This season has been one for the record books for nearly every state in the Corn Belt. Extreme rainfall and delayed planting forced many farmers to plant well into June and in some cases, July. As every seasoned farmer knows, conditions like what we saw in 2019 will have consequences. A carefully laid fall harvest plan will help to limit further losses come harvest time. If we look back one year to 2018, many of these same environmental conditions occurred across Southern Minnesota and Northern Iowa. There are lessons to learn and adapt to help us be more successful in 2019 across the Midwest.
Environmental Impacts on Corn Development
Corn growth and development is driven by heat unit accumulation. However, as planting becomes delayed, corn tends to mature at a faster pace. In fact, it requires about 6.8 fewer heat units for every day planted after May 1. Specifically, this faster rate of development tends to abbreviate the vegetative growth stages which is when the majority of nutrient uptake occurs. With a shortened period of vegetative growth, there is less time to acquire essential nutrients and thus less supply to build yield during grain fill. This is why later planted hybrids tend to yield less than their earlier equivalents.
The length of time required for the reproductive growth stages, for the most part, remains largely unchanged with delayed planting. For a year like 2019 where much of the Midwest was planted extremely late, this means that black layer is going to occur late, assuming there was an adequate moisture supply. This also means that corn plants will prioritize remobilizing all available nutrients to fill ears, even at the expense of deteriorating their stalk quality. During the fall of 2018 in the northern Corn Belt, this is exactly what happened.
Key Watch Outs for 2019 Harvest
- Late planting: Shortens the opportunity for a limited root system to acquire nutrients
- Reduced capacity for nutrient uptake: Root systems are limited from extreme rainfall and wet planting conditions
- Reproductive stages: Corn will attempt to fill grain even at the expense of stalk integrity
- Stalk lodging: Stalk rot pathogens are opportunistic. In any given year, they are present within the plant; however, when stress is high and nutrition is scarce, pathogens will take over and cause lodging issues
- Corn will likely mature late: If rainfall stays normal, the crop will continue to fill grain, and black layer will be much later, allowing more time for pathogens to take over and reduce standability
- High moisture: We will not be afforded the luxury of allowing grain to dry down in the field this fall
Have a Harvest Plan!
Much of the Corn Belt has experienced environmental conditions that have our crop stressed to the max, and we could be facing a late and grueling harvest season. This will likely be a year when everyone wants to allow corn to dry in the fields as long as possible, but the reality of the situation is that we will not be afforded that luxury in 2019.
Now is the time to have conversations with your trusted advisors. It has already been a long growing season, but we are not done yet. Plan to harvest fields with a high incidence of crown and stalk rot, fields that were not treated with a fungicide, and fields that were planted into marginal conditions. Sticking to your harvest plan and being willing to dry grain may save you the heartache of losing grain to lodging or harvest inefficiency.
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