Postemergence Weed Control in Lima Bean

July 19, 2013 in Vegetable Crops

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Options for postemergence broadleaf weed control in lima beans are limited to Sandea, Raptor, or Basagran. Remember, Reflex is labeled only for snap bean and can severely injure lima beans. Do not spray Raptor or Basagran before the first trifoliate is fully expanded and Sandea requires at least two fully expanded trifoliates. All of these products should be applied before the beans have started to flower. These products are not effective on most weed species over 3 inches tall. So they need to be applied early (approximately 3 to 4 weeks after planting). Basagran will not effectively control pigweed. Raptor and Sandea are group 2 herbicides (same mode of action as Pursuit) and a lot of fields have pigweeds resistant to group 2 herbicides.

Raptor is labeled for lima beans in Delaware and Maryland at 4 fl oz. The label requires the addition of Basagran at 6 to 16 fl oz/A to improve crop safety and minimize the yellowing in the young tissue. In addition, it is labeled for use with a non-ionic surfactant.

Postemergence grass control can be accomplished with Poast or Select Max. Select Max allows for the use of non-ionic surfactant in place of crop oil concentrate. Tankmixing either of these grass herbicides with Raptor, Sandea, or Basagran can result in an antagonism that reduces grass control. Finally, Select will not control goosegrass. See photos of goosegrass at the VT website: http://www.ppws.vt.edu/scott/weed_id/elein.htm