Historic GDU Data Useful in Predicting Crop Success!
After a long winter, I’m excited to soon be kicking off my 16th season of compiling and sharing weekly GDU and weather data. I know this information is of interest across all facets of agriculture because I have everyone from bankers to crop insurance reps to market analysts to farmers signing up for it. It is called Swenson’s Snapshot, and you can sign up at the end of this post.
For those of you who know me personally, you realize I’m an agronomic guy. From pumpkins to weather, I love focusing on a subject and digging in. Last year, with the help of Kelsey Stumvoll, we put together a historical summary of season-long GDU data and have since updated it with 2022 data.
We built charts for 99 locations across the tri-states showing GDU data from 1981 – 2022. Then we overlaid a “Green Day Window” for each location to easily identify the historical window of growing opportunity between the last spring and the first fall frost.
Why should farmers care? Because knowing the “Green Day Window” for your farm allows you to make wise decisions on how to maximize your crop. It can inform your decisions regarding:
- Hybrid Selection: you can utilize the chart to target correct hybrid maturities and reign in the desire to select products based on the experience of the last few years.
- Yield: by building maturity curves for your location to maximize the crop’s potential.
- Test Weight/Black Layer: recognize that pushing maturity is fun but isn’t always worth the gamble of a potential cool season.
- Dryer Set-up: depending on infrastructure, deciding whether pushing maturities a few days is a possibility if you can handle the possibility of wet corn.
- Farming Practices: equipment size, tillage practices, and labor for planting and harvest which all are affected by your planting and harvest window.
- Planting and Harvest Dates: can you typically plant in mid-April or do you need to wait until early May?
Our handy historical chart can be a useful reference to quickly compare growing seasons across the years.
If you’re not able to find your location within the set, send me an email. I’m happy to run a custom report for your farm.
During the growing season, I also send out a short weekly email called Swenson’s Snapshot where I chat about the weather, GDUs, and crop progress. It ends each year with the first front or on October 1 – whichever comes first. You can sign up for that weekly email here.
Kelsey and I spent a lot of time on this project and being agronomic geeks, we loved every minute of it. We hope you enjoy it!
