Watch out for black cutwork feeding!

As I have been out monitoring my black cutworm pheromone traps I am seeing a spike in moth flights, which could eventually lead to serious black cutworm issues in the next following month. DATCP is projecting that May 20th will be the average date when larvae are reaching their maximum damage potential.  One black cutworm can cut down as many as 4 or 5 plants in its larval stage.

With a wide range of hosts black cutworm can be a problem not only in corn but also in soybeans, sunflowers, and other agronomic crops. When scouting be sure to pay attention to low wet areas, patches of fields that have early weed development as well as fields that use reduced tillage systems.

When scouting fields check 10 plants in 10 different areas of the field to record the percent of plants displaying feeding symptoms, if feeding is greater than 3% an insecticide treatment may be considered.

Consult your Allied Agronomy Advisor for control options if you believe you are at threshold. — Josh Johnson, Agronomist

BCW pheromone traps

Pictured above are the black cutworm moths that I found in my pheromone trap.

Cutworm damage

Evidence of black cutworms feeding on young corn plant.

Cutworm_corn

A young corn plant that was cut off by a black cutworm.

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

Soybean harvest under way

The soybean harvest has taken off in the area. I just talked with a grower west of Galesville and they are opening up some fields as we speak. He said they are definitely dry enough and to plan on soil sampling everything early next week. Fall is a great time to get all of your soil sampling completed. A few key things to remember about sampling this fall: sample the fields prior to any tillage, and before any manure, fertilizer, or lime is applied. This way you get an accurate sample. A corn field was also recently harvested up this way, the moisture ranged from 16% to 31% and test weights from 49 to 52.

– 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

WARNING: WHITE MOLD FOUND in soybean fields!

We have found areas of white mold starting aggressively in area soybean fields. It is too late to use the herbicide Cobra®, but you could us a fungicide such as Domark®, at 5 oz. per acre, to help slow down the progression of this devastating disease. It is also recommended to add in 6.4 oz. per acre of MasterLock® (a new premix of Interlock® and Preference®) to aid in the dispersal of the fungicide on the soybean plants. Below are some photos to assist you in determining if you have any white mold in your fields. (Click photos to enlarge them.) Please let us know if you need any help scouting your fields.

– Rob Shields, Agronomist

White mold 1 White mold 2 White mold 3

Crop Update

Corn

Our black light traps are showing low to very low levels of western bean cutworm moths, European corn borer, and corn earworm, especially compared to the levels we were finding this time last year. We have found a few corn leaf aphids on some of the heavier ground in our area so be sure to be monitoring your fields for this pest as the summer progresses. Much of the corn in our area is at the tail end of pollination and is looking good. Low levels of rust can be found in most all of the fields in our area. Anthracnose leaf spot is common in fields that are corn after corn. We have only found a few fields with trace amounts of Northern corn leaf blight to date, but with wet weather on the forecast it is likely to spread.

Soybean

Japanese beetle, green clover worm, aphids have been the main insects we have been finding these past few weeks, but no fields have reached economic thresholds yet. Be vigilant in scouting for aphids as the extended forecast of cool weather will be very conducive to aphid reproduction. University thresholds are 250 aphids pre-plant which may sound like a lot, but when the population can double every few days it does not take very long for a field to become infected. Septoria brown spot is slowly building in the lower canopy of many of the soybean fields in our area. Consider a foliar fungicide if you have moderate or heavy disease pressure at this time. The key time for fungicide on soybeans is the R1 (beginning flower) to R3 (beginning pod) stage. Many of our fields are in the R3 stage to R4 (full pod).

Potato

Late blight continues to be a problem and is slowly but surely spreading with each week, bringing one or two more fields found to have been infected. So continue to apply fungicide on your scheduled interval being sure to add premium late blight material especially on the weeks of cool wet weather like we have been having. We are currently in the midst of second generation Colorado potato beetles with adults already laying eggs and larvae hatching. Some of the petiole numbers are starting to crash as the crop begins to pour energy into the tubers. We have been checking tubers for shape and size last week and this week to see if an MH30 application is needed to correct the shape of the tubers.

– Otto Oemig, Agronomist

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

Disease pressure is high in soybeans this year…

Today we looked at a number of soybean fields that have been attacked by a number of soil born diseases. Because of the extreme conditions this season – cool and wet, then hot and dry – a lot of fields are starting to show problem areas. The field pictured below in particular looks like it has some areas of rhizoctonia starting. We are sending some samples down to the plant pathology lab to confirm our diagnosis.

– Rob Shields, Agronomist

Diseased area in soybean field.

Diseased area in soybean field.

Rhizoctonia in soybeans.

Rhizoctonia in soybeans.

Japanese Beetles Attack!

A lot of our field and vegetable crops are now being attacked by Japanese Beetles, see photos. They consume the leaves of many crops, such as corn, soybeans, snap beans, tomatoes, melons, etc. Please check your fields now or contact one of our Allied Cooperative agronomists to assist you.

 – Rob Shields, Agronomist

Japanese beetle 1

Crop Update

Corn

This past week we found the first rust pustules of the season which means that rust spores are in the area. Carefully monitor your corn fields for rust as the season goes on, especially those fields with sensitive or less resistant hybrids. Start planning ahead to tasseling which for some may be right around the corner, with as wet a year this has been we should expect higher than average foliar fungus pressure this year so consider an application of a fungicide at Tasseling and R1 in the corn this season.

Soybeans

We are finding low levels of brown spot of soybean in a few fields across the area. Soybeans are growing rapidly at this stage. We are finding soybean aphids in most fields this year. With these levels of aphids this early in the season, combined with the favorable aphid weather we have been having it is very likely that control will be needed in many of the fields in our area this year.

Potatoes

Late blight was found in south central Portage county today. This point of infection is 20 miles north and east from the original infection site. In most of the fields in our area we have the Colorado Potato Beetles under control at this point with just trace levels left in most fields. Early blight continues to remain in check on the lower canopy in fields that are receiving regular fungicide applications. Also we are just starting to find bacterial vine rot in some of the more sensitive varieties.

– Otto Oemig, Agronomist