Preharvest Downtime Tasks to Check Off Your List: Part I
It's that time of year . . . the calm before the storm, the preparation for the mad dash, the time when you may try to pace a trough in the floor waiting to get into the field and start picking corn and combining soybeans.
But wait! Even if you think you've got all the equipment spit-shined and ready to roll, you still probably have a few things to take care of before go-time, says Purdue University Extension agronomist and corn expert Bob Nielsen.
Two years ago, getting ready for harvest revolved more around things you could do to counteract what was mostly a drier-than-normal growing season.
What a difference a couple years can make. Now, the homestretch toward corn harvest is peppered with growing disease concerns in many areas because of the wet weather in recent weeks. That puts a premium on a good, comprehensive scouting stroll through your fields before you hit the field.
"Conditions back around pollination were favorable (cool and moist) for infection of the ear silks by some of the ear rot fungal organisms. Most of us remember the challenges (some say nightmares) brought on by ear rots back in the fall of 2009. Two in particular to look for are Gibberella (pinkish-red mold generally near tip of ear) and Diplodia (whitish-gray mold generally near base of ear). Severely affected fields should be targeted for early harvest, rapid drying of harvested grain to 15% moisture or less, and segregation from healthy grain," Nielsen says. "This year's high yield potential is being partially driven by large kernel numbers per ear. These high kernel numbers per ear create, in and of themselves, a photosynthetic stress on the plants because of the demand for photosynthate by the developing kernels. Normally, this photosynthate is generated on-the-fly by active photosynthesis in a healthy crop. If, however, other stress (foliar disease, nitrogen deficiency, drought, hail, late-season flooding, etc.) limits the photosynthetic rate of the crop, the plants sometimes resort to cannibalizing the carbohydrates stored in the lower stalk tissue and remobilizing them to the developing grain. This remobilization physically weakens the lower stalk and makes it more vulnerable to infection by root- and stalk-rot fungal organisms."
If you see this in your fields, check stalk strength by "pushing on the stalks" and "pinching lower stalk internodes" to see if they give in easily. If so, you could be facing some lodging dangers once harvest starts. Plan accordingly, namely, consider harvesting any such affected fields as soon as possible.
However, don't just make your preharvest planning about this year's crop. Nielsen recommends going on a "Sunday afternoon stroll" in your fields. See what hybrids have worked and which ones haven't. Take notes and make sure you're factoring in some often-neglected plant characteristics.
"Choosing hybrids for next year can be very challenging for many reasons. During this downtime prior to harvest, make the effort to visit those signed corn hybrid trials in the neighborhood," he says. "Make notes on those visual hybrid characteristics that are important for your decision-making process."
Think about these traits when you're on your stroll:
Ear height. "Hybrids with high ear placement can be more prone to stalk lodging because of the high center of gravity the high ears represent," Nielsen says.
Disease resistance. If your crop hasn't reached physical maturity, it's a good time to check for how well it's faring disease-wise, especially for foliar diseases like Gray leaf spot and Northern corn leaf blight, according to Nielsen.
Stalk health. This goes back to the importance of good scouting this time of year. "Target severely affected fields for early harvest to minimize the risk of significant stalk breakage/lodging prior to harvest," he says.
Ear size. Check row numbers and kernels per row. Taking note of this can both help you get a feel for your yield potential as well as how well your crop pollinated and made it through any disease pressures it may have faced earlier in the growing season.
Husk coverage. This will affect some critical crop variables for this time of the year. "Some folks favor husk coverage way beyond the tip of the ear that may offer some protection against earworms; others favor shorter husk leaves that may allow for faster drydown," Nielsen says.
Ear droop. "Once kernel black layer occurs (physiological maturity), there is some advantage for ears that shift from an upright to a declined position (droopy, if you prefer)," he adds. "Droopy ears tend to shed rainfall better than upright ears during the important field drydown period, so they may dry down slightly faster than upright ears."