The SmartStax corn trait has cleared a major regulatory approval, gaining registration from the U.S. Environmental Protection Agency and regulatory authorization from the Canadian Food Inspection Agency.

The trait, which is the outcome of a cross-licensing agreement between Monsanto and Dow AgroSciences, remains on track for a 2010 commercial launch. Both companies estimate the rollout will put the trait on up to 4 million corn acres, the single largest introduction of a corn biotech seed product.

SmartStax is a combination of above- and below-ground insect control traits as well as weed and grass control traits. It combines Dow AgroSciences’s Herculex I and Monsanto’s VT Pro, as well as Monsanto’s YieldGard VT Rootworm/RR2 technology and Dow AgroSciences’s Herculex RW Insect Protection technology. It also uses the Roundup Ready 2 technology and LibertyLink from Bayer CropScience.

The decisions by U.S. and Canadian regulators will allow a refuge reduction from 20% to 5% for SmartStax in the U.S. Corn Belt and Canada, and from 50% to 20% in the U.S. Cotton Belt.

Both companies are working with regulatory agencies in key export countries to receive import approvals for SmartStax prior to the 2010 growing season. These regulatory submissions are on track to support commercialization for the 2010 U.S. crop season, according to both companies.