Study shows significant growth in herbicide management in crops cultivated with RR soybeans

Genetically modified or RR soybeans, cultivated throughout Brazil, developed to be resistant to the herbicide glyphosate, have been the target of competition from weeds equally resistant to the agrochemical, such as horseweed (Conyza bonariensis), bittergrass (Digitaria insularis) and so-called 'invasive corn' or 'volunteer corn' (Zea mays). This scenario, which intensified in the 2016-17 harvest, resulted in a significant increase in the applications of herbicides with active ingredients complementary to glyphosate.

The finding comes from the Spark Intelligence Strategic consultancy, a company specializing in market research for the agrochemical sector, among other segments of agribusiness. According to the survey, in the 2016-17 harvest, the area of ​​soybeans treated with herbicides complementary to glyphosate increased to 40%, compared to 33% recorded in the 2015-16 harvest. This factor, emphasizes Spark, increased the total revenue of the herbicide market by 27%.

According to Spark, the total market for soybean herbicides was worth US$1,36 billion in the 2016-17 harvest. The share of alternative or complementary products to glyphosate was US$492 million in the period, an increase of 55% compared to the previous harvest, when the segment reached US$318 million. On the other hand, glyphosate revenue remained stable, at US$740 million, reinforcing the importance of this active ingredient in the management of herbicides in soybean farming.

The research also showed that in the 2016-17 harvest, producers had to apply herbicides complementary to glyphosate to control the so-called 'invasive corn' in 12% of the soybean area, compared to 8% in the previous harvest. The invasive corn comes from RR corn seeds that are also resistant to glyphosate, whose planting alternates with that of soybeans, which sprout after harvest and begin to compete for nutrients with the oilseed crop. 

In the State of Mato Grosso, for example, the largest soybean producer in Brazil, control of 'voluntary corn' was carried out in 22% of the soybean area. “This corn has become a problem in soybean areas, due to the growth of glyphosate-tolerant RR hybrids. In this situation, it is recommended to apply a specific and selective herbicide for corn, a cereal, and that also preserves soybeans, a legume”, reinforces Cristiano Limberger, agronomist and service manager at Spark Inteligencia Estratégica.

For Limberger, the company's survey mainly proves that the isolated use of glyphosate no longer has an effect on several weeds, which have acquired resistance to the agrochemical due to repetitive and prolonged use of the product.