Corn hybrid selection and fertility planning are key in alkaline, or high pH, soils. High-pH soils reduce the availability of plant nutrients, including zinc, iron and phosphorus. Interveinal yellow stripes on middle to upper leaves are signs of iron deficiency, while white stripes on young leaves are characteristic of zinc deficiency. Dark green or purple coloring of lower leaves indicates phosphorus deficiencies.

Traditionally a problem disease in the western Corn Belt, Goss’s wilt is now prevalent across the Corn Belt and spreading into Canada. Once corn plants are infected, yield potential can be reduced by up to 50 percent. There are no effective chemical control measures for Goss’s wilt. The best way to limit spread of the disease is by selecting hybrids with strong Goss’s wilt tolerance. This bulletin provides information about Goss’s wilt and tolerance ratings for Mycogen® brand corn hybrid families. The ratings are the result of 2011-15 field trials conducted in Illinois, Iowa, Minnesota, Nebraska, South Dakota and Wyoming.

DISEASE INFORMATION
Goss’s wilt is caused by the bacterium Clavibacter michiganensis subsp. nebraskensis. It overwinters in infected corn residue, primarily found on or near the soil surface. Inoculum in the infected residue primarily spreads by wind and splashing rain. To a minor degree, Goss’s wilt also can survive in seed. To infect a corn plant, the bacterium needs an entry point or wound, which is generally caused by heavy rainstorms, hail, wind, blowing sand or mechanical damage. Humid, wet weather is another risk factor because moist or wet leaves are conducive to the spread of disease.

The key to a successful growing season is advanced preparation. Early hybrid selection and ordering helps to give the best hybrid selection and maximize the yield potential on your farm. Agronomist Jon Erickson offers seven steps on selecting the right grain corn hybrids for your acres.

A successful harvest is very important to dairy producers. Planning, dry matter, kernel processing, particle length, and storage are critical because dairy producers will use that silage for the next year or greater. John Brouillette, Mycogen Seeds dairy nutritionist and Jon Erickson, Mycogen Seeds commercial agronomist provide tips for quality silage harvest.

For more information about silage harvest, check out this agronomy article.

With so many Bt trait offerings on the market today, it can be challenging to determine which package best fits your farm. Each package contains different combinations of traits with different levels of effectiveness against specific pests. Understanding best management practices is critical to ensuring control options for years to come.

A successful harvest depends not only on crop conditions but also on properly functioning equipment. While you can’t eliminate all harvest losses, you can identify the source and adjust harvest equipment for optimum performance.

Fertilizer programs should begin with accurate soil testing. Growers who can self-sample reduce costs and better understand their soil situations. Review best practices so your samples lead to more reliable results and more educated management decisions.

Contrary to some studies, dry matter losses after blacklayer are not overwhelming. Still, growers should carefully manage their corn harvest timing to minimize loss altogether.

A corn rootworm (CRW) beetle infestation can decimate corn yield. They have a keen ability to adapt to control strategies, which makes vigilant scouting and management a priority. Regions with heavy continuous corn acres can harbor high CRW populations. However, rotation-resistant beetles and extended diapause beetles contribute to increased populations, even with a rotation in place. With careful monitoring, a timely insecticide application can manage CRW pressure and mitigate damage the following year.

Grain corn ear molds can lead to yield loss at harvest. If mycotoxins are present, grain may be toxic to animals and ultimately unusable. It’s important to understand environmental conditions that lead to diseases and how those diseases affect grain.

Factors that stress corn throughout the growing season can lead to stalk rots, which can lead to yield loss due to premature plant death or lodging. Understanding stalk rots risk factors and management practices are critical.

Corn growers often mistakenly correlate test weight (TW) to yield. Understand why the two measures are only marginally related.

Traditionally a problem disease in the western Corn Belt, Goss’s wilt is now prevalent across the Corn Belt and spreading into Canada. Once corn plants are infected, yield potential can be reduced by up to 50 percent. There are no effective chemical control measures for Goss’s wilt. The best way to limit spread of the disease is by selecting hybrids with strong Goss’s wilt tolerance.

This bulletin provides information about Goss’s wilt and tolerance ratings for Mycogen® brand corn hybrid families. The ratings are the result of 2011-14 field trials conducted in Illinois, Iowa, Minnesota, Nebraska, South Dakota and Wyoming.


DISEASE INFORMATION
Goss’s wilt is caused by the bacterium Clavibacter michiganensis subsp. nebraskensis. It overwinters in infected corn residue, primarily found on or near the soil surface. Inoculum in the infected residue primarily spreads by wind and splashing rain. To a minor degree, Goss’s wilt also can survive in seed.

To infect a corn plant, the bacterium needs an entry point or wound, which is generally caused by heavy rain storms, hail, wind, blowing sand or mechanical damage. Humid, wet weather is another risk factor because moist or wet leaves are conducive to the spread of disease.


IDENTIFYING GOSS’S WILT
Scouting is important because infection can occur at any point during the growing season. Infested seedlings show systemic wilting, stunting and a variety of leaf symptoms.

More-mature plants demonstrate the foliar leaf blight version of the disease. The first signs of infection are dark green to black, oblong spots that are water-soaked with a greasy look that appear parallel to leaf veins. Streaks of freckles within the lesions are a distinctive feature of Goss’s wilt. Droplets of bacterial exudate ooze from the freckles, leaving a crystalline substance that glistens in direct sunlight. The spots coalesce as they enlarge, forming long lesions with wavy edges. As the lesions age, they turn tan and can blight much of the leaf. Systematically infected plants have discolored (orange) vascular tissue and likely slimy stalk rot.

Key Symptoms:
• Freckles in lesions
• Crystalline deposits
• Droplets of exudate

Commonly confused with:
• Drought damage
• Heat stress or sun scalding
• Other leaf blights


CONTROLLING GOSS'S WILT
Because Goss’s wilt is a bacterial disease, it cannot be treated with fungicides. The best method of control is planting hybrids with strong Goss’s wilt tolerance. Tables 1 through 4 demonstrate the wide range of tolerance in hybrids.

Growers can limit the spread of Goss’s wilt to uninfected fields by selecting tolerant hybrids, harvesting infected fields last and thoroughly cleaning harvest equipment. Destroying infected crop residue will lower the amount of bacteria present. This is most effective when done immediately after harvest. In most situations, rotating to a nonhost crop, such as soybeans, dry beans, sugarbeets or alfalfa, is a more viable option. Last, manage irrigation to reduce humidity in the field during the growing season.

Talk to your Mycogen Seeds sales representative or customer agronomist to learn more about managing Goss’s wilt on your corn acres.