The company's agriculture subsidiary, Dow AgroSciences, had said late last year that it hoped to sell the seed for 2013 planting, once it was approved by the U.S. Department of Agriculture and Environmental Protection Agency. 

The technology, called Enlist, is genetically modified to withstand applications of the herbicide 2,4-D. It is part of an industry response to the emergence of weeds resistant to glyphosate, a widely-used herbicide used in tandem with genetically modified corn and soybean seeds from Monsanto.

Critics have said Dow's new seed, along with a separate seed being developed by Monsanto (MON) that withstands the herbicide dicamba, will lead to an increase in the use of herbicides, posing a greater risk to the environment and adjacent farms. Some critics say that ultimately weeds will develop resistance to these products as well.

A coalition of produce farmers dropped its opposition to Dow's Enlist in September after the company made commitments to track farmers' herbicide applications and investigate claims that the herbicide drifted onto neighboring fields.

Dow is also developing an Enlist soybean seed, which it has said it plans to sell to farmers in 2015.

-Write to Ian Berry at ian.berry@dowjones.com

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