Just like other commodities, “generic” versions are increasingly available for many common fungicides as patents expire on various proprietary active ingredients. By law, generic products must contain the same amount of active ingredient as the original fungicides, but the formulation may be different. As a result, confusion continues as formulation of a fungicide is proprietary information that may not be included in a generic product.
For maximum effectiveness, formulation describes the processes performed to the active ingredient affects to improve efficacy. This process can include reduction to appropriate particle size, the addition of ‘inert ingredients’ that alter the characteristics of the fungicide, and improves delivery and persistence of the pesticide. Growers are familiar with this in the myriad of glyphosate (i.e., Round-Up(R)) products available, and their differing performance on the diversity of weeds.
Generic products tend to be more economical than brand name products, but most have not have been separately evaluated for disease control efficacy. And although the active ingredient is the same, the products are not. Generics are assumed to be similar in efficacy to their brand name counterparts. However, few studies exist to evaluate these products, or evaluate them in comparison to the parent product. For this reason, carefully read the label! Do not assume generics or their labels are the same as the brand name product even though they all contain the same active ingredient at the same dose. Work on the Midwest Fruit Pest Spray Guide this fall brought about a number of surprises included differences in the crop registrations (e.g., Tebuconazole products such as Orbit, Elite, Tebustar and Tebuzol all contain 45% tebuconazole, but Orbit and Elite are labeled for berries and stone fruit; Tebuzol45F (tebuconazole) is labeled for stone fruit, PLUS apples and pears but NOT berries; TebuStar45WSP (tebuconazole) is labeled for stone fruit and grapes). Read the fungicide label just as carefully for generics before use as you would for any new product to prevent any conflicts from arising.
For more information on individual products, check out their labels or material safety data sheets at www.cdms.net.