June 12, 2008
In this issue
§ Now is the time to check wheat fields for armyworm
§ Soybean Aphid Overwintering Survey
§ Common lambsquarters escapes in sugar beets: What are my options?
§ Optimizing fungicide timing for the control of Rhizoctonia crown and root rot of sugar beet and issues about mixing Quadris with Roundup.
§ Volunteer potato control in corn
§ Managing corn and soybean fields submerged by recent heavy rains
§ Damage from late May frost now appearing in small grains
§ Regional reports
§ Weather
Christina DiFonzo, Entomology
Check wheat fields for armyworm.
Reports the week of June 9 range from none to a bunch, with
Armyworm can attack corn and soybeans as well, and I had a few reports of both. Fields with cover crops and weeds are at risk for armyworm infestation although even clean fields can be infested. As with wheat, caterpillars hide out at the base of plants during the day, and also in the whorl of corn, feeding leaves behind tattered leaves (Photo 5). With warm temperatures insects can grow quickly, so damage can increase in just a matter of days. Recognizing an over-threshold infestation early and treating smaller larvae, which are more susceptible to insecticides and eat less, protects yield. In soybean, treat at 25 percent defoliation (this may be difficult to judge). For corn, treat when 25 percent of plants have two or more larvae per whorl, or when 75 percent of plants have one larvae. For both corn and soybean, you can choose from the same product list as for wheat. Check labels for rates and precautions; of course pre-harvest intervals are not an issue in either crop. Note that armyworms sometimes originate in one field and move into another. In that case, you may be able to limit your spraying to an edge or barrier treatment near the infested field.
Christina DiFonzo
Entomology
A report from Dave Voegtlin from the
“Given the low fall flight numbers, I was not expecting to
find many aphids and was also wondering how the cool, wet spring might have changed
the dynamics. To my surprise, we managed to find some colonies at every major Rhamnus
cathartica location that we visited from northeast
Christy Sprague
Crop and Soil Sciences
Rainfall and inclement weather conditions have lead to common lambsquarters escapes in many non-Roundup Ready or conventional sugar beet fields. This is particularly prevalent in many of the sugar beet fields being treated with micro-rate herbicide programs. When application timings are missed, common lambsquarters is often the number one weed escape. Over the last several years, common lambsquarters escapes have been extremely common in sugarbeet fields at harvest. These escapes can reduce yield by competing for moisture and light, cause problems with topping and harvest, and produce seeds that will lead to future problems. In fact, one common lambsquarters plant can produce as many as 72,000 seeds per plant and these seeds can remain viable in the soil for as many as seven decades. For example, if one common lambsquarters plant escapes control and produces 72,000 seeds, after 12 years as many as 36,000 of those seeds will still remain in the soil. Missed micro-rate application timings and erratic weed control due to unfavorable conditions can exacerbate these problems. So, in 2006 with the help of funding by Michigan Sugar Company, two studies were designed to determine the best options for common lambsquarters control if a micro-rate herbicide application timing was missed. Since common lambsquarters escapes can also occur with other weed control programs the second trial was conducted to examine rescue treatments for common lambsquarters control.
A standard micro-rate treatment of Betamix at 8 fl oz/A + Stinger at 1 fl oz/A + UpBeet at 0.125 oz/A + 1.5 percent v/v of methylated seed oil (MSO) was applied to all treatments when common lambsquarters was less than 1/8-inch in height after planting. To simulate a missed micro-rate application, the second micro-rate application was delayed until 400 growing degree days, base 34°F after the first micro-rate (0.25- to 0.75-inch lambsquarters) application for half of the treatments and 500 growing degree days (0.5 to 1.25-inch lambsquarters) for the other half of the treatments. The strategies examined to overcome a missed micro-rate application included: 1) increasing the Betamix rate in the next micro-rate application (12 fl oz/A and 16 fl oz/A), 2) adding Nortron to the next micro-rate treatment (2 fl oz/A and 4 fl oz/A), 3) increasing the Betamix rate and the Stinger rate to 2 fl oz/A in the next micro-rate treatment, 4) shorting the interval for the next micro-rate treatment to approximately 75-100 GDD34 (3 to 5 d), and 5) switching to a standard-split application of 2 pt/A of Betamix + 0.25 oz of UpBeet + 0.5 fl oz/A of Stinger + 0.25 percent v/v of non-ionic surfactant (NIS). Each of these strategies were implemented at the two missed micro-rate timings and compared with a standard micro-rate treatment. The third and fourth applications of the standard micro-rate were then applied 225 growing degree days after the second micro-rate application for all treatments. Seven days after the last micro-rate application, common lambsquarters control was 75 percent when the standard micro-rate treatment was delayed 400 growing degree days and 71 percent when it was delayed 500 growing degree days (Figure 1). Regardless of the missed micro-rate timing, shortening the interval between the missed micro-rate and the next micro-rate application or switching to a standard-split application provided the greatest common lambsquarters control, 90 percent or greater. Increasing the Betamix rate and Stinger rate to 2 fl oz/A or adding 4 fl oz/A of Nortron to the standard micro-rate also improved common lambsquarters control compared with the standard micro-rate treatment for smaller common lambsquarters. For the larger common lambsquarters, increasing the rate of Betamix to 16 fl oz/A in the micro-rate also improved common lambsquarters control compared with the standard micro-rate treatment.
In 2005 we conducted a study that examined several different
options for control of escaped common lambsquarters. This study focused on
increasing rates of micro-rate treatments and incorporating several different
herbicides and/or adjuvants. At the time that the herbicides were applied in
this trial, common lambsquarters heights ranged from two to 12-inches tall. There
were no treatments other than glyphosate that showed any promise of
lambsquarters control at this stage. This gives us an option in our Roundup
Ready sugar beets, but what about our non-Roundup Ready sugar beets? The first
step in keeping lambsquarters under control is to treat it at a much smaller
stage. It is extremely important to recognize common lambsquarters escapes
early. In our 2006 trial for control of larger common lambsquarters we treated
common lambsquarters when plants were 1 to 5-inches tall and sugar beets were
in the 4 to 6-leaf stage. Treatments that provided the greatest common
lambsquarters control 14 and 21 days after treatment included: 3 to 4.5 pt/A of
Betamix + 4 fl oz/A of Nortron + 4 fl oz/A of Stinger + 0.25 percent v/v of
Willie Kirk, Plant Pathology; Christie Sprague, Crop and Soil Sciences; Steve Poindexter, MSU-E educator; Linda Hanson, USDA; Corey Guza and Ralph Fogg Michigan Sugar Company
Recent weather conditions may have been suitable for the development of Rhizoctonia crown and root rot and possibly damping-off. Quadris can be applied early in the sugar beet growing season for control of Rhizoctonia damping-off and Rhizoctonia crown and root rot caused by Rhizoctonia solani anastomoses groups (AG) 4 and 2-2, respectively. Work at MSU/MSC has evaluated fungicide application timings based on crop growth stage and soil temperature thresholds in inoculated small-scale trials and in commercial fields with a history of Rhizoctonia crown and root rot. Soil temperature thresholds 50°F, 59°F and 68°F were selected for fungicide application timings and used to test whether soil temperature could be used to better time applications of azoxystrobin. In both small and large plot trials, timing applications after attainment of specific soil temperature thresholds did not improve efficacy of Quadris in controlling damping-off or Rhizoctonia crown and root rot, compared to application timings based on either planting date, seedling development, or leaf stage in a susceptible (E-17) and a resistant variety (RH-5). Application rate and split application timings of azoxystrobin had no significant effect on severity of crown and root rot. Other environmental factors such as soil moisture may interact with soil temperature to influence disease development. The variety RH-5 had higher sugar yield attributes than the susceptible variety (E-17) in seasons conducive and non-conducive to crown and root rot development. The rate of 0.4 or 0.6 fl.oz./1000 row feet were equally effective but the best timing over the three years of trials was at leaf stage 4 to 6 and 6 to 8.
Quadris is only labeled for banded applications for Rhizoctonia crown and root rot control (up to leaf stage 6 to 8) and at a lower broadcast rate for foliar diseases such as leaf spot. The broadcast rate (max 15.5 fl.oz./A) is equivalent to about 20 percent of the in-furrow application rates and an equivalent rate for control of crown and root rot as a broadcast application would be about 40-60 fl.oz./A. There are no known data for crown and root control using 15.5 fl.oz./A of Quadris and it is likely that control of crown and root rot would be compromised as such a low rate. Mixing Quadris and Roundup is not an illegal tank mix, but there is no information available on the efficacy of such a mixture, given maximum permitted rates, for crown and root rot control. In addition, no phytotoxic studies have been completed using this combination, and the risk of crop damage to the beets has never been assessed.
Wes Everman
Crop and Soil Sciences
Corn growers in potato growing regions will be looking to
control volunteer potatoes where potatoes were grown in 2007. It is important
to control volunteer potatoes to preserve corn yield, however, it is as
important to control volunteer potatoes to manage pests that can be a problem
if potato is in rotation for next year. There are a few different options that
will provide suppression of volunteer potato and significantly reduce the
number of daughter tubers per plant; however, there currently are no herbicides
available that will completely control volunteer potato.
Good
suppression of volunteer potatoes in the MSU trial was also obtained with
Starane (1.33 pt) + atrazine (0.5 lb ai). 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 has a similar mode of action as Distinct, Clarity,
Stinger and 2,4-D and has been used in small grains for a number of years and
has been registered for use in field corn. 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. 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.
Something to consider
Corn
inbreds are sensitive to many herbicides labeled in field corn. Consult the
seed company agronomist before using any herbicides for weed control on
inbreds. The only treatments that can be applied to seed corn that provided
good suppression of volunteer potatoes were Callisto and Callisto + atrazine.
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.
Kurt Thelen
Crop and Soil Sciences
Last week’s heavy rains have resulted in isolated areas of severe ponding in parts of the state. This problem has left growers struggling with the question of whether or not to replant water damaged stands. The replant decision is further complicated by the fact that we are now nearing the end of the viable planting season window for corn and soybean.
Assessing
plant viability
The first step is to determine whether plants
survived being underwater or in saturated soil. Seed that has germinated, but
not emerged is also susceptible to excessive water damage. In corn, most of the
plant mortality will be in localized low areas of the field that were subjected
to standing water. The survivability of plants or seedlings underwater is
dependant on temperature, growth stage, variety, soil type, nutrient status and
other factors, but is generally in the 24 to 96 hour range. In cool
temperatures, plants will survive longer as respiration slows. Conversely, when
temperatures warm up, plants consume oxygen quicker, and submerged plants will
not survive as long. In cool conditions, corn can survive four days submerged.
With soil temperatures warmed up in the upper 70s, submerged corn may survive
for only 24 hours. Unfortunately, the warm temperatures experienced throughout
much of
In soybeans, soil borne disease such as pythium and phytopthora can result in plant mortality beyond those areas that were under water. In assessing a soybean stand, for more fertile soils a minimum of 80,000 to 100,000 living plants per acre are needed to approach the full yield potential of the field. In poorer soils, 100,000 plants per acre are needed. In situations with less than the minimum number of plants remaining, the cost of replanting should be weighed against the expected increase in yield to determine if replanting will be economically feasible.
Generally, the time it takes for submerged soil to dry out enough to get equipment on for replanting, is usually time enough to make a determination whether or not plants have survived. However, it can be difficult to determine survivability when plants are covered with soil and plant residue left behind by receding water. In these cases, split a plant lengthwise through the stem. The growing point should be relatively firm and white or cream colored. Darkening or softening of the growing point indicates a nonviable, dead plant.
How late
into the year can I plant/replant and still expect a reasonable chance of
maturing grain?
For
corn, planting after June 15 is not recommended. Corn intended for grain
harvest has a significant chance of not reaching physiological maturity when
planted after June 15. Corn intended for silage can still reach a harvestable
maturity, but feed quality will be diminished relative to corn planted in the
optimum window of late April to early May. Soybeans can generally be planted up
to the end of June although yields will likely be reduced commensurate with the
later planting date. If replanting soybeans, do not drop more than one maturity
group from what you usually plant. For example, if you generally plant group II
soybeans, replant with group II or group I soybeans.
Considerations for replanting into existing stands
When replanting flooded out areas that still have some viable plants, it is usually best to tear up the existing stand and start over with an even-emerging stand. This may require you to manage the area differently than the non-flooded parts of the field with regard to activities based on plant growth stage such as weed control and time of harvest. Other considerations in flooded out areas include potential weed problems from weed seed brought in by encroaching waters, herbicide residue washed in from adjacent fields, loss of herbicide control from excessive leaching or erosion, loss of nitrogen through denitrification or leaching and increased incidence of phytophthora and other root disease. Nodule function in soybeans is also reduced in saturated soil. However, nodule activity resumes to normal levels once the soil dries out. Scout fields closely for these factors and use a PSNT soil test to determine nitrogen losses.
Other
considerations for late planting/replanting
Following
are other considerations with late planting that I have compiled over the years
including some from Bob Nielsen at Purdue University and Jim Beuerlein at Ohio
State.
Bt corn
hybrids. For most
Previous
herbicides applied. Before replanting review potential label
restrictions associated with previously applied herbicides.
Seeding rates. There is no need to
consider changing seeding rates for corn simply because planting is delayed.
Optimum seeding rates for most growers’ fields range from 28,000 to 33,000
seeds per acre. Lower rates (low to mid-20s) are suitable for fields with yield
levels historically near or below 100 bushels per acre. Unlike corn, soybeans
have a great propensity to compensate or “flex” when plant populations vary. Therefore,
the optimal planting population range is wider for soybeans than it is for
corn. Determining the minimal scale of that optimal soybean planting population
range will optimize profitability and still maintain yield. As a starting
point, begin with a planting population of 175,000 seeds per acre for drilled
systems and 130,000 seeds per acre for 30 inch rows and then adjust down or up
from there based upon field productivity, planting date, and planting
conditions. When planting late, resulting soybean plants will be smaller than
earlier planted soybeans. To compensate for the potential yield decrease of
smaller plants due to late planting, increase your planting population by 20
percent.
Seeding
depth. The
key factor that should be used for determining seeding depth for corn is the
importance of adequate and uniform soil moisture in the seed furrow. Some might
say this is a moot point given the current soggy soil conditions. Remember,
though, how quickly Mother Nature can change and how quickly shallow-placed
seed can find themselves in bone-dry soil. A seeding depth of 1.5 to 2.5 inches
for corn and 1.0 to 2.0 for soybean is acceptable over a range of soil
conditions. Shallower depths for corn are risky if rains stop altogether and
surface soils begin to dry rapidly.
Field tillage operations. Remaining pre-plant field
operations should be scrutinized carefully to determine whether they are truly
necessary. With today’s modern corn planters, there is little reason to
overly-prepare a field to create a picture-perfect seedbed. In delayed planting
situations, every day wasted overworking a field is a day lost to planting and
represents lost yield potential. Furthermore, unnecessary tillage operations on
soils that may be marginally wet increase the risk of creating tire and tillage
compaction layers that can haunt root development and corn health later if
excessively dry conditions suddenly become the norm.
Planter sidewall compaction. Another concern to watch
for is the potential for significant root restriction by severe sidewall
compaction when a rapid shift from wet to dry conditions occurs. If at all
possible, avoid planting fields when soil moisture conditions favor the
smearing of furrow sidewalls by the coulters or double-disc openers of the
planter. The potential yield loss from planting in fields that are too wet far
outweighs the potential yield loss from delaying planting until field
conditions are suitable. Planting in wet conditions often results in sidewall
compaction of the seed furrow. This causes poor seed to soil contact which has
several negative consequences including: reduced germination and poor stands;
uneven emergence which reduces yield due to plant-to-plant competition; and,
restricted root growth which compromises the plant’s ability to withstand
moisture stress later in the growing season. In addition, the limited rooting
can result in phosphorus deficiency even though soil test phosphorus levels are
adequate. This occurs because the plant uses all of the phosphorus that is
immediately available within the seed furrow. The roots of these plants will
appear thickened and gnarled –a visual sign of compaction. After a period of
time, the roots may break through the compacted sidewalls and explore more of
the soil. As this occurs, the phosphorus deficiency may be overcome and the
plant will begin growing normally again. However, the sidewall smearing and
compaction is likely to have set the crop back by a week or more as it tries to
overcome the inhospitable soil environment.
Nitrogen fertilizer applications. It is not recommended to
plant corn after June 15, in
Starter fertilizer. Where soil phosphorus and
potassium soil test levels are adequate or better and tillage is other than
pure no-till, consider eliminating starter fertilizer use for the remainder of
this season’s corn planting. Soil temperatures at planting from here on should
be more than adequate for rapid corn germination and early seedling growth,
thus greatly diminishing the value of starter fertilizer. Eliminating starter
fertilizer will not only reduce your costs, but will save some time during the
planting operation. No-till corn, however, will likely continue to benefit from
starter fertilizer applications, especially the nitrogen component, for
planting throughout the remainder of the month.
Diane Brown-Rytlewski
Plant Pathology
Wheat heads with
barren florets have been showing up recently. The problem has also been observed
on winter barley and rye. It is likely that frost or freeze injury is
responsible for the damage that is now being seen.
Temperatures that
cause freeze injury to wheat from the extension bulletin, “Spring Freeze Injury
to Kansas Wheat” are reprinted below.
Freeze injury should
not be confused with damage from Fusarium head blight as shown in photo 2. With
fusarium head blight the florets in the portion of the head that was infected
are bleached in appearance, but are normal sized and do contain grain. Symptoms
of fusarium head blight can appear within a few days when temperatures are in
the 77°F-86°F range and moisture is continuous. Symptoms are usually evident by
the soft dough stage. Grain from these heads may be shriveled, and have a
chalky white or pinkish appearance.
Ned Birkey
Weather has changed from warm to hot with several storms of locally heavy rain and high winds. Most of the four-county-area had 1.5 to 2.5 inches of rain over the past week.
Alfalfa cutting continues as the weather permits, and the new growth looks good. Yields and quality of the first cutting are very good. Prices for small, square bales are in the $6 range.
Barley is starting to turn.
Corn is mostly at the V8 leaf stage and is quickly approaching knee high. Side dressing of nitrogen is finishing up and some post-emergence herbicide spraying is also being applied. European corn borer counts ranged from zero up to 20 moths found in traps in Monroe, Wayne, Lenawee and Washtenaw counties this week.
Soybeans are still very small in the V3 leaf stage with several fields yet to receive any weed control.
Wheat is mostly
pollinated and generally continues to look very good with little disease
pressure, though some fungicidal spraying has occurred. There is a concern
about infection of fusarium head scab as we have had several periods of
moisture and wet plant conditions within the past ten days. A pre-harvest field
day at the MSU Wheat Variety Trial at the Dave and Jason Woods’ farm will be on
Monday, June 23, from 5:00-8:00PM. The plot is located on
Miscellaneous
The last trip to the MSU Soil and Plant Nutrient Lab to take soil nitrate samples will be on June 18.
Bruce MacKellar
What a difference one
week can make in the crop environment. With an extraordinarily cold and dry
spring, crop growth and development had been well behind the norm. That all
changed late last week when temperatures reached the 90°F mark and a series of
heavy thunderstorms dropped up to eight inches of rainfall overnight on
Saturday, June 7. The hardest hit areas include portions of Allegan,
The earliest planted commercial corn fields are beginning to canopy over. Corn, which had grown little with cold temperatures, is growing so rapidly that it often has a spindly appearance. For those fields that are roundup ready or where total post herbicide programs are being planned, rapidly growing weeds will soon be causing potential yield losses. Research conducted by the MSU Weed Control Program has shown that to avoid yield losses, weeds should be controlled by the time they reach four inches in height in corn.
Weeds have the potential to grow from four inches to six inches in two to four days under ideal conditions, so timing getting herbicides on soon will be critical for many producers. With more wet weather in the forecast and lots of nitrogen sidedressing operations also delayed by rains, it will be a challenge to get everything accomplished before corn height becomes an issue for some producers. We have also seen a lot of windy days associated with this weather pattern, which means there is likely to be more risk of drift if producers are trying to spray to keep ahead of the weather. We need to be careful, particularly around field edges where yards, gardens and sensitive crops are being produced. One example of this is Glyphosate drift, which can potentially cause minor plant growth delays in tomatoes, but can lead to very high harvest losses due to green tomatoes being dumped back on the field by color sorters on harvesters at the end of the season.
Insect pests. We have seen a few fields that have very small European corn borer larvae feeding. These larvae have caused mostly window pane feeding on leaves, but have recently migrated to the whorl of the plants.
Weed escapes. Grass escapes are still common in fields where pre-emergence herbicides may not have had sufficient rainfall to activate the herbicides. Most fields I have walked are fairly clear of broadleaf weeds.
Wildlife damage. Sandhill cranes have been active in
several areas in southwest
Replanting drowned out areas. For those who are considering replanting in drowned out areas, be sure to consider the pesticides that have been applied to the field. If roundup ready corn was planted, and no soil insecticides were applied, it may be possible to plant soybeans in parts of fields damaged by floods if they dry out early enough that you plant and access the areas through the surviving crop. Second crop soybeans are often planted following very early wheat harvest in St. Joseph County, so if conditions allow, producers may be able to regain some value by planting late soybeans in these areas.
Wet soil conditions have delayed the final planting of seed corn on a few fields. Most seed
fields look pretty good, with good male row stands. Flaming has begun to help
spread out pollen shed on some male rows.
There was plenty of sand blowing June 6 with the strong southwest winds.
Producers may want to examine fields for sandblast injury and to make sure that
plants remain healthy, particularly in open fields with high exposure to south
west winds. Armyworm has also been seen sporadically in
The soybean crop is growing rapidly, as are the weeds in many instances. We are beginning to work on the third trifoliate in early planted fields. Many of our presumably roundup ready soybean fields are quite weedy and are awaiting the first application of herbicide. Remember, MSU Weed Control Research suggests that weeds should be controlled before they reach four inches in height for drilled or narrow row soybeans, and six inches in height in 30-inch row soybeans. Weeds are growing very rapidly with the hot, moist conditions, so getting herbicides on in a timely manner is very important to achieve top yields. We have seen increasing bean leaf beetle feeding, with a very few pockets in fields approaching the threshold level of 50 percent defoliation. Chris DiFonzo reminds us that the main concern with bean leaf beetles is actually for damage by the summer generation later in the season, when they feed on pods and developing seeds. With higher numbers being seen in the southwest this season, it is a pest to keep on the radar screen. Stands continue to look good in most fields.
Alfalfa hay harvest has been a big challenge for producers, especially those that were working on fields crops at planting. Lots of hay was cut prior to the last wet period, and at least some of it was ruined by the rainfall. Regrowth on fields that were cut earlier has been very good. We should be on track for a productive second cutting. Leafhopper activity has been low, but with the strong southwest flow from the recent storms, producers should be looking for the pest over the next week or so.
Most of the wheat
in
We have had several reports of armyworms in wheat spread throughout the area. For more information on armyworm control in wheat, see the article in this edition of the Field Crop CAT Alert. It would be a good idea to walk your fields and evaluate the fusarium head blight and armyworm pressure in your fields to protect the crop.
Fred Springborn and Roger Peacock
Weather
Much
needed rain fell over the entire region this week. Most areas received between
two and three inches over a five-day period. Flooding has been minimal, the
poorly drained soils have some ponding of water. Several fields have experienced
some soil erosion due to the rapid rainfall. High temperatures have been in the
mid-70s to mid-80s. Low air temperatures have been in the 60s. Low soil
temperatures have been in the mid- to upper 60s
Crop report
Alfalfa is starting
to blossom. Grasses are maturing quickly. Harvest is under way with 20 percent
of the crop cut or harvested and nearly all farms that have, or are currently
harvesting, are harvesting haylage. Alfalfa weevil damage continues to increase
with larvae present and many fields are at or above threshold. Growing Degree
Day base 41 (GDD 41) are well past 750 at all locations, many locations are at
900 to 950 GDD41. In pastures with similar growth patterns, it is becoming over
mature very quickly. Clipping or cutting surplus for hay will be needed.
The
majority of the corn crop is at the
V3 to V5 growth stage with a few advanced fields at V7 and still a few others
just emerging. Color and growth has improved again over last week with improved
moisture and temperature. Some of the heavier soils have water standing in low
spots.
The majority of the soybean crop is
planted. Early planted fields are at V2 to V3. Several fields have beans that
are still emerging with the improved surface moisture. It is not entirely
uncommon to find fields with beans that are just emerging and others at V2
within a few feet of each other.
Wheat has completed
flowering with a few late fields still in flower. Foliar disease pressure
remains fairly low with powdery mildew present in several varieties low in the
canopy. Many oat fields are in boot
with little disease or insect pressure.
Dry
bean planting has begun, but is currently on hold, it will be in full swing
when the weather forecast clears up.
Sugar beets are doing well with good stands, one grower commented that his stand was too good and is considering thinning options.
Paul Gross
The region received a good three inches of rain over the past week. In some areas there were high winds that took trees down as well as power lines leaving some farmers without power as of Wednesday, June 10. For the most part, fields took the water pretty well. Some areas will have some stand loss due to flooding, though as of Wednesday there is very little water standing. Most farmers are reporting fields just too wet to get in at this time. Crops have really progressed with the warm weather and rain. It is amazing how quickly corn and soybeans can make up for a slow start with the right growing conditions.
The corn crop ranges from just emerging to about V-6. The warm weather and rains have really jump-started the crop as well as the weeds. Many fields are in need of herbicide applications as soon as field conditions allow. Weeds are quickly getting past the ideal size for control.
Soybean stands are variable, but the crop is making up for lost ground with the early season cool and dry weather. There will be some additional stand loss due to flooding in some areas. Some seedling diseases are being reported. The weeds are also loving the good growing conditions and quickly getting past optimum size to control. Weed control should be made as soon as conditions allow.
The wheat crop is just completing flowering. There is powdery mildew in most fields after the wet week, but remains low in the plant. Farmers are advised to scout fields for armyworms. They have been reported in the Thumb area of the state. The wheat withstood the high winds over the weekend very well. Yield potential is good at this point in the season.
The oat and barley crop is approaching the boot stage. Stands look very good. Herbicide applications are going on as fields dry out.
Alfalfa harvest has been halted with the rainy week and there was some quality loss. The crop is starting to flower. We have observed alfalfa weevil in nearly all fields. We expect the damage to increase rapidly with the warm weather. Cut fields as soon as possible to manage this pest. Scout the regrowth for alfalfa weevil. New seedings are doing very well.
Sugar beet stands are very good, but are not filling the row at this time.
Dry bean planting will continue as fields dry out.
Bob Battel
Weather
Warm
temperatures and rains have sparked crop growth and slowed field work. The area
has received between 1.5 and 2.5 inches of rain in the last week, and daytime
high temperatures have ranged between 75°F and 90°F.
Wheat has flowered or is flowering. Many are spraying wheat with a fungicide to limit head scab and vomitoxin development.
Alfalfa has been cut, and some were able to finish harvest operations before the rains, but there is much alfalfa that was left in the field and soaked up a lot of moisture. Any uncut fields probably have alfalfa weevil feeding. Alfalfa that was cut and harvested has three to four inches of re-growth.
Warm, wet, weather has really helped corn growth. Development generally ranges between the 4-leaf to 7-leaf stage with the majority at 5 to 6 leaves. Weed growth is extensive in many fields.
Soybeans generally range at the one to two trifoliate stage with some soybeans at the unifoliate stage, and others at the third trifoliate. There are also many soybean fields that need to be sprayed for weeds as field moisture conditions allow.
Some sugar beets are at the 6-leaf stage with more advanced fields at the eight to ten leaf stage. Conditions are right for rhizoctonia development.
Dry bean planting had begun, but was delayed due to the rains.
Jeff
Andresen
Agricultural Meteorology
Geography
Several rounds of severe thunderstorms brought heavy rains,
strong winds, and hail to many sections of
Looking ahead, the very active weather pattern across the
Further ahead, the medium-range forecast guidance generally
calls for significant changes in the upper air pattern across the