebuthiuron and indaziflam + diclosulam, whereas for morningglory, the top performers were indaziflam + sulfentrazone, indaziflam + diclosulam, indaziflam + tebuthiuron, flumioxazin + diclosulam, and clomazone + sulfentrazone. All treatments significantly reduced the weed biomass, with indaziflam + tebuthiuron being the safest option for protecting sugarcane.