The resistance genes protect the soybeans. Sij is comparing 20 Roundup Ready soybean varieties in field trials at Beaumont, using only Roundup for weed control. Transgenic varieties that resist the herbicide sulfonylurea may open other doors to broader weed management strategies. Sulfonylurea controls sedges and some broadleaves better than Roundup. The herbicides can complement one another.
Some farmers think the transgenic soybeans have lower yield potential than conventional varieties.
Commercial breeders will soon raise the transgenics' productivity. But extensive use of transgenics could result in herbicide-resistant weeds. If herbicides are sprayed year after year, selection pressure might shift the weed population to weeds that tolerate the herbicide better. When the crop is hailed out, it's often too late to replant cotton but soybeans will still make a crop. Soybean production in Texas peaked at about 1 million acres in the early 1980s, then dropped to around 200,000 acres.