​The new reality of weed management in sugarcane cultivation

According to data from the National Supply Company (Conab), the 2016/2017 harvest of sugar cane produced by Brazil is expected to reach 691 million tons, an increase of 3,8% compared to the previous harvest, when 665,6 were harvested. .XNUMX million tons. This will be the largest crop ever harvested in the country.

Despite the very promising numbers, a problem is growing and is already causing drops in productivity, which could worsen even further in the near future. The change from manual harvesting and, consequently, burning sugarcane straw to mechanized harvesting, defined by the Agro-Environmental Protocol to take place until 2017, despite being very beneficial from an environmental point of view, brings a new reality for the farmer to adapt to when talking about in managing changes in the population dynamics of weeds in sugarcane fields.

The end of the fires was an advance in the environmental impacts caused by cultivation, but it opened space for an increase in weeds of the broad-leaved class, such as castor beans, mucuna, merremias, viola strings, loofah, among others, which were rarely seen in the sugarcane fields.

These weeds, if not controlled correctly, can quickly infest sugarcane cultivated areas and cause serious consequences. The first of these is operational. During harvesting, they make it difficult for the harvesters to operate, which needs to be stopped until cleaning is done. This lost time generates great losses for the producer, since the cost of this type of equipment is high and every minute lost affects the deadline for harvesting.

The second is the influence of the herb on the industrial quality of the raw material sent to the industry. The mixture of sugar cane with weeds made during mechanized harvesting reduces the sucrose content and purity of the final extract, reducing the quality of the product that the farmer has in his field and, consequently, the technological performance. As a result, the plants start paying less, generating even more losses for the producer.

Another risk factor caused is the drop in productivity, common in all crops where broadleaf control was inadequate during cultural treatments. Currently, “reboleiras” - as weed growths in the middle of sugarcane fields are called - can cause a reduction in the results of the 2016/2017 harvest in most sugarcane production units in the country.

Sugarcane producers' lack of knowledge of the infestations that occur within already developed sugarcane fields, as it is difficult to observe when in the final harvest phase, means that this problem is neglected, an accommodation on the part of the farmer to prevent a future risk. It is necessary to anticipate the problem at the time of planting so that these large leaves do not infest the sugarcane field and take on proportions that make control difficult.

To face this new challenge, sugarcane producers need to prepare themselves to manage difficult-to-control broadleaf weeds correctly until the sugarcane field is closed. After this, the difficulty increases, as control can only be achieved with aerial application of specific herbicides using an airplane or even a helicopter, representing a high cost.

Exchanging information with farmers who work with other crops is also important. Soybean, cotton or corn producers have been facing this problem for years and can provide important experience in combating it and in how to carry out preventive management.

The sugarcane sector has already faced serious crises over the last few years and needs to take precautions to avoid facing another one in the future. The new reality of mechanized harvesting will bring great benefits to everyone, but like any change it generates an adaptation phase. Those who plan and prepare for change should emerge stronger and unharmed.