Important Corn Pest Information

This spring Penn State Extension in Franklin County set up a network of eight sites to monitor populations of black cutworm moths and true armyworm moths. One of these sites was in the St. Thomas area. This trap received significant flights of both black cutworm moths and armyworm moths. These numbers raise the risk of damage by these pests, please read the following statements for management considerations.

The most important step for you to take at this time is increase your level of observation and scouting in your corn fields. The distribution of these pests can be very spotty, so it is often the case that very few acres are infested and will need to be treated with insecticides. Specific information pertaining to scouting, economic thresholds and life cycles are important to understand and consider. Initial scouting for these pests involves moth trapping, which indicates a possibility of local populations of caterpillars developing. Unfortunately, higher local populations of moths does not always lead to damaging populations of caterpillar, but the correspondence is strong enough to warrant a warning of potential damage to growers in the vicinity..

Black cutworm moth:

Cutting behavior of black cutworm caterpillars is expected 300 growing degree days after the significant flight. The Penn State Agronomy program in Franklin County has recently established a weather station in Chambersburg Pa and has been tracking growing degree days since the significant flight occurred. The threshold was reached on Sunday 5/23/2010. Now is the time to start scouting corn fields to look for cutting damage. Economic thresholds for treatment are 2, 3, 5, and 7 cut plants per 100 for seedling, V2, V3, and V4 respectively.

Treatment options for at-risk areas vary but can include higher rates of neonicotinoid seed treatments where corn has not been planted and planting lines of Bt corn with activity against black cutworm if seed is still needed; however, growers should recognize that neither of these options are completely effective. The most economical control method for cutworm is scouting fields and applying rescue treatments where cutting activity exceeds economic thresholds.

More information on this pest can be found online at http://ento.psu.edu/extension/factsheets/black-cutworm , or by visiting the local extension office.

True armyworm moth:

One of the most important management considerations when dealing with true armyworm is to make sure in areas where you have cover crops or heavy weed cover that you allow a 2 week period after the plants are dead until you plant. This would lead producers trying to get a timely planting of corn who have yet to spray to use a quick killing herbicide such as gramoxone instead of glyphosate.

Once corn is established scout fields closely, especially where heavy cover was. If you find more than 10 percent of your corn in a given field has an infestation of armyworms treatment is encouraged. Armyworms typically are found hiding in the whorl of corn during the day and their feeding creates a ragged looking leaf. In bad cases the leaves will be fed on until nothing but the mid-rib is left.

More information on this pest can be found online at http://ento.psu.edu/extension/factsheets/armyworm, or by visiting the local extension office.

Finally, I would ask that you share this with other farmers in your area who may not receive Agronomy Notes. The greater the awareness of this issue, the less likely we will have economic losses due to these pests. As always, if you have any questions or need hard copies of the fact sheets mentioned above feel free to contact me at the extension office 717-263-9226 ext. 227. I am often away from my desk but check messages frequently.

Rules of the Road: An Update for Agriculture

There is no question that agriculture and the public are constantly interacting. One of the most common areas, for good or for bad, is on public roadways. The large question that does remain, however, is what public regulations do and do not apply to those who are in production agriculture. This question has received heightened awareness over the past months with new legislation passing in regards to farm operations on public highways. Although, like most legislation, some of the law is written in ways that are not so plain, hopefully this article will bring some clarity to the situation.

In 2007 Pennsylvania's motor carrier regulation were audited by the Unites States Department of Transportation's Federal Motor Carrier Safety Administration. As a result of this audit deficiencies were found in our current regulations. These deficiencies had to be changed by March of 2010 in order to stay current with the Federal regulations. After much deliberation the final outcome to those involved in agricultural production is one of little change. The changes to our regulations mainly focus around the operation of farm trucks above 17,000 lbs. GVW.

New Intrastate (within state) Requirements for farm trucks above 17,000 lbs:

• Age: Those under age 18 are not permitted to operate a farm truck/trailer combination on public roadways (All licensed drivers can operate straight trucks).


• Medical Certificate: Required for farm trucks (straight and combination) operated more than 150 miles from the farm.


• Inspections: Pre and post trip inspections for both straight and combination farm trucks


• Vehicle Maintenance Records: Required for straight and combination farm trucks

New Exemptions:

• Planting and Harvest season has been extended to include all 12 months


• Service Hours/Logs: Not required if operating within 100 miles of the farm
  
• Additional Logs: Not required if operating more than 100 miles but less than 150 miles from the farm


• Driver History/Testing: Not required for drivers operating within 150 miles of the farm


• Custom harvest operators receive 'farming' exemptions


• Beekeepers receive 'farming' exemptions

A common question that comes with the increased regulations is often; 'what do I do to get a medical certificate. An online form can be printed from http://www.fmcsa.dot.gov/rules-regulations/topics/medical/aboutdotexam.htm and filled out by your family doctor. This completed form may be used as the certificate or you may use it to qualify yourself to purchase a medical card.

Another question arises with pre and post trip inspections. The post trip inspection must at least cover the following areas: brakes, parking brake, steering, lighting and reflectors, tires, horn, windshield wipers, rearview mirrors, coupling devices, wheels and rims and emergency equipment. The driver must list any conditions found or state that no conditions were found, either way the driver must sign the form. Prior to the next trip the next driver must sign off on the form stating any deficiencies have been corrected or that they do not require immediate attention. If a post trip form lists deficiencies it must be kept with the certification of repairs on file for three months from the date of preparation. A sample form can be found at http://www.agriculture.state.pa.us/portal/server.pt/gateway/PTARGS_0_2_24476_10297_0_43/AgWebsite/Files/General/Transportation%20Forms.pdf on page 4.

Hopefully this will help you to stay within regulations this season while operating your farm trucks. Just as a reminder, remember that this only applies to vehicles with GVW over 17,000 lbs. These regulations do not apply to tractors operated on the road. Although this may seem like it gives more unwanted record keeping a simple clipboard in each of your trucks with a maintenance record as well as some copies of the driver's vehicle inspection report and a pen should keep you in compliance when you are traveling less than 150 miles from the farm. I might suggest getting something similar to this clipboard (http://www.gemplers.com/product/G58514/8-1-2x12-Clipboard-Removable-Compartment ) for 37 dollars that will allow you to fill and file forms all in the truck.

Nitrogen Confusion Correction

A few weeks back I authored an article about nitrogen stabilizers available to our producers. In this article I made mention of Twin N as a products that mitigates volatilization and nitrate leaching. Please note that this information is not correct. Twin N is actually a microbial mix of nitrogen fixing bacteria. Sorry for this confusion, however this does bring us back to the fact as stated in the article to make sure you know what type of inhibitor you want, a urease or nitrification inhibitor. Similar to our herbicide and insecticide counterparts if we know the active ingredients and/or pathways we won't have to worry about specific brand names. Again I apologize for any confusion this has caused.

Frost Damage

With an unusually warm April is seems strange to be talking about frost damage in the second week of May, however here we are. Some of you may have experienced some localized frost damage in corn fields on Sunday to Monday night. If you have recently scouted your emerged corn you may have found water soaked leaves that are unusually dark in color or brown leaves depending on how soon after the frost you may have discovered the corn. These are typical symptoms of frosted corn. If you're wondering what will happen now the best answer is just wait. Prior to making any replant decisions allow a few days to a week for the corn to recover from the frost damage. At the stages that most of our corn is at (emergence-V4) we should be ok. Due to the lack of prolonged cold in our area you will likely find any frost damage sporadic at best with little to no pattern in the field. Low lying fields and areas of fields are more likely to have been damaged as well as fields no-tilled with substantial cover. Again, corn is very resilient at this point in time so give it a little while before decisions are made to replant. I would be very surprised if we have any stands that warrant a replant for frost damage.

Soybeans, on the other hand, are less resilient to frost. I am not aware of any beans that were up and damaged by frost, however if temperatures hold below 30 degrees for any extended period of time beans will die. Again, I would be surprised if we have this type of damage, however localized damage may have occurred in low lying area and could warrant a quick check if you know you had some emerged beans.

IPM Update

As it seems moth numbers are starting to dwindle all over the state it is a good time to look back on what we have found this spring. As noted previously, St. Thomas was the only area that received significant numbers of true armyworm or cutworm moths. When looking at the graph above you can see the trap locations and the sporadic numbers throughout. Populations of both of these species are notoriously spotty. This year's network, I believe, has confirmed this once again.

Due to their sporadic nature it is very hard to know if and when you may have an issue on your own farm with these species. This unknown is why we typically rely on a pre-season application of insecticide as a little insurance policy against these pests. Two issues arise with this type of management. The first issue is that this certainly does not follow the IPM framework of spraying only when a pest population is present and at threshold levels. The second issue, which also has become apparent this year is the timing of the insecticide application may often be wrong for the pest. St. Thomas's significant flight happened on May 28^th. This means any insecticide applied more than a day or two before would have little to no affect on these pests. The moral of this means you are not limiting your damage simply by placing an insecticide up front with your burn down. If you had an insecticide placed on your fields prior to the significant flight you would still have to scout and possibly spray if thresholds were reached just like your neighbor who did not apply an insecticide.

Another question often raised with these pest centers around Bt corn and its control on these pests. Traited corn has become somewhat a norm in much of our industry, however it is not a solution to all problems. A few lines of Herculex Products do have activity on black cutworm, however none of the Bt lines can claim control of true armyworm.

All of these facts and more lead to the conclusion that we all must be vigilant in scouting for pest pressure and understanding pests life cycles and tendencies. Hopefully you can find some help in information such as these posts, and as always feel free to contact me for any additional assistance you may need.

IPM BULLITEN

Penn State Extension in Franklin County has established a grid of eight trapping sites across the county to attempt to survey populations of black cutworm and true armyworm moths. We previously reported that true armyworm moths have been found in the St. Thomas area in large enough numbers to call for added scouting in that area. Now we have detected economically significant flights of black cutworm in the St. Thomas area. Growers in the vicinity and surround areas should be aware of a heightened risk to their corn fields. Note that corn fields planted following soybeans can often sustain heavier populations of black cutworm caterpillars.

Now that significant flights have been detected we can begin accumulating degree days. Cutting behavior of black cutworm caterpillars is expected 300 growing degree days after the significant flight. The Penn State Agronomy program in Franklin County has recently established a weather station in Chambersburg Pa and will be tracking growing degree days. This bulletin will be followed by another once we begin to approach the 300 growing degree days. When the second bulletin is received, folks should start scouting corn fields to look for cutting damage. Economic thresholds for treatment are 2, 3, 5, and 7 cut plants per 100 for seedling, V2, V3, and V4 respectively.

Treatment options for at-risk areas vary but can include higher rates of neonicotinoid seed treatments where corn has not been planted and planting lines of Bt corn with activity against black cutworm if seed is still needed; however, growers should recognize that neither of these options are completely effective. The most economical control method for cutworm is scouting fields and applying rescue treatments where cutting activity exceeds economic thresholds.

More information on this pest can be found online at http://ento.psu.edu/extension/factsheets/black-cutworm , or by visiting the local extension office. Please share this information with others who may be interested in it. Again it appears that the pressure at this point is limited to the greater St. Thomas area. I will continue to keep you up to date if populations build elsewhere.