By Todd Jeffries, Vice President, Seed Genetics Direct
Speaking to a plethora of growers across Ohio, 2022 has been a rollercoaster. Some areas had perfect conditions and were able to get the crop in the ground, only to have it get hammered with five inches of rain 24 to 48 hours after planting. Other areas struggled to get a crop planted and many growers had to take actions they were not proud of, like mudding the crop in because it was June and they needed to get something planted. We can plan and have best practices all we want, but we need Mother Nature to cooperate.
While we may not have the record yields across Ohio as we did last year, we still need to do everything we can to protect plants and yield. Hopefully by now, you’ve scouted your fields, applied fungicide and insecticide if you needed it, and have been diligent in keeping the weed-pressure at bay.
With a number of acres that were planted in less-than-ideal conditions, compaction has been a major issue this year. This has caused nutrient deficiencies in corn while saturated soils have had nitrogen run-off or leach. It’s not only a problem throughout the growing season, but it can spell big trouble as we get near harvest.
In compacted soils followed by droughty to early-dry soils, availability of nutrients, such as potassium, may be limited. Restricting potassium uptake directly affects the overall health of the corn plant, stalk strength and standability. This is because potassium plays a vital role in managing water pressure and movement in plants which affects its standability. Since it has a role in water movement, a lack of potassium can also affect photosynthesis and respiration, which in turn affects carbohydrate movement. If there is a potassium deficiency in corn, it can have a negative effect on stalk quality for those reasons. With late rains this year, plants can garner higher yield potential, which is a good thing quite literally, but when stalk quality has already been compromised, the plant stalk may not support higher yielding crops.
Saturated soils also lead to corn not being able to absorb much-needed nutrients. We all know that a corn plant will take whatever nutrients it needs from the stalk and put all available energy and nutrients toward the ear. When this happens, the stalk will be compromised and lead to stalk lodging. Typical stalk rots like anthracnose, diplodia, pythium and more might also cause lodging issues this fall.
Dan Quinn, corn specialist at Purdue University, recommends the push or pinch test to test lodging in corn. For both tests, evaluate 20 plants in at least five random areas in a field.
To conduct the pinch test, grab the stalk somewhere between the lowest two internodes and pinch it between your fingers to see if the stalk is strong enough to handle the force. If the stalk collapses, it fails the pinch test.
To conduct the push test, push the stalk to a 30-degree angle. If it pops back up when released, it passes the test. If 10% or more of the stalks (two out of 20 stalks) fail either test, prioritize those fields and harvest them first.
Additionally, when planting occurs under soil conditions that are too wet, side wall compaction can occur, smearing soil in the furrow and preventing good seed-to-soil contact. Then, as the soil dries, it becomes hard like a brick and impossible for the roots to penetrate, thus hindering root and plant development.
Excess moisture early in the season also leads to root lodging because roots don’t need to travel very far for moisture as plenty is available near the surface. If root lodging occurs early enough in the season, the plants will straighten back up and be fine. If root lodging happens later at pollination, yields will be greatly reduced.
It is important to walk and scout your fields this fall so you can prioritize harvesting the ones that may have the greater risk of root and stalk issues. Even if you have to harvest it a little bit wetter than you’d prefer, you’ll be protecting yields and preventing headaches. Have a good and safe harvest.