Corn observations: It seems amazing to me to be where we’re at with harvest and it’s only October 4th as I write this! Many farmers finished beans last week and started on corn. It’s a good feeling to be at this point; can also appreciate there’s been no rain and not a lot of breaks either. Please be safe!
This past week was spent taking corn notes and starting to harvest corn studies. Besides harvest stand counts, I also like to look at percent stalk rot in fields. This gives an idea regarding standability and harvest priority. To do this, I use a pinch test using my thumb and first finger to pinch the elongated first or second internode above the soil line on 20 plants in an area of the field. Stalks that are compromised will “give” or “crush”. Obtain a percentage for the number of stalks that do so. Quickly doing this in five areas of the field provides a better idea of stalk health and harvest priority. Stalk quality pinch test video at: https://youtu.be/7z75VN1c51Q. So far, much of the corn is standing well. I’m mostly finding compromised stalks on plants that had premature ear droop. It will be especially important to assess stalk rot for fields that had high southern rust pressure and weren’t sprayed with a fungicide.
Another observation is some weakened ear shanks, although I can’t say this is a problem yet or even widespread. Weakened shanks makes sense on ears that prematurely drooped as that ear shank collapsed. Things we know cause weakened ear shanks and ear drop include stresses like high heat and/or moisture stress around pollination, large ears after this type of stress due to long grain fill, fungal disease like Fusarium infecting the shank, and to an extent, genetics (regarding shank diameter size). As we think of this year, we had the July 8th wind storm shortly before tassel which caused additional stress on plants. Corn also had a long fill period creating larger ears. So again, not saying this is a problem, just something to watch.
Stress cracks and broken kernels are another thing to watch for and seek to minimize. We know this can occur during the grain drying process in the bin when high moisture corn is dried with high heat followed by rapid cooling. In one conversation this week, a farm family was wondering if there were conditions that led to more stress cracks to corn in the field this year. I really don’t know. Found one publication that said internal, invisible stress cracks can also occur during kernel fill as a result of high temperatures and/or high moisture. However, the focus of the publication was viewing cracks with other types of imagery instead of the physiology, so I don’t have more to share on that. Broken kernels can also occur with harvesting higher moisture corn (above 20%), particularly with too high of rotor speed. A handful of guys have mentioned seeing broken kernels as they’ve been harvesting above 20% and shared the combine adjustments they’ve made to minimize them, so thought it may be something to mention. Combine setup is not my expertise but with a quick search, there’s a number of YouTube videos and websites regarding reducing broken kernels that may be helpful.
Corn Drydown Calculator: If you’ve never seen it or used it before, Iowa State University has a neat tool that estimates corn drydown in the field based on weather forecast for a particular area. It’s called the corn drydown calculator and you can find it at: https://crops.extension.iastate.edu/facts/corn-drydown-calculator.
Land Leasing for Solar Development Oct. 9th: Just a reminder of this virtual seminar to be held October 9th from 11 a.m. to 1 p.m. You can register at https://go.unl.edu/solarleasing. This seminar is open to the public. Farmers, landowners, and their families in areas with potential solar development have much to consider and should consider attending. This webinar will give an overview of solar development and touch on major issues to consider when negotiating a solar lease agreement. More info. on this topic at: https://cropwatch.unl.edu/2020/considerations-leasing-land-solar-development.