I wanted to provide clarification on the effectiveness of Group 15 herbicides (metolachlor products, Outlook, Zidua, Anthem Flex, and Warrant.) I looked back at some of my data and then spoke to a well-respected weed scientist in another state who works in peanuts.

First, we need to use multiple applications of Group 15 herbicides. PRE right after planting, early POST with paraquat plus Basagran and then with a later POST spray with contact herbicides or clethodim products. This can really help control weeds during the critical period of weed interference (first 3 to 6 weeks) and then well into the season. Generally, the recommendation is to just pick a few of them and apply them so that residual control is present well into the season.

We have a lot of weeds to deal with in peanuts, but our key drivers are Palmer amaranth, common ragweed, Texas panicum (Texas millet), morningglory, and sicklepod. Others are present too, but these are the drivers and are listed in farmer surveys as most problematic.

If you have Palmer amaranth, there is generally no difference among Group 15 herbicides. There are individual data sets that can show one Group 15 performing slightly better than another, but the products may switch in another trial. On balance, the Group 15s are the same when it comes to Palmer amaranth control. I would say the same is the case for common ragweed.

Texas panicum control with Zidua is 10 to 15% better than control with Dual Magnum. In fields with Texas panicum, make sure you have several Group 15 herbicides in the program. You will need them. Including Zidua in your program could help you. Apply Zidua with your early POST spray or your next POST spray. Anthem Flex has the same active ingredient as Zidua (along with Aim or carfentrazone,) so it too would be slightly better than Dual Magnum. When we have multiple residual sprays of Group 15s, the difference described above gets minimized. But if you are trying to stretch a single residual out as long as you can on Texas panicum, Zidua or Anthem Flex are the best choices. Just be ready in terms of more initial (and transient) injury from Anthem Flex caused by the carfentrazone.

In fields with Texas panicum, for next year, applying Prowl incorporated can really help on Texas panicum.

Morningglory control can vary among Group 15s, but control is about the same, and control is never complete.

Control across several weeds drops off with Warrant compared with other Group 15s. But in many fields and in a lot of situations, Warrant does as well as many of the other Group 15s early in the season.

The Group 15s do not have appreciable activity on sicklepod.