Corn: Eye Spot (Aureobasidium zeae)

Excerpt from Chapter 1, Field Crop Protection Guide, Order this publication

Table of Contents

1. Description
2. Integrated Pest Management Options
• pyraclostrobin – Headline EC
• azoxystrobin + propiconazole – Quilt
• propiconazole – Tilt 250 E, Bumper 418 EC
3. Related links...

Description

The disease produces characteristic round or oval spots (1-4 mm (1/16-1/8 in.)) with a tan/brown centre and a brown or purple margin. A translucent yellow halo forms around the margin, and when held to the sun, the lesions resemble an eye. Leaf blighting may occur when these lesions join, killing large portions of leaf tissue. The disease may be confused with non-infectious physiological leaf spots or insect damage.

Image 1. Eyespot causes round or oval leaf spots with a tan/brown centre, a brown or purple margin, and a translucent yellow halo when held up to the sun.

Integrated Pest Management Options

This disease is becoming more common in Southwestern Ontario. Some hybrids are tolerant/resistant to the disease. Crop rotation and tillage will reduce inoculum levels in surface residues. In reduced tillage systems, rotation and resistance are necessary. Chemical control usually not economical in field corn.

Comments
Ground and aerial application only. Use a minimum water volume of 100 L/ ha. For optimal disease control, begin applications prior to disease development. Do not graze treated crop within 6 days of last application. 7 days to harvest. Maximum of 2 applications per year.

Comments
Ground and aerial application. Apply when disease first appears, followed by a second application 14 days after the first, if environmental conditions are favourable for disease development. Do not apply to field corn or field corn grown for seed after brown silk. 30 days to harvest for forage. 14 days to harvest for sweet corn. Maximum 2 applications per season.

Comments
Ground and aerial application. Apply when disease first appears. Can be tank mixed with Ripcord or Matador insecticide for insect and disease control. 14 days to harvest.

Related links...

• Agronomy Guide for Field Crops - Publication 811
  • Corn: Eye Spot
• Disease
• Corn