9/30/2020

Fusarium Ear Rot

Written by Mark Jeschke

Disease Facts

  • Fusarium rot is the most common fungal disease on corn ears.
  • Caused by Fusarium verticillioides (previously known as Fusarium moniliforme) and several other Fusarium species.
  • The causal organism survives on residue of corn and other plants, especially grasses.
  • Infection can occur under a wide range of environmental conditions, but is more severe when weather is warm and dry.
  • Disease enters ear primarily through wounds from hail or insect feeding.
  • Airborne spores can germinate and grow down the silk channel to infect kernels.
Fusarium Ear Rot Symptoms

Disease Symptoms

Fusarium Ear Rot - Closeup - Photo
  • Scattered or groups of kernels are typically affected.
  • Mold may be white, pink or salmon-colored.
  • Infected kernels may turn tan or brown.
  • "Starburst” pattern often associated with the disease (light-colored streaks radiating from top of kernels where silks were attached).
  • In severe infections, ears may be completely consumed by the fungus, leaving lightweight husks cemented to the kernels by mycelia.

Mycotoxins

  • Fusarium verticillioides and Fusarium proliferatium produce fumonisins, the most commonly occurring mycotoxins in the Corn Belt.
  • Fumonisins can be fatal to horses and pigs.
  • Fumonisins can damage organs in other mammals and are carcinogenic.

Management

  • Since the disease enters the ear primarily through injury and insect feeding, hybrids with one or more aboveground insect protection traits can have a lower risk of Fusarium ear rot.
  • Hybrids differ in their susceptibility to fusarium ear rot. If Fusarium ear rot has caused significant damage in the past, growers should consider planting only hybrids with a Fusarium ear rot rating of 5 or higher.
Fusarium Ear Rot Comparison

Left:  Bt ears — no insect feeding or disease symptoms
Right: Non-Bt ears — insect feeding allowed entry of Fusarium fungus with resulting symptoms

Harvest and Storage

  • Clean bins before storage.
  • Harvest at 25% moisture and dry to 15% moisture or lower if storing grain into the following summer.
  • Cool infected grain below 50°F as quickly after harvest as possible and store at 30°F.
  • Clean grain before storing to remove infected kernels, cobs and fines.
  • Store infected grain separately, if possible.


The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary.