Tattnall County Extension

Local News for 4-H, Agriculture, and Family and Consumer Science

Pecan Weed Control

Its time to burn down those herbicide strips in pecan orchards in preparation for the growing season. There are many combinations of herbicide applications you could use. Here are a few for trees of different ages. Information provided by Lenny Wells.

Trees 1-2 Yrs:

At budbreak:

Glufosinate + Prowl

May/June:

Glufosinate or Glyphosate or Paraquat +

Flumioxazen (Tuscany, Chateau) or Pindar**

August/September

Glufosinate or Glyphosate or Paraquat +

Flumioxazen (Tuscany, Chateau) or Pindar**

 

If you have more grassy weeds glyphosate will be the best option for the burndown material. If broadleaf weeds are more of an issue, go with paraquat or glufosinate. Regarding the pre-emerge materials, Prowl is safer to use during the budbreak application than Flumioxazen, which has enough post emergence activity to damage the tender foliage if you get a little wind, which can occur this time of year and Prowl is good on both grasses and broadleaves. Flumioxazen tends to last longer than Prowl. Pindar is a new product for us and offers two modes of action. Like Flumioxazen, Pindar does provide some burndown of existing weeds that Alion does not, but we still suggest you put glyphosate or glufosinate out with it as you usually have some larger weeds that Pindar will not totally kill. Pindar does provide broadleaf and grass control but over time it did dissipate and weeds started to emerge after about 3-5 months in Dr. Timothy Grey’s trials compared to season long control with Alion.  But if you have new trees, it would be a good consideration to rotate with Flumioxazen as your pre-emerge material.

 

Trees 3 Yrs and Up:

At budbreak:

Glyphosate  or Glufosinate or Paraquat + Alion (5 oz)*

July/August

Glyphosate or Glufosinate or Paraquat +Alion (5 oz)

*After 1st season using Alion drop down to 3.5 oz rate

 

Trees 3 Yrs and Up Rotate in Alternate Years With:

At budbreak:

Glyphosate or Glufosinate or Paraquat

+ Flumioxazen or Pindar**

July/August

Glyphosate or Glufosinate or Paraquat

+Flumioxazen or Pindar**

September (if needed)

Glyphosate or Glufosinate or Paraquat

+Flumioxazen or Pindar**

 

Regardless of tree age, if you have less than 70-75% bare ground at application, apply your burndown material first and come back with the pre-emerge after the weeds have died down. Otherwise, you can tank mix the two. Pre-emerge materials generally need contact with bare ground to work properly. Most need rainfall with 7-10 days to activate as well.

There are other weed control options besides those listed above. This is simply one option that seems to work well. Consult the UGA Pecan Spray Guide for more options.

** Update On Pindar:  Pindar is a combination of oxyflurofen, a PPO MoA, and pinoxsulam, a ALS MoA, with both having PRE and POST activity. Pindar’s residual may not last as long as indaziflam’s but Pindar will still provide 3-5 months residual control,  which is quite good. The only real problem I see with Pindar is that the label states it can only be applied after harvest and up until the emergence of green leaf tissue, which provides a short window for its use. Since bud-break has arrived we are about out of that window. However, Pindar is a good option for growers who want to keep their strips clean over the dormant season.