A wetter and cooler May has many Oklahoma cotton growers reaching for their soil thermometers before hitting the fields. With seed availability already at critical lows, it’s vital that growers plant the seed they have been able to source in as optimum environment as possible because replanting may not be an option.
In the May 9 “Cotton Comments” newsletter from the Oklahoma State University Southwest Oklahoma Research and Extension Center, Extension Assistant Jerry Goodson wrote that “cooler than normal and saturated fields have prevented the start of planting this year.”
The Oklahoma Mesonet shows that 4-inch bare soil temperatures across the state range from 50 degrees in the panhandle, to 67 degrees in the far southeast corner as of May 9. The next seven days weather forecast calls for lows ranging from 38 to 60 degrees, and highs from 51 to 77 degrees. And, just about every day has a chance of rain and thunderstorms in the forecast, according to the newsletter.
Already, across much of Oklahoma, the last two weeks have accumulated up to 6.97 inches of rain in the southwest corner, to 9.77 inches of rain in the far northeast corner of the state, according to the Mesonet, further delaying planters getting into the field.
“The optimum temperature for cotton germination is near 85 degrees,” Goodson wrote. “Cooler temperatures can lead to poor stands or stand failures if the correct conditions align.” Slow germination because of the cold can lead to slow growth, which adds time that the cotton seedling is susceptible to disease pathogens.
Goodson advised growers to:
• Delay planting until mid-morning temperatures in the rooting zone are higher than 60 degrees at a 6-inch planting depth, and 68 degrees at the 2-inch planting depth;
• Wait until the Mesonet’s 5-day forecast calls for dry conditions and at least 25 DD60 heat units; and
• Wait until that same five-day forecast calls for lows above 50 degrees.
For more information, visit www.cotton.okstate.edu, or call 580-482-8880.
Jennifer M. Latzke can be reached at 620-227-1807 or firstname.lastname@example.org.