ABSTRACT
Sugarcane is the most important source of sugar worldwide especially in tropical and subtropical regions where this crop is grown. The structure of weed communities associated to sugarcane production is consistent across growing regions, and there is a small group of species that are frequently found in sugarcane fields and that drive weed control decisions. Although weed interference can reduce sugarcane yield up to >70%, the highly competitive canopy this crop has reduces the risk of yield loss when weed control actions are implemented at the right time. Among weed control tools herbicide and cultural practices play a major role to ensure that weed populations are minimized during the critical period of weed control, which usually extends from 3 to 12 weeks after planting/emergence. Mechanical control use is decreasing as adoption of green harvest and reduced-tillage increases to reduce greenhouse gas emissions. This trend might increase reliance on herbicides raising concerns about the possibility of herbicide resistance evolution, which has not been a major issue in sugarcane. Diversification of production and weed control practices is needed to prevent population increase of frequent and problematic weed species. Opportunities for diversification include use of alternative crops or cover crops during the fallow period, optimization of irrigation and fertilization strategies, and dynamic use of harvest and tillage strategies.
