North Central and Northeast Iowa
Tom Larson says farmers in his area have endured a variety of drastic weather events, which has drawn out the planting season. The corn needs some heat and moisture to push it along, especially in some stressed areas where some yellowing is occurring.

With the possibility of uneven emergence in soybeans, Tom says it’s time to scout for bean leaf beetles. Last year fields in north central Iowa that had spotty emergence saw infestations of eight to 10 times more than the economic threshold.  These beetles move pretty quickly, so spend some time walking fields and looking for the classic “shotgun” effect in the first trifoliate of leaves, a lesion on the stem, or a complete cutting of the upper half of the plant.

Central Iowa
In central Iowa, Bart Peterson reports the corn is up to the V6 growth stage and is close to forming a canopy.  The area has also received timely rains, and the soybeans are coming along nicely.

East Central Iowa
Wayde McNeil says that two cases of cutworm in western Marshall County have caused 4% damage. He has also noticed a couple of small cases in central Poweshiek County. In the past week, parts of his territory have received up to two inches of rainfall. He says the corn is coming along good with some in the V6 growth stage. Soybeans are anywhere from VE to V2 growth stage. Farmers are working hard making hay, as well.

Eastern Iowa
Brad Beatty reports corn planting has finished, and the soybean planting is 98% done. Farmers’ focus is turning to spraying both corn and soybeans, and Brand is reminding growers to also scout for cutworms in corn. Producers who have alfalfa are all hoping for a window of opportunity to finish making their first cutting. He advises producers to check with their suppliers on NH3 prices as he has heard prices that are half of what they were last year.

South Dakota
Soybean planting is pretty much complete and 80% has emerged, according to Bill Eichacker. Right now a lot of corn is being sprayed, and he is advising farmers to read and follow label directions. Corn is up to the V5 growth stage. Farmers also have been working hard on cutting alfalfa, and at least 60% of first crop is complete.

Eastern Nebraska
Brian Banks reports that once again rains have been spotty, and where it does rain, it is not enough. Cooler than normal temperatures help compensate for lack of moisture. Overall, the corn is growing well despite the lack of moisture.  Corn growth stage ranges from 4- to 7-leaf.  Dry land corn fields are 2 to 4 inches shorter than they should be at this time.

Cutworm has not yet been much of a problem.  He has only found a couple fields with damage to more than 1% of plants; both black and dingy cutworms are responsible.  Post-emergence herbicide applications are in full swing this week. Pre-emergent residual herbicides are holding on in irrigated fields, but dry land fields are getting very weedy since there wasn’t enough moisture to get a good recharge on the herbicide.

Even in these challenging growing conditions, the performance of Latham Hi-Tech Hybrids LH 6598 VT3 is standing out.  On more than one occasion, LH 6598 VT3 emerged before other (competitive) hybrids that were planted 5-7 days earlier!

Current soybean seeding development ranges anywhere from emergence to 2nd trifoliate.  There are a few guys who are just finishing up planting soybeans in the northern part of the territory.  Emergence has been pretty good, but there are some uneven stands because of inconsistent planting depth.  Normally we get enough rain to get those beans near the surface to sprout, but this year most places were not so lucky.  Populations are still at or above 85% of what was put in the ground, so we haven’t ran in to any replant situations yet.  It looks like the L 2635 R and L 3184 R2 have had the best emergence this year.  Some post herbicide applications have started on soybeans but mostly in cases where there was not a burn down prior to or at planting time.

Latham is a partner in the Iowa State University Extension Corn and Soybean Initiative. That means we get timely alerts when any farming condition emerges that could impact a number of growers.

We recently received an alert about possible emergence of black cutworm in Iowa. The alert is reproduced below. Also, we have a simple spreadsheet calculator available for estimating stand-loss threshold of black cutworm as insecticide is applied.

Just give me a call at 1-800-798-3258 or email me at mark@lathamhybrids.com and I’ll be glad to send you the calculator document and explain it to you. For example, one simple calculation on the spreadsheet shows a corn stand planted at 32K plants per acre with an expected yield of 200 bu/acre at a market price of $6 per bushel and receiving insecticide application at a cost of $15/acre could realize an estimated loss of 400 plants per acre, or 1.25%.

Black cutworm to start cutting May 24: scouting is advised

From Iowa State University Extension Corn and Soybean Initiative

Black cutworms could start cutting corn May 24-26 in the southern two-thirds of Iowa, and the first week of June in the northern three tiers of counties. Growers should scout for cutworms as soon as corn emerges, paying special attention to late-planted or weedy fields.

Most at-risk fields:

• Late-planted
• Reduced tillage
• High weed populations – especially of winter annuals
• Near natural vegetation areas
• Poorly drained or low-lying, such as in the floodplain of a stream or river.

Damage signs
• Small, irregular holes in leaves (from young, above-ground larvae feeding)
• Cut stems or clipped leaves (from older larvae, in 4-6 instar – usually feed underground at night)

When scouting

• Examine 250 plants (50 plants in five locations) weekly until corn reaches V5.
• Check for wilted, discolored or damaged leaves and missing plants.
• If damaged leaves are found: dig around the base of the plant and look for larvae. If soils are dry or crusted, larvae  may burrow to moist soil and move to new plants.
• Flag suspected “hot spots” and monitor larval feeding (or lack of it) for a few days.

Economic Threshold & Treatment Options
•Economic thresholds for black cutworm were adjusted last year due to higher crop value and corn stands.
•A tool to calculate treatment thresholds for stand loss will be published in ICM News next week.

To tell black from dingy cutworm larvae

Both feed on corn, but dingy cutworms rarely cut leaves. Black cutworms have two prominent tubercles (dark bumps) of differing sizes on each body segment; dingy cutworms have two of the same size.

Long story short: Black cutworms may start cutting corn May 24 in the southern two-thirds of Iowa. Scout for corn as soon as it emerges, especially in late-planted, weedy or reduced tillage fields. Use the attached threshold calculator to determine the best treatment for your fields.

Source: Erin Hodgson and Jon Tollefson, ISU Department of Entomology

Hi all. I want to introduce our intern for this summer, Andrew Kilburg. We look forward to Andrew’s weekly reports from the field.  –  Shannon

I am Andrew Kilburg and I just completed my sophomore year at Iowa State. I am majoring in Agronomy and Agriculture Systems Technology, and this summer I will be an intern at Latham Hi-Tech Seeds. One of my duties will be posting weekly blog updates on planting progress for corn and beans, stages of growth, and any weed or pest issues.

It sounds like central Iowa is pretty close to completing corn planting, and has a good start on getting the beans planted. Travis Slusher says “they need a day or two to finish up with planting corn.” Central Iowa has received rain this past week which has kept farmers from the fields.

In northwest Iowa, progress sounds good. Bruce Anderson says“95% of corn is in the ground and 80% of beans are planted.” Growth of corn also looks good in NW Iowa with 75% of the corn up and able to be rowed. Sounds like there isn’t any insect problem yet, but Bruce has heard there is a possibility of cut worms that could hatch around the 22^nd of May. He also says that alfalfa and pastures are growing great. He said the forecast for next week looks to be in the 70’s with a couple days is in the lower 80’s.

Jeff Weier in Western Iowa has reported that planting progress is coming along great. He says “99% of corn is planted with 30-40% of the corn being in the V2 stage of growth”. He also said “the beans are about 50-60% planted, and if the weather holds out this week farmers could begin to finish up with beans.” He hasn’t seen any bug or disease issues yet.

In Wayde McNeil’s territory of Jasper, Poweshiek, Marshall, and Tama counties in Iowa, corn planting is pretty much 100% done with most of the corn in the V1 stage and some in the V2 stage. The beans in his territory are 80% planted. He hasn’t seen any bug or disease problems yet. On Sunday May, 17 he said there was a slight frost, but didn’t cause any damage.

In Eastern Nebraska Brian Banks is saying the bean planting is coming along good with a few spotty rain showers keeping some farmers out of the fields. He says “that some beans are starting to emerge this week, and if things go well most farmers will be finishing up this week. Most of the corn is in the V2 stage.” He hasn’t seen any bug, disease, or weather related issues yet. He did say “they are a little behind average with GDD’s at this time.

In South Dakota Bill Eichacker is reporting that planting is happening earlier than previous years, although the northern part of the state is lagging behind due to flooding and rains.

Bob Colins in Central Iowa reported that corn is pretty much all in the ground and beans will be finishing up in 2-3 days. He hasn’t seen any bug or disease issues at this time.

Brad Beatty around Benton County reported that 95% of corn is planted and 60% of beans are planted. The biggest issue in his territory is the cold soil temperatures. He said “some of the corn is rotting instead of growing, so farmers will have to evaluate to see if they need to replant.” With the cold weekend we just had he thought that most of the corn should be fine, but the few beans that have already emerged will also have to be evaluated to see if replanting is necessary.

Jason Obermeyer in Minnesota reported that all corn planting is done and beans should be finishing up this week. He hasn’t noticed any widespread bug or disease issues. Most of the corn has emerged, and all they need is some warmer temperatures to help with growth.

Bill Latham of Latham Seeds was interviewed by SeedWorld, a major agricultural and commercial seed media company. Bill shared his thoughts on a variety of topics, from students entering the seed business to shifts in the demand for and roles of genetics and traits.

Click here to take a look at one of the interview installments.

To view the entire six-part series, Giant Views of the Seed Industry, click here.

Bill may have giant views, but Latham Seeds and Latham-Hi-Tech Hybrids are committed to being anything but giants. We just want to keep doing what we’re doing: being a trusted, independent, innovative partner with Midwestern farmers every day, every year.

Harvest is here, and I’m optimistic that we will see some great yields. I think however, that we’ll also see more stalk rot and premature plant death due to wet planting conditions, severe storms throughout the growing season and low rainfall periods.

You may notice that some areas of fields are maturing more slowly. Other areas may have died early. When corn plants don’t live for the full season, they don’t achieve maximum potential yields. Even though kernels on “prematurely dead plants” display a black layer, the lack of kernel size indicates they reached this stage too soon.

Why have plants and areas of fields died prematurely this year? Reasons for premature death, that I have witnessed this year, include: moisture stress, nitrogen loss, anthracnose top-dieback, stalk rot and wind/hail damage.

In summary: All of the stresses have likely contributed to the overall rapid shutdown of photosynthetic leaf area. Given the importance of live, viable leaves and their contribution to the grain filling process, the rapid leaf senescence evident in corn fields this year will likely shave some bushels off the upper limit of yield. Plants suffering from such stress struggle to complete grain fill before they die. As plants struggle to complete grain fill, they often resort to cannibalizing the carbohydrates and nutrients from the leaves and stalks in order to fill the grain. This leads to root and stalk rots.

There is nothing that can be done now to prevent premature death; however, growers should walk their fields, monitor the stalk health, and adjust harvest strategies accordingly to manage fields where stalk lodging may be a big problem.

I am beginning to get reports that corn is lodging this year. What is particularly alarming is that stalk lodging is occurring in fields with hybrids that typically have very strong stalks. And, even more perplexing, when stalks are split open, they appear to look healthy however the pith is gone right above the node where the stalk lodged over. Many farmers are asking how this can happen.

Typically, weaker stalks result from smaller root systems. This leads to less nutrients going into the plant to satisfy the high demand for carbohydrates of the grain. If the roots bring in less nutrients than the demand of the grain then the grain will pull the carbohydrates it requires from the leaves and stalk. This creates hollowed out pockets above the nodes, which weaken the stalk, and predispose stalks to lodging whenever we get strong winds.

Below, I have put together some talking points that can be helpful in diagnosing weak stalks that may be found in your fields this harvest season.

The most effective management practice at this point in the season is to monitor fields and determine the level of weak stalks in the field. Randomly walk each field and test stalk strength of 50-100 plants by squeezing the stalk at the lower two internodes. If the stalk collapses between the thumb and forefinger of 25 or more plants, weak stalks have advanced to problem levels. These fields are at high risk to wind damage and should be harvested first to decrease lost yield from unharvestable ears.

#1 Wet Spring (late planting, small roots, side-wall compaction, N loss, and poor potassium uptake)
Corn plants have smaller than normal root systems this year. Later planting did not allow the plants time to generate roots that will reach water deep in the soil profile. In addition, when soils are wet, sidewall compaction at planting time can cause nutrient deficiencies later in the season, particularly nitrogen and potassium.  We probably lost some applied nitrogen due to wet conditions early. In essence, the plant will do all it can to “pump” carbohydrates into the kernels, sometimes at the expense of the health and maintenance of other plant parts including the roots and lower stalk.

#2 Dry periods (drought) during grain fill
Fields subjected to several weeks without rain will stress the plant and cause the plant to move nutients from the stalk into the ear to fill the grain.  This weakens the plant to the point that lodging can occur. Additionally, pathogens can invade and infect the plant causing premature plant death, dropped ears, lightweight grain and encourage the development of stalk rot.

#3 Cooler temperatures and cloudy conditions during grain fill
Cooler temperatures and cloudy days during grain fill can reduce sunlight to the leaf area that provides carbohydrates to the developing kernels. As a result, the corn plant draws reserves from the stalk tissue. The mobilization of nutrients our of the stalk creates hollowed out pockets which weaken stalks and can predispose the plant to stalk rot diseases.

Harvest is drawing near, and I’m optimistic that we will see some great yields. I can’t help but think that we’ll also see more stalk rot and premature plant death due to wet planting conditions, severe storms throughout the growing season, and low rainfall periods in July.

We expect corn plants to begin maturing this time of year, but you may notice that some areas of fields are maturing more quickly. Other areas may even die early. When corn plants don’t live for the full season, they don’t achieve maximum potential yields. Even though the kernels on “prematurely dead plants” display a black layer, the lack of kernel size indicates they reached this stage too soon.

Why do plants and areas of the fields die prematurely this year? While every field is a little different, there is almost always more than one factor involved. Reasons for premature death that I have witnessed this year include: moisture stress, nitrogen loss, anthracnose top-dieback, stalk rot, and wind/hail damage.

Moisture Stress. Generally, corn root development was not good this year because of early season wetness over an extended period. During grain fill, a plant needs a lot of water. Shallow, poorly developed and partially decayed root systems can’t provide enough moisture to keep the plant going especially during hot summer days. This scenario is particularly noticeable in places where there was standing water earlier in the season.

Nitrogen loss.  Some plants are showing significant signs of nitrogen deficiency before they die. Wet conditions early in the season have resulted in the loss of nitrogen in many fields or parts of fields, and plants prematurely die because of a severe nitrogen deficiency.

Anthracnose top-dieback.  This phase of the anthracnose disease is less common than the typical stalk rot that occurs at the stalk base. With top-dieback, the plant dies from the top down. The upper leaves turn yellow or reddish purple, then dry out. The fungus usually infects through the whorl earlier in the season and remains dormant in the stalks until late in the season.  Late-season stress triggers the development of disease symptoms.

Sighting of a yellowed, or purple flag leaf on the corn plant is a key symptom of anthracnose top-dieback.  (above).  Another key sign will appear during wet conditions.  A pink substance will be observed on the stalk (below).  Photos courtesy of Iowa State University.

Stalk rot.  Some plants might die because the base of their stalk is rotted by Gibberella or Fusarium.  The onset of these stalk rots is also stress related. When the stalk base is rotted, the whole plant wilts and dies rather suddenly. To see the symptoms, you may need to split the stalk all the way up the base, from below the soil line.

Wind/hail damage.  Plants that were damaged by wind and hail earlier in the season are vulnerable to a number of problems that may show up now. Because of the physical damage to leaves, stalks, and roots, these plants are especially likely to suffer from stalk rot or a moisture-stress-related death.

To summarize, all of the stresses have likely contributed to the overall rapid shutdown of photosynthetic leaf area.  Given the importance of live, viable leaves and their contribution to the grain filling process, the rapid leaf senescence evident in corn fields this year will likely shave some bushels off the upper limit of yield.  Plants suffering from such stress struggle to complete grain fill before they die. As plants stuggle, they often resort to cannibalizing the carbohydrates and nutrients from the leaves and stalks in order to fill the grain.  This leads to root and stalk rots.

Obviously there is nothing that can be done now to prevent premature death.  However, growers should walk these fields during the next few weeks, monitor the stalk health, and adjust harvest strategies accordingly to manage fields where stalk lodging may be a big problem.

With late plantings and a wet spring, this year has created disease conditions in areas with:

• Wet, humid soils combined with recent high temperatures
• Fields with high residue
• Reduced or no-till ground

Anthracnose is among the diseases that thrive in these conditions. It’s caused by a fungus and can affect the plant at any stage of growth. Look for these symptoms: leaf blight, stalk rot, top-kill of the stalk, and kernel rot. The disease causes the most problems at the leaf blight and stalk rot stages.

ABOVE: Anthracnose leaf blight (Ohio State University)

ABOVE: Anthracnose stalk rot (Ohio State University)

Grey Leaf Spot can be easily confused with other types of disease in its first stages of development. The tell-tale sign for this disease is small lesions surrounded by yellow rings or halos. The fungus will begin in the lower leaves and move to the top of the plant. Lesions travel through the tissues in the leaf, elongating and eventually merging together. The plants then become much more susceptible to other disease such as stalk rot.

ABOVE: Gray Leaf Spot

Northern Leaf Spot is a fungal disease that, like Grey Leaf Spot (GLS), is identifiable by its narrow elongated shaped lesions surrounded by a pigmented border. The disease will spread to all parts of the plant including leaves, sheaths, husks, and ears. Spores are released and are capable of traveling and infecting neighboring fields.

ABOVE: Northern leaf spot (Ohio State University)

For each of these specific diseases, I recommend control methods of fungicides or resistant/tolerant hybrids. For more information on these and other mid-season corn diseases, Purdue University’s Desktop Reference link is a great resource.