Extension Service.

"Products that are claimed to 'stimulate plant growth in a special way' or 'enhance nutrient absorption' usually don't meet advertising claims," says Rehm. "The same is true for products that claim to 'balance soil life' or provide 'special energy for seedling growth.'"

Rehm says it's not always easy to sort out products that can have a positive economic impact on crops.

"Many non-conventional and non-traditional products have been evaluated by land grant universities throughout the Corn Belt," Rehm points out. "When in doubt, don't hesitate to ask if the 'new' product has been tested."

"There's no substitute for unbiased data," he adds. "If the sales people don't provide that data, the product usually has no value. If there are no data to support the sales claims, don't buy the product – save some money."