Monday, November 9, 2009

Corn Ear Mold Update





I just wanted to provide an update on corn ear molds. We are getting a lot of questions here in the clinic regarding Fusarium and the potential for mycotoxins. We are seeing Fusarium on corn, but whether or not it will lead to mycotoxins is debatable. The information we are gathering says it depends on the moisture content of the corn going into storage. Amy Ziems, Diagnostician from the University of Nebraska, has posted the following to our GPDN listserv: "In Nebraska we are experiencing a tremendous amount of grain mold. Currently the harvest is approximately 3 weeks behind due to all the wet weather we have been experiencing the past 2 months also majority of the corn in the field is testing between 18-40% moisture. In the lab we have been seeing a few of the common ear molds such as Diplodia and Fusarium ear rots, however we are seeing a lot of corn with green/black sporulation on the ears and cobs. The green/black sporulation is a combination of several different saprophytic fungi including Alternaria, Pithyomces and Ulocladium. Attached are a couple of photos of the "moldy" corn. Our current recommendation here is dry the corn below 15% within 24 hrs after harvest prior to storage. We are feeling that these fungi have the potential to cause some major damage during storage if the moisture levels are not dropped significantly. We are also receiving a lot of questions regarding mycotoxin testing with the fusarium ear molds being detected." Amy has also provided a list of companies that do mycotoxin testing. If you are interested in having your corn tested, please feel free to contact me at the diagnostic clinic and I will be happy to provide you with the list or I can direct your sample to the nearest lab for you.
Additionally, Tamra Jackson, Extension Plant Pathologist & Corn Specialist at UNL, has posted a video talking about corn ear molds as well as a newsletter explaining corn ear molds. The video can be viewed at http://marketjournal.unl.edu/103009, scroll down to corn ear mold/Tamra Jackson to view the specific video. The newsletter can be found at http://cropwatch.unl.edu/web/cropwatch/archive?articleID=1904835.