April 17, 2008
In this issue
§ Insects to watch 2008 - Part II - Asiatic garden beetle
§ The clock is ticking for herbicide applications in winter wheat
§ Why biofuels are better for the environment
§ Spring checklist for improving soybeans yields
§ 2008
§ Soybean seed quality and planting strategies for 2008
§ Partial budget for using fungicides to control head scab in wheat
§ Regional reports
§ Weather
Next issue May 1
Chris DiFonzo, Entomology and Bruce Mackellar, MSUE educator
The last issue of the Field
CAT Alert discussed winter cutworm, a cold-hardy caterpillar that
overwintered in large numbers in northern
Adults are 1/3-inch long (smaller than a June beetle), chestnut brown and barrel-shaped. The last few segments of the abdomen are exposed beyond wings and the underside of each abdominal segment has a row of yellow hairs.
Larvae are typically C-shaped grubs, up to ¾-inch in their last of three stages. As usual, grub types are identified by looking at the butt end. The anal slit is Y-shaped, and there is a broad U-shaped pattern of stout hairs under the anal slit. The insect appears to have a smile on its back-end. On the head, the grub has an enlarged structure on its maxilla, or second set of jaws. This appears as a white, bulbous “cheek” that is obvious to the naked eye or using a hand lens on either side of the head.
Asiatic garden beetle, as the name implies, is native to
AGB has a single generation per year. Eggs are laid in
clusters from July into early fall. Grubs are present from July through the
winter into the following May. Reduced stand in field crops occurs as grubs
feed in early spring. Prior to its discovery in
Grubs move down in the soil profile and overwinter, then
begin to pupate in May, with the first adults emerging in June. In
Currently, the distribution of AGB and its potential to
damage field crops is being determined in
§ AGB grubs are more common in fields with sandier soil.
§ Early-planted fields will be exposed to grub feeding longer.
§ There are no economic thresholds for AGB in corn, but the threshold for another grub, European chafer, in corn is estimated at four per square foot.
§ Seed treatments may suppress AGB, but are not 100 percent effective. In 2007, some fields with damage and poor stand were seed-treated.
§
Adult feeding damage is not expected to be
economic on field crops.
Asiatic garden beetle is yet another species to add to our list of damaging early-season grubs. Several factors likely contribute to the recent increase in overall grub problems:
§ The use of reduced and no tillage, so grubs are not injured or brought to the surface during plowing.
§ Mild winters that increase grub survival into spring.
§ Fall and spring annual weeds growth which may provide a “green bridge” (a food source) for grubs when the crop isn’t present.
§ Earlier planting dates that expose emerging seedlings to grub feeding.
§ New grub species – including European chafer and AGB - moving into the region.
§
Asiatic Garden Beetle in Michigan Field Crops:
http://www.ipm.msu.edu/cat08field/pdf/4-17agb.pdf
§
http://www.ext.vt.edu/pubs/entomology/444-108/444-108.html
CAPTION: Asiatic garden beetle pupae (left) and adults (right). Note the deep reddish-brown color and barrel-shaped body.
Christy Sprague, Crop & Soil Sciences
Of all the crops grown in
There are several different herbicides that growers can use for weed control in winter wheat. However, not all of these herbicides have the same weed control spectrum or application timing. As growers look for weed control options, they need to keep in mind that herbicide choices need to be based on what weeds are in the field and more importantly the stage of wheat growth. Late herbicide applications can lead to excessive herbicide injury that can cause kernel abortion and blank wheat heads, ultimately reducing yield. Plant growth regulator herbicides including 2,4-D amine and ester, dicamba (Banvel or Clarity), MCPA and Curtail (2,4-D amine + Stinger) all need to be applied prior to winter wheat jointing (Feeke’s stage 6). These herbicides are typically good on summer annual weeds like common lambsquarters, pigweed and common ragweed, but vary in their control of some of the more common winter annual weeds like common chickweed. 2,4-D, MCPA and Curtail will not control chickweed. With the warmer weather conditions, it is important to scout fields and make sure wheat has not exceeded the maximum growth stages in which these herbicides may be applied.
Herbicides including Affinity BroadSpec, Harmony Extra, Harmony and Express do not have the same restrictions as many of the plant growth regulator herbicides. These herbicides can be applied when the wheat is at the 2-leaf stage (Feeke’s stage 1.2) to just before the flag-leaf is visible (Feeke’s stage 7.9). All of these herbicides also have better control of common chickweed than many of the growth regulator herbicides. Peak, another herbicide, is also an option for common chickweed control, however longer rotation restrictions (22-months) on many crops including soybean often restrict the use of this herbicide.
Buctril, Stinger, Starane and Widematch (Stinger + Starane) are other herbicides that will control broadleaf weeds in winter wheat. These herbicides have the longest application window. They can all be applied to winter wheat up to the boot stage (Feeke’s stage 9). However, many of these herbicides have fairly narrow spectrums of weed control. Buctril provides better control of summer annual weeds and is not very effective against winter annuals. Starane has a very narrow weed control spectrum, but is excellent in controlling hemp dogbane. Stinger, on the other hand, provides excellent Canada thistle control.
More information for control of winter and summer annual weeds including hard-to-control grasses, like annual bluegrass, cheat and windgrass can be found in Chapter 3 of the MSU 2008 Weed Control Guide for Field Crops (E-434) http://www.msuweeds.com/files/2008SMALLGRAIN.pdf.
Kurt D. Thelen, Crop & Soil Sciences
Recent popular press articles have blamed
What are the direct net global warming effects of producing
ethanol? Based on research conducted at
The data clearly show that the biofuel systems improve GWP relative to using gasoline. How can this be? The mechanism involved is based on photosynthesis. Carbon that is released to the atmosphere from combusting biofuels is carbon that was photosynthetically produced in the first place. In other words, the corn and switchgrass that produced the ethanol acquired the carbon from the air to make the starch and cellulose that produced the ethanol. Of course, some new carbon (from petrochemical sources) was used in the manufacturing and transporting of the fertilizers, herbicides and other inputs to grow the corn and switchgrass, and petrochemicals were also used in field operations to plant and harvest the crops and to process them into ethanol. All these inputs need to be included in the evaluation of net GWP and this explains why annual crop systems that do not return sufficient crop residue to the soil can have a slightly positive GWP. However, if the farmer uses good management practices, he can overcome the input carbon debt, and then some, by properly managing the carbon present in the crop residue.
Conservation based farming practices such as no-till can result in net carbon removal from the atmosphere by sequestering (storing) carbon in the soil. Perennial crops such as switchgrass have more extensive root systems relative to annual crops and subsequently partition more photosynthetically derived atmospheric carbon into the soil. The same process explains how cropping systems using manure can have a net negative GWP. When appropriately used as a soil amendment, manure can effectively transfer atmospheric carbon to the soil. Carbon emissions associated with manure include, CH4 emissions (flatulence) from the livestock, CH4 and NOx generated during manure storage and application, and the diesel and gasoline used in gathering and land applying the manure. The CH4 (and NOx) emitted from livestock and stored manure must be included as a net carbon emission since the atmospheric warming potential of CH4 is greater than that of the CO2 from which the carbon originated. The CO2 released and organic carbon in manure is not assessed as a net emission since it was photosynthetically derived in the first place. Conversely, when gasoline is combusted, the carbon that is emitted into the atmosphere is new carbon, carbon that was safely sequestered (for millions of years) far below the earth’s crust. All this new carbon deposited in the atmosphere from years of burning petroleum-based fuels is a major source of our global warming problem today. Every time we choose biofuel as an alternative to gasoline, we displace a new carbon emission from the gasoline with a recycled carbon emission. This direct analysis clearly shows the smaller environmental footprint of biofuels relative to petroleum based fuels. A comprehensive evaluation of the indirect effects of biofuels vs. petroleum based fuels is very complex and far beyond the scope (and space) of this article.
Figure 1. Net global warming potential (kg of CO2 equivalents per acre) of biofuel cropping systems compared to the GWP of the gasoline displaced by each system.
Annual crop system net GWP
data represents annual average of a corn-soy-corn rotation.; grain calculated at
150 bu/acre (420 gal ethanol/acre) + 3.5 ton/acre stover (250 gal ethanol/acre)
; annual crop + manure = same as grain + stover system with manure applied to
soil; annual crop systems GWP from MSU field research data, East Lansing, MI.
Perennial crop system was
switchgrass calculated at 8 ton/acre (576 gal ethanol/acre) switchgrass net GWP
carbon data source was Frank et al. 2004, Crop Sci.
Gasoline displaced was calculated
as 0.7x the ethanol produced by each respective cropping system. CO2
values for gasoline were from 40 CFR 600.13.
Mike Staton, MSU Extension educator and Soybean 2010 coordinator
The following checklist summarizes management practices that are proven to contribute to high-yielding soybeans.
Inspect, repair and calibrate planting equipment. Uniform seed spacing in the row will
improve yields. Small seed will plant more evenly and will experience less
mechanical damage than large seed when planted with a drill equipped with a
fluted metering system. Always calibrate your drill by seeds per foot of row or
seeds per acre. Recalibrate whenever seed size changes.
Control weeds prior to planting. Always plant into weed-free fields. Delayed
burn-down applications have resulted in yield losses of 8 bushels per acre in
MSU research trials. Tillage and/or herbicides can be used to control weeds.
Broadcast potash on coarse-textured or organic
soils if needed. Fall
applications of potash are not recommended on coarse-textured soils having CECs
less than 6 meq/100 g or on organic soils due to the potential for leaching
losses.
Apply phosphate fertilizers if recommended. MSU recommends applying maintenance level
phosphorus (0.8 lbs. of actual P2O5 per bushel) when
phosphorus soil test levels are between 15 and 30 ppm. No phosphorus is
recommended when soil test levels exceed 40 ppm.
Plant into good soil conditions. Adequate and uniform soil moisture, soil
temperatures higher than 50oF
and a level surface will promote uniform seedling germination and emergence.
Plant soybeans early. The first two weeks of May is considered the ideal
planting window for soybeans in the lower half of the
Inoculate seed whenever soybeans are planted. Researchers from
Consider a soil-applied residual herbicide
application followed by a post-emergence application. Benefits include: reduced early-season weed
competition, consistent control of weeds that emerge over a long time period,
consistent control of hard-to-control weeds and herbicide resistance
prevention.
Plant at the optimum seeding rates. Plant 175,000 seeds in 7.5” rows, 150,000 seeds
per acre in 15” rows and 130,000 seeds per acre in 30” rows.
Plant in narrow rows. University research trials have shown that
planting in narrow rows significantly increases soybean yields.
Plant at the optimum depth. Plant beans between ¾-inch and 1-1/4-inch
deep. In general, plant at the shallower end of the range when planting early
and in no-till, and plant at the deeper end of the range later in the season.
Plant a range of maturity groups. Planting a range of soybean maturity
groups spreads your risk during the growing season, allows more of the crop to
be harvested at the optimum stage and allows for timely wheat planting.
Use seed treatments where warranted and provide
uniform coverage of the seed. Fungicide seed treatments are warranted when planting very early and/or
where pythium is known to be a problem (
Monitor fields closely beginning at emergence. Diagnose emergence problems early. Emergence
can take six to 18 days depending on soil temperature and soil moisture
conditions. If slow and uneven emergence occurs, dig up the delayed plants and
look for disease or insect damage. Plant stands of 100,000 plants per acre will
produce optimum yields if the plants are relatively evenly spaced. After
emergence, continue checking fields for bean leaf beetles and black cutworms. Monitor
weed heights and use this information to time post-emergence herbicide
applications.
Mike Staton, MSU Extension educator and Soybean 2010 coordinator
The updates and recommendations for each topic area will be
recorded by Michigan State University Extension specialists. The messages will
not be updated on a set schedule. Instead, they will be updated as needed to
provide
Mike Staton, MSU Extension educator and Soybean 2010 coordinator
The widespread
occurrence of green stem disorder last fall adversely affected the quality of
soybean seed farmers will plant this spring. The green stems delayed harvest
operations exposing the seed to repeated wetting and drying cycles, which
reduced the thickness and integrity of the seed coats. When seed was finally
harvested, it was difficult to adjust combines to be both gentle to the tender
seed coats and also aggressive enough to remove the green plants. Mechanical
damage occurs when the embryo, which is near the surface of the seed coat, is
bumped or hit. This causes a break or bruise to the radicle (root) of the
germinating soybean plant. Depending on the severity, some plants will die and
others may have weak root systems due to the primary root being broken and the
formation of secondary roots. Mechanical damage is often not detectable with
the naked eye and should be determined with laboratory tests such as the
Tetrazolium (Tz) test.
In the
Tetrazolium (Tz) test, individual seeds are stained, dissected and evaluated
for breaks or damage to the embryo to determine viability and damage. Warm
germination results, which are printed on the seed tag may not completely
reflect the total mechanical damage. The warm
germination test indicates how the seed will perform under ideal conditions and
may not predict how the seed will perform when planted into cool, wet soils
common with early planting.
Seed suppliers
and growers should handle all of this year’s soybean seed with great care to
avoid further mechanical damage to the seed coats or the embryos.
Soybean producers
may want to use the following planting strategies in 2008. Determine the
quality of your seed lots by asking for tetrazolium (Tz) or cold germination
test results from seed suppliers. If the information is not available, consider
having the seed tested by the Michigan Crop Improvement Association. With test
results in hand, growers can rate the relative quality of their seed lots and
determine their planting order. Always plant your highest quality seed first
and your lowest quality seed last. Consider delaying soybean planting this
spring until ideal conditions exist if you are not sure of the quality of your
seed. Also consider increasing your planting population if you typically plant
low populations. If planting into ideal conditions, use the warm germination
test information to adjust your seeding rates. Growers may also want to protect
their seed with seed-applied insecticides and/or fungicides this year. These
products will not improve the vigor or the germination of poor quality seed. However,
they have been shown to improve emergence in seed having reduced vigor.
Dennis Stein, Extension educator, Farm/Business Management
Diane Brown-Rytlewski, Plant Pathology
Along with record prices expected for wheat, there has been a high degree of interest in fungicides to control Fusarium head blight and decrease DON levels. In the last Field CAT Alert, we discussed instances where a fungicide application could either be cost effective or result in inadequate return to growers. A partial budget worksheet has been prepared to help you calculate the cost of applying a fungicide and the potential benefits of an application to determine whether a fungicide application will be economical in your situation. A sample budget has been included as an example, but your own numbers should be used to prepare a budget that reflects your expected yields and costs. (MEGAN: Image to PDF included here.)
CAPTION TEXT: Example: The information used above is only an example of what could happen for your farm. Please take the time to input your farms projected yields, and your farms projected cost for the application of fungicides to your wheat crop. You should also adjust the price to reflect your contract price or the price you expect to receive at wheat harvest.
Ned Birkey
Weather in April has moderated to bring normal temperatures and below normal precipitation. This is gradually allowing soils to dry out although the soil temperatures have not increased from April 1 (39.3ºF) through Tuesday, April 15 (37.8ºF). Sunny days with wind have been helpful in drying things out and tile lines and streams are not running nearly as full now.
Alfalfa is greening up nicely. Fields received significant heaving during the winter. Acreage will be down this spring and supplies may run short of demand. With the expected mild temperatures, alfalfa weevil feeding should begin.
Corn is still in the bag though some farmers will be able to plant on exceptionally dry soils yet this week. Tuesday, I saw a farm work truck stuck up to the axles in a field that appeared dry. The price and availability of fertilizer is still questionable at some dealers.
Soybeans are not planted yet as most fields are too wet, even if parts of a particular field are dry. There may be many situations in which part of a field is planted and the rest of the field is too wet and left till later.
Wheat has overwintered in generally good condition and most fields have greened up completely and have or will soon have topdressing of nitrogen applied. Stands appear good and most fields that have not had significant ponding will likely stay in wheat.
Farmers are ready to go whenever the soil conditions allow. If the warmer temperatures stay, then warm soils will allow crops to germinate quickly. Weeds have been late germinating also.
Bruce MacKellar
Warmer conditions brought 1.5-2 inches of rainfall to most
of southwest
Wheat continues
to look good in the area. Wheat really greened up following the warmer
temperatures, and is beginning to fill in quite nicely. Some fields may have
challenges with standing water, especially in
Alfalfa has broken dormancy and both established stands and seedling alfalfa is beginning to look good. You can see some very minor signs of alfalfa weevil adult feeding on a few fields, especially those that were protected from wind with southern exposed hillsides. The alfalfa could really use warmer temperatures to kick growth into high gear.
Potato planting continues where soil moisture conditions allow the operations to occur. Some of the larger growers are faced with delays due to poor planting conditions at other locations in the country which may be tying up some of their equipment.
Corn and soybean planting will be somewhat
behind what the earliest planted fields have been in recent years around
With the cold soil temperatures, there has been very little movement of white grubs towards the soil surface to feed at this point. Winter annual weed growth is just beginning to move forward, so there may be more opportunities for these larvae to feed on growing root tissue in the next week or so. I have been out surveying fields with a tiling spade looking for white grubs, but have found very few at this point. We will be focusing on areas where damage to late harvested potatoes was found last fall, down along the Michigan/Indiana state line. I continue to urge producers to keep an eye out for white grubs during primary and secondary tillage operations this spring. The cold temperatures may mean that the grubs will be late in ascending to the surface to feed.
Fred Springborn and Roger Peacock
Soil conditions remain
cool and wet. The last few days with high temperatures in the 60s has brought
us closer to adequate conditions to start spring work. Only limited activity
has occurred in the past week on the sandy, well drained soils.
Wheat broke dormancy in early April. Stands and early growth are generally
good. Drowned out spots is a concern on the heavier, poorly drained soils. Many
fields have yet to be topdressed with nitrogen.
Alfalfa green up has started, crown growth is underway, and associated grasses
are growing (2-4 inches). Little winter injury has been observed.
The first few oat fields have been planted and also the
first pea fields.
Paul Gross
Most of the region received approximately three inches of rain over the past two weeks. Most fields have taken in the water very well with very little standing water today. Soil temperatures remain very cool with light frost Monday and Tuesday. The warm and windy weather Wednesday has dried fields nicely.
The wheat crop seems to have come through winter in very good shape. Stands are generally uniform and growth stages vary from Feeke’s 2-4 based on the planting date last fall. Heavy rains in the past two weeks have some saturated spots in fields and we expect some small drown outs. Growers are reminded to monitor the growth stage of your wheat to determine the appropriate herbicide for weed control. Warm weather can move the crop quickly past Feeke’s 5 which is then past the stage when we can safely use a growth regulator (2,4-D) herbicide.
Alfalfa is beginning to grow. The fields that have been observed are in good shape with good re-growth from the crowns. It appears there has been very little if any winter damage to the crop.
We expect some planting of oats and alfalfa seedings this week on our lighter soils if the weather cooperates.
Growers are reminded to get the burn down herbicide applications applied as soon as field conditions allow so we are planting into clean fields.
Bob Battle
Growers have begun working the ground and spreading manure.
Wheat has broken dormancy and areas of varying sizes that were lost due to ice sheeting are becoming evident. Growers have begun topdressing applications of nitrogen.
Alfalfa is starting to break dormancy. Any winter kill problems will be showing up in the next week or so.
Sugar beet planting has begun. Expect most beets to be planted in the next ten days, or so, if the weather allows it.
Jeff
Andresen
Agricultural Meteorology
Geography
Changes in the upper air pattern across
A second frontal system is forecast to approach the state by early next week, with more rainfall possible in the Tuesday/Wednesday time frame. Temperatures during the next few days will range from near normal levels across northern sections to above normal levels in the south. Highs will range from the upper 40's or low 50's north to the low 70's south through Friday. With cloudy skies expected this weekend, highs will fall back a few degrees statewide to a range from near 50ºF far north to the mid-60's by Saturday continuing through Monday. Low temperatures should range from the low 30's far north to the upper 40's south through Sunday. Normal temperatures for the third week in April range from highs near 50ºF north to 60ºF south, with lows falling to the mid-30's north to the upper 30's south.
In the medium‑range, forecast guidance suggests a
transitional pattern, with the eventual return of upper air troughing and
cooler weather by the end of April. Above normal precipitation totals are
expected across