NovaSource announces it is offering its Herbicide Classification Guide FREE in a counter mat format for use at retail counters or as a desk blotter. The colorful mat features a sturdy vinyl surface with a 1/8” rubberized backing and is 14” X 19”.

The mat contains the herbicide classification group numbers, developed by the Weed Science Society of America (WSSA), for many common herbicides. It classifies herbicides by their site of action. Growers and consultants can use the guide to better plan their herbicide programs to avoid continuous use of herbicides from the same group, which can lead to the development of resistance.

“Even though herbicides may belong to a different chemical family, they might still have the same site of action and be in the same group,” explains Mike DeRiso, director of marketing and business development. “Continuous use of herbicides from the same group can lead to weed resistance developing. This tool provides a quick and easy reference, delivering the data users need to make the proper herbicide rotation decision”.

The tool also is available on the Web at, and a mobile version at  To obtain a free mat, visit and look for the “Herbicide Classification Guide”.  Quantities are limited and only one mat per email address will be provided. The promotion is available only to residents of the United States and Canada.