2009 Regional Scouting Reports

by Alicia Lund, Agronomy Scouting Intern
by Amy Robak, Agronomy Scouting Intern

For Rosholt Research Updates

Final Reports

August 24

Alicia Lund, Agronomy Scouting Intern: This past week we spent a lot of time out talking to farmers about fall fertilizer. A question that has been asked frequently is how far behind is the corn compared to other years and how long before maturity. As of today, we have accumulated around 1600 GDU's and most of the corn in our area reaches maturity at around 2400 GDU's.  On average we accumulate 15-20 GDU/day, so the corn should reach physiological maturity between October 3 and October 10.
With the summer coming to end, I would like to thank everyone for reading my weekly reports; I hope they helped keep you updated on the agronomic events happening in the area. I had fun working here this summer and enjoyed meeting all of the area farmers.  This fall I will be returning to the University of Minnesota in the Twin Cities to finish my last semester of college. Once I graduate, I hope to find a job in the agronomy field somewhere in Minnesota.   

August 21

Amy Robak, Eastern Report: I was involved this week in evaluating alfalfa stands to see if re-seeding is needed or even if the alfalfa field was good enough to keep. Based off the information from the University of Wisconsin- River Falls, stand evaluations in the fall are better because it leaves the farmer more time for planning. The fall evaluation allows a farmer to identify less profitable fields and those likely to suffer winter injury in time to allow for fall tillage and alternative cropping strategies before fall fertilization and spring herbicides are applied for other row crops. It can also help farmers anticipate weed control needs.

To help evaluate alfalfa stand counts, we use the stem count method. To use this method, select 3 or 4 representative areas of the field, marking off a 2-square-foot section in each area. Count only those steams that are tall enough to be harvested by a mower (over 2 inches tall). Then divide your count by 2 to get stems/square foot. Calculate the average steam count for the field and use the graph below to estimate yield potential.

This method will give you an estimate yield potential and help you decide if the alfalfa stand is good enough to keep. If you have any questions, please contact your agronomist.

This summer was a busy summer for many farmers and agronomist in the Elrosa and Long Prairie areas. There were many different agronomic problems that arose all summer long. This report will finalize agronomic problems in my respective area such as weed identification, alfalfa weevils, pea aphids, and soybean aphids.

Common weeds that was seen this summer in my area was Lambsquarter, Redroot Pigweed, Wild Buckwheat, Canada Thistle, and various grasses. One noxious weed I seen this past summer was Marsh Elder. This weed can get out of control if not properly controlled. As of now, the only chemical that can control this weed is Clarity or Status. Keep this in mind when you are creating winter farm plans with your agronomist.

Alfalfa weevils were back again this year. When planning for alfalfa fields next year, keep in mind that around the beginning of June you should be watching for chewing in your alfalfa fields. In addition, when creating your farm plans this winter, remember to include Baythroid as an option on your chemical plans.

Pea aphids are only found in alfalfa fields. This summer there were many field monitored for these aphids. They "suck" the nutrients out of the plant, eventually killing the alfalfa plant. However, you need about two cups per 10 sweeps from a sweep net across an alfalfa field to do any damage or even spray for them. Again, consider this when developing your farm plan this winter with your agronomist.

Soybean aphids were back again this year. Even now, as the summer is coming to an end, farmers still need to watch their soybean fields for aphids. The threshold for aphids is 250 aphids per plant and with the warmer weather; this threshold can be reached in just a few days. Lorsban, Yuma, Warrior, and other chemicals can help for aphid kills. Contact your agronomist to get more information on these products.

As the summer is coming to an end, I will be returning for my final semester at the University of Wisconsin-River Falls. After graduating in December, I hope to return to the agronomy field and work with central Minnesota farmers, including potato farmers. I feel very lucky to have the experience from Prairie Lakes Coop for the last two summers. I have learned a lot not just from the agronomist, but from the farmers as well. I built relationships among those farmers that will never fade. Thank you for all your support and knowledge. 

August 17

Amy Robak, Eastern Report: This week I continued to scout for soybean aphids. As the week progressed, more fields were being sprayed for soybean aphids and spider mites. If you sprayed your soybean fields for aphids more then two weeks ago, you may want to scout the fields again for a second wave of aphid infestation. Contact your agronomist for information on chemicals to use to fight aphid infestations.

This week I also checked wheat fields for pre-harvest Roundup. Roundup is used to stop the production of the seed inside the wheat head. This allows the wheat that is behind to catch up a little and the wheat that is mature to stop production. After pre-harvest Roundup is applied, the wheat can usually be harvested after seven days. Check with your agronomist for more information about pre-harvest Roundup on wheat. 

August 17

Alicia Lund, Western Report: It's finally feeling like summer! This week we have been busy spraying soybean aphids, after the warm weather this weekend the aphid numbers have doubled.  The average numbers around the area this week are between 150-200 aphids per plant.  I have been finding aphids on all parts of the plant, but the highest numbers this week have been on and around the pods.  Continued feeding during reproductive stages reduces pod and seed set, and potentially seed size, if pressure continues. The biggest effect is on pod set. Yield reductions may be significant, exceeding 50% in severely infested fields. (University of Minnesota Extension)

August 7

Alicia Lund, Western Report: The aphid numbers are slowly increasing in the area.  Most of the fields I looked at this week had around 50-100 aphids per plant.  In some areas, there were around 150 aphids per plant. The aphids I found this week were more spread out on the plant compared to the weeks before. Prior to this week, I was finding the majority of the aphids on the new trifoliate leaves. This week I was finding them on the pods, along the stem and on both the new and old leaves. We did spray a few fields this week for aphids and weeds.  I also went out this week and swept a few alfalfa fields to see if there is any insect pressure.  In all the fields I swept, I found quite a few pea aphids (see picture).  Pea aphids commonly feed on new growth, and heavy infestations in the spring can damage the first cutting. If temperatures remain cool (50°F to 60°F) and humidity is low, aphid densities may explode. The suggested economic threshold for pea aphids is as follows (University of Illinois Extension Field Crop Scouting Manual): "If pea aphids average more than 100 per sweep, and beneficial insects are not plentiful, economic damage may result."  Pea aphids may turn leaves yellow and stunt overall plant growth when present in moderate numbers. (University of Illinois Extension)

August 3

Amy Robak, Eastern Report: The majority of this week I spend scouting for aphids and spider mites. I found many fields that were not at the threshold for aphids. However, many fields were showing signs of spider mites. The best way to scout for spider mites is to take a white piece of paper and place it under the canopy of the soybeans. Gently hit the soybeans so all the mites fall onto the white piece of paper. When you look at the piece of paper, if there are little specks moving around that is spider mites. When/if you decided to spray for aphids and spider mites, the chemical to use is Lorsban. Contact your local agronomist for more information.

July 31

Alicia Lund, Western Report: This week I spent the majority of my time scouting fields for aphids and spider mites, to determine how fast the populations were growing and if any of the fields needed to be sprayed. I did not find any fields that were at threshold.  I found 50 aphids per plant at most scattered across the field. Because of our dry weather conditions, I have been seeing high spider mite populations scattered across some fields. Once the spider mites begin to cause visual damage to the plant they should be sprayed.  I have saw a few fields with visual damage in some spots, but not consistent enough to be sprayed.

July 28

Amy Robak, Eastern Report: This week, after scouting some corn fields, I have noticed some nitrogen deficiency on corn. George Rehm from the University of Minnesota describes nitrogen deficiency as yellowing (chlorosis) along the leaf midribs, starting at the leaf tip and moving toward the stalk. Nitrogen deficiency will first be observed on the lowest leaves of the plant. The chlorotic areas will turn brown as the season progresses. Severe N deficiency will result in a poorly-developed crop canopy that will be unable to intercept all of the sunlight during grain fill. Nitrogen-deficient leaves also have a lower capacity for photosynthesis, further limiting the potential for grain fill. This normally is not a problem if a farmer is apply the correct amount of nitrogen each growing season for that crop. If you think you have a server nitrogen deficiency, please contact your agronomist.

The photo below is a example of what nitrogen deficiency will look like on the lower leaves of the corn plant.

July 27

Alicia Lund, Western Report: I have once again been out scouting for aphids this week and have still not been finding consistent populations throughout any field.  While I was out scouting, I did find Two-Spotted Spider Mites in a few fields.  Spider mites are minute insects (<0.002 inch) that cause damage to the plant by sucking out cell content causing the leaves to become yellow and eventually die.  Spider mite populations increase due to drought conditions.  If aphids and spider mites are found in the same field, a different type of insecticide will need to be used on that field.  The insecticide used to kill aphids does not work well on spider mites and may cause the spider mite population to increase.  The pictures show magnified Two-Spotted Spider Mites on a leaf and the damage of spider mites across a field. (University of Minnesota) 

July 20

Amy Robak, Eastern Report: This past week, I had the opportunity to go to Crookston, MN to the Agriculture Professional School sponsored by the University of Minnesota. There I learn about various agriculture topics including herbicide damage, soybean aphids, weed identification, and nutrient management. The best part of the training however, was learning how to identify herbicide damage to various crops.

In addition to the Agriculture Professional School, I was able to examine Elrosa's iron chlorosis soybean test plot. It was interesting to see that in different parts of the plot, on different soils, that the chlorosis can be better or worse. In addition, different varieties also made a difference. There is not enough data at this time to draw any conclusions. Data will be collected throughout the summer to make a conclusion which soybean varieties control iron chlorosis the best on that type of soils.

July 17

Alicia Lund, Western Report: This week I spent some time scouting soybeans for both weeds and aphids.  Because of the cooler weather we are having, not much is happening out in the fields.  The second flush of weeds has already been sprayed in most fields around the area. I have scouted many fields of soybeans in the last week and have not found any soybean aphids. It is still a little early in the season, but you want to continue to keep an eye out for them.

July 10

Alicia Lund, Western Report: This week I scouted soybean fields to determine the weed pressure and check for aphids.

The picture shows soybean aphids. (University of Minnesota)

A few of the fields I looked at are beginning to get enough weed pressure to be sprayed a second time within the next week. While looking for aphids, I found a few on some soybeans that are right next to a tree line. Aphids begin colonizing soybean fields at V1-2 (two or three nodes with open leaves). In early July, start scouting to become familiar with the aphid pressure in your fields. Aphids are small (1/16" or less), so a hand lens or other magnifier is needed. Check these locations:
•During vegetative growth, look for aphids under young upper leaves, petioles, and stem.
•During later vegetative stages also check new branches in the lower canopy.
•During reproductive stages, aphids move to undersides of mid-canopy leaves and to stems.
Look for other obvious insects that aphids attract: ants that tend aphids or ladybird beetles that eat them. Also check for signs of aphids, such as the white cast skins of molting aphids, honeydew (sap excreted by aphids), or sooty mold (a black mold that grows on honeydew). The development of aphid populations in each field will be unique. Scout two times per week because aphid populations double every 2 to 3 days during this time period. Continue scouting through pod set.

July 10

Amy Robak, Eastern Report: This week some new bugs started to move into this area; the well known soybean aphid! I just happen to come across a field with about 50 aphids per plant. This is nothing to be concerned about at this threshold, but you would need to keep a watch on the field. We found a couple other fields with aphids, but not close to threshold.

The threshold for aphids is 250 aphids per plant, according to the University of Minnesota. You can go on to their website to find more information about soybean aphids. We are very early in the season for aphids but you still need to keep an eye out of the little buggers. Lorsban, Yuma, Warrior, and other chemicals are used for aphid kill. Contact your agronomist to get further information.

Pictured to right: Aphids on the back of a soybean leaf. Aphids are usually on the new soybean leaf growth on the under-side of that leaf, along with the main and secondary steams of the soybean plant

July 2

Amy Robak, Eastern Report: This week I was focusing on scouting corn for re-spray. I would take a walk around the outer edge of the field and determine from there if the field needed to be re-sprayed. One should walk the outer edge of the field first because this is where the weed will come back and then make their way into the inner part of the field. So just take a "nature" walk around the edge of the field to see how the new weed pressure is.

This week I have also been starting to determine our "Growing Degree Days" (GDD) for the Elrosa and Long Prairie areas. GDD is defined as a measure of heat accumulation during a growing season. We can use this to determine when different events of insect and plant development are going to happen. There is an easy formula that one can use to help determine the GDD for that day.

GDD= Temperature high + Temperature Low
           _______________________________     - 50
                                           2


For example: On Monday July 6th, in Elrosa, we had a high temperature of 81 degrees and a low temperature of 59 degrees. We add this together, divide by 2, and subtract 50; we get 20 GDD. So, on Monday July 6th, we added 20 GDD to our corn plant from the time of planting. This is important once again because different hybrids require different GDD to mature. To find the exact total GDD of your corn variety, contact your agronomist.

July 2

Alicia Lund, Western Report: We all know the saying "knee high by the 4th of July;" most of the corn around the area has made it to that mark despite the poor spring growing conditions. This week I continued scouting for alfalfa weevil and I also scouted some corn and soybeans. One soybean field I looked at had been sprayed with Cadet to control the large population of Lambsquarter.  The picture below, shows the effect the Cadet had on the Lambsquarter.  I have also been seeing iron chlorosis in a few of the soybean fields around the area.  Iron chlorosis is caused by a deficiency of iron available to the plant due to high pH levels in the soil. The main cause of iron chlorosis is low soil temperature, wet soil and compaction

June 29

Amy Robak, Eastern Report: Soygreen is a new trend in soybean production. This product is specially formulated to reduce the stress of iron chlorosis in soybeans. The photo below is of a test plot location outside of Padua, MN that has rows of soygreen vs. non-soygreen soybeans. The one yellow row represents the non-soygreen soybeans.
This week I have been also taking soil samples for soybean cyst nematodes. SCN can go undetected for years because many time visible symptoms do not appear until yield losses reach 30% or more. Visible symptoms of SCN should not be confused with iron deficiency chlorosis (IDC) because IDC shows up early in the growing season, whereas SCN will show similar symptoms at the end of the growing season. To take a sample, please contact your local agronomist. Information source: Agvise Laboratory

June 26

Alicia Lund, Western Report: Most of my scouting for the week involved sweeping alfalfa fields looking for alfalfa weevils.  The weevil larvae cause the most damage to the new alfalfa growth, by chewing up the leaves.  The larvae have a black head and are green with a white stripe along the middle of the back.  At maturity they are about 3/8 inch long. If the field starts turning brown after cutting and there is not a lot of re-growth, there is a good chance that weevils are present in the field. The picture shows a field with weevils present.  We recommend spraying when there is obvious defoliation of the leaves to prevent further damage to the crop.  I also took some tissue samples in two corn fields to determine whether or not the plant needs more nutrients to grow to its potential. The results of the tissue sample will determine whether or not more fertilizer will need to be added to the field.    

June 22

Alicia Lund, Western Report: We finally got some rain and warm weather to get the crops growing. From June 15 to today, we have received about a half an inch of rain.  Most of the corn around the area is in the V4-V5 stage now and the soybeans are around V1-V2.  I have been seeing all the same broadleaves as the previous weeks.  Most of the seeds that I mentioned in my last scouting report have started to emerge, so now we are seeing some corn within the same field in the V1-V2 growth stage and some in the V4-V5 stage. With this weekends rainfall and the warm weather forecasted for this week, all the crops should shoot up this week!

June 22

Amy Robak, Eastern Report: This week I had a busy week with tissue sampling corn plants. This is a monitoring tool for production crops. It is used to asses the nutrient statues of plants in relation to the fertilizer program used. This tool will tell you if you have sufficient amounts of nitrogen, phosphorus, potassium, sulfur, calcium, magnesium, boron, copper, iron, manganese, and zinc. Sampling is collected at silk emergence. This is mostly done at this time because nutrient concentrations decline substantially after this point in a corn's life cycle. However, samples can be collect now, at this point in time, to monitor how much nutrients are in the plant. If a farmer is to sample now, I recommend taking three more samples up to silking to get a better understanding of the nutrient deficiencies. To take leaf sample now, you must collect the highest-fully developed leaf collar on the stalk. If sampling is to be done at silking, the leaf sample should be the one on the opposite side of the stalks and below the emerging silk. Remember, this must be done before the silks turn brown. Plant analysis, if used correctly, can be a management tool in today's modern agriculture.
Source: George Rehm, University of Minnesota Department of Soil, Water, and Climate

This week we also had some considerable hail damage. The leaf tissue was moderately damaged by the hail. However, after examining the growing point tissue, it was not damaged. In this situation, there will be no delay in tassel emergence, silking date, or kernel moisture content at harvest resulting from partial or complete leaf removal. The University of Minnesota supports this data. However, grain yields is reduced according to the amount of leaf area destroyed and the growth stage when the damage occurs. If you experienced hail damage this past weekend, wait 5 to 6 days to give the plant a chance to grow out of the damage. Contact your agronomist to evaluate the hail damage on your corn crop.  

June 15

Amy Robak - Eastern Report: This week I have been scouting for those alfalfa weevils again. Just keep an eye out on your newly cut alfalfa fields for no new re-growth. If there is none, contact your agronomist to come and take a look.
Lambsquarter is still a huge issue not only in Elrosa, but Long Prairie also. The key is to spray the Lambsquarter before it gets too tall. When the corn gets to the sixth leaf stage, the plant is determining how many rows of corn there will be on the cob, so it is important to keep the weed pressure down.
I started soybean scouting this week also. Some fields have been ready to spray, others have not. Just keep an eye out for those weeds like Lambsquarter, Redroot Pigweed, and foxtails. Remember to contact your agronomist for spraying recommendations.

June 12

Alicia Lund - Western Report: This week I have spent most of my time scouting corn and soybean fields. Now that we finally received a little rainfall (around 5/10 in. in Hoffman), everything has came to life a little more than what we were seeing the last couple of weeks. We have been spraying mostly corn and soybean fields and a few wheat fields. The main weeds being seen in the area include Lambsquarter and Red Root Pigweed. I also have been looking at a couple fields of wheat under seeded with alfalfa. One of the fields was mature enough (3 to 4 trifoliate) this week to burn down the wheat and broadleaves. Another common problem being seen out in the field is skips in the rows due to seeds not germinating.  When I dug down to find the seed, I have been seeing many of the seeds starting to germinate so hopefully most of them will still emerge.  Now hopefully we can get some more rain and warmer weather to keep everything growing!       

June 9

Amy Robak - Eastern Report: The alfalfa weevils are back! Prairie Lakes Coop is recommending that farmers keep an eye out on their newly cut alfalfa fields. If there is any sign of "chewing" on the new alfalfa growth, it is recommended that you spray ASAP. We are recommending that farmers spray Baythroid at 2.8 oz.
Corn scouting has begun once again this week. In photo to left, alfalfa weevil, courtesy of the University of Wisconsin Madison.

Just a reminder, keep an eye on lambsquater. If you feel that the field is getting out of control with weeds, contact your agronomist to take a look.

June 5

Alicia Lund - Western Report: This week I scouted both wheat and corn.  I also looked at a few fields that had already been sprayed to see how well the herbicide was working on the weeds.  I also looked at a couple fields that had pre-emergent burn down applied to them to see how well it worked.  In the photo to the left, Valor SX Roundup tank mix was used to burn down the weeds in a no-till field of soybeans. Because we haven't received any rainfall everything is at a standstill including the weeds. The main weeds I have been seeing are mostly broadleaves including Lambsquarter, Red Root Pigweed, Canada thistle, and Dandelions. The Lambsquarter I have been seeing has a brighter than normal purple color on the underside of the leaves and on the stem, which is a sign of drought stress. All we can do now is keep hoping for rain and warm weather to get the crops going again!

May 30

Amy Robak - Eastern Report: This week has been filled with scouting small grains and corn crops. In most of the small grain fields, I am seeing common weeds such as Lambsquarter, Redroot Pigweed, Wild Buckwheat, Canada Thistle, and grasses. Depending on the field conditions and farmers situation, spraying that small grain field can vary.

As the corn has been growing, so have the weeds. Some farmers are starting to spray for weeds in their corn crops. Just remember, check with your agronomist before you spray. They can help you determine what chemicals to use to kill those noxious weeds.

Seedling Lambsquarter Source: University of Iowa

One noxious weed to not let out of control this cropping season is Lambsquarter. This weed has been very prevalent due to the dry conditions. Do not let this weed get out of control! If out of control, this weed can be detrimental to crop yields. Increasing Glyphosate rates in RR corn, adding additional adjuvant, or tank mixing a residual type herbicide are all advised.

Another very common, noxious weed that I have seen this week is Marsh Elder. This weed can cause serious problems in any crop and needs to be monitored. As of now, the only chemical that controls this pest of a weed is the herbicide family Benzoic Acid or better known as, Clarity or Status. Pictured is a photo of a seedling Marsh Elder. The cotyledons are oval; leaves toothed, has a long petiole, opposite leaf arrangement, bristly hairy on petioles and leaf blades; plant is erect.

May 29

Alicia Lund - Western Report: Now that most of the crops are in the ground the summer crop scouting has began.  This week we looked at some wheat, oats, barley and cornfields. Some of the area received a small amount of rain (around 3/10 at Hoffman), which has helped both the crops and the weeds. The areas that did not receive rain are seeing less weed pressure.  The main weeds seen in the small grain fields include Lambsquarter, Red Root Pigweed, Mustard and Common Ragweed. There was also some Smartweed, Foxtail, Wild Buckwheat and Common Cocklebur, but it was less prevalent than the other weeds seen. Because of the high weed pressure in some fields, herbicides are starting to be applied. Today we went and looked at a field of newly seeded alfalfa planted with oats. Walking through the field, there were small patches of 5-6 alfalfa plants randomly spread out throughout the field, but for the most part the alfalfa was not growing. When we dug down into the soil the top 2 inches was dry.  Because the seed was planted into dry soil and the area has not received rainfall, the alfalfa seeds did not germinate. Hopefully we will get some rain soon to give everything an extra boost! 

May 26

Amy Robak - Eastern Report:  As a returning intern to Prairie Lakes Coop, my first week has been filled with adventure. Just finishing up with classes at the University of Wisconsin-River Falls, I was prepared for the days of alfalfa weevil scouting. Going from farm to farm, in Elrosa and Long Prairie, I was seeing alfalfa weevil adults and larva in the fields. However, not to be concerned, the weevils were not causing any damage to the alfalfa. Prairie Lakes Coop is suggesting to cut the first crop of alfalfa and then come back to look for those weevils again.

Coming from a dairy farm in Foley, Minnesota, I am very familiar with these weevils and know that they can cause extensive damage to alfalfa. Just keep an eye out for chewing on your alfalfa plants and let Prairie Lakes know if damage is occurring, small or large. This is it for this week. Come back next week for more information.  

May 20

Alicia Lund - Western Report: Next week I will begin the scouting reports for the season.  As the crop-scouting intern, I will be scouting fields for Prairie Lakes Coop in both Hoffman and Starbuck. Mike Staples, Josh Staples and Larry Anderson will also be giving their input into the weekly reports. I am currently attending the University of Minnesota-Twin Cities and plan to graduate this December with a degree in Animal Science and Applied Plant Science.  I grew up on a small dairy farm near Brandon, MN. My goal for the summer is to learn as much as I can about the agronomic side of the Ag Industry. I am excited for the summer and look forward to meeting all of the producers in the area.