In this week’s crop report, you’ll see some references to corn that’s tipping back or experiencing premature denting. Yesterday, a Wallaces Farmer article highlighted the topic. Brian Lang, Iowa State University Extension area agronomist at Decorah said, “Corn is showing some ‘tipping back’ of the kernels at the ends of the ears, which is normal.” If there is no ‘tipping back,’ that usually means that excessive seeding rate would have resulted in higher yield.

Lang went on to explain, once the ears reach the R2 (blister) stage, if the plant is stressed and starts to ‘become less optimistic,’ kernel abortion will occur from tipping back. Kernel abortion will continue to the end of R3 (milk) stage if stress is present. Once the plants are into the R4 (dough) stage, the only adjustment the plant can make is to the kernel size. Early denting would be an indicator that the plants are continuing to be ‘less optimistic’ and are adjusting kernel size down, which will result in lighter kernels at harvest.

Click here for the full article.

Northeast Iowa

Nick Benson reports the corn is maturing nicely although there is some tipping back from excessive moisture.  Some early silage harvest is underway. He’s seeing some ear worm and army worm pressure, but Latham® Hi‑Tech Hybrids LH 5777 SS ears look perfect! Beans are in the R5 to R6 stage with very little spraying being done for aphids. Latham Hi‑Tech Soybeans L 2440 R2 look awesome.  There are a lot of four-bean pods plus the pods are higher on the plant this year, which will help in harvest. Northwest Iowa looks to have very good bean crop to harvest.

East Central Iowa

Brad Beatty reports many eastern Iowa corn fields showing signs of tipping back, so many farmers are asking me why it’s so prevalent this year. He said we usually want one-half to 1 inch of tip back, which indicates we’re pushing the population to its limit.  If we have no tip back, we probably should have pushed the population. Under very wet and cloudy conditions, the corn plant doesn’t function efficiently.  It’s not producing enough sugar to fill the whole ear, so the tip becomes expendable.

Tipping back is caused by embryonic kernel abortion due to poor or unfavorable conditions. Kernels will shrink with the embryo visible (yellowish in color). Kernels are susceptible to abortion during the blister and milk stage with the tip being most sensitive.  Stresses that affect kernel development early in the grain fill period can be: excessive heat, drought, nitrogen loss, high disease infestations, cloudy weather, excessive seeding rate, wet conditions, compaction, cool temps, etc. These stresses can also lead to early denting indicating that the plants are continuing to be less optimistic and are “down sizing” the kernel size; which can result in lighter test weight. Stresses this year are heat, nitrogen loss, high disease pressure, cloudy weather, wet conditions, and compaction.  Growers need to scout their fields before getting surprised when harvest hits. The bad news is there is nothing we can do at this stage of growth to change this scenario.

Central Iowa

Kevin Meyer says his area lucked out and missed heavy rains and winds this past week. Corn continues to progress with most kernels dented at this time.  Preliminary yield estimates are being made with much of this crop looking good considering the weather challenges during the last couple of months.  SDS is the major concern for soybeans. Aphid counts stayed below economic thresholds, so very little treatment was actually applied.  Great weather is being forecast for plot days.

Many eastern Iowa corn fields are showing tip back, so many farmers are asking me why it’s so prevalent this year.  We usually want one-half to 1 inch of tip back, which indicates we’re pushing the population to its limit.  If we have no tip back, we probably should have pushed the population. Under very wet and cloudy conditions, the corn plant doesn’t function efficiently.  It’s not producing enough sugar to fill the whole ear, so the tip becomes expendable.

Tipping back is caused by embryonic kernel abortion due to poor or unfavorable conditions. Kernels will shrink with the embryo visible (yellowish in color). Kernels are susceptible to abortion during the blister and milk stage with the tip being most sensitive.  Stresses that affect kernel development early in the grain fill period can be: excessive heat, drought, nitrogen loss, high disease infestations, cloudy weather, too high a populations, wet conditions, compaction, cool temps, etc. These stresses can also lead to early denting indicating that the plants are continuing to be less optimistic and are “down sizing” the kernel size; which can result in lighter test weight. Stresses this year are heat, nitrogen loss, high disease pressure, cloudy weather, wet conditions, and compaction.  Growers need to scout their fields before getting surprised when harvest hits. The bad news is there is nothing we can do at this stage of growth to change this scenario.

North Central Iowa

Sudden Death Syndrome continues to prevail in soybeans across north central Iowa.  Now is the perfect time of year to take crop notes, so in the future, you can plant different varieties in affected fields.  Corn continues on a rapid pace with isolated diseases like Eye Spot, Grey Leaf  Spot and some Gosses Wilt in the western part of this territory.

South Central Iowa

Gentle showers fell early this week across South Central Iowa.  Although conditions have improved immensely this week, several spots are still showing effects of last week’s flood.  Travis Slusher’s area will struggle with harvest due to stalk and grain quality issues from the debris left in flooded areas.  Corn across much of his territory is denting, and beans are filling the pods nicely.  The usual foliar diseases are present without one being more prevalent than the next.  Travis said he still hasn’t seen very many issues with aphids but some growers went ahead and added a residual insecticide with the fungicide when spraying beans.

Wisconsin

Steve Bailie’s area was hit by storms and high winds, which caused some soybeans to lodge. It’s been interesting to see the difference in the standability between soybean varieties; standability issues will be magnified as white mold sets in. There are a few fields suffering from Sudden Death Syndrome and Brown Stem Rot, as well.  At the beginning of last week, you had to be in the fields to detect these diseases but now you can see it from the road. Many dairy farmers are switching their choppers from hay to corn. A few samples last week dried down to 70% moisture after being tested, so corn silage harvest is only about 7-14 days away. Many of the fields I’ve been walking are denting or are at full dent stage in southwest Wisconsin. With tomorrow’s field day at Bailie farms, many growers will get a first-hand look at what Latham can provide to help them hit their yield and personal goals. It’s a very exciting year to be in agriculture!

Minnesota

Farmers in Jason Obermeyer’s area continue to spray for aphids, and there are a lot of bean fields showing SDS and some BSR symptoms. Latham Hi‑Tech Soybeans L 2085 R look fantastic as do L 2440 RR2 and L 2183 RR2. Corn is ahead of schedule, and if the heat remains, we should harvest lots of bushels.

South Dakota

Several rainfalls of one inch or more occurred again in Bill Eichacker’s region this past week.  Temperatures have been warmer than average, pushing the crop development. Over half of the corn is at or beyond the R4 stage, with 10% at the R5 stage. Corn crop development is slightly ahead of South Dakota’s five-year average. Sudden Death Syndrome, white mold and aphids are present in soybeans. Over 80% of the soybeans are at the R5 stage.

Eastern Nebraska

While walking fields this week, Mike Lorenz hasn’t seen a lot of insects, bug damage, or fungus on the soybean crops.  It’s turning out to be a great year for the soybeans despite the wet weather.  Corn is in early black layer, and fertility levels seem to be holding out so far.

Managing SDS

Due to the number of SDS mentions in this week’s report, we wanted to share some SDS management tips shared in one of Monsanto’s recent Agronomic Alerts.

If SDS is present, little can be done this season.  However, management decisions for next year can be made. Fungicides are not an option for SDS control due to the nature and timing of the disease. An integrated management plan for SDS may include the following:

1. Balance the overall disease package. Balancing the disease package in next year’s crop is better than focusing on SDS tolerance, especially since soybean fields from this year will likely not be soybean fields next year.
2. Plant soybeans described as resistant or moderately resistant to soybean cyst nematode (SCN).
3. Delay planting or plant earlier maturing varieties to possibly help soybeans escape infection from SDS.
4. Implement cultural practices that improve drainage in low spots, reduce SCN populations, or remove soil compaction layers may lessen SDS severity.

We also want to share SDS management tips provided in last week’s blog (you’ll need to scroll to the bottom of the article), as well as a helpful Iowa State Extension article that was published recently by Alison Robertson and Daren Mueller, Department of Plant Pathology.

White Mold

There were a few mentions of white mold in this week’s crop report, and a recent Iowa State Extension article states that fields at higher risk of developing white mold are those that had disease in previous years and are in high-yielding sites where the canopy closed early. Also, fields that have had plenty of soil moisture, high humidity and little airflow. Below is a link to an article from Iowa State Extension highlighting white mold management tips – while it may be too late to apply some tips for this year’s crop, there are some general management tips you may want to keep in mind if you’re seeing white mold in your field this year.

http://www.extension.iastate.edu/CropNews/2010/1230yang.htm

Central Iowa

Bob Collins’ area recorded another 5 inches of rain on Monday night with more rain and flooding last night. Outside of flooding, the crops look pretty good although SDS is showing up in some bean fields.

A large storm passed through Bart Peterson’s western area over the weekend.  The storm had strong winds and rain, leaving some corn fields flat near the Schaller area.  Beans are in the R3 to R5 stages and in a plot in North Central Iowa, the 100- to 102-day corn is already denting.

Below are some images that show the incredible rainfall Ames, Iowa, has already received. (Note:  More rain has fallen already this month than normally falls in the entire month.) The second photo is Ames’ Hilton Coliseum on August 11.

East Central Iowa

Sudden Death Syndrome is hitting Brad Beatty’s eastern Iowa territory hard, so below he addresses the top questions he’s getting asked:

1. What is Sudden Death Syndrome?  Sudden Death Syndrome (SDS) of soybeans is caused by a fungus strain known as Fusarium solani.  The name “sudden death” is misleading since the disease may take weeks to fully develop. However, symptoms may not be noticeable until the disease is well advanced and the leaves turn or start to defoliate.
2. What can I do to prevent SDS?  First, identify the disease. Second, in fields where SDS was present a year or two ago (when the field was last in soybeans), make sure that you plant a soybean that has high tolerance to SDS. Third,  SDS likes to hit soybeans that were planted early and /or fuller season varieties because early planting conditions are more favorable for infection. Thus, planting beans later when the soils are warmer and dryer will help. Fourth, where feasible, improve soil drainage in the field and reduce soil compaction to help the field drain excess water. Fifth, varying maturity through a group or varying planting dates can also be an effective way of spreading out growth stages. Sixth, control cyst populations. Research shows that presents of soybean cyst nematode can help spread SDS because of the added stress that they put on the soybean plant. Soybean cysts have been found to carry this fungus, but it hasn’t been proven that they can translocate this fungus into the soybean plant. Although crop rotation has had little effect on this disease, farmers should not plant continuous soybeans. There is no spray that can help SDS.
3. What will my yield loss be? Losses commonly do not exceed 10% to 15%, but it can be as high as 50% in severe situations.
4. What are the symptoms? SDS symptoms begin as small yellow spots on the upper most leaves of a plant. These may get overlooked or may be easily misdiagnosed. Spots gradually enlarge and develop a brown dead center. They continue to enlarge until all of the interveinal tissues are killed, leaving a green vein pattern on the leaf. The time involved for this symptom to develop is dependent on weather conditions and variety in the field.  

 North Central Iowa

Kevin Meyer reports another great week for crop development in his region.  Corn is well into the grain fill and looks good overall.  He’s keeping a cautious eye on late season diseases and related stalk quality issues. Soybeans are being affected by SDS and White Mold will likely show up in the near future.  Producers need to take note of these fields and make variety selections that will offer some resistance as they rotate soybeans back into these fields.  This week brought light increases in aphid populations but numbers are still below threshold for treatment.

What a difference a week makes!  Last week we didn’t see much disease or insect pressure but this week we’re seeing a lot of Sudden Death Syndrome (SDS) in soybeans.  This soil-borne disease, which originated in the south and has worked its way north, made its presence known over the last seven days in North Central Iowa.  Soybean aphids are also starting to reach threshold numbers in some areas, keep we’re keeping a sharp eye out for them as well.  If the temperature breaks, the population of aphids could rise.

South Central Iowa

The northwestern part of Travis Slusher’s area has seen heavy torrential rains over the last few days, creating flash flooding issues.  On Monday, he witnessed fields in this area where corn had water standing over the ears with only the top couple of feet visible of the plant.  This will surely cause stalk and grain quality issues in these areas come harvest.  The northern part of this territory is showing heavy SDS in soybeans.  As you move further south, SDS becomes less prevalent but it is still showing up in small areas throughout this region.  Most of the corn in South Central Iowa is beginning to dent with the soybeans beginning to fill the pods.

Northeast Iowa

The big news in Nick Benson’s territory is how well soybeans are doing.  His area has received plenty of moisture for pod fill, and barring a large onset of White Mold and SDS, we should be looking at some nice bean yields.  Aphid numbers are now starting to reach thresholds in some fields, but in general, he doesn’t think many fields will be sprayed this year in his area.  Corn is looking exceptional in fields that have good drainage and an ample amount of Nitrogen.  Where that isn’t the case, premature senescence is occurring.  Nick has looked at some good fields of Latham® Hi‑Tech Hybrids 5425 VT3 where ears are already busting out of the husk.  In a field of LH 5777 SS, he saw perfect worm-free ears, which should add to the overall yield.  The next big move in this area is the silage harvest; farmers are only a few weeks out on that as this corn is maturing at a very rapid pace.

Wisconsin

Steve Bailie reports the crops are looking good in his area. In the southwestern part of the state, many soybeans are at R4-R5 stage. Many of Latham Hi‑Tech Soybeans with the Genuity® Roundup Ready® 2 Yield trait have a number of 4 bean pods again this year.  Insect pressure has backed off, and many growers are hoping to get away without spraying.  Fungicide applications on beans are coming to an end.  White Mold is starting to show up in bottom ground.  Unfortunately, the southwest received rains Sunday afternoon and early Monday morning that caused many of the beans fields to lodge.

South Dakota

The sun is finally shinning in South Dakota!  The crops are fairing well despite the recent weather patterns. Farmers are still scouting for aphids but have seen very few.  The next problem will be battling the wet fields when it is time to cut silage.  In South Dakota, corn has passed through the R2 stage and soybeans are in R4.

Central Nebraska

Steve Edwards says his area is still headed for a bumper corn crop. The recent high heat followed completion of pollination, so it should have little or no effect on yield.  Good soil moisture, GDUs and the crop response to superior growing conditions have been excellent.  There was some slight hail damage in western north central Nebraska, but it wasn’t significant and most of the damaged fields will have average yields. Soybeans are headed for a slightly above average yield. It remains to be seen if the string of days with extremely high heat will shed blooms and depress yield, but he doubts it because he hasn’t seen signs of stress on the crop. The only down side to this year has been the excessive moisture for the soybeans in east central Nebraska, the effects of which will haunt low lying or poorly drained soils throughout the year. All things considered, it will still be at least an average yield, if not slightly up from last year.

Minnesota

Jason Obermeyer reports corn is looking great but soybeans are showing some signs of Brown Stem Rot (BSR) and Sudden Death Syndrome (SDS). Plot days are being inked in for the last days of August and September, so we hope to see good crowds in the coming weeks.