June 18th, 2021

posted by Andrew Blomme on 6/18/2021 in Weekly Newsletter

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June 18th, 2021

GDU Tracking

Our area had another hot, dry week punctuated with a pop up storm that came through Wednesday night. We accumulated around 160 GDU's this week. The map below shows the GDU accumulation for the state from April 22nd to today. It seems that the data from the Audubon station is skewed lower compared to what we have actually experienced. By my calculations the Audubon area is closer to 837 GDU's for this period. 

GDU Totals

Based off of current GDU accumulation and current trends we can look ahead to predict when the corn crop will start tasseling. The corn hybrids that are adapted for our area typically tassel when they accumulate 1300-1500 GDU's. The exact number of GDU's needed to tassel is hybrid specific and can be found in a hybrid profile guide. You can find information for your specific AgriGold hybrids at the following link: AgriGold-Corn Hybrid Guide. You can find information for your specific Hoegemeyer hybrids at the following link: Hoegemeyer-Corn Hybrid Guide

Our area is currently sitting around 840-850 GDU's. We need an additional 450 GDU's to reach the 1300 GDU threshold that some early season hybrids need to tassel. Currently we are averaging about 150-160 GDU's every week. At this pace, we will accumulate the necessary 450 GDU's in 3 weeks. If trends hold true, we can expect tassels to start to emerge around July 9th-10th and pollination to occur shortly after that.

Pollination is the most important stage in a corn plant's lifecycle. Crop conditions during pollination are extremely important to determining how many embryos get fertilized to form kernels. With pollination just 3-4 weeks away, any positive changes in the crop condition will be welcome.

Storm Damage

The system that came through on Wednesday night brought some damaging forces along with it. Pockets of high wind and hail caused some localized damage to crops in the area. The picture below shows a corn field that was damaged by hail.

Hail Damaged Corn

Leaf tissue damage was very apparent but overall the damage was non fatal. New leaves appear to be coming out of the whorl intact and unimpeded. I expect these plants to fully recover.

Some areas received winds in excess of 80 MPH. High winds like that can cause damage to corn plants that is fatal at this growth stage. Proper scouting is encouraged to determine the extent of the damage in some fields. 

Looking Forward

The longest day of the year is a couple days away. June 21st is an important date in soybean development. After the 21st, the lengthening nights trigger soybeans to begin flowering. Beginning flowering is the first of eight reproductive stages in soybeans. Some corn fields are quickly approaching V10. After V10, it takes a corn plant 56 GDU's to progress through each leaf stage instead of 82 GDU's. Corn development will progress quicker with this change and we can expect roughly 3 new leaves to emerge every 7 days for a corn plant. Next week's newsletter will talk about these topics as well as other observations from the field.

About The Author

Andrew Blomme
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