Oct. 16, 2017
A study by consultancy firm Spark Strategic Intelligence has noted that the genetically-modified Roundup-Ready soybean, grown all over Brazil and developed to be resistant to glyphosate herbicide, has been attacked by weeds that are also resistant to agrochemicals.
These weeds are the Argentine Fleabane (Conyza bonariensis), the sourgrass (Digitaria insularis) and the so-called ‘voluntary corn’ (Zea mayz). Therefore, the percentage of soybean-growing areas that are treated with complementary herbicides and glyphosate has jumped to 40% from the 33% registered during the previous crop.
The alternative or complementary products to glyphosate has registered sales worth US$492 million in the period, a growth of 55%, compared to the previous crop season, when the sector reached sales worth $318 million. The revenue for glyphosate remained stable at $740 million.
In Mato Grosso, for instance, the growth of voluntary corn was controlled on 22% of the soybean surface, while at the national level it was 12%. This corn started to be a problem in the soybean areas because of the growth of RR hybrids that are tolerant to glyphosate. In this situation, it is recommended to apply a selective and specific herbicide for corn, a cereal, and also preserve soybean, a leguminous,” Cristiano Limberger, agronomist and service manager at Spark Strategic Intelligence, said.
According to the agronomist’s evaluation, the survey by the company has proved that the isolated use of glyphosate does not work on weeds, which acquires resistance to the agrochemical, owing to the repetitive and prolonged use of the product.