Use this data to your advantage as fall approaches.
Much of the Midwest has been smothered in two recent heat waves — one in late August and one in early September. But make no mistake — frost is still a hot topic of discussion in agriculture right now. That's because rampant delays in planting, coupled with a generally cool spring and summer, has a significant number of corn farmers worried their crop will reach black layer before the first killing frost.
The trouble with predicting an early frost is that it’s not reliable to do so until about 10 to 14 days out, says Laura Edwards, an Extension climate field specialist with South Dakota State University. However, there are a few online resources you can use to better gauge your crop's progress and the likelihood a killing frost is on the way. Here are three tools to help you calculate your frost risk.
1. GDU Calculator. To know how many growing degree units (GDUs) your crop still needs, you need to know how many it has already collected. The Weather Channel has a handy GDU calculator on its website. Enter your ZIP code, planting date and current date, and you’ll get a quick look at how many GDUs your crop has collected to-date.
2. Average Frost Data. Want to know your general odds of frost? A website called Dave’s Garden has gathered information from the National Climatic Data Center and tallied it into easy-to-digest tables. Enter your ZIP code to see what dates your crop is most susceptible. The website tabulates frost risk from 10% to 90%.
3. Early Freeze Risk Analysis. Early fall freeze is one of six climatic calamities covered by Total Weather Insurance (TWI) policies for corn available from The Climate Corporation. The company's corn TWI policies issue payouts to policyholders based on any growing degree day (GDD) shortfalls that exist when the first killing freeze (defined as 28 degrees or colder) of the fall occurs. The GDD shortfall is calculated by looking at planting date, relative maturity and to-date GDD accumulation, says director of agronomic research Jeff Hamlin. Using this and other data, Climate Corp has created a unique look at fall freeze risk with a map that shows the risk of early fall freeze damage to corn in each part of the Corn Belt, he says.
Forewarned is forearmed.