With the continuing dry weather, I have had more inquiries about the use of Aflaguard as an aflatoxin preventative.  

Aflatoxin is more likely to develop in fields with a history of the disease where conditions are hot and dry at silking.  

Planting early, good fertility and using Bt hybrids to reduce insect stress on the crop can help reduce the chances for developing the disease. Unfortunately, this year planting early has not guaranteed us good moisture and temperatures are already running high for May so there is real concern among grain producers.

Aflaguard from Syngenta is a biological control for aflatoxin and is the only product on the market offered as a preventative for aflatoxin when used as an over-the-top treatment.  

The product is actually a form of Aspergillis flavus that is benign (doesn’t make aflatoxin) that is applied to the field in a large enough quantity mid-season so that it outcompetes the aflatoxin-producing form of Aspergillis

Key thing to making it work — it must be applied timely to work. Applying too early or very late will make results much more inconsistent and would be a waste of money.

Does it work? Based on 2 years of work at Jackson, Aflaguard reduced the level of aflatoxin in our ear samples when applied to V10-V12 corn. It did NOT always reduce the amount to zero and sometimes the levels in plots treated with Aflaguard were still running above 20 ppb. But, the levels were lower on average than the untreated checks. Just be aware that you may still have some aflatoxin in fields treated with Aflaguard.

Timing of application

When should I apply Aflaguard? Apply Aflaguard at V-10 corn or slightly later (most of our work at V10-V12 was the more consistent timing). Syngenta is allowing later applications up to silking, but our results were less consistent after V-12. V10 corn occurs about 8 weeks after planting when plants are exhibiting 10 leaf collars and is typically waist (dry year) to chest high (good rainfall year) on a short person. 

For example: corn at Milan planted March 26 is at V10 now and growing slowly due to very dry weather and is a little above waist high on a short person (me). To accurately count collars, count any visible collars (area where leaf wraps around the stalk) and add the number of dried up bottom leaves that may have already separated from the stalk (usually 2 or 3 at this point).

Is it worth the cost in year like we are having? Product runs $11-12 per acre plus the cost of application for a 10 pound per ace rate. With the cost of aerial application, a treatment runs close to $20 per acre.

Folks ask if it is worth the cost to treat. This is an individual judgement call. Most folks are optimistic that we will have rain in June, but we all know there aren’t any guarantees. All I can tell you is the treatment has been shown to help lower aflatoxin levels in a dry year and may help make corn more marketable in higher aflatoxin areas. 

I would consider using this product on fields with some history of aflatoxin, but the rest would depend on your pocketbook.

• Ground versus aerial application? Most Aflaguard is applied by airplane. Last year, a retailer in west Tenn., rigged up a ground spreader that applied the correct rate and got over the corn without damage. It is very important to put Aflaguard on at the right time — if corn is still short at V-10 and you can get over it with ground equipment without damaging the plants that would be okay. Just don’t try and spread it by ground prior to V10 just to save a few dollars because I think you will lose a lot of consistency of the product.

• Growers who use Aflaguard on their corn may need to inform their grain handler when they deliver their seed this fall. Some elevators who still use blacklight as detection for Aspergillis may get false positives on corn treated with Aflaguard since the Aflaguard is a form of Aspergillis, can create some ear mold, and may show up similarly with blacklight.