Crops

Farmers are battling “superweeds” and pests like the rootworm that have developed tolerance to Monsanto’s chemical pesticide Roundup in recent years. As an alternative, farmers began relying on stronger herbicides, including 2,4-D—a major ingredient in Agent Orange. But that too has recently begun to show signs of pest resistance, a new study finds.

Used primarily on plants that have become resistant to glyphosate, the main ingredient in Roundup, 2,4-D is receiving its own share of concern from experts who feared it would lead to more resistance along with additional environmental and human health issues. Still, Dow AgroScience says the chemical is necessary to fight the weeds that have taken over millions of acres of farmland. Coupled with severe drought now plaguing U.S. farmers, resistant pests and weeds are  problems farmers simply can’t afford to take lightly.

But the use of 2,4-D could be making the situation worse for struggling farmers as a report published in the recent issue of the journal Weed Science says that 2,4-D-resistant waterhemp has been discovered growing throughout Nebraska corn and soy fields. Once a rare problem for farmers, it’s has become a large concern for Midwestern growers using 2,4-D products like Dow AgroSciences’ Enlist brand. The study noted that in fields where the highest doses of 2,4-D was used, the pesticide could not control even half of the waterhemp population, and 28 days after treatment, the plants showed a 10-fold resistance to Enlist.

Resistance to 2,4-D could also mean farmers are forced to use more frequent and heavier applications of the pesticide, similar to what has been happening with Roundup resistance. The heavier applications quickly become ineffective at treating pest and weed issues, while creating more damage to the environment and more health risks.

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Image: Nicholas_T