Digital Corner

Adding Value to Yield Maps

Have you shared your yield data on winter wheat with your local AGRIS location? A yield map from a yield monitor can be used to adjust nutrient application rates based on the harvested yield.

The average yield suggests a nutrient removal of approximately 109 pounds of MAP and 129 pounds of potash including the potash in 2700 pounds of straw removed.  Using the yield map the range in application rate based on the yields obtained is 40 pounds of MAP and 51 pounds of potash at the low end up to 150 pounds of MAP and 180 pounds of potash at the high end.  Applying the average rate of 109 pounds of MAP and 129 pounds of potash would over apply in the low yield areas by a factor 270 %   and in the highest yield area it would only apply 72% of the nutrients removed at harvest.

A current soil test is required to estimate the need for additional nutrients assuming in thpis case the soil test values are at optimum levels then a crop removal application rate to maintain the soil test has merit. Replacing the nutrients based on the crop removal from actual yields places them back where they came from. The precision in doing that requires a yield map. If you have not yet shared your yield data with us, this example is one way to add value to your on farm technology and make good use of your data.

Reach out to your Crop Sales Specialists to learn more on how to share your yield data.

Article by Dale Cowan

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Properly Identify Ear molds

The environmental conditions at critical growth stages in corn often determine the incidence and severity of ear molds. Initial infections often occur at brown silk (R2-R3) and continue to develop based on weather conditions post infection. Wet canopies throughout the month of August can provide an ideal environment for growth of ear molds. It is not just rainfall the keep canopies wet for several hours in a day, dew, fog, and high humidity also favour continued development of ear molds.

The first question often asked is where do these diseases come from. Simple answer is they are endemic or always present in our soils. The next question what causes them to infect? We must think in terms of the disease triangle. We have 3 points, first is the presence of host or susceptible crop second is the presence of the disease and third point is the environmental conditions that support infection. When all three points are aligned, we have a problem.

The main Ear Mold of concern is Gibberella Ear rot caused by Fusarium Graminearum the same pathogen that causes head scab in wheat. The main issue beyond yield depression is the production of mycotoxins mainly DON and to some extent Zearalenone. These mycotoxins limit the use of grain in human and livestock feed especially swine but evidence in poultry and ruminants is also a factor in animal performance.

The main way to reduce incidence and severity in corn is time an appropriate fungicide application at R1 to R2.5 growth stage. This has proven to reduce DON by as much as 50%. After the last major disease outbreak in 2018 the Seed Corn companies made a concerted effort to rank their hybrids for susceptibility to Gib Ear Rot and remove from their offerings any highly susceptible high-risk hybrids. There are no hybrids that are resistant to Gib Ear Rots but hybrids do vary in their susceptibility. By ranking their hybrids farmers have a heads up on the risk associated with purchase of hybrid seed corn. It is all about risk reduction not risk elimination.

As I recall in 2018 there were reports from farmers that had fields with ear molds and no associated DON and others with fields with less moldy ears and high DON levels, upon further field inspection it was revealed that there were many different ear molds in some of the fields. Not all molds produce mycotoxins. I thought it might be useful to review some of the ear molds we might see in our corn crop. Identifying the mold helps with the appropriate harvest strategy to mitigate any quality concerns

Gibberella Ear molds are usually found at the tip of the ear and progress down the cob towards the shank end. A fuzzy pinkish mold is a characteristic diagnostic factor. Often infection occurs through the silk channel. As silks dry out and shrink back it becomes easier for the Graminearum spores to germinate and enter the cob. Western Bean Cutworm can also be a vector for the disease and bird damage. Most ear molds result in rotted cobs that can make it difficult to thrash and can add to the fines in the sample.

Diplodia Ear Rot

• The characteristic ear symptom of Diplodia infection is a white mold that begins at the base of the ear and will eventually cover and rot the entire ear.
• Mold growth can also occur on the outer husk which has small black bumps embedded in the mold.
• Unlike Gibberella and Fusarium, Diplodia does not produce any known toxins.

Trichoderma Ear Rot

• Abundant thick greenish mold growing on and between the kernels make Trichoderma ear rot very easy to distinguish from Diplodia, Fusarium, and Gibberella ear rots.
• However, other greenish ear rots such as Cladosporium, Penicillium and Aspergillus may sometimes be mistaken for Trichoderma ear rot.
• Like several of the other ear rots, diseased ears are commonly associated with bird, insect, or other types of damage.
• Another very characteristic feature of Trichoderma ear rots is sprouting (premature germination of the grain on the ear in the field). Although some species of Trichoderma may produce mycotoxins, these toxins are usually not found in Trichoderma-affected ears under our growing conditions

If you find ear molds present in your corn fields this fall it is important not to assume it is always Gibberella Ear Rot. Proper identification leads to better management decisions. Reach out to your Crop Specialist for assistance in identifying the ear mold.

Article by Dale Cowan

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Filling the Gap Between Now and Harvest

With corn fungicide season behind us now is the time to focus on tasks to fill that void between now and harvest and put plans in place to have us prepared for the fall season ahead.

Out of date soil sampling is a great place to start. Whether it be putting in orders for farms that currently have crop in them or on your already harvested wheat ground. Utilizing the equipment and technology we have at AGRIS we can capture a better picture of your farms soil health through grid sampling, zone sampling or Soil Optix. Using that along with harvest yield data is the first step to help us make better more informed fertilizer and lime recommendations for your farms this fall.

Preparing for wheat planting should also be top of mind. It starts with the order of your certified seed, followed by plans for P and K fertilizer applications, utilizing the soil test data we just discussed. But as the weather seems to become more unpredictable in the spring each year, shortening the window for herbicide application, fall herbicide applications have become the preferred route giving us better results and an opportunity to control resistant weeds.

Some benefits to fall applied herbicide is getting a head start on over wintering species and giving your wheat crop a better opportunity to start clean. As well as the benefit of being able to use a product like infinity especially if you normally under seed your crop to red clover. Planning a fall application allows you to still spray Infinity as well as safely under seed red clover in the spring.

Article by Jordan SIsson