Between the R2 and R3 stage, the corn has take up about 75% of the nitrogen for the season. During this time I am often asked “Is my crop running out of nitrogen?”
One common confusion is that many of the symptoms shown in the lower canopy of healthy corn, where there is not a lot of sunlight anymore, falsely resemble a true nitrogen deficiency.
Normal Re-mobilization Nitrogen Deficiency Vs True Nitrogen Deficiency
Even when corn has the optimal nitrogen levels, it’s normal for the very bottom leaves to die off. The corn has out grown those leaves because sunlight cannot reach them anymore. The nitrogen nutrients mobilize and move to the more effective leaves, higher in the canopy.
When taking a closer look, these normal re-mobilization nitrogen deficiencies differ from true nitrogen deficiencies. First, it only effects the very bottom leaves, the next leaf up will be fully green and healthy. Also, you wont see the classic yellow inverted v down the center of the leaf that comes with true nitrogen deficiency. What you will more likely see is just a yellowing on the outside of the leaf that moves it’s way inward.
At armor strip trial. To help advance new armor numbers that we potentially bring to market.
One experimental from last year that we are excited to bring to market in 2021 is 0711. It’s had a stellar and consistent performance.
Last year we not only ran the 0711 hybrid through strip trials but also through the first independent seed testing trials. It excelled in both.
In the first trials, located in southern WI and Norther IL, it placed 2nd among 66 hybrids. In the independent first trials located in central Iowa it placed 11th out of 54 hybrids.
From all the trials it has averaged in the top ten hybrids. Besides being reliable, it has shown excellent standability, and it comes out of the ground well.
In July we had over 60 mph winds at our Walcott Iowa research farm and I noticed some stalk lodging.
As you may know, corn with lower than optimal potassium levels, yield less grain. On top of that, potassium deficiency also reduces stalk strength, causing both root and stalk lodging.
One factor at our intensive soybean management trial is a Fungicide/ Insecticide application at R3. This is one of the more consistent measurement factors that you can implement on your farm to increase yield and ROI.
Generic Vs Branded
I understand farmers want to save a few bucks with the generic fungicide. However, that tech was built in the 70s and 80s. Newer fungicides have longer residual, more systemic and multiple modes of action, making them a more reliable investment. In my research and field experience, the extra yield you will receive from branded fungicides exceeds the added cost.
With the weather forecast in the 90s for July, the most significant disease expected is Grey Leaf Spot. When deciding whether or not to apply fungicide, the gut reaction tends to be based on corn prices. Yes the price of corn has an impact on the profitability of apply fungicide, but there are other decision drivers to consider.
You should consider these big time drivers for fungicide response:
Crop Rotation – If you are on corn after corn, expect a much higher response to fungicide than normal
Tillage Method -Reduced-till, no-till or strip-till create higher amounts of residue that can harbor diseases.
Another helpful tip is understanding the hybrid’s response to fungicide application. We have a great partnership with WinField United and they do several tests comparing hybrids with and without fungicide application. This helps us inform you of the genetic predispositions of various hybrids and their response to foliar fungicide.
If you have any questions, please contact us. We are here to help.
The DKC 61-40/41 is a valley girl. She is high maintenance but brings the yield! The hybrid features high drought and heat tolerance, but doesn’t handle water as well. Place it on well drained acres. The roots are narrow and penetrating. Keep the population moderate to prevent the roots mass from dwindling and getting “tippy”.
Potassium deficiency in soybean plants can be confusing. Typically in corn we see signs of deficiency worst at the bottom of the plant. This is because the nutrient is very mobile and potassium will prioritize leaves at the top of the plant. However, in soybeans, we often see the deficiency towards the middle to top of the plant with yellowing edges and necrotic leaf margins, while lower leaves can remain healthy and green.
This morning I am getting lots of questions about what impact yesterday’s cold rain had on corn stand establishment. The short answer is the cold rain likely had very little impact on seed viability or final stands. For a further explanation, I would like to point you to a very well done video explanation by our new DeKalb Technical Agronomist, Nicole Stecklein. She is very knowledgable in agronomy and I encourage you to get to know her after meetings and other co-sponsored Liqui-Grow/DeKalb events.
Dr. Brad Bernhard discusses the key management factors needed to overcome the yield penalty when planting corn on corn.
- Residue Management
- bury or size the residue
- Nitrogen Management
- keep nitrogen fertilizer and residue apart
- Starter Fertilizer
- helps plants overcome early season nutrient deficiencies
- Field Selection
- select high yielding fields
- Foliar Fungicides
- disease protection
- Hybrid Selectionge
- stress emergence, yield stability, and disease package