May 24, 2007
In this issue
§ Insect update
§ Volunteer potato control in corn
§ The story on soybean rust so far this year
§ MSU documentary – Dying to be heard
§ Regional reports
§ Weather
Christina DiFonzo
Entomology
It has been fairly quiet on the insect front this week. No new information on soybean aphid – I expect to find aphids on emerging soybean in the first week of June. Alfalfa weevil continues to be a problem in some fields. Cutting is the preferred method for dealing with weevil, although regrowth must be checked.
Black cutworm damage has been reported to the south of us in
Christy Sprague
Crop & Soil Sciences
Volunteer potatoes may be a problem this year in corn fields where potatoes were grown in 2006. Not only is it important to control volunteer potatoes to preserve corn yield, but controlling volunteer potatoes is critical for the management of potato pests, such as late blight disease that can be a problem if potato is next year’s rotational crop.
Currently, there are no herbicides available that will
completely control volunteer potato. However, there are a few different options
that will provide good suppression of volunteer potato and significantly reduce
the number of daughter tubers per plant.
Starane (1.33 pt) + atrazine (0.5 lb ai) was another treatment that also provided good suppression of volunteer potatoes in the MSU trial (Figure 1). However, in this trial Starane was applied at 1.33 pt/A, and is currently labeled at 0.67 pt/A for suppression of volunteer potatoes in corn with a maximum application rate of 1.33 pt/A per growing season. Starane is a herbicide that has been used in small grains for a number of years and has just recently been registered for use in field corn. Starane has a similar mode of action as Distinct, Clarity, Stinger and 2,4-D. Therefore, it is important to remember to be cautious when using this herbicide around sensitive broadleaf crops, such as, soybeans, sugar beets, grapes, and dry beans, etc. Starane is labeled for preplant and postemergence applications up to V5 (5 fully exposed leaf collars) corn at 0.67 pt/A for suppression of volunteer potatoes.
Of the treatments that provided good suppression of volunteer potatoes, Callisto and Callisto + atrazine are the only treatments that can be applied to seed corn. Corn inbreds vary in their sensitivity to herbicides including Callisto, so it is important to consult the seed company on their inbred tolerances to Callisto.
Diane Brown-Rytlewski
Plant Pathology
Although scouting for soybean rust hasn’t started in
This find is of interest because the Gulf Coast (Louisiana,
Texas) is the southern end of the Puccinia pathway that carry cereal rusts to
the north and the Midwest, including Michigan at the northern end of the
pathway. Although the weather has been very dry in much of the south, soybean
rust is still active in six counties in
Christina DiFonzo
Entomology
For those of you in central
Populations of birds, particularly robins, declined dramatically. Dead and dying birds were frequently observed and collected across the campus, and bird reproduction stopped. Dying birds exhibited a classic symptom of DDT poisoning, “DDT-jitters.” Wallace’s work helped explain the link between DDT applications and bird deaths. DDT sprayed on the trees did not break down or wash off. Instead, DDT-covered leaves fell to the ground in the fall and were fed on by earthworms, which in turn bio-accumulated the insecticide in fatty tissue. The following spring, robins fed on the DDT laden earthworms, with as few as 11 worms providing a lethal dose.
Wallace’s observations (and the story of DDT use at MSU)
were highlighted in Rachel Carson’s book Silent Spring in 1962. However,
Wallace’s observations also threatened his career. Many agriculture
professionals, in and outside the university, pushed hard for him to be fired. Eventually
his findings were confirmed. Regulations on pesticide registration and use went
through a major revision in the early 1970s. Ultimately, the spray programs
proved useless anyway, as there are few elms left in
If you don’t get WKAR, this documentary will be picked up
and repeated at a later date by other public TV stations in the
Ned Birkey
The weather has been dry and warm, even reaching record high temperatures on Wednesday, May 23, and again forecasted for today. The weather has been suitable for drying soils and planting to progress. Strong, westerly and northerly winds have prevented some pesticide spraying however.
Alfalfa is starting to be cut. Alfalfa weevils are over threshold. Grasses are fully mature though alfalfa is not blooming yet. I am surprised to not have seen any potato leafhoppers.
Corn planting is nearly finished, with advanced fields at the V4 stage. I have not seen or heard of any cutworm or armyworm feeding. Most fields are clean of weeds.
Soybean planting is progressing, with bean leaf beetles out and feeding.
Wheat is at the Feekes’ 10, 10.1 and even 10.5-growth stage. We are not in flowering yet, though may be by the end of this holiday weekend. Septoria leaf blotch and powdery mildew are present, though at very low levels and not on the flag or flag minus-one-leaf.
It seems that the normal weather for May is extremely variable. The spring planting season weather has been varied with some fields still too wet to plant, while others are dry with cracks in the soil.
Bruce MacKellar
Sunny skies and warm temperatures have been the story here for the last several days. The region escaped significant damage from frost in the wake of a strong cold front, which triggered the severe thunderstorms of May 15. High winds from some of these storms did an incredible amount of damage in localized areas. The storm also produced one of the highest damage totals to center pivot irrigation systems from a single event of anywhere in the country. Somewhere between 50 to 70 systems were damaged, at least to some degree, with a significant number being “totaled.” Rainfall totals from the severe storms ranged from localized 2 inches plus to around 0.5 inch. Favorable conditions over the weekend allowed planting to continue in the area, particularly seed corn (View photos).
Commercial corn
planting is all but wrapped up now in the Southwest portion of
We continue to see some evidence of black cutworms in isolated fields. Corn flea beetle feeding is also on the rise. Watch for signs of silvery feeding on the corn leaves. Relatively limited areas of the region had significant hail damage from the May 15 storms.
It seems that all of the stops have been pulled out of seed corn planting this last week, and almost every field that was not planted previously has a tractor in it completing some task last weekend and this week. Early planted fields have emerged, and are growing very well. Irrigation has been going on many fields to help ensure enough water for even germination. Be sure to monitor the later planted fields that had cover crops for black cutworm or potentially armyworm injury, as well as flea beetle activity.
Soybean planting continues at a very rapid pace. Most of the earlier planted beans are at the unifoliate leaf stage. Insect damage in the fields remains light. Monitor fields for the beginning activity of bean leaf beetle feeding. It remains to be seen what the effect of the pounding rainfall and hail from the May 15 storm will have on the condition of the emerging soybean crop.
Alfalfa harvest is in full swing in the southern portion of the region. The first cutting has had its challenges, and yields are not stellar, but at least somewhat of a harvest window has presented itself. Watch for the effects of “residual” alfalfa weevil larvae feeding on the re-growth. Also with the strong push of southerly winds over the last couple of days, we should also begin to monitor the area for the arrival of potato leafhoppers.
Wheat continues
to grow rapidly. The heads are fully emerged in advanced fields and are getting
ready to flower. With a weather change in the forecast, producers should begin
to monitor wheat for the development of leaf diseases. I also continue to worry
about the potential for armyworm infestation in wheat. It is time to watch the
upper two leaves of the plant carefully to protect them from insects or
disease, to ensure the ability of the plants to produce energy for crop yields.
Fred Springborn
Seven days of relatively dry weather has led to good progress in planting and crop development. Many areas could benefit from a light rain. High temperatures in the last week have ranged from the mid 60’s to the mid 80’s. Light spotty frost was observed late last week, but resulted in minimal damage. Minimum soil temperatures are well into the 50’s and lower 60’s.
Wheat is in Feekes growth stage 9 in most fields and in boot in others. Few disease problems have been reported or observed at this time, powdery mildew is present at low levels. Oat stands are good with weed control application going on or needed in most fields.
Corn planting is
wrapping up with 95 percent of the crop planted in Montcalm, and 80-85 percent
planted as you go north into
Volunteer potatoes are popping up in many fields that were potatoes last year. It is important to remember that volunteer potatoes are not just a weed, but also a potential harbor for diseases that can effect this years potato crop in neighboring fields. (See article in this issue.)
Soybean planting is progressing with 50 percent or more of the crop in the ground, and several fields emerged with growth up to V1.
Sugarbeet stands are good to excellent, with most fields having 2 to 3 true leaves emerged. Weed control may be an issue, if timely application of herbicides was not achieved. This appears to be the case in several fields.
Cutting in alfalfa
fields has begun in earnest in some locations, some baled as well as chopped. Alfalfa
weevil damage ranges from below threshold to well over threshold. Most new
spring seedings are emerged and looking good, a gentle rain would be beneficial
to all our crops. GDD41 is over 700 in several locations: Freemont 718, Entrican
684, Hart 653, Ionia 708 and
Paul Gross
The past week has been dry allowing planting to progress at a rapid pace. This spring has been a little challenging with cool wet soils and variable planting conditions. It may be best described by saying, the farmers who were patient and selective waiting for fields to dry out are the ones that are having good emergence and good stands. There have been several reports and observations of poor emergence, crusting and side wall compaction due to planting in wetter conditions. By Memorial Day, most planting of corn and soybeans will be complete across the region. A nice warm rain would be welcomed.
The corn crop will be planted by the weekend, except for that occasional field. The early planted fields have emerged and are enjoying the warm weather. Some fields may need some rain for good emergence. Pre and postemergence weed control should go on as soon as possible, so weeds are not competing with the crop. If you plan on nitrate testing, the rule of thumb is to take the tests as close to side dressing as possible for the best results.
Soybean planting is winding down. Early planted fields have emerged. Apply weed control where needed to prevent competition with the emerging crop.
Wheat is at or near the boot stage across the region. For the most part, the crop is in very good condition. We are seeing some powdery mildew and some septoria. Scout fields for foliar diseases.
Oats are planted and emerged. Stands are very good. Herbicide applications are being made. There are reports of cereal leaf beetle in the southern part of the region. Scout fields for this pest.
Alfalfa harvest is just getting under way. The PEAQ readings have been 35-37 NDF. It appears that you can enjoy a family cookout on Memorial Day and begin cutting on Tuesday. We are seeing some alfalfa weevil feeding, but timely cutting will be the best option to manage this pest.
Sugar beets are doing nicely, with herbicide applications being made.
Mark Seamon
High temperatures and a break from rain have allowed good soil drying and a lot of planting progress.
Sugar beets are showing good growth and development with warmer temperatures. Most of the beets are at the 4 leaf stage. Where Quadris applications are planned, growers should watch for good conditions and time between microrate applications. Target beet size is 4-6 leaf stage for Rhizoctonia control.
The wheat crop looks fair to good in most areas. We expected to see improvement of marginal fields with good weather, but this crop has not received the conditions to improve significantly. Fields that looked fair coming out of the winter are still fair. Average growth stage is around the Feekes 9 with a range of 8 to 10. Some powdery mildew can be found.
Corn planting has made progress in the past week, which gets this area to about 95 percent planted (the exception to this being the Southern Thumb, which is about 75 percent planted). Emergence looks good in most fields. This crop will need good growing conditions throughout the year, since soil conditions were less than ideal at planting in many cases.
Soybean planting has gained a lot of progress this week with about 60 percent of the crop planted. A few fields have emerged and are in the cotyledon stage.
Jeff
Andresen
Agricultural Meteorology
Geography
Unseasonably warm air moving northward around a large area of high pressure just off the eastern coast of the United States, will lead to another day of summer-like weather across Michigan and much of the central United States. Look for high temperatures to remain from the upper 70's far north to the mid and upper 80's Thursday, May 24, with some southern areas of the state approaching 90EF. A cold front is forecast to move west to east across the state beginning Thursday evening, which will lead to the next chance for rainfall. Given that the front will be passing through most of the state during the late evening or early morning hours, rainfall area coverage is expected to remain on the scattered side, with some areas remaining dry. Best chances for rainfall late Thursday will be across far northern sections of the state. Cooler and dry weather is expected Friday statewide.
Looking ahead to the holiday weekend, another frontal system approaching from the west will lead to a cooler and unsettled weather pattern. Showers and thunderstorms will be likely, especially overnight Saturday and Sunday. Temperatures will fall back to below normal levels, with highs by Friday dropping back to a range from the 60's north to low 70's south and lows generally in the 40's to low 50's.
Further ahead, medium range forecast guidance suggests
mostly west to east zonal upper air flow across the