Agronomy Notebook

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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How do you analyze test plot data?

Most farmers plant single strips of several hybrids and try to select hybrids for the following year. Single strips are OK for observations but replications can measure variability and give you more reliable results. Consider the following points for analyzing test plot data.

• One location or test is not enough to draw conclusions about the performance of a hybrid or variety but it is a lot better than not planting any test plot at all. However, when combined with information from other unbiased sources, your own test plots become a powerful tool for the selection process, especially when you start accumulating data for several years.

• For analyzing yield data whether from university trials, data from Seed Consultants test plots or third party data, make sure you are looking at data from replicated tests.

• Replications must be randomized which allows every hybrid or variety an equal chance of being on a certain piece of ground or next to a certain treatment as any other.… Continue reading

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Corn maturity and drydown

Corn kernels are about 32% to 30% moisture content at physiological maturity or when black layer develops. Several factors influence field drydown after black layer. Kernel moisture content decreases faster with warm, dry weather and may decrease slowly in a wet and cool environment. Fuller season corn hybrids that require more growing degree units (GDUs) to mature will likely be slower drying as the fall progresses within an area. A full season Hybrid like DKC64-87RIB requires about 2,850 GDU’s to reach black layer. Crop maturity can be delayed by dry weather, which usually results in a loss of potential yield because plant death occurs before the kernels gain their full weight and size.

Did you know that the optimum grain moisture for grain corn harvest is 23% to 25% moisture? Typical drying rates after black layer range from 0.4% to 0.8% kernel moisture content loss per day. I like to use the guide of about 3 days are needed to remove 1 point of grain moisture from the kernel.… Continue reading

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Causes and cures of ear droppage in corn

There are several reasons for ears falling off of corn plants. Ear droppage may be caused by both genetic and environmental factors. Corn breeders try to discard the experimental hybrids with a tendency to drop ears and select hybrids with good ear retention.

• I had observed a lot of European corn borer damage in conventional corn fields this year in July. Larvae of second brood of borer can tunnel into the shank and weaken the attachment of ears to the shank.

• During crop scouting recently, I noticed several dropped ears in a corn field. Investigation revealed that corn borers were one of the causes of ear droppage in conventional hybrids.

• Check the shank attachment of each hybrid. Select those with strong attachment with good ear retention characteristics.

• Select hybrids with tolerance to Diplodia ear rot, the whitish fungus that usually starts at the base of ears, causes ear rot and can result in ear droppage as well.… Continue reading

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Factors affecting corn dry down in the field

Growers like to have hybrids with high yield potential, excellent disease tolerance, great standability, faster dry down and lower grain moisture at harvest. Well there seem to be a contradiction here. Hybrids that live longer are not going to die earlier and dry fast. Management decisions such as planting date, plant population, amount of nitrogen used, and use of foliar fungicides all affect the rate of dry down and grain moisture at harvest.

• Corn breeders have to constantly compromise to find hybrids with the right combinations that will produce the highest income for the growers. What are the agronomic and genetic characteristics of corn hybrids that affect rate of dry down?

• Hybrid relative maturity, thickness of pericarp or skin of the kernel, ear angle after maturity can all affect dry down rate. Hybrids with thinner cobs tend to lose moisture faster.

• As corn matures, moisture is lost through cob and ear shank, exposed ear tips and husks.… Continue reading

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How to prevent N leaching

Even though it appears that we are headed for a record corn crop, some farmers have noticed signs of nitrogen deficiency showing up in their crops. According to some of the Seed Consultant professionals, these growers applied the nitrogen fertilizers by splitting application and side-dressed as late as possible. However, the drenching rains that followed a week after caused nitrogen to leach down and, later in the season, fields showed up with N-deficiency symptoms. It is too late for this year’s crop but what can you do for the growing crop to compensate for N loss due to too much water and what may be done to reduce nitrogen leaching for future?

Consider the following approaches to nitrogen management:

• If it happens again, to rescue a growing crop in the field, you might consider reapplying up to half your N fertilizer if it rained three to six inches over a day or two, or if you have field ponding lasting three days or more.… Continue reading

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Maximizing soybean yield potential

The payoff of a year’s worth of planning, planting and preparation is finally getting started with soybean harvest this fall.

The soybean yield at harvest is affected by several factors starting before planting occurs. Although most are focused on late season rainfall and preparing for the upcoming harvest, it is always important to review current management practices and ways to improve for next year’s crop.

The highest yielding soybean fields start by selecting the best varieties for your geographic area, soil types and planting conditions. There are numerous varieties to choose from and multiple sources of information, but first it is important to understand your fields and the traits that are needed to maximize yields. Do you have soybean cyst nematode or other diseases? Look for varieties that are consistently in the upper yield tier in multiple tests like the state trials. Understand that statistics may show that the performance of many varieties can’t be separated in the results due to variation at the testing sites.… Continue reading

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How does flooding affect corn?

We have seen a lot of corn fields that were flooded in the low-lying areas. How does flooding affects corn plants and what can we do about it?

• Like people, if plants can’t breathe, they can’t 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 are affected.

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

• Plants older than V6 stage survive better because the growing point is above ground after this stage. If the growing point is still below ground, it may start to rot.… Continue reading

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