The third wet growing season in a row has left many growers struggling to control weeds, again. A recent Vegetable Crops Hotline newsletter article (Purdue Univ.) addressed this issue. Unfortunately they couldn't offer much advise other than spray them again with glyphosate, cultivate or mow them off.
If glyphosate is not controlling weeds like you expect, note the weed control tips in the irrigation water quality article. Hard water can reduce the effectiveness of glyphosate.
FOR NEXT YEAR, some growers may want to try including a herbicide that provides some residual control against germinating weeds with a burndown (glyphosate or gramaxone) to the row middles. Three products to consider obtaining are:
REVISED: December 2, 2015