Agronomy Notebook

Stress during grain fill

Rains during June and July set new records in some areas of the Cornbelt this year, causing weak root development, nitrogen loss and even affected pollination in some fields with poor ear-tip fills. Leaf diseases like Northern Corn Leaf Blight and Gray Leaf Spot were rampant in some areas causing additional stress on the corn crop. Some of the effects of this stressful environment on grain-fill are indicated below:

• After pollination, we need 50-60 days depending on the relative maturity of the hybrid, for the grain-filled period. This is when the plants’ primary focus is to fully develop the kernels.

• If there is severe heat or moisture stress during the grain-fill period, the plants start to cannibalize their leaves and stalks to fulfill the growing needs of their progeny, the seeds or grain.

• Plants, like animals, don’t want to produce runts. So, if there is stress during the grain-fill period, the plants start to abort the youngest kernels causing tip die-backs so that the remaining kernels can fully develop.… Continue reading

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Do cover crops reduce leaf diseases?

Five years ago a lot of the ground was left bare during winter without any cover crops. Recent surveys have indicated that the number of farmers using cover crops in the Corn Belt states is increasing every year.

Many benefits of cover crops have been reported but a major advantage has not been emphasized. While scouting corn fields during the last three years, I have noticed fewer disease lesions of fungal diseases like Northern Corn Leaf Blight (NCLB) and Gray Leaf Spot (GLS) in fields following cover crops than those following corn or even soybeans. The disease lesions were more prevalent even on fields where corn was grown two years ago in a corn-beans rotation.

I scouted some corn fields near Batesville, Indiana in the last three years and saw several fields with NCLB and GLS where cover crops were not used. However, less than 20 miles away where Marshall Alford has been using cover crops for many years, I had hard time finding any disease lesions on hybrids with exactly the same genetics.… Continue reading

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Factors for Phosphorus loss from land to surface water

Most of us have reduced fertilizer inputs as crop prices have gone down and this is documented by reduced phosphorus fertilizer sales. But still, I am often asked about issues of phosphorus from an agriculture and water quality standpoint, “Is rate the only concern?”

Rate, and more appropriately soil test level, is important from a water quality standpoint. If we are at a soil test level that does not require any fertilizer application, perhaps 35% of our fields, then risk of loss is reduced to whatever background levels are coming from the soil. If the soil test is in an agronomic range (15-40 ppm Bray P1), water concentration of Total P in runoff is 0.5 ppm or less. If soil test levels are four to five times agronomic levels, however we can see this produce a runoff concentration of 1 ppm or more.

Recently applied P is subject to loss based on the timing, source and placement during the nutrient application.… Continue reading

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Productivity issues for your 2015 corn crop

Yellow corn and soybeans have been widespread the first part of July in most of Ohio. Since May 1,

many parts of Ohio have received at least three to four inches above the five-year average. Growing Degree Days (GDD’s) for the same period have accumulated 1,300 to 1,400 units, which is 200 to 300 GDD’s ahead of normal. We use the GDD’s to track the overall progress of corn development. I like to consult the numbers weekly to track the progress of rainfall and temperature in the state. You can also track these at the Ohio page for the National Agricultural Statistics Service:

Another great service for tracking rainfall comes from The Climate Corporation. Climate Basic is a free service that will send you e-mail alerts when rainfall is detected at your farm. The nice feature of Climate Basic is that it will send you alerts daily on a field-specific report.… Continue reading

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Fungicide economics

Mother Nature has been too generous with moisture this year in most of the Corn Belt states. It has hurt some crops but has been conducive to the development for diseases like Northern Corn Leaf Blight and Gray Leaf Spot. Some of the early planted corn has already been sprayed with foliar fungicides. Late planted corn is starting to pollinate. I have seen a lot of these two diseases during the last two weeks especially on corn after corn ground and have been asked by some farmers if these fungicides applications are economical at the current prices. Some of the guidelines for economic thresholds are given below:

• Corn needs to be protected from leaf diseases mostly during the grain-fill period. Depending on relative maturity of the hybrid, 45 to 55 days, are needed from pollination to physiological maturity or Black Layer.

• We need to protect leaves above the ears which produce most of the grain yield.… Continue reading

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Oxygen a vital nutrient for corn

There are many things in life that we take for granted, such as the sun rising in the east and setting in the west, April 15 being tax day and a salesman showing up just before you were wanting to leave early for the day! There are also some things in the world of crop production we take for granted — it will be hot in August and the weather forecast modules are always wrong after we mow hay.

Crop nutrients can be taken for granted as well, with oxygen being one of those. Growers spend considerable amount of time talking and managing nutrients such as N, P and K (and if we are in a really risky group we may whisper the words boron and zinc). But to bring up oxygen at the coffee shop as a vital nutrient we should manage — that will reward you with the bill.… Continue reading

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Is your corn N deficient?

June 2015 has been a very wet month in most of the Corn Belt setting new records in many places. Some of the corn fields I have visited recently are showing N-deficiency symptoms. Nitrogen is one of the most important elements needed by all green plants for chlorophyll production and for photosynthesis. Urgent action is needed in some fields to save this crop.

• If lower leaves of your corn crop are getting yellowish, starting in mid-rib and moving towards edges, there is a good chance it is a sign of N-deficiency.

• Should you apply additional nitrogen? It depends on how, when and how much nitrogen you have already applied? Did you apply it in the fall and use a nitrogen stabilizer? What form of nitrogen did you use? Do you generally sidedress?

• Some people have suggested soil testing before sidedressing. Well, that may be OK if you had plenty of time, but in my opinion, these tests during the growing season are not reliable, especially with lot of rains we have experienced in June this year.… Continue reading

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Stress during ear development affects corn yield

Understanding how corn ears respond to stress can help determine what stress was present, when the stress occurred, and how to mitigate the stress in the future.

Environmental stresses during any of four ear development stages significantly affect the number and weight of harvestable kernels. The four critical stages are: (1) when the corn ear is setting the maximum number of kernel rows around the ear (approximately V7), (2) when the ear is establishing the maximum number of ovules along the length of the ear (just before pollination), (3) when the maximum number of ovules are pollinated to form kernels (at pollination), and (4) when the ear sets maximum kernel size during the latter portion of grain fill (approximately R3 to R5).

The first yield component determined by a corn plant is the development of ovule rows on the ear, which begins at about the V7 growth stage. Each ovule row will eventually divide to produce a pair of rows.… Continue reading

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Flooding effects on corn

Recent rains have caused a lot of ponding in low lying areas of the fields. What effects would ponding or flooding have on corn plants? Below are some facts:

• Under flooded conditions plants can’t breathe and survive for long. Flooding interrupts the breathing and photosynthetic processes of plants. Obviously, plants which are completely covered by water are at higher risk than those which are partially submerged.

• Oxygen in the soil also gets depleted within 48 hours of flooding and the plant growth functions like nutrient absorption is affected.

• Duration of ponding or flooding is critical. Cooler temperatures after flooding will help the survival of the young plants. Warmer temperatures above 75-80 degrees F following flooding can kill the plants.

• Corn plants which are partially submerged may continue breathing, photosynthesizing and living. Obviously, the longer they are under water, the lower their survival rate.

• Plants older than V6 stage survive better because the growing point is above ground after this stage.… Continue reading

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Seedling blights of corn

We like growers to plant their corn early, however, we want them to wait until the ground is ready and soil temperatures are 50 degrees and above. When you have a lot of area to cover, you have to plant when the weather will let you. But this can create opportunities for disease organisms and insects to attack the newly emerging plants. This year after planting, it turned cold and the seedling blights had their chance to invade. There have been several reports of seedling root-rot in corn fields. Some of the causes for seedling blights are as follows:

• Seedling diseases are favored by wet and cool soil conditions (50-55 F) after planting. Corn planted early or in no-till ground is more susceptible to these diseases. Recent cool and wet periods were ideal for the pathogens that cause seedling blights.

• The disease organisms that infect corn seedlings are species of Pythium, Fusarium and Rhizoctonia.… Continue reading

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Watch fields for black cutworms

Black Cutworm moths are starting to arrive in the Corn Belt with the recent weather fronts moving from southwest and we need to be ready with the rescue treatments, if necessary. We need to learn about their habits and what to look for while scouting. Some of the important points are as follows:

• Black cutworms can’t survive the winters in the Midwest. They fly south before the winter arrives.

• Every spring, moths come back with spring storms and lay eggs on grasses and weeds like mustards, chickweed or even winter wheat.

• From egg hatching to becoming adults it takes 40-50 days depending on temperatures. Even though cooler temperatures earlier may have killed some of the moths, warmer temperatures that followed increased the speed up their development and more will come. Some cutting activity has already been observed in Southern Illinois.

• Corn and soybeans are not their favorite hosts.… Continue reading

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Corn plant development

Much of the corn crop has been planted in the Corn Belt but establishing a good plant stand is most important for getting good yields. The seedling stage is the most critical phase in the life of a corn plant. The young stage of every organism is critical for development and productivity of the adults. If we understand how our crops grow, we can do a better job of meeting the needs of our crops and improve yields. Let’s look at what happens as the young corn plants develop.

• V1 to V2:  It takes 110-120 Growing Degrees for corn seedling emergence. The seedlings emerge when coleoptile, the spear-like leaf pierces thru the ground. First and second leaves develop six to seven days after the seedlings emerge.

• The first roots start to supply water and nutrients to the young seedlings. Roots are very small and banded fertilizer close to the roots at this stage should be very helpful in stimulating early growth.… Continue reading

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Tips for managing a late spring

As winter begins to wind down and the first warm spell of the year arrives in March, many growers are most likely anxious to get into the field. However, ideal weather for spring field work may not be right around the corner. As of the beginning of March, 88% of the Great Lakes were still covered with ice and extended forecasts were calling for colder than normal weather to last into April. Should these predictions be correct, Ohio’s farmers may be looking at a slow start to spring in addition to many other challenges.

One area of concern some producers may have after experiencing harsh winter weather is the current condition of winter wheat stands. Are they sufficient to produce a profitable wheat crop? According an article in a 2014 C.O.R.N. Newsletter written by Laura Lindsey, Ed Lentz, Pierce Paul, “Fields should not be evaluated until completely green from warmer temperatures for at least 10 to 14 days.… Continue reading

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Getting the most out of soybeans might mean planting them sooner

On many farms, getting the corn crop in the ground will be the top priority this spring as planting season gets started. But, more research is suggesting that planting soybeans in April can offer real advantages for that crop as well.

“If you ask most guys when they plant soybeans they will tell you, ‘after corn.’ We think a change needs to be done there,” said Missy Bauer, with B&M Crop Consulting. “With better planters that get seed in the ground more uniformly, and new seed treatments with fungicides and insecticides, we think early planting dates are important. The earlier the planting date the more opportunity we have for sunlight. Sunlight is one of our biggest issues for soybeans. The more we can capture the better off we are.”

Practical Farm Research work from Beck’s Hybrids has consistently shown yield benefits from getting soybeans planted in April compared to May planting dates.… Continue reading

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Match your corn hybrids to your needs and your soils (Even if the seed is in the shed)

Selecting and matching the right hybrids to soils on your farm and for your needs & purpose is one of the most important decisions you will make for meeting your yield goals. Make the hybrid selection on a field-by-field basis and check out the following points:

• No-till, minimum-till or conventional — Hybrids for no-till ground should have very good seedling vigor and strong disease tolerance package.

• What is the CEC and pH value? Hybrids do differ in their response to different soil types. Soil Type Response — Is the soil sandy, loam, clay, with high organic matter content?

• For lighter ground select hybrids with Drought, Heat and Stress Tolerance — Even though we had two years of good growing weather, you never know when Mother Nature wants to turn the heat on again. Hybrids with good drought and stress tolerance are available from Seed Consultants.

• Hybrid Maturity — Generally, full-season hybrids for your area will have the highest yield potential.… Continue reading

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What did we learn from 2014 growing season?

I asked several farmers and Seed Consultant Reps what new things they learned from 2014 growing season. I will be discussing some of those ideas in these articles for next three weeks. It is difficult to learn new things every year but each growing season either teaches us some new ideas or reinforces what we are already know and are using. Some of the things we learned this year are given below:

• Tiling pays big dividends in the long run. We had lot of rains during early spring and fields with drainage tile had a clear advantage in getting planted early. It also emphasizes the value of good drainage for growing corn.

• Early planting pays-off again. The fields which were planted earlier this year pollinated during the cooler weather and were harvested earlier. These fields generally yielded higher and had higher test weight as compared to the same hybrid planted later and harvested at higher moisture.… Continue reading

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Should we be using soybean maturity group as a tool for variety selection?

Over the last decade I have noticed a subtle shift across much of the northern soybean growing region towards planting later maturity group soybeans. This shift, either conscious or unconscious, may be attributed to earlier planting dates, relatively favorable fall harvest windows, and the drive for maximum yield as influenced by high commodity prices.

As with all trends sooner or later, we have a correction year: 2014 was that year for many farmers. As farmers, consultants, and the battered and bruised seed suppliers sort through the plethora of product offerings for 2015, a common question arises: “In 2015, how much weight should we really give to maturity group in these seed decisions?” For those of you with short attention spans like me, the short answer for soybean is not much. For the rest of you, please read on to understand my reasoning.

In 2011, the Wisconsin Soybean Research Program published an article in the journal Crop Management titled: “Optimal soybean maturity groups for seed yield and quality in Wisconsin” (Furseth et al, 2011).… Continue reading

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More questions for your seed rep

I strongly believe that your Seed Rep should be able to answer some tough questions whether he is working for Seed Consultants or some other seed company before you sign on the dotted line. If they can’t answer some of your questions, they should be able get the answers from an agronomist. Below are some more questions:

• Do you have a replicated testing program? How many locations do you have? Where are these locations in my state?

• Does your company enter their corn hybrids and soybean varieties in the university tests? How do you compare with the other brands? Can you explain what LSD means at the bottom of the yield tables and how to use it?

• Where do you produce your seed? How do you spread your risk of seed production? Can I depend on your company to supply me good seed every year?

• With the lower grain prices, you may have to budget tightly for the 2015 crop.… Continue reading

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Interpreting least significant difference in yield data

For studying yield data from university, seed companies or third party sources, always look for the LSD value or Least Significant Difference at the bottom of the data set or Table. What does it mean and how to use it in evaluating data?

• LSD value measures variability in the test which may be caused by soil types, population density variations, micro-environment or experimental errors.

• LSD or Least Significant Difference means that the yields must be greater than the LSD value between any two hybrids, varieties or treatments to be considered significant, to make sure the differences are real and not because of chance or due to soil variability.

• Uniform tests have smaller LSD values and are more reliable. That’s why the Agronomists and Researchers try hard to look for uniform ground for conducting the tests. The differences of 10-20 bushels in high yielding corn test plots are generally not significant and are within the LSD value and it is a mistake to make a big deal because a hybrid tops in one test plot.… Continue reading

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Plan now for 2015 weed control

As herbicide resistant weeds become more prevalent across the Eastern Corn Belt, university weed experts and agronomists continue to advocate the importance of fall herbicide applications. University research has proven to be practical and applicable in the field. Growers who make fall herbicide applications have an easier time keeping weeds under control in the following growing season, and as a result, have cleaner fields.

As harvest winds down, it will be important to take some time to plan for fall herbicide applications. There are many resources available, including articles and discussions of research studies performed by university experts. There are many questions concerning these applications such as: When to apply? What products? What rates? How much should I spend? If you only have time to read one article on the subject, check out this excellent article by Ohio State University’s Mark Loux by clicking here.

As always, Seed Consultants’ agronomy staff is available and has provided the sales staff with resources to assist customers in making sound agronomic decisions this fall.… Continue reading

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