
There have been increasing issues with perennial vine infestations in soybean and corn fields in recent years. The two most commonly found species are honeyvine milkweed and trumpet creeper. Others that show up less frequently are hedge bindweed, burcumcumber and Carolina coralbead.
In soybean, an application of Enlist One plus glyphosate is one of the better options to provide some suppression. In corn, Status would be a better option to provide suppression. Regardless of what is sprayed expect those vines to recover and be a problem at harvest. A harvest aid application of glyphosate or Gramoxone in soybean will likely be needed to help with harvest efficiency. Harvest aid options in corn would be Aim or glyphosate.
Unfortunately, there are no good options that will control perennial vines in the spring or early summer. The reason for this is that those perennial plants are primarily translocating carbohydrates from the roots and rhizomes upward in the plants to make new stems and leaves. Therefore, any herbicide that is applied has to move against that gradient which rarely happens. That is why the vine tops may burn back but they quickly recover from the rhizomes.
The best time to apply systemic herbicides to control perennial vines is about 2 weeks after harvest. During that time of the year those vines prepare for winter by rapidly translocating carbohydrates from the leaves downward to the roots and rhizomes. The herbicide can much more easily translocate down with that natural movement to the rhizomes and provide much better control.
The best herbicides to use would be dicamba and/or 2,4-D. A mixture of the two also can work well. Finally, the primary avenue for perennial vines to infest fields is via rhizomes rather than prolific seed production. This results in a more gradual infestation of fields compared with annual weeds. Typically, it takes years for perennial vines to take over fields. Likewise, in fields severely infested with these vines it may well take two or three sequential years of dicamba and/or 2,4-D applications in the fall to provide adequate control.