July 18, 2014

Brazilian Scientists Worry Bt Corn Losing its Effectiveness

Scientists from the Agriculture and Livestock Research Foundation of Mato Grosso have found that Bt corn in the state is losing some of its effectiveness. The insect resistant technology was introduced in 1997 in the U.S. and it has been used in Brazil for the last six years. The Bt gene used in these corn hybrids produces a protein that is toxic to insects, but over time, resistant insect populations can develop reducing the effectiveness of the technology.

As a way to prolong the lifespan of this technology, Brazilian scientists stress the importance of the use refuses to help maintain the effectiveness of the technology. A refuse is an area where conventional corn hybrids (non-GMO) are planted and it acts as a sink where the insects can migrate thus slowing the development of resistant populations.

The refuse must be no more than 800 meters from the field of Bt corn and it can be planted as a border to the field or as a block within the field. There is some doubt in Brazil as too the level of compliance of these required refuse areas. Some research institutions and scientists are pushing for regulations that would require larger refuse areas. The Brazilian government is reviewing the regulations concerning the size and locations of the refuse and the level of adherence by farmers.

The state of Mato Grosso is the largest grain and fiber producing state in Brazil and the farmers in the state planted 11 million hectares of GMO crops during the 2013/14 growing season. The state represents 27.5% of all the GMO acreage planted in Brazil. Brazilian farmers planted 40.3 million hectares of GMO crops in 2013/14, which ranks it second behind the U.S. at 70.2 million hectares. If the state of Mato Grosso was a separate country, it would rank fourth in the use of GMO technology.

Mato Grosso has the largest acreage of GMO technology in Brazil followed by the state of Parana with 6.8 million hectares and Rio Grande do Sul with 5.6 million hectares. The principal GMO crops in Brazil are soybeans, corn, and cotton. The main benefit of the technology is that it lowers costs and reduces losses from insects at the same time that it increases operational efficiencies. The long term concern about this technology is that eventually insects will become resistant to the Bt gene which is also happening in the U.S. as well.