Agronomy Notebook



Minimizing herbicide injury for crops

By Jeff Rectenwald, Asgrow/Dekalb agronomist

Post-emergence herbicide tank mixtures are an important element of integrated weed management of tough-to-control broadleaf weeds in corn. Environmental conditions, such as those that have favored development of thin cuticles on the leaf surfaces of corn this spring, influence the absorption of post-emergence herbicides and potential crop tolerance. Warm, humid conditions promote rapid absorption while cool conditions may slow crop development, herbicide uptake and crop selectivity. Crops under stress may not metabolize herbicides quickly enough to avoid crop injury. Therefore, it is important to take appropriate steps to minimize the risk for injury.

 

Basics of leaf cuticles

The leaf cuticle changes during early corn development. From emergence to V4, under normal conditions, corn leaves have crystalline deposits of wax on the cuticle, which reduce herbicide spray retention and leaf wet-ability by trapping air under the spray droplets. There is rapid change in the cuticle from V5 to V8 as the wax becomes a smooth film on the leaves.… Continue reading

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Watch for seedling blights in corn

By John Brien, AgriGold agronomist

The spring of 2012 is shaping up to be another planting season to remember. Late March was warm and beautiful and got a lot of growers excited about planting corn, then April hit. The first portion of April was decent but after April 10, the temperatures were less than ideal. While the soil conditions were good in most areas, the less than ideal soil temperatures kept most growers wondering when to plant corn. Unfortunately the cool to cold soil temperatures were, in fact, a major hindrance in corn growth.

While most corn planted in Mid-April emerged, that emergence took 2 to 4 weeks and once it emerged, the growth has been less than ideal. The latest concern on the corn planted on April 17 through April 20 is a large and often devastating infestation of seedling blights. Seedling blights is a generic term for soil-borne pathogens such as Pythium and Fusarium attacking the struggling corn plant.… Continue reading

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2012 off to a good start compared to 2011

By Matt Hutcheson, CCA, Associate Agronomist, Seed Consultants, Inc.

What a difference a year makes! According to a recent USDA crop progress report, as of May 20, 94% of Ohio’s corn crop was planted and 74% of the state’s soybeans were in the ground — a big difference compared to last year when almost nothing had been planted at that point. This year’s planting progress is also well ahead of Ohio’s 5 year average. Some growers planted corn as early as late March and some were sidedressing nitrogen in early May. The unseasonably warm weather in early March created favorable conditions for field work and had farmers in their fields earlier than normal.

It is a common understanding that early planting will provide corn with a higher yield potential; however, planting too early can leave plants vulnerable to adverse weather conditions, such as below freezing temperatures. Some of the earlier planted corn in Ohio was stunted by frost.… Continue reading

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Now is a good time to evaluate plant stands

Jeff Rectenwald
, CCA, Territory Agronomist for Asgrow/Dekalb

Now is a good time to be evaluating corn and soybean stands for plant populations, inter-row plant spacing, and seedling plant health. It takes about 100 growing degree units (GDU) before corn will emerge. While in the field, be on the lookout for black cutworms and bean leaf beetles.

When scouting fields, I like to take a piece of rope 17.4 inches long for determining corn plant populations, a hoop 28.2 inches in diameter for soybean populations, a tile spade for quickly digging plants out of the row, and a bucket with a lid and some water for washing off roots and looking for disease. These are just a few of the scouting tools that can be used for diagnostics in the field.

Evaluating plant emergence and viable plant population shortly after emergence is important for future management decisions. If population is greatly reduced, replanting may be justified and should be accomplished as soon as possible.… Continue reading

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Wheat is at a critical disease stage

By Dave Scheiderer, Integrated Ag Services

Now is the time to take a close look at your wheat crop. Most of the wheat in central Ohio is nearing complete flag leaf emergence (Feekes 9). This is the critical growth stage to determine the need for a fungicide application to control leaf diseases. Integrated Ag Services (IAS) consultants have been scouting several wheat fields, and so far we’ve seen very low disease pressure. Septoria leaf has been found on some of the lower leaves and Powdery Mildew has been found in some over seeded areas, such as overlaps on point rows, but these areas are very limited. In general, we don’t think a lot of fungicide will need to be sprayed on wheat in central Ohio.

For those farmers concerned about grain quality and yield reductions caused by Fusarium Head Scab, the timely use of a fungicide like Prosario can reduce the incidence of this disease.… Continue reading

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Uneven corn emergence issues

By Jeff Rectenwald, Monsanto territory agronomist

Several factors can contribute to uneven corn emergence and growth early in the season. Replanting is not often justified due to uneven stands; however, understanding why uneven emergence occurred can help minimize the risk in the future. Additionally, consideration should be given to how uneven early growth can affect the implementation of some management tools the rest of the growing season.

Potential causes of uneven growth:

• Soil Moisture Variability in Seed Zone — a corn kernel imbibes approximately one third of its weight in water during germination. When kernels within a row are exposed to different amounts of soil moisture, the rate of germination and emergence can vary from plant to plant, resulting in uneven emergence and early growth, or possibly stand loss. Small differences in soil moisture within a row can lead to considerable differences in germination and emergence. Planting deeper to reach uniform soil moisture, managing residue to minimize trash getting wedged into the seed trench, and reducing additional loss of soil moisture can help achieve more uniform emergence and early growth.… Continue reading

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White mold resources

A new online resource called WhiteMoldInfo.com is now available for soybean growers seeking timely information and disease prevention strategies to stay one step ahead of white mold this year.

Developed by MANA Crop Protection, growers can utilize this exclusive online resource and enroll for Soybean White Mold Weekly Updates by accessing URL address http://whitemoldinfo.com/, or by simply typing whitemoldinfo.com into their Internet browser.

Dave Feist, Project Development Leader for MANA Crop Protection, said the new online resource was created to deliver highly relevant information to soybean growers seeking disease management insight behind the complexities of white mold.

“Growers who have soybean in high alert areas for white mold are encouraged to utilize the information to gain an understanding of the disease’s profile and proliferation trends, ways to minimize spreading between fields, evaluate its economic impact on yields, and learn preventative approaches to minimize risk,” he said. “Also, growers can opt to receive a weekly email update which will give additional insights during the season, along with regional planting progress and outbreak reports.”… Continue reading

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Assessing frost injury in corn

By Mike Kavanaugh, AgriGold Agronomy Manager

 

As the first significant cold front of the 2012 growing season passes through, many

questions are arising concerning the fate of planted corn in the case of near or below freezing temperatures. With such a warm, early spring, many acres have been planted throughout the central and southern Corn Belt.

The key through the frost evaluation process is to understand the growth pattern of these small corn plants and give it at least a week for proper evaluation. Obviously, the bigger the corn is, the more susceptible it is to freeze injury. This is true because the depth of the growing point becomes shallower within the soil surface as the plant continues to grow. Keep in mind that the growing point or crown is located at approximately .75-inch below the soil surface, providing that planting depth itself was below 3/4 inch. The growing point does not actually reach the soil surface until the plant reaches the V5-V6 growth stage.… Continue reading

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Tips to maximize planting

By John Brien, AgriGold agronomist

Planting corn is a race against time — trying to cover all of the acres in a very narrow window. Because of the time crunch, planting is often seen as just another operation that needs to be completed quickly, when in all actuality, planting is the single most important operation to achieve a bumper corn crop. Planting is not just about putting seed into the ground, planting is about providing the proper conditions to achieve an even stand with a quick and uniform emergence. The key to planting success is the corn planter.

Why is so much emphasis put on the planter? Because once a corn seed is planted, there is very little to nothing that can be done to fix the errors of planting. Therefore, properly planting the crop the first time is essential. The following is a list of some last minute tips to help get the corn crop off to a great start.… Continue reading

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Get corn plants off to a good start

By Kirk Reese, Agronomy Research Manager, Pioneer Hi-Bred International

When considering corn planting for 2012, one certainty is that the growing season will be different than past growing seasons. However, there are some tactics, including planting at the proper depth, that will help overcome weather challenges in the crop.

Corn planting depth is easily measured shortly after emergence. Taking care to dig up as much of the plant as possible, the distance between the growing point, also known as the first node or crown, and the soil surface is usually three-quarters of an inch deep when planted at recommended planting depths. Measuring the mesocotyl, the area between the seed and the growing point, then adding three-quarters inch, will determine planting depth in the soil. Under ideal conditions, corn can emerge in a week to 10 days. Under more stressful conditions, such as wet soils or extended periods of temperatures below 50 degrees, corn may take up to three weeks to emerge.… Continue reading

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Anhydrous injury in corn

By John Brien, AgriGold agronomist

Each year, many corn growers that use spring applied, preplant ammonia find some degree of anhydrous ammonia injury within their corn fields. Severe injury can cause significant germination problems or root pruning, which leads to stand loss or uneven stands, which can ultimately lead to significant yield losses.  

As the spring of 2012 begins, much of the Corn Belt has found itself putting on a lot of ammonia and considering planting very soon. This means that the time between anhydrous ammonia applications and planting will most likely be very minimal in many cases. Injury from anhydrous ammonia can be easy to diagnose but somewhat difficult to prevent. Below are some precautions and preventative measures to take to avoid anhydrous injury in corn.

The first step in preventing anhydrous ammonia injury in corn is to understand how anhydrous moves in the soil. When anhydrous ammonia is applied to the soil, it can disperse approximately 3 to 4 inches away from the injection point. … Continue reading

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Fighting winter annuals

By John Brien, CCA, AgriGold regional agronomist

 

The Eastern Corn Belt is experiencing one of the warmest winters on record. Temperatures have consistently been 5-10 degrees Fahrenheit above normal for most of the winter months, with some locations recording 60+ degree temperatures in the month of February. The warm weather throughout the winter could lead to a lot of unwanted situations in 2012. One of the unintended situations caused by warmer than normal temperatures is the potential for high infestations of winter annuals.

Winter annuals are unique in that they grow during the cool times of the year when other annual weeds become dormant. The life cycle of winter annuals begin anytime between late summer and early spring. The newly sprouted weeds overwinter as small seedlings and then when the weather begins to warm in the spring they continue to grow, flower, put on seeds and then die. Winter annuals typically grow close to the ground for protection against cold winter days.… Continue reading

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A last look at 2011 Ohio corn yields

By John Brien, CCA, AgriGold regional agronomist

Corn yields are the holy grail of corn production, high yields are worthy of bragging rights at the coffee shop and low yields are all the more reason not to leave the shop during the winter. All growers strive for the highest yields possible, but after anytime of farming a grower quickly realizes that we are not in total control of the entire yield equation.

2011 corn production proved to be quite an adventure no matter where you lived. The weather was challenging early to almost the entire state and caused major delays and challenges to planting. To some growers the weather continued to be challenging all year long, while to other growers the weather later in the growing season was extremely rewarding. The old adage of “rain makes grain” held true again in 2011. As the spring of 2012 quickly approaches, a final look at how the 2011 corn crop makes a nice bookend to a year no one will forget.… Continue reading

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Will Goss's Wilt be a challenge in 2012?

By John Brien, CCA, AgriGold Regional Agronomist

Goss’s Wilt is one of the most devastating and feared leaf diseases a corn grower can experience.

There have been several “reports” of finding Goss’s wilt in Ohio corn fields in 2011, but no confirmed cases to AgriGold’s knowledge. All the cases have been a case of misidentification. Even though there are no cases of Goss’ Wilt in Ohio, nor does AgriGold believe there will be for several years, some background information and how to identify the pathogen should help extinguish any false rumors and/or fears.

Goss’s Wilt was first observed in Nebraska more than 40 years ago. For much of that time, the disease seemed to be content in Nebraska but beginning in 2008 it began to march eastward into Iowa, Illinois and Indiana. Since that time Goss’s Wilt has continued to grow exponentially in the I-states, most notably Iowa and Illinois.… Continue reading

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Will Goss’s Wilt be a challenge in 2012?

By John Brien, CCA, AgriGold Regional Agronomist

Goss’s Wilt is one of the most devastating and feared leaf diseases a corn grower can experience.

There have been several “reports” of finding Goss’s wilt in Ohio corn fields in 2011, but no confirmed cases to AgriGold’s knowledge. All the cases have been a case of misidentification. Even though there are no cases of Goss’ Wilt in Ohio, nor does AgriGold believe there will be for several years, some background information and how to identify the pathogen should help extinguish any false rumors and/or fears.

Goss’s Wilt was first observed in Nebraska more than 40 years ago. For much of that time, the disease seemed to be content in Nebraska but beginning in 2008 it began to march eastward into Iowa, Illinois and Indiana. Since that time Goss’s Wilt has continued to grow exponentially in the I-states, most notably Iowa and Illinois.… Continue reading

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Boosting the solar power of corn

By Dave Nanda, Seed Consultants, Inc.

These days we hear a lot about reducing the use of fossil fuels and producing more clean energy by solar panels or wind machines. However, I don’t know of a better system than the corn plant that not only captures sunlight efficiently and simultaneously reduces carbon dioxide and gives us oxygen so we can breathe. A very small percentage of the solar energy is captured by the plants; most of it is either wasted on the ground or is reflected back. So what can we do to make a more efficient use of this free energy?

Our corn breeders have been collecting germplasm from all over the world and developing superior hybrids for a long time. We have designed hybrids with upright leaves, which can capture more sunlight and also allow the lower leaves to receive and trap greater amounts of light. These hybrids may also be planted at higher populations.… Continue reading

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Zinc's role in corn production

By John Brien, CCA, AgriGold regional agronomist

Zinc is a micronutrient, meaning it is needed in very small amounts by the corn plant. Actually the amount is measured in ounces per acre instead of the normal pounds per acre of other major nutrients such as nitrogen and potassium. A 150-bushel corn crop is known to remove only 0.25 pounds of zinc. Even though zinc is needed in small amounts, it has a huge impact on how a corn plant grows and ultimately how much yield is produced. In a study performed by the University of Nebraska on a low zinc testing soil showed a 53-bushel increase in yield by adding one pound of zinc to a starter.

Zinc plays a critical role in the following systems of a corn plant:

• Aids in the synthesis (production) of growth hormones and proteins.

• It is needed in the production of chlorophyll and carbohydrate metabolism.… Continue reading

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Zinc’s role in corn production

By John Brien, CCA, AgriGold regional agronomist

Zinc is a micronutrient, meaning it is needed in very small amounts by the corn plant. Actually the amount is measured in ounces per acre instead of the normal pounds per acre of other major nutrients such as nitrogen and potassium. A 150-bushel corn crop is known to remove only 0.25 pounds of zinc. Even though zinc is needed in small amounts, it has a huge impact on how a corn plant grows and ultimately how much yield is produced. In a study performed by the University of Nebraska on a low zinc testing soil showed a 53-bushel increase in yield by adding one pound of zinc to a starter.

Zinc plays a critical role in the following systems of a corn plant:

• Aids in the synthesis (production) of growth hormones and proteins.

• It is needed in the production of chlorophyll and carbohydrate metabolism.… Continue reading

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Tips for contending with emergence issues this spring

As spring emerges, so can emergence issues if growers don’t focus on mitigating the stresses of early planting and high residue, according to experts from Pioneer Hi-Bred, a DuPont business. 


Early planting can be appealing to growers with many acres to plant who want to get ahead of spring rains like those in 2011. In addition, early planting can provide potential benefits, such as more time for crop development and the potential to help reduce the effects of mid-summer droughts in some years.

“Predicting the best time to plant can be tricky, as each growing season provides unique environmental challenges,” said Imad Saab, Pioneer research scientist in crop genetics, research and development. “Emergence can be delayed or reduced if planting conditions are less than ideal, and this commonly leads to yield loss for the grower.” 


To maximize emergence, Saab recommends growers avoid planting until soil temperatures are 50 degrees or more, and preferably with a near-term warming trend.… Continue reading

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Should you use starter fertilizer?

By Dave Nanda, Director of Genetics and Technology for
Seed Consultants, Inc.

Why is starter fertilizer becoming more important than in the past? When we plant early, the growing conditions for germination and early growth of the seedlings are very harsh. The soils are cold and wet and anything we can do to help the little seedlings will give them a head start. In addition, planting in no-till or reduced tillage ground is becoming more prevalent. For applying starter fertilizer, you may have to modify your planter. It is important to have the nutrients, especially, nitrogen available immediately after germination to the young seedlings where little roots are developing. What are benefits of starter fertilizer?

• I have seen better stand establishment where starter was used as compared to the check rows.

• Corn is more robust and healthier. The canopy formation is slightly faster and corn seedlings are ahead of the early weeds.… Continue reading

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