Next issue September 7

Recommendations for removing established legume stands without tillage
David Hillger and Jim Kells
Crop & Soil Sciences

Growers have the option of using tillage and/or herbicides to remove a forage stand. If they choose to use herbicides, the ideal time to kill an established legume stands is in the fall. When removing a clover cover crop or an old alfalfa sod, the most effective and consistent approach to killing these forages is similar. The field should be mowed in late August or very early September in central and Lower Michigan or mid-August in northern Michigan. Following cutting, allow the plants to re-grow for four weeks before the herbicide application. At the time of application, the plant canopy should be at least six inches in height.

MSU trials have shown that a properly-timed fall application of glyphosate should be adequate at killing the weed and legume species commonly found in an old alfalfa or clover sod. Glyphosate at the minimum rate of 0.75 lb a.e./A is recommended for effective results (see Table 1 for glyphosate products and use rates). Always add ammonium sulfate (AMS) to the spray solution at 17 lb/100 gal. Farmers may choose to add a growth regulator herbicide, like 2,4-D ester or dicamba, to the glyphosate for insurance of adequate control of broadleaf perennial weeds. This practice is fairly inexpensive and may be beneficial under certain conditions such as applications made under less than ideal conditions. However, if a growth regulator is added to the tank mix, do not reduce the glyphosate rate as this could result in lost glyphosate efficacy due to herbicide antagonism.

For the past few years, MSU has studied chemical methods for the removal of glyphosate resistant alfalfa. Although glyphosate resistant alfalfa has been available for only a couple years, it is important that growers know how to remove it when it becomes necessary. Our results have shown that applications of 2,4-D (at 32 fl.oz./A), dicamba (at 32 fl.oz./A) or 2,4-D + dicamba (at 16 fl.oz./A + 16 fl.oz./A) in early fall or in the spring were more effective at removing old alfalfa stands than fall tillage alone. It is also critical that the plant canopy be at least six inches tall and actively growing at the time of application.

All removal applications should be targeted when the daytime high air temperatures are at least 60°F, when there is adequate soil moisture and preferably during sunny weather. Application should be made when the leaves are dry, the wind is calm and there is no risk of rainfall for several hours. The plants should be green, actively growing and not showing symptoms of frost injury.

Once removed, the logical rotation crop to following either an old alfalfa or clover sod is corn, since corn would benefit from nitrogen, produced by the legume. The amount of nitrogen available will depend upon the density of the legume stand at the time of removal. Consult extension bulletin E2904-Table 5 for more details about the nitrogen credits calculated from legume crop rotations (http://web2.msue.msu.edu/bulletins/Bulletin/PDF/E2904.pdf ).

Table 1. Equivalent product rates for different glyphosate formulations at the recommended minimum application rate (0.75 lb a.e./A) for removing an established legume stand in the fall.

Herbicide resistance in weeds is a growing concern for growers, due largely to the recent occurrence and spread of glyphosate-resistant horseweed and occasional failures to control other annual weeds in Roundup Ready crops. Currently, there are more than 180 weed species resistant to one or more herbicides in the world (Heap 2006) and at least 15 weed biotypes resistant to one or more herbicides in Michigan. These weeds have developed resistance to very effective herbicides in field, vegetable and fruit crops, as well as tree plantations and nurseries. (view photos)

Confirming herbicide-resistant weed populations is the first step of any resistance management program. Verification will provide Michigan producers with the knowledge to implement the best possible management strategies, with the ultimate goal of preventing or limiting the spread of herbicide-resistant weeds.

If you suspect resistance in any weed species and would like to confirm this, seedheads can be collected upon maturity and submitted to MSU Diagnostic Services for a resistance screen. The next several weeks prior to harvest are perfect for collecting mature, high quality weed seed. Select plants that were definitely sprayed (not along field edges or sprayer skips). Harvest seedheads by cutting the stem just below the seedhead. Place seedheads into a brown paper bag or collect seed in a small envelope or container. Do not seal plants or seed in plastic!

Fees associated with herbicide-resistant weed testing are generally $50 per sample per herbicide site of action (ie: ACCase inhibitors, ALS inhibitors, Photosynthesis inhibitors). Each additional site of action is $30 per sample. Two exceptions to these fees are horseweed (a.k.a. marestail, Conyza canadensis) and common lambsquarters (Chenopodium album) collected from Michigan soybean fields. These two weeds will be screened for glyphosate, ALS and triazine resistance at no cost to the Michigan soybean producer. All sample costs are covered by check-off dollars through the Michigan Soybean Promotion Committee.

Please contact Steven Gower (517-432-9693, sgower@msu.edu ) with any questions regarding sample collection. Send samples to:
MSU Diagnostic Services
101 Center for Integrated Plant Systems
East Lansing, MI 48824-1311
Attn: Steven Gower

Many farmers in Michigan hire some farm work to be done or else perform custom work for others. What is a fair amount to charge or to pay for such work? Michigan State University has Extension Bulletin E-2131 (Revised October 2002) available free of charge, which outlines labor, tractor and machine rental rates based upon a survey from around the state of Michigan.

Because there is no standardized market structure for custom machine services, determining a fair price can be difficult. Some fields may be very small, rocky or very weedy, or non-farm road traffic and transport of the equipment to the field can be difficult. These and many other factors can influence the cost of custom machine work locally, either higher or lower than the average numbers listed below.

Some custom machine rate numbers for the following items might be helpful for farmers to use as a guide as they settle up accounts for tillage or other work. The following numbers are average rates from bulletin E-2132, which means half of the survey numbers are lower and half are higher. All rates are per acre unless otherwise noted.

Dennis Stein, District Farm Management Educator for the Thumb area of Michigan, does a survey of farmers for the Saginaw Valley of Michigan. Farmers interested in his 2005-06 Machine Work Rates should contact any county Extension office in that part of the state. His numbers also include dry beans, forages and silos, manure work and sugar beets.

Doane’s, as well as Ohio State, Purdue and the University of Illinois, do surveys in their states, which provides other sets of numbers for farmers to consider.

Remember that the MSU survey of custom rates was done in 2002, which means that fuel and other costs have gone up considerably since that time.

Soybean producers can learn strategies for dealing with the soybean cyst nematode (SCN) and view SCN-resistant soybean varieties during the 2006 Soybean Cyst Nematode Field Day, set for four locations across the state.

The event will be held August 29 from 5:00 to 8:00 PM in Lenox; August 30 from 10:00 AM to noon in Saginaw; August 31 from 4:00 to 7:00 PM in Edwardsburg; and September 5 from 5:00 to 8:00 PM in Dundee.

Guest speaker George Bird, nematologist and Michigan State University (MSU) professor of entomology, will discuss selection of nematode-resistant varieties and soil quality improvement for SCN management.

MSU Extension, the Michigan Soybean Promotion Committee and the soybean industry recognize SCN as a devastating pest that severely limits soybean yield in the state. The variety trials that will be discussed during the meeting are a combined effort by MSU Extension researchers, the Michigan Soybean Promotion Committee and agricultural businesses.

All soybean farmers are invited to attend. There is no charge to attend the event, and a complimentary meal is provided at all locations. Preregistration is required for the Lenox and Edwardsburg sites and requested for the Saginaw site to assist in meal planning.

For more information about the Lenox session, call Lapeer County MSU Extension at 810-667-0341; for Saginaw, call the Saginaw County MSU Extension office at 989-758-2500; for Edwardsburg, call the Cass County MSU Extension office at 269-445-4438; and for Dundee, call the Monroe County MSU Extension at 734-240-3170.

Research and the Soybean Cyst Nematode Field Day are supported by the Michigan Soybean Promotion Committee and are parts of the Soybean 2010 project.

Regional reports
1 -- Southeast
Ned Birkey

Weather
For the past two weeks, we have generally had above normal temperatures and virtually no rain. Some isolated showers of up to one inch have occurred, though no general rains, although most farms will get some rain today. Our area has been dry for the entire month of August.

Commodity reports
Alfalfa third cutting is under way with very good quality. Potato leafhoppers are above threshold.

Corn can use some rain for added test weight as most corn is dented. Some fields have lower leaves firing, though other fields have nice, green plants, top to bottom. I am planning to fly around Monroe County to see what the corn really looks like. I suspect that the early season “ugly” fields remain so, though “masked” by the outside rows, which look good. One farmer had an ear with 24 rows and 37 kernels, which means we could some very high yielding corn. Second generation European corn borer trap count numbers are diminishing. This has been a good year for giant ragweed, which is taller than some corn. Corn harvest will be early this fall, probably starting ahead of the harvest of some soybean fields.

Soybeans are really showing some stress, with sudden death syndrome, soybean cyst nematodes, spider mites, Japanese beetles, bean leaf beetles, manganese deficiency, Sclerotinia white mold, but no western bean cutworm! I was in one soybean field with true white grubs – only the third time that I have seen this problem in soybeans. Yields are suffering and will continue to do so without an inch or two of rainfall yet this month. Rains in July have brought on late season weeds, which are a real problem in some fields, while others are clean as a whistle. Bayer will be having a fall farmer meeting on September 12 to promote some new herbicides and fungicides. Based upon the weeds present now, farmers will do even more fall weed control than in the past. The Monroe and Lenawee aphid and soybean rust sentinel plots have been very clean, with only a few aphids present.

Wheat stubble has been mowed or sprayed for weed control. Field tile and lime are also being applied into wheat ground. Deep chiseling and ripping has been very beneficial but has made the tractors smoke.

Miscellaneous
Our soybean sulfur and soybean cyst nematode soybean plot field day will be Tuesday, September 5, from 5:00 to 8:00 PM at Arting Farms, Milwaukee Road, Dundee. Our conventional soybean plot field day will be Wednesday, September 13, from 5:00 to 7:30 PM at the Herb Smith farm, Morocco Road, Temperance. ADM Grain Company has about 500,000 bushels of wheat moved to on-ground storage to make room for the corn and soybean harvest. Tiger playoff tickets will go on sale September 19, which last happened in 1987!

3 -- West Central
Fred Springborn

4 -- Central
Paul Gross

Weather
The region received varied amounts of much needed rain Wednesday evening (August 23). Some areas went from extremely wet during wheat harvest in early August to very dry. The rains will bring relief to a soybean crop that is trying to fill pods. The region could use an additional 1 to 2 inches. Field activities include weed control and tillage in wheat stubble and getting wheat ground ready for fall planting.

Commodity reports
The corn crop is looking very good. Many growers think they may have yields similar to 2005 in fields with good stands. The recent rains will be helpful in finishing off the crop. Our GDD are somewhat ahead of last year’s pace. Silage harvest will begin as the crop matures. It is important to get whole plant moistures to determine when to harvest silage. Visual estimates are seldom accurate.

The soybean crop will really benefit from the recent rains. Many fields have good yield potential where stands are good. We are seeing several different root and stem diseases.

Harvest of third and fourth cutting alfalfa is underway. Most are reporting very good yields and quality. Potato leafhoppers are still present in fields over threshold. Summers seedings have been planted and will benefit from yesterday’s rain.

Dry beans are a few weeks away from harvest. The crop has had a hard time all season. The wet spring and summer has brought numerous bacterial diseases. We expect yields to be below average.

5 -- Thumb
Mark Seamon