CHICAGO, Nov 17 (Reuters) - A weed killer blamed for damaging millions of acres of U.S. crops this summer did not reduce yields for most of the soybeans checked by BASF SE , which makes a version of the herbicide, the company said on Friday.
BASF, the world's third-largest maker of crop chemicals, investigated 787 complaints involving soybeans that showed signs of damage linked to sprayings of the herbicide that contains a chemical known as dicamba, according to the company.
In most of those cases, there was no impact on yields, BASF said. The company said it did not have specific yield data.
"In a few isolated cases, yield may have been affected," BASF said.
Farmers, government regulators and insurance companies have been waiting to assess yields of crops affected by dicamba herbicides since signs of damage linked to the chemical began appearing during the summer.
The United States has faced a weed-killer crisis this year caused by new formulations of dicamba-based products, which drifted away from where they were applied on to nearby fields that were not intended to be sprayed.
Farmers and weed scientists say the herbicides vaporize and can hurt the height and leaves of soybean plants that cannot tolerate dicamba.
BASF and Monsanto Co, which make competing dicamba-based herbicides, say the products are safe when properly applied.
Nationwide, 3.6 million acres of soybeans suffered harm from dicamba, and states launched 2,708 investigations into dicamba-related crop damage, according to data compiled by the University of Missouri.
Missouri farmer Milas Mainord said his soybeans did not suffer yield losses after being affected by dicamba sprayed by a neighbor.
In Arkansas, farmer Reed Storey said he believes dicamba damage caused yields to decline 5 to 10 bushels per acre, or about 15 percent, on some of the soybeans he grew.
"It always upsets me when I don't reach my full yield potential," he said.
Farmers and weed specialists said they remained worried about damage to gardens and trees located near farms that sprayed dicamba during the summer.
Weed killers also should not cause signs of damage on fields of crops after drifting away from where they were sprayed, said Bob Hartzler, weed specialist for Iowa State University.
"Even if it doesn't affect the yield, it's still not acceptable," he said.
Reporting by Tom Polansek; Editing by Matthew Lewis