How To Identify Various Ear Molds

October 17, 2018

2018 Planting Season Weather In Review

2018 was another interesting year for the western corn belt. In most areas we started the planting season with normal to above normal soil moisture which brought along planting delays and acres that were prevented to plant. Then we proceeded into the growing season and the rain continued. We saw areas of flooding and drowned out crops. Rain accumulations during the growing season were 20%+ more than the total annual rain fall. The rain brought other weather concerns besides the saturated soils, the lack of sunlight.  We also saw a period of time that added stress to young seedlings, much above normal temperatures in early June added a compounding affect to plants growing in saturated and possibly compacted soils.

The Disease Triangle

Environment – Mother nature created an idea environment for fungi, bacteria and many other pathogens to grow in parts of our footprint. Rain created water and high humidity. Early temperatures were hot and most of the growing season we had warm evenings. The saturated soils caused less mineralization of nutrients and leaching of nitrogen.

Pathogen – Every region has a host of pathogens sitting idle waiting for the perfect environment to have the opportunity to attack a host. Insect pressure and adverse weather help create entry points for the pathogen to enter the host. Some of the pathogens include bacteria, fungi, mycoplasmas, spiroplasmas and virus.

Host – The crop is the host for these pathogens and are stressed from the environment. Each hybrid and variety are susceptible and resistant to many pathogens. With the extreme weather in some regions even host with some degree of resistance contracted the pathogen because of the additional stress the host was put under.

Identifying 5 Most Common Ear Molds

Aspergillus Ear Rot

Most severe in drought conditions (especially during pollination and grain fill), extreme heat or where insects have damaged ears.

Diplodia Ear Rot

Initially appears at the base of the ear and works its way to the tip. Damage from insects such as WBCW and ECB often provides an entry point for infection. Diplodia is favored by wet weather during grain fill and is usually more severe in hybrids with upright ears and tight husks.

Fusarium Ear Rot

Usually infects individual kernels or groups of kernels scattered over the ear. Fusarium is most severe when hot, dry conditions occur during and after flowering. It produces a pinkish-white fungal growth on infected kernels, or sometimes a "starburst" pattern with white streaks radiating from where silks were attached.

Gibberella Ear Rot

Overwinters in corn residue, infecting ears through the silk. Gibberella ear rot is a result of the same fungus that causes stalk rot. It thrives in cool wet weather after silking and is a red- or pink-colored mold that usually starts at the tip of the ear. Gibberella mold is favored by a long, tight husk cover.

Penicillium Ear Rot

Powdery green or blue-green mold that develops, usually at the ear tip, as a result of mechanical or insect damage.

Be sure to scout your fields prior to harvest to determine if ear molds are present and which types. Contact your local Hoegemeyer product agronomist or dealer for questions on how to manage these molds.

- Stuart Carlson, Northern Product Agronmist 


Categories: ear rot, harvest    

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