The U.S. Department of Agriculture said Friday that it will assess the environmental impact of controversial new biotech crops developed by Dow AgroSciences, a venture of Dow Chemical, and Monsanto, before it makes a determination on approval of the new crops.

The news frustrated Dow officials, who had hoped to already have their new herbicide-tolerant corn called "Enlist" on the market, but now see 2015 as their new best hope for commercialization. Both companies say they will fully cooperate in the government's preparation of environmental impact statements.