Cool temperatures can have an adverse effect on the efficacy of cotton defoliants. Extension experts are recommending that growers in at least one state delay the application of those materials until temperatures warm. That's expected to happen after this weekend.
Mississippi State University Extension specialists are advising cotton growers to consider delaying applications of defoliants until after the round of cooler temperatures predicted for this weekend has ended.
Nighttime temperatures in the upper 50s and low 60s are predicted across Mississippi for Friday, Saturday, and Sunday nights. After Sunday night, nighttime temperatures are predicted to be above 70 degrees.
“Consider delaying defoliation applications and enjoying the holiday weekend without worrying about whether or not your defoliant is going to work as desired,” said Darrin Dodds, Extension cotton specialist with Mississippi State University.
“You can make applications toward the beginning of next week once weather conditions begin to warm.”
Dodds said cooler temperatures can seriously limit of several defoliants, particularly thidiazuron or Dropp.
Producers in other states should consult Extension specialists in their areas for advice on whether to delay applications.