The developer of biotech corn and soybean varieties that tolerate 2,4-D and glyphosate pesticides said it is putting restriction on sales of the seeds to prevent the crops from moving into the marketing channel, said Reuters. Dow said the genetically engineered strains, called Enlist, will be carefully monitored while it awaits approval of the crops by China. Corn growers, for instance, will be required to feed their crop to livestock on the farm and they will be required to have isolation areas around fields planted with the seed. For soybeans, Dow will manage storage and handling after harvest, said Reuters. Dow has been waiting for two years for China to approve the Enlist varieties. China rejected imports of more than 1 million tonnes of U.S. corn over the past year because the cargoes contained an unapproved GE variety from Syngenta.