Last week the question was: What is wrong with these cotton leaves?
These leaves are showing symptoms of 2,4-D damage. Cotton is extremely sensitive to 2,4-D. Damage can occur when sprayers are not cleaned out well, by wind drift, or by volatilization in hot weather. 2,4-D resistance traits have been developed and were available in several varieties this season, though 2,4-D was not labeled for use in cotton (it’s expected to be labeled for the 2016 season). This trait (called Enlist) won’t be available in all cotton varieties, so 2,4-D damage is not a thing of the past.
Here is this week’s question: What happened to this tobacco hornworm?