8 Feb 2010
Choose Wisely……Avoid unprofitable strategies to manage moldy grain
Kiersten Wise, Charles Woloshuk, and R.L. (Bob) Nielsen
Botany & Plant Pathology Dept and Agronomy Dept., Purdue Univ.
West Lafayette, IN 47907-2054
Email addresses: firstname.lastname@example.org, email@example.com, or rnielsen
ndiana corn producers are concerned by the amount of moldy corn in their bins. Many producers are also dealing with high levels of mycotoxins in grain, resulting from infection by the fungus Gibberella in 2009. Producers faced with bins of poor-quality grain may be eager to purchase products claiming to improve grain quality and reduce mycotoxin levels in stored grain. However, before investing in chemical treatments for grain, consider the facts:
1. Mold inhibitors and binders are not the same thing.
Mold inhibitors are products that are typically added to grain to prevent mold growth. These products are usually a mixture of organic acids. Because these acids are volatile and can corrode the bin structure, one should choose products that are formulated to reduce the volatilization. Typically, mold inhibitors are applied as a spray to the grain during bin loading. The amount of inhibitor needed is related to the moisture content of the grain; the higher the moisture, the more inhibitor is required. Grain stored at winter conditions would see not benefit of a mold inhibitor. Any beneficial effect would be seen during warm weather when temperature becomes optimum for mold growth. Mold inhibitors are commonly used in tropical regions where keeping grain dry is a challenge. In Indiana, keeping corn dry (14.5% or less) can be achieved by aeration, and little mold growth should occur under these conditions. Mold inhibitors do not reduce mycotoxins already present in grain.
Binders are products that are added to livestock feed to reduce the effects of mycotoxins. Binders are made of various types of clay, and they work by binding to various molecules. Clay binders are very effective at binding the mycotoxin known as aflatoxin. Despite claims of efficiency, these clays have not proven to be effective at binding vomitoxin (DON), and zearalenone.
Non-clay binders are available on the market, which can contain a combination of clay, yeast cell walls and enzymes. These non-clay binders may reduce the toxin effects of vomitoxin and zearalenone when added to feed. One needs to consider cost effectiveness when considering these products. For more information on binders, contact Brian Richert (firstname.lastname@example.org) in Purdue's Animal Science Dept.
2. Stored grain should not be treated with fungicides to prevent mold growth. There are no fungicides labeled for this use.
At this point in the season, there is not much that can be done to improve the quality of the 2009 corn. The best strategy to prevent deterioration of grain in storage is to keep grain dry and cool, and monitor poor quality grain to prevent hot spots from forming.
3. Plan Ahead for 2010.
For producers that had issues with ear rots in 2009, now is a good time to plan ahead for the 2010 season. If ear rots were a problem in certain fields, choose a different hybrid for those acres. Consider methods to reduce the likelihood of disease development by rotating out of corn in 2010 or implementing tillage to break up inoculum-infested crop residues. Visit with your seed dealer to identify hybrids less susceptible to ear rots. Remember, the weather conditions at silking in 2010 will ultimately determine if ear rots will be problematic again in 2010, but preventative steps to reduce the impact of potential ear rot problems should be taken now.
Don't rely on chemicals to reduce vomitoxin contamination of corn. Purdue Ag Answers (2/2/2010). Online at http://www.agriculture.purdue.edu/agcomm/aganswers/story.asp?storyID=5734. [URL accessed Feb 2010]
Vomitoxin on the minds of growers during corn hybrid selection. Purdue Ag Answers (2/4/2010). Online at http://www.agriculture.purdue.edu/agcomm/aganswers/story.asp?storyID=5738 [URL accessed Feb 2010]
Wise, Kiersten, Charles Woloshuk, and William Field. 2010. Safety first! Tips for safely handling moldy corn. Corny News Network, Purdue Univ. Online at http://www.kingcorn.org/news/articles.10/MoldyGrain-0210.html. [URL accessed Feb 2010]
Woloshuk, Charles and Kiersten Wise. 2009. Diseases of Corn: Diplodia Ear Rot. Purdue Extension publication BP-77-W. Online at http://www.extension.purdue.edu/extmedia/BP/BP-75-W.pdf. [URL accessed Feb 2010]
Woloshuk, Charles and Kiersten Wise. 2010. Diseases of Corn: Gibberella Ear Rot. Purdue Extension publication BP-77-W. Online at http://www.extension.purdue.edu/extmedia/BP/BP-77-W.pdf. [URL accessed Feb 2010]
For more information on the broader issues associated with ear rots, mycotoxins, and grain storage of damaged grain, visit the Purdue Web site: Crop Maturity, Disease & Harvest Issues at http://www.kingcorn.org/cafe/harvest. [URL accessed Feb 2010]