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
Pictured above are the black cutworm moths that I found in my pheromone trap.
Evidence of black cutworms feeding on young corn plant.
A young corn plant that was cut off by a black cutworm.
Congratulations to our Intern from Galesville, Alissa Geske, for being the first one on our staff to fine a WBCW (western bean cutworm) moth this summer. Some of our hybrids, like the Smart Stax varieties, have protection against this pest. But a lot of our field corn and sweet corn varieties are still at risk. The best way to determine when this pest is in the area is with the pheromone traps, like the ones our interns are checking every week. Please click on the links below for reference materials to help you learn more about this destructive pest.
Western Bean Cutworm tech sheet
Moth ID guide A3855
If you need help determining if this pest is a problem on your farm please contact your local Agronomy Advisor at Allied Cooperative. — Rob Shields, Agronomist
The short answer is neither. I have looked at a number of fields in the area and it looks like we have some Bacterial Blight in our soybeans. I attached a photo from an area field, and some nice publications from Iowa State going over what these disease look like. When I looked closely at area fields you could find the missing pieces of the soybean leaf. So this helped to prove that nothing had eaten the plant but rather it is the result of a bacterial disease attacking the plant and pieces of the leaf tissue falling to the ground.
Remember a foliar fungicide will not do anything for bacterial diseaseas, but if you have any fungal diseases present in your soybeans, fungicides will help in that situation.
Please let your local Allied Agronomy Advisor know if you need help looking at your soybean fields. We would like to help you evaluate what, if any, disease pressure you are experiencing currently and offer recommendations to assist you. — Rob Shields, Agronomist
Bacterial Blight soybeandiseases
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
Corn Plant in Trouble
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
Is now a good time to evaluate your 2013 weed control program? Yes it is. Once your corn fields are harvested, or even while you are harvesting them take a look to see what survived or competed with your crop this summer.
This photo shows a field that had some crabgrass competing with the field corn during the summer of 2013. This matt of crabgrass not only stole moisture but crop nutrients as well. I would have like this field to have been spayed again prior to canopy with some residual corn herbicides. An example of a recipe that could have been is a 5# glyphosate, Capreno, Atrazine, Prowl H20. Rates and products used always depend on crop stage and weeds present. Always be sure to follow label directions, and in some areas of our state Atrazine can NOT be used. The Wisconsin DATCP site has an excellent, interactive map showing what areas can not receive Atrazine. For more on this click the link below. Let us know if you have any questions this fall that we can assist you with. — Rob Shields
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.
– Rob Shields, Agronomist