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.

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.

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.

Cover crops planted after harvest can improve and maintain soil quality in today’s intensive corn-soybean rotations. Understand how different types of cover crops recover unused nutrients, retain soil moisture, suppress weeds and break up compaction.

Utilizing winter cover crops for hay and corn production allows you to realize soil conservation benefits while increasing dry matter production per acre. Proper cover crop management in the spring can ensure the subsequent corn crop is successful, as well.

Zipper ears, or ears with missing kernel rows, are a result of stress during pollination or grain fill. Ears affected by zippering have kernels that developed poorly or more slowly than other kernels or have ovules that aborted shortly after pollination. It’s important to understand how and why zipper ears occur and how to minimize their occurrence in the future.

Between the V3 and V5 growth stages, corn transitions from deriving energy directly from the seed to acquiring energy from sunlight through photosynthesis. Visual appearances during these stages offer clues to overall plant health.

Northern corn rootworm (NCRW) is one of the most damaging corn pests in North America. Because the NCRW typically has a one-year life cycle, rotating corn with another crop has been a successful management strategy. Unfortunately, some populations of NCRW have successfully adapted to a corn soybean rotation and now have a two-year life cycle. This is called extended diapause because the eggs remain dormant in the soil for almost two years before hatching.

Seed treatments can help protect soybean seeds and seedlings against a wide range of yield-threatening insects and diseases. Treatments can help to increase stand and vigor, promote earlier canopy closure and improve yield potential. The need for seed treatment depends on soil type, field history and pest pressure. Assess all factors before deciding whether to order seed treatment.

Seed treatments are valuable tools for protecting soybean genetic yield potential against a wide range of insects and diseases that threaten early growth. With so many seed treatment options, it is important to understand how each one works to protect your soybean crop.

Producers who plant insect-traited corn are required to manage refuges to preserve Bt technology. With so many trait options, following refuge management guidelines has become more complicated. SmartStax^® Refuge Advanced^® available in Mycogen^® brand hybrids simplifies achieving higher whole-farm yield potential by making refuge management easier. Refuge Advanced ensures refuge compliance in the Corn Belt¹ with a blend of 95 percent SmartStax seeds and 5 percent non-insect-traited refuge seeds in one bag.

Soybean growers can maximize the yield potential of their crop by ensuring it is planted at an ideal population. Plant populations vary by geography, so it is important to consider local conditions as well as the variety, row width, seed treatments and other factors.

Planting larger seeds creates challenges. Growers should follow some basic management tips.

Utilizing winter cover crops for hay and silage production allows you to realize soil conservation benefits while increasing dry matter production per acre. Proper cover crop management in the spring can ensure the subsequent corn crop is successful, as well.

Planting corn at the appropriate population can help maximize the crop’s yield potential. Specific populations can vary by geography so it is important to consider management practices, ear type, row width and other environmental factors.

The optimum time to select corn hybrids for the next season is often in the fall, shortly after harvest is complete and your observations from harvest are still fresh in your mind or can be reviewed in your records. Additionally, early ordering often can help ensure availability of hybrids and seed sizes that best fit your farming practices.

Harvesting corn for silage leaves little plant residue on the ground to help control water runoff and soil erosion. A cover crop either interseeded before or planted immediately after silage harvest will help protect the soil from wind and heavy rains. An established cover crop also helps improve soil structure and uptake of nutrients.

Many factors contribute to how early frost in the fall will affect corn harvest and the expenses associated with drying and storage. Damage severity will depend on the stage of the crop, the duration of freezing temperatures and subsequent plant damage.

Many factors can cause stand reduction in soybeans. Replanting may be one option to consider.

A high rate of black cutworm (BCW) moth catches, green fields and late planting dates are the perfect recipe for significant damage from black cutworm. Damage can range from very little to almost 100 percent stand loss. To give late-planted corn the best yield potential, make controlling this pest a high priority.

Planting corn at the proper depth helps to ensure proper germination and development, allows for optimum seed-to-soil contact, leads to more uniform emergence and helps achieve top yield potential.

When corn planting is delayed due to inclement weather and poor field conditions, you can still take advantage of the compressed growing season and achieve reasonable yield results by adjusting your hybrid selection and managing cropping activities with later planting dates.

When corn planting is delayed due to inclement weather and poor field conditions, you can still take advantage of the compressed growing season and achieve reasonable yield results by adjusting your hybrid selection and managing cropping activities with later planting dates.

If your cornfields have been damaged by heavy rain, hail, pests or poor emergence, you may consider replanting.

Greensnap occurs when wind causes corn stalk breakage. This yield-robbing phenomenon is most prevalent in the central and western Corn Belt, where high winds are common. Corn is most susceptible to greensnap during the five- to eight-leaf stages and again from the 12th-leaf stage to one week after silking. During these rapid growth stages, lignin is not deposited into the new cells, leaving them brittle and vulnerable.

A bacterial disease that has been prevalent in areas of the western Corn Belt for decades, Goss’s wilt has expanded to additional areas of the central and eastern Corn Belt in recent years. If infections occur early in the season, during key crop development times, yield potential can be reduced by up to 50 percent.

Warm, moist conditions from July to September can cause increased disease incidence in corn. Recent studies have show potential economic benefits from foliar fungicide applications. Fungicide treatments can give protective or curative benefits for corn diseases such as: gray leaf spot, common rust, eyespot and antracnose. These diseases can limit photosynthesis due to tissue death. Loss of leaf tissue also may result in grain production loss or harvest loss due to weakened stalk strength and harvestability issues.

Excessive rainfall can accelerate stem canker development in soybean fields, causing devastating yield reductions of up to 90 percent. Effective field management and surveillance practices can preserve crop health.

Each year, alfalfa stands risk being injured or killed by cold temperatures, ice sheets or heaving. Evaluating alfalfa stands for winter injury is crucial to crop rotation decisions.

Increased use of reduced tillage and no-till production practices has increased gray leaf spot occurrence. Caused by a fungus, the disease leads to leaf tissue loss, resulting in a decrease in plant sugars and decreased grain production. Potential yield losses range from 5 percent to 40 percent.

The most common problem associated with poor canola yield is a weak stand, so establishing strong, healthy canola stands is crucial for successful results. Before planting, take time to consider what is needed to get the crop off to a healthy and productive start.

Sunflowers are very adaptable and can be grown under different environmental and soil conditions. Several university studies illustrate how sunflowers planted at varying populations, depending on the environment, can result in similar yields. When determining planting populations, consider environmental, agronomic and marketing factors to maximize yield and profit potential.

Several methods provide growers with a reasonable estimate of corn hybrids’ relative maturity, but differences among rating systems sometimes confuse growers. Are you familiar with each method?

Downy mildew is a soil-borne fungus that infects sunflowers shortly after germination and again at the four- to eight-leaf stage. It also can lead to a secondary infection if spores are splashed or blown on the leaves. New strains of downy mildew have overcome genetic resistance in some sunflower hybrids.

Poor nitrogen (N) application methods or application timing could result in a shortage of available N to meet your corn crop’s needs next season. Understanding proper N application methods can help maximize N efficiency on your operation.

Sunflower growers have many choices when choosing sunflower market segments that best fit their farming operations. Understanding the risks and benefits of each market will help a grower decide which can be the most profitable in any given year.

Iron deficiency chlorosis (IDC) of soybeans is a physiological disease caused by iron deficiency capable of sizable reductions in yield potential. Know and understand how to mitigate your risks.

Southern rust is a common threat to corn crops across the southern United States. The disease damages crops in the Corn Belt only about once every five years, but when it does yields may be cut by more than 40 percent.

If foliar diseases threaten brown midrib corn (BMR) silage fields, growers can mitigate risks under the right circumstances with proactive management. Are you familiar with best practices for protecting your silage crop?

Growers across the High Plains are constantly looking for the crop option with the most return opportunity per acre. Sunflowers as a late-planted double crop bring production challenges, but offer lower inputs with high crop value to maximize profit potential.

Sclerotinia, or white mold, is a fungal disease that cripples sunflower yield potential. Caused by sclerotia, a soil-borne fungal body, it has evolved to become one of the sunflower industry’s most damaging problems.

Sunflower rust is capable of wiping out yields throughout sunflower-growing regions. Scouting is essential to preventing widespread damage.

Blackleg can be found in most canola fields throughout the northern Plains and much of North America. Though the disease is common, diligent growers can overcome its effects.

Growers in dry areas are constantly looking for the crop option with the highest return per acre. Sunflowers perform in dry conditions because of deep, aggressive root systems. With high crop value, low input costs and multiple marketing opportunities, sunflowers may help maximize profit potential.