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Issue 1 - May 2, 2007 Sign up for the SWROC Crop Production list serve IPM Stuff Classics Corn
Planting Depth - 3/5/99 SWROC Pages: Home Page Other Cropping Newsletters: Minnesota Crop eNews - Regional Newsletters Minnesota Fruit and Vegetable IPM News The Bulletin - Other States IPM Newsletters
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To keep up to date on all the crop weather details during the growing season see: http://swroc.cfans.umn.edu/Weather/weather.htm.
The past week continued windy with a few breaks for spraying and much of SW Minnesota received welcome precipitation over the weekend. A few spots received a bit more precipitation than they needed with some standing water. Mr. Jeff Irlbeck, intrepid plot technician, mentioned that the rainfall should have stopped after the first inch. He had been worried about a shortage of rainfall last week. As you may have already guessed, Mr. Irlbeck farms when he is not working at the SWROC.
We are now set with soil moisture as we enter the period of rapid vegetative growth for most crops.
If you have been pondering your options for fields with herbicide application delays; or wonder where has all the glyphosate gone; the following MN Crop eNews article by Gunsolus, et. al. should provide some answers: http://www.extension.umn.edu/cropenews/2007/07MNCN25.htm.
Windy conditions must have been
spotty based on the wheel tracks and dying weeds in a large percentage
of fields here. This spring's spraying under adverse conditions is expected
to lead to an above average number of reports of perceived herbicide tolerant
weeds. Nightlife
at Lamberton and Fulda European corn borer (ECB) has been represented by a single specimen from the Lamberton black light trap on June 5th. Degree-day models and blooming peonies indicate that the flight should be well underway by now. Cool, windy nights are probably reducing moth captures. Nevertheless, as a result or low black light trap activity, I am not expecting big things from multi-voltine ECB in SW Minnesota this spring. We'll continue monitoring the situation through light traps and perhaps uni-voltine ECB will make a better showing in July. Other areas may have higher populations. Check Bill Hutchison's VegEdge website at http://www.vegedge.umn.edu/moth.htm for results of other light and pheromone traps.
Forage loopers are the large brown moths you are seeing in grassy areas and alfalfa. A few armyworms and the small, erratic flying webworms are also present. The latter species are relatives of the recently rare corn borer. Identifying Lepidoptera by their flight patterns can be an enjoyable low impact sport.
More colorful specimens are starting to show up and the black light traps usually hold at least one pleasant surprise this time of year. A few species of tiger moths, Arctiidae, are now flying. This is family, is represented by a number of species in SW MN. They are for strictly for our enjoyment as no members of the family are pests of area crops. The banded wooly bear caterpillar, famous for predicting winter severities, is a member of this family.
The white specimen is a "Virginian" tiger moth. Its fuzzy yellow orange larva is known as the Yellow woolly bear. Although several species are similar, the specimen with the yellow hind wings is probably a "Little Virgin."
Alfalfa - Potato leafhoppers are out there. Watch for economic populations in second cutting.
Small grains - There are some great looking small grain fields this spring. Spring wheat and oats are jointing. Tim Moline reports one spring wheat field with flag leaves emerging. Small grains are no longer disease free. Leaf rust is increasing in winter wheat at the SWROC and present in spring wheat as well. One susceptible winter wheat variety has lost its lower canopy to this disease with pustules beginning on the flag. Predictive models for scab, leaf rust and other wheat diseases are available at: http://mawg.cropdisease.com/. The current forecast for wheat leaf rust does not look very optimistic.
Char Hollingsworth provided the following efficacy data for foliar fungicides. Remember, that although it performs well on wheat leaf rust, Folicur is only labeled as a heading application for Fusarium Head Blight (Scab) on Minnesota wheat. Spring wheat resistance to leaf rust will, in part, determine the risk of delaying application.
Fortunately, Southwestern Minnesota does not have large acreages of wheat to provide disease inoculum to other areas.
Corn - There is some very good potential out there. Early planted 30 inch row corn is closing the rows. Early planted narrow rows are canopied. Knee high corn by the 4th of June - what an interesting change from the typical early season struggles.
A crop is usually killed; the first of several times; at emergence. However, this year, corn stands are so typically good, that a missing or malformed plant here and there is causing an unusual amount of concern. Remember that 98% germ means that 2 seeds out of 100 aren't going to make it. Given a reasonable seeding rate, there is no way that an occasional plant missing will reduce yield.
Please contact me if you
are planning fungicide application for corn this summer and would like
to participate in a project.
Soybeans - Populations at Lamberton are well below last spring. Steve Sodeman and Alain Bellicot have also reported very low levels of Bean Leaf Beetle.
Soybean aphid - Dave
Ragsdale has reported this insect on soybeans at Rosemount and Jerome
Lensing has observed low levels of soybean aphid near Kellogg and they
have been found in Wisconsin as well. Mark Bernard, temporarily confused
by volunteer soybeans surviving a glyphosate application, found soybean
aphids in a Blue Earth County corn field. Soybean aphids have been found
in intensive scouting of soybeans at Lamberton. I have not had time to
check the usually early season hotspots. Then again, from a management
standpoint, it is much too early in the season to worry about soybean
aphids. Aphid researchers, on the other hand, are another story. Crop production events in SW MN Thursday, July 12 - SWROC Summer field Day Thursday, September 6 - This one's not in SW MN but should be good. Regional Soybean cyst nematode resistance management summit Best Western North Mankato, MN
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Barley
yellow dwarf virus (BYDV) symptoms are quite severe at Lamberton this
spring, perhaps as bad as I have ever observed. Symptoms of BYDV range
from none visible to a distinctive yellow to red flagging to severe stunting
as seen in the lower left of the photo. There is no cure for infected
plants. This disease is vectored by aphids. The severity of this disease
at Lamberton may be due to the large amount of winter wheat and rye here.
These crops would have provided an early season host for viruliferous
aphids migrating into the area this spring. I will be checking other spring
wheat in SW MN for BYDV as I come across them. There is a possibility
that these symptoms may be caused by another disease. Samples are in route
to Char Hollingsworth at Crookston for virus confirmation. Fortunately,
Southwestern Minnesota does not have large acreages of wheat to provide
disease inoculum to other areas.