Today on #AskTheAgronomist we are discussing late season cover crops and the benefits below the ground.
0:40 — Crop report update
1:50 — Dec. 1 Iowa cover crop planting deadline
2:42 — Cover crops and compaction
3:33 — Cover crop below-ground benefit
6:50 — Cover crop investment
8:30 — Cereal rye germination
11:35 — Final thoughts
Science has enabled us to delve deeper into the feed bunk and discover some hidden secrets of the silage fermentation process. At Latham Hi‑Tech Seeds, we evaluate hybrids to help guide the selection process for both nutritionists and farmers.
Nutritionists are focusing on the conversion of indigestible starch to digestible starch over time. Each hybrid has its own unique starch digestibility, and research shows that it takes up to 240 days for some high prolamin zein hybrids to fully breakdown. Prolamin zein is a protein the encapsulates the starch molecule, making it unavailable to the digestion microbes for a food source.
Corn hybrids with lower levels of prolamin zein are more easily digested. Select Latham® forage products have low levels of prolamin zein and are more easily digested by cows, which is great news for our customers because undigestible feed turns into manure instead of milk.
Corn test weight also can be an indicator of how much prolamin zein is available. While higher test weights are good thing for grain farmers, higher test weight corn tends also to be higher prolamin zein. As the chart below from Progressive Dairy indicates, prolamin protein tends to break down and more of the starch is exposed over time in an ensiled environment. The challenge is that time isn’t always on a dairy or beef producer’s side.
When feed supplies are low, producers often start feeding corn silage right away. If feed is your end use, choose hybrids that are either lower in prolamin zein or tend to have a lighter test weight. Leafy hybrids from Latham Hi‑Tech Seeds tend to have better starch digestibility scores early. These Latham® Leafy Hybrids can improve early feed conversion: 5400, 5495, and 5742. Order now while our prices are lowest and our supplies are highest!
Is 40,000 plants per acre the answer every time? Tune in for a deeper dive into our LH 5245 VT2 PRO RIB hybrid and the results from our population test. #AskTheAgronomist
0:25 Crop Report Update
1:28 Population test introduction
2:30 LH 5245 VT2 PRO RIB hybrid introduction
4:15 Low population to high population and flex
5:20 Yield Estimates
7:00 How does LH 5245 VT2 PRO RIB flex?
8:13 Stalk quality
10:43 Final thoughts
What is Tar Spot?
Tar Spot is a corn fungal disease that has been infiltrating the Midwest within the last few years. Tar spot has the capability to severely impact yields up to 30%. Concern about the intensity of this fungus grows as researchers learn more about it. We urge farmers to scout their fields through harvest for tar spot since this fungus can survive over winter year to year.
Tar Spot Identification
Tar spot will show up as small, raised blacks spots, on the upper and lower corn leaves. The raised black spots are also known as stromata. If severe enough, it can spread to leaf sheaths and husks. Typically, it will start lower in the canopy and move upward. Tar spots are usually accompanied with a yellow halo or fish-eye effect around the black spots. Note the stromata, cannot be rubbed off unlike a common or southern rust pustule.
The Importance of Scouting
This corn fungus has nearly made it across Iowa and is continuing to spread in Wisconsin, Illinois, Indiana and Missouri. Tar Spot likes cool temperatures and humid conditions, with prolonged leaf wetness or heavy dew and will concentrate towards the middle of the field. It can cause lodging and hasten maturity.
Final Thoughts
This is one of the variables in farming we continue to learn about. Scout now and start planning for next season. Product selection is key when fighting these variables year to year and important to integrate into your plan for the next growing season.
One comment I often hear from farmers is “I just can’t seem to get an increase in soybean yields as I do for my corn yields.” This is the perfect time of year to reflect on the growing season while analyzing yield results. It’s also the best time to sample for soybean cyst nematodes.
What is SCN?
Soybean cyst nematode is a microscopic ground worm. When analyzing soybean roots, it’s important to correctly identify the difference between nitrogen-fixing nodules and cysts. Nodules for nitrogen production are larger and the size of a pea. Cysts are microscopic and smaller than a grain of sand.
One of the biggest challenges when identifying SCN is that it is not accompanied with many symptoms, but can cause up to a 30% yield loss. Usually SCN shows up in hot spots, where you can see severe stunting, yellowing, shorter crop, lack of canopy or early maturity. These symptoms tend to show up on lighter soil or during tough growing seasons. Wherever soybeans are grown, typically SCN is an issue. Below are two maps to show the growth of SCN over the years.
What is the life cycle of SCN?
Essentially the cyst is the life cycle of a nematode. Juvenile nematodes come in and infect the root. Typically, just the females feed on the root which takes away nutrients from the plants results in a loss of yield. They will then mate and produce eggs. When they produce eggs, they expand in the root, erupt and spread 20 to 500 eggs throughout the soil. The cysts then harden on the root and the process begins again.
In Iowa, we can see that happen for at least three generations per season. Each cyst can have between 20 and 500 eggs inside, creating opportunity for juveniles to come back and begin feeding on the soybean root.
Once the eggs get in the soil, it’s important to understand the number that you have in the soil. Those eggs can stay dormant year-over-year in the soil. Since these eggs are so small, they require very little oxygen to survive.
Management of SCN
The most important management practice of SCN is IPM – Integrated Pest Management. In the Midwest, having a corn and soybean rotation is a great start. Corn is not a host crop whereas soybeans are. I also suggest soil sampling this fall to identify the egg population in your soil. Pull a core from about 8 inches down, right next to the soybean plant right in the root zone.
I also advise to stay away from sampling in the middle of a hot spot for SCN. Often the eggs are concentrated along the edge of the hot spot, so sampling that area will give most accurate results. Population thresholds vary by state. I suggest looking closely to your management practices if results are anywhere from 2,000 – 5,000 eggs per sample. Once you know what is in your field, you can begin to manage it.
Here are three ways to help manage this pest:
Feel free to call into the Latham Seeds office or email me at phill@lathamseeds.com with any questions.
Is SCN really a problem in your fields? Tune in to find out! #AskTheAgronomist
The maps below sourced from ISU show the growth of SCN from 1990 to 2017.
How many points per day does corn dry down in October? Tune in to find out!
:25 — Topic introduction
:50 — Crop report update
1:50 — High moisture corn in October – how long should you wait?
4:30 — Example 1: LH 5965 VT2 PRO planted May 15
6:25 — Example 2: LH 5245 VT2 PRO planted June 4
7:33 — What happens if frost hits before black layer?
10:08 — Final thoughts
Use on-farm research to plan for the 2020 planting season. Tune in the hear tidbits from Phil Long!
0:10 – Crop update
1:40 – Assess plant population and ear size
3:45 – Plant population example (15,000 plants per acres – 55,000 plants per acre)
5:00 – When flex ears determine girth, length and depth
6:25 – Tipback, aborted kernels and zippered ears
8:00 – Stalk strength vs population
11:15 – Take notes this harvest season
Many Latham sales managers, dealers and customers have shared their concerns about the excessive rainfall received. Most of Latham Country in the last few weeks have been wetter than normal.
Wet weather brings to mind diseases, and too often we see corn fields with some leaf and stalk quality issues late in the season. I’ve personally seen a lot of Common Rust, Northern Corn Leaf Blight, Gray Leaf Spot and Eyespot this year.
Even with harvest underway, it’s important to continue checking fields and assessing stalk integrity as weather conditions can cause crop conditions to change. Ideally, farmers harvest the driest fields first so crops can dry naturally. This obviously saves time and money, but those plans must be revised if stalk rot shows up.
There are two primary ways to check corn plants for stalk rot: (1) Pinch the stalk at the base of the plant, usually below the first and second nodes. If the stalk pinches easily between your fingers, stalk rot is likely. (2) Take the entire stalk and bend it to a 45-degree angle. If stalk rot is present, the plant usually breaks at the lower part. Do this with at least 10 plants from different areas of your field to provide a good sampling. If stalk rot is present, harvest that field as quickly as possible regardless of the moisture content. The yield that could potentially be lost during high winds or complete rot will far outweigh the extra cost of drying grain.
Weather will, of course, dictate how corn stalks hold up to disease and normal decay. Adjust your harvest plan if needed to harvest the worst first.
