Field corn growers who do not control tropical spiderwort/Benghal dayflower in the fall after harvest are missing a HUGE opportunity to reduce seed-rain back into a field. Failure to control this plant in the fall is one reason why many Georgia growers continue to have major problems with this weed.
Check out the following data/pictures from a test that we currently have in a Grady Co. harvested corn field (Thanks Cale!). You will note that the most effective treatment at this time was a split application of Gramoxone 3SL @ 32 oz/A + Induce @ 0.25% v/v. I would expect better control from the other treatments if they would have been applied earlier to smaller plants and/or also included a COC or MSO (I was trying to save $$ and determine if a tank-mix with a "loaded" glyphosate would be adequate).
Since we are not likely to get a hard freeze until ~November 15 in south GA, there is still plenty of time left for tropical spiderwort/Benghal dayflower to produce viable seed. Viable/ripe seed can be produced within 14 to 22 days after aerial flower opening. Additional information about the post-harvest control of tropical spiderwort/Benghal dayflower can be found on page 74 of the 2024 UGA Pest Control Handbook.
Newer county extension agents might also want to print out this publication that the UGA Weed Science Team wrote a few years ago. It's still very relevant.
https://secure.caes.uga.edu/extension/publications/files/pdf/C%20884_2.PDF
