Determine Your Ear Rot Disease and Mycotoxin Risk, Now!

The cool, wet weather continues to be favourable for corn ear mold fungi. This alone is sufficient to cause concern amongst corn producers. The extent of pink ear rot damage (aka Gibberella ear rot; Fusarium graminearum) together with the number of such ears in the field is proportional to the concentration of vomitoxin in the harvested crop. In affected areas, there is also the potential for accumulation of the mycotoxin zearalenone. This has been a less common problem in Ontario corn in the last 20 years but there were years in the late 1980s in which zearalenone concentrations were relatively high.

For these reasons, exercise caution in feeding moldy corn to livestock, especially to hogs. Grain with pink or reddish molds are particularly harmful. Suspect samples should be tested for toxins, especially Deoxynivalenol (DON) prior to storage and feeding. If necessary feed to less sensitive livestock species such as beef cattle or poultry.

Check all your fields carefully and note their current condition. Be sure to check for differences due to hybrid and planting date; in some case these factors have had a large influence on the amount of mold infection.

A quick method includes scouting 100 plants from the field (5 areas of 20 ears each). Fields with 25 % of the ears having mold growth should be harvested sooner rather then later. The production of toxins is a major concern when these ear rots are present but it is not always the case that mold growth equates to high toxin levels and vice versa (high toxin levels can occur with little visible fungal growth or ear rot).

 

It is essential to examine a field and determine which ear molds and mycotoxins are present. This will allow for the implementation of grain harvest, storage and feeding management options to minimize toxin development and maintain grain quality.

Livestock producers should concentrate on fields with the highest quality and focus on harvest/drying those first in a timely manner. For dry corn, dry to less than 18% as quickly as possible. This will help maintain quality, reduce fungal growth and limit further increases in mycotoxin levels since both DON and zearalenone production will stop.

Some other considerations are:

 

 

 

 

 

Grain handlers and producers need to be cautious when handling corn containing mycotoxins under certain conditions it can be a health hazard. Grain dust can contain many times the concentrations of mycotoxins as measured in a sample (10-100x). Work in a well-ventilated area and use protective equipment such as gloves, masks, etc to limit exposure.