Weed management is essential for high yields in ratoon sugarcane

The ratoon sugarcane harvest period – between April and November, in the Center-South of Brazil – raises an alert to rural producers regarding the risk of spreading weeds with the potential to considerably reduce the plantation's productivity.

Amid the drought and cold (and even frost) that arrive in the country at this time of year, mechanized harvesting has been carried out with raw sugarcane, which creates a straw mattress. And it is this straw mattress that can be a factor conducive to the development of dangerous weeds, especially broad-leaved weeds.

Among the farmer's main enemies are castor bean, mucuna, lemongrass and species of brachiaria, as well as plants from the genera ipomoeas and merremias, which are the dreaded guitar strings. These herbs are widespread throughout the country and may be resistant.

The losses are great. Viola string, for example, is present in 50% of sugarcane fields. Colony grass, if not controlled, causes losses of up to 60% in the crop, depending on the infestation and the stage of cultivation. When there is no treatment, or the treatment is not effective, some of these enemies can completely devastate the plantation.

This happens because weeds generate what we call "weed competition": the invaders compete with sugarcane for water, nutrients, space and light. All of this hinders the cultivation's maximum potential, which is severely impacted by weeds.

In this scenario, ratoon sugarcane requires good herbicides, with a broad spectrum of control, including for resistant plants. Amicarbazone compounds (either in combination with hexazinone and diuron or added to tebuthiuron) are highly effective management solutions.

These active ingredients – present in Dinamic and Oris, manufactured by UPL –, when formulated, have the ability to overcome straw, cause low photodegradation and a long residual period. The Brazilian market already has advanced technology solutions that can provide productive benefits to farmers.

However, it is necessary to remember that the use of the herbicide must consider the harvest period of the ratoon sugarcane: wet, semi-humid, semi-dry or dry. These points are relevant for the correct allocation of molecules to control weeds.

Herbicides in ready mixes are relevant resources to help manage weeds with quality, providing practicality, safety, synergy and efficiency in use.

Our country has more than 66 million hectares of sugarcane treated with pesticides, considering the cultivated area, number of products and applications, which reveals the great concern that pests (and diseases) raise in the country. Investing in efficient management means achieving maximum quality in the sugarcane field and maintaining high productivity, with sustainability and profitability.

Luciano Almeida, business management specialist and marketing supervisor for sugarcane and pasture at UPL Brasil