This week’s topics include:
- Late Planted Corn concerns
1. High grain moisture
a. Test weight and harvest moisture are inversely related. In other words, the higher the moisture, the lower the test weight.
b. As grain dries in the field or in a dryer, test weight increases. A general “rule of thumb” is that for every 1% moisture
drying, TW increases 0.25lbs
I. exceptions to this happen if grain during harvest/handling, or very premature freeze
c. Test weight increases as corn dries due to smaller kernels/smaller air pockets, and “slicker” grain, allowing more grain
to pack into a space
2: Stress during grain fill
a. Foliar disease drought stress, cloudy conditions, lack of soil N and K, etc. can impact test weight by causing the
plant to shut down early.
b. In 2019 , shortened daylight in late September/October, combines with large swings in temperature throughout
August and September, likely contributed to less starch deposition in some cases.
c. In addition, saturated soils and limited root growth due to compaction may have impacted plants’ ability to take
up N and K sufficiently.
3. Premature frost/freeze
a. Some late-June planted fields of corn may not have reached blacklayer before frost freeze events. Significant freezing
temperatures halt starch accumulation and result in lower test weights.
4. Ear rots
a. As a result of above-average moisture, along with damage from western bean cutworm/corn/earworm/birds, ear and
cob molds have occurred in some areas. Ear molds gain energy from mature grain, and can lower test weights
and result in poor quality grain.
b. Ear molds, as well as drought stress, can also result in spongy cobs, which make combine setup for clean
c. Nigrospora cob/ear mold has been noted in several cases this year. The presence of this ear/cob rot indicates plants
that were under stress. Harvest should be prioritized in order to prevent ear drop/quality and yield declines.
Agronomy information provided by: