Time for CORN Tissue Testing

Well after 2.5 inches of rain yesterday afternoon and evening at our house, my wife should not have to water the garden tonight.  I had wanted a little bit of rain to keep the crop moving forward but I received a lot more than that.

 

Last week we looked at a lot of corn that was V2 to V4.   This week is critical in field corn.  The weeds need to be cleaned up and a residual product laid down to keep the field clean until canopy.  An example of a recipe you could use in glyphosate tolerant corn would be 24oz of a 5# glyphosate, 1.5pts Atrazine 4L (if you are not in a restricted area & you have not already used Atrazine), and  2 to 3 oz. of Capreno.   Remember to always check labels and check with your Agronomist at Allied before making any applications.

 

Now is the perfect time to call us to have your tissue samples taken for field corn.  We want them pulled at V4 to V5 to confirm where the nutrient levels are at in the corn plant.  We have many interns and staff available to help in this effort.  We will also ask when the last time you pulled a soil sample.   If it has been more than 3 years we will want to pull a soil sample at the same time the tissue sample is pulled.

 

Please take the time with the weather delays to check on your corn stands (see pictures below).   Check populations, look for missing plants, find out why they are missing.   Bring along a shovel and check planting depth and look for any disease or insect pressure.   If you do not have time please give us a call we would like to help you evaluate your fields.

 

Have a safe and productive week!   — Rob Shields, Agronomy

looking at corn populations

Looking at Corn Populations

Corn plant in trouble


Corn Plant in Trouble

Sign Up Now for Private Applicator Training & Testing

We have to get used to writing 2014 now.   The year 2013 is now over, and what a roller coaster ride it was — a late wet spring followed by a dry summer. Hopefully 2014 can provide us with a season that is more favorable for crop production in Wisconsin.

The 2014 season is only a few months away. Now is a great time to start planning for what is needed during the next crop season.  One thing you don’t want to limit yourself on is what crop protection product your farm has access to. If you do your own spraying please check to make sure your Private Applicator license is up to date.  If not please sign up NOW with your local UW Extension office. (See below for more information on these classes.)  This way you will have access to any of the crop protection products that are sold at your local Allied Cooperative Agronomy center. Please have a safe and productive 2014 season!   — Rob Shields, Agronomist

Private Pesticide Applicator Training classes will once again be offered by your local UW-Extension office. Anyone who intends to purchase, mix, load, apply, or direct the use of restricted use pesticides as a private applicator must be certified. Certification is good for five years. There are two ways to become certified. Purchase and study the training manual and attend an all-day training class offered by your local UW-Extension office. These classes consist of presentations followed by a written exam at the end of the day. If you are unable to attend one of the classroom sessions, the second option is to self-study and schedule time through the UW-Extension office to take the exam on your own. Training manuals are available at your local UW-Extension office and must be purchased at least five (5) days before the class or individual exam is taken.

January 23 – Green Lake County

January 24 – Waushara County

January 31 – Adams County

February 5 – Marquette County

February 14 – Wood County

February 21 – Juneau County

February 21 – Portage County

February 27 – Waupaca County

March 4 – Waupaca County

March 7 – Portage County

March 10 – Adams County

March 14 – Green Lake County

March 21 – Waushara County

Harvesting your corn early to avoid field loss

You may be tempted to leave your corn crop in the field to dry down and reduce your drying expenses.   But by waiting you increase your chances of field loss.  Most fields have some anthracnose present, and this year we had a lot of moisture stress to add to the stalk quality issue.  Another fact to consider is that a lot of our corn was planted late in poor conditions.   This has resulted in may plants that have poor root systems.   These plants will have a much harder time standing during a October wind storm when you combine the anthracnose, poor stalks and smaller root systems.   I attached a nice piece from Ohio State going over what anthracnose looks like and what it is to help you identify it in the field.   Please consider harvesting your field corn early this year.   I do not want to see any down corn in our area.   Thanks for looking over my info on this blog and please have a safe harvest!

Anthracnose Leaf Blight and Stalk Rot of Corn

AC-0022-01

Patrick E. Lipps and Dennis R. Mills
The Ohio State University

Anthracnose has become one of Ohio’s most important corn diseases. This disease was first detected in Ohio in 1961, causing stalk rot in research plots at Wooster. Later reports of the disease were mainly concerned with the leaf blight phase and little damage was attributed to the stalk rot phase except in a few localized areas. Since 1972, the evidence of anthracnose has increased greatly. Anthracnose stalk rot has been severe in the state since 1979 when stalk rot was observed in more than 50% of the fields surveyed and the range of infected plants in those fields was 10 to 90%; some fields had 50 to 80% of the stalks lodged. Yield losses occur from premature plant death that interrupts filling of the grain, and stalk breakage and lodging causing ears lost in the field. It can be safely stated that anthracnose occurs in all corn growing areas of the state and that losses in certain years could be as high as 10 to 20%.

Symptoms

Anthracnose of corn may appear as a leaf blight, stalk-rot, top-kill of the stalk, and kernel rot. However, most damage results from the stalk rot and leaf blightanthracnosephases. The anthracnose fungus can attack corn plants at any stage of development. Lesions can be found on leaves of very young plants soon after emergence when the fungus has overwintered in the field. Leaf lesions are generally brown, oval to spindle shaped, about 1/4 inch wide by 1/2 inch long. Usually, a yellow or yellow-orange area surrounds the disease portion of the leaf. The actual size and shape of the leaf lesions varies greatly among different hybrids making diagnosis in the field very difficult. The fungus can usually be seen on the leaf surface with the aid of a hand lens. Spore masses within characteristic fruiting bodies are easily identified based on the presence of small, black spines (setae) arising from the leaf surface. Spines can usually be detected within fruiting bodies near the midrib of heavily diseased leaves or within older lesions on lightly diseased leaves.

Symptoms of the stalk rot phase are easy to recognize and usually are not confused with other stalk rot diseases. Late in the season shiny black, linear streaks and blotches appear on the surface of the lower stalk above the brace roots. Occasionally, the entire stalk becomes blackened. The internal stalk tissue or pith becomes discolored, turning dark gray to brown and shredded. Severely diseased stalks are weakened and are likely to lodge before harvest. Anthracnose may develop in the upper stalk above the ear, resulting in top dieback. These blighted tops may top-lodge above the ear.

Disease Cycle

Anthracnose of corn is caused by the fungus, Colletotrichum graminicola. This fungus has many strains, some of which cause various diseases of rye, wheat, barley, forage and weed grasses as well as corn. The strains appear to have a restricted host range so that only isolates from closely related grasses will cause disease when cross inoculated. For instance, isolates from johnsongrass, sudangrass, and sorghum will attack corn, but are not as pathogenic on corn as those originally isolated from corn. Isolates from small grains do not attack corn.

The overwinter survival of C. graminicola is dependent on corn residues being left on the soil surface. Deep plowing of infested residue for one growing season would eliminate the pathogen from the residues. In spring, conidia (spores) are produced with acervuli (fruiting bodies) on residues left overwinter on the soil surface. Conidia are rain splashed onto the surface of the leaves of young plants and cause primary infections. Leaf blight has been observed on the lower leaves of young corn plants in early June with little or no further disease spread until after tasseling. The disease is favored by warm, moist weather and disease severity is increased during protracted periods of low light intensity and high humidity. Therefore, severe leaf damage can result after long periods of heavy overcast, rainy weather. If weather conditions are favorable during late July and August the leaf blight may spread to the upper leaves. Yield reductions can be expected when significant leaf death occurs before six weeks after tasseling. Top dieback or top lodging can occur at any time after tasseling and premature death of the entire plant is an indication of stalk rot. The black stalk symptoms begin to appear soon after plants show signs of early death.

Control

  1. Hybrid selection is the first step in disease control. Hybrids available vary widely in their level of susceptibility to anthracnose. Hybrids with some resistance to the leaf are not necessarily resistant to anthracnose stalk rot. Growers should carefully select hybrids with the proper leaf blight and stalk rot resistance, with good standability, and high yield potential.
  2. Since the anthracnose fungus survives in corn residues, especially on the soil surface, the disease may be more serious under reduced tillage systems and in continuous corn. A tillage system that chops and completely buries the residues coupled with a one-year rotation  away from corn will eliminate the local source of inoculum. A two-year rotation away from corn may be necessary under no-tillage or reduced tillage systems.
  3. Avoid excessive plant stress by using a balanced soil fertility program based on soil tests. Plant at populations suggested for the particular hybrid, and control insects such as the European corn borer and corn rootworm.

Additional information on Anthracnose leaf blight and stalk rot is in Ohio State University Extension Bulletin 802, Corn Disease Control in Ohio, available from your local Extension office or The Ohio State University web site Ohioline at: http://ohioline.osu.edu.

– Rob Shields, Agronomist

Green Plants and Brown Pods?

The picture below was take by Dr. Mike Weiss, showing a curious condition we are seeing in some areas.   It has been brought about by the weather conditions we have seen this season.  It is best to be aware of it and plan your harvest schedule accordingly.    I also attached an article from Purdue giving some additional information.    Please have a safe and productive harvest!   Let us know if we can yield check any of your fields.

rob 10-10-13

 

Green stem syndrome present in some Indiana soybean fields

?????????????????By Amanda Gee | Posted on 9/30/2013

WEST LAFAYETTE, Ind. – Some Indiana soybean fields are showing symptoms of green stem syndrome, a Purdue Extension soybean specialist says.

Green stem syndrome occurs when soybean pods and seeds mature – turning harvest color and drying out – while the stems remain green. Late-season stresses that interrupt seed-fill, such as weather, the environment, viral diseases or insect infestations, usually cause the problem.

“It’s been noticed around the state, spots here and there where later-in-the-season weather stressed the plants,” Shaun Casteel said. “The dry weather and heat caused plants to abort pods. The plants’ demand for pod development and seed fill wasn’t there anymore, so the plants started maintaining the stem as the plant matured.”

Casteel said farmers should go into fields that seem to be browning and see if both the pods and stems are maturing.

“This year with some of those green stem-type fields, producers need to take a look at the pods themselves and the grain to see if they are dry enough for harvest,” he said.

Soybeans should be harvested at or slightly above 13 percent moisture to maximize yield, but green stems are tough to harvest.

Casteel said producers with fields exhibiting green stem syndrome have two options.

The first is to harvest the beans at optimal grain moisture to capture water weight. Doing so likely will slow harvest and increase fuel costs because of the green stems.

“For harvest, be prepared to have to ‘chew’ through fields with green-stem syndrome with the combine, especially with older equipment,” Casteel said.

Another option is to wait and harvest the plants when the stems turn brown. This option is easier on equipment but likely will reduce yield due to lost water weight. Delaying harvest for a few weeks also could allow the pods more time to dry out and possibly shatter.

“Producers need to be aware that this phenomenon is occurring so they can make informed decisions about optimizing harvest and reducing losses in yield and profit,” Casteel said.

Source: http://www.purdue.edu/newsroom/releases/2013/Q4/green-stem-syndrome-present-in-some-indiana-soybean-fields.html

— Rob Shields, Agronomist

Stink bugs damaging my corn?

According to the following article from Ohio State, we can see injury in corn. See the pictures they provided in the article below so you can see what the damage looks like. The authors also mention that sweet corn is more prone to stink bug damage. Read the article below for further information and let us know if you think you spot some in one of your fields.

Corn Ears Showing Stink Bug Injury

Andy Michel, Ron Hammond, Celeste Welty, Peter Thomison, Ohio State University  |   September 23, 2013
Stink bugs on corn.

Stink bugs on corn.

Stink bug damage in soybeans is well documented in Ohio. However farmers may be surprised to learn that stink bug injury can also be seen in corn. Usually the damage in field corn is localized to “scarring on kernels” or causing a “mottled” appearance near the tip of the ear but severe injury has been observed (see photo). Sweet corn is particularly susceptible to stink bugs, with similar damage symptoms.’

Stink bug damage on corn.

Stink bug damage on corn.

Last week we saw stink bug injury at the Northwest Branch near Hoytville and the Waterman Farm in Columbus. At Waterman, the damage was associated with brown marmorated stink bugs, but green stink bugs were more common at NW Branch. Damage was evident on husks where stink bugs appeared to be feeding (see photo). In the southern states, stink bugs cause significant losses in field corn. When stink bugs pierce through the husk and feed on the ear during early development, the cob will not develop on that side, but continue growing on the back side giving the ear a characteristic banana shaped appearance.

The shuck will also stop developing, exposing the grain to bird and insect damage. Injury also includes shrunken and/or missing kernels. Heavy stink bug populations can reduce not only yields but also the quality of the grain. While we have not seen any economic losses from stink bugs in field corn, growers should be aware of their presence and the damage they can cause.

Source: http://corn.osu.edu/newsletters/2013/2013-31/corn-ears-showing-stink-bug-injury.

– Rob Shields, Agronomist

– Rob Shields, Agronomist

A new soybean disease enters Wisconsin: Soybean Vein Necrosis Disease (SVND)

Soybean Vein Necrosis Disease

Soybean Vein Necrosis Disease (source: http://agdev.anr.udel.edu/weeklycropupdate/?p=3762)

Soybean diseases are always hard to diagnose. I use the color picture guides as a reference but if I cannot positively identify them I usually send down a sample to the UW Plant Disease Diagnostic clinic for a positive identification. Remember a virus, like the soybean vein necrosis virus, cannot be controlled with a fungicide. The best way to prevent a soybean virus is to keep the thrips away from your crop. Thrips infect the soybean plants when they feed upon them, similar to how mosquitoes transmit the west Nile virus. No matter what disease you suspect you may encounter out in your soybean fields, the best defense is a having a strong, well-fed plant with as few stressors acting upon it as possible.

I found the following article by Damon Smith (Extension Field Crops Pathologist, Department of Plant Pathology, University of Wisconsin-Madison) in the recent edition of the Wisconsin Crop Manager to be very insightful.

In 2012 soybean vein necrosis disease (SVND) was described for the first time in Wisconsin. This is a relatively new disease of soybean, which is caused by Soybean vein necrosis virus (SVNV). SVNV was first described in 2008 in the Mid-south soybean production region. Since then, SVND has been found in much of the major soybean production region of the U.S. including the North Central region.

SVNV is a Tospovirus similar to Tomato spotted wilt virus. It is the first Tospovirus known to infect soybean. Tospoviruses are known to be very destructive on other plant crops, therefore, there is a lot of interest in determining the importance of SVNV in soybean production systems. Very little is actually understood about the epidemiology and also the management of SVND. Researchers around the country are working on various aspects of the system and several state and regional soybean commodity boards have funded research on SVND.

Recently Zhou and Tzanetakis (2013) described some of the first studies on the epidemiology of SVNV. Their findings suggest that SVNV is like other Tospoviruses in that it is primarily transmitted by thrips vectors. Soybean thrips are a commonly occurring insect in the Mid-south and were used in their studies to demonstrate that the virus can be transmitted via thrips vectors. In Wisconsin, soybean thrips are not as common. However, other species of thrips can be found in soybean fields depending on the time of the season. Through funding granted by the Wisconsin Soybean Marketing board, our laboratory is currently monitoring thrips populations in soybean fields around the state. We are evaluating thrips species and populations over time through trapping methods. We are also surveying these fields for SVND severity and documenting any variety resistance in soybean cultivars commonly grown in Wisconsin. Finally, we have separate trials were we are evaluating yield loss due to SVNV. Our research will complement research in other states and the results will be used to develop and disseminate management recommendations for SVND in the North Central Region over the next several years.

(Source: http://ipcm.wisc.edu/blog/2013/09/soybean-vein-necrosis-disease-in-wisconsin-with-video/)

– Rob Shields, Agronomist

Pockets of soybean aphids found…

Soybean aphids found north of Galesville today.

Soybean aphids found north of Galesville today.

We were out scouting some soybean fields north of Galesville today and found some pockets of aphid pressure. Please remember to be checking your fields on a regular basis.

On a related note, here is a pop quiz for the day: Is the insect pictured below a friend or foe?

Lady beetle Larvae

Click to enlarge photo.

The answer? Friend! This little guy is actually the larval stage of the lady beetle. The lady beetle eats soybean aphids. Remember with the insects the stages are egg, larvae, pupa, and adult.

– Rob Shields, Agronomist

Insect activity found today…

Near Galesville today I found my first Western Bean Cutworm Egg Mass. The moth counts are very low this year. We put out 5 pheromone traps and have found very few this season. I also found a fair number of Corn Rootworm beetles feeding on the fresh silks today. Please keep a watchful eye on your corn fields during the critical pollination phase. The published threshold is “when silk clipping is occurring on 25% or more of the plants during pollen shed.” Also, if this field will be corn next year, it is best to plan your management strategy to combat this pest now due to the fact that they will be laying eggs now to attack next year’s corn crop. Please let us know if you have questions on any of these issues. Thank you.

– Rob Shields, Agronomist

Western bean cutworm egg masses.

Western bean cutworm egg masses.

Corn rootworm beetle feeding.

Corn rootworm beetle feeding.

Corn rootworm beetle feeding.

Corn rootworm beetle feeding.

Soybean aphids are showing up in certain areas…

Soybeans aphids from today, July 30.

Soybeans aphids from today, July 30. Click to enlarge.

Soybean Aphids found in Waushara county today. Please check your soybean fields every 3 to 5 days to make sure you don’t have a population that is building. Let us know if you need any help looking for this pest.

– Rob Shields, Agronomist

Armyworms ATTACK area corn fields

Please keep a close eye on your corn fields, especially those with a lot of trash or weeds. These photos taken by Wayne Roemer, an Agronomist out of our Plover location, show the extreme damage they cause. Wayne took these photos 8 miles south of Waupaca. Sally Turpin, an Agronomist out of our Mauston location, also found a heavily damaged field just north of Mauston. This pest moves rapidly and can leave only the stalk and mid rib on the corn plant. It is important to spray before the damage gets this bad. Please let us know if you need any help checking your fields.

– Rob Shields, Agronomist

Armyworms in Waushara county.

Armyworms in Waushara county.

Armyworms in Waushara county.

Armyworms in Waushara county.

Armyworm damage north of Mauston.

Armyworm damage north of Mauston.