Morningglory Identification - Prostko

Just got out of a peanut field with Tift County Agent, Scott Carlson.  We were talking about weed ID and general peanut stuff.  Many of the weeds that were present in this peanut field were various species of morningglory. Consequently, I thought you might benefit from some of the following information:

1) An old publication that helps with the identification of adult morningglory plants.  Great to keep in your truck!  

Figure 1.  Identifying Morningglory Species.  Source: Dr. Dick Oliver, University of Arkansas,  Weeds Today

2)  Some very good close-up pictures of seedling morningglory plants.  Pictures are from LSU and Virgina Tech.  Also, something good to keep in your truck (besides a sandwich and a Dr. Pepper).

3) Why is this important?  Not all morningglories are controlled equally by certain herbicides. Here are a few examples:

a) Gramoxone (paraquat) is generally good on most morningglory species but not smallflower. 

b) Basagran (bentazon) is generally not effective on most morningglory species but will control smallflower.

c) Staple (pyrithiobac) is generally considered to be an excellent morningglory herbicide but not on tall.

d) 2,4-DB is less effective on pitted morninglory than other species.

e) Aim (carfentrazone) is considered a good morningglory herbicide but not on smallflower. 

Peanut Weed Tips for July - Prostko

A few things to consider as we head into July:

1) Cobra or Ultra Blazer applications should be avoided if possible when the peanut plants are in the R5 (beginning seed) to R6 (full seed) stage of growth (Figure 1).   Results from a 9 location study conducted in 2005-2006 indicated that Cobra applied at this time could cause a significant peanut yield loss (~5%).  

Figure 1. Peanut Stages of Growth.

2) Nearly all 2,4-DB labels limit the official number of applications that can be made in peanut to 2.  Results from trials conducted in 1997 indicated that peanut plants (Florunner and GK-7) were tolerant of multiple applications (1, 2, or 3) of 2,4-DB.  Research is currently underway in 2015 to confirm these older results using GA-06G.  Check out Figure 2 for a list of how much and when 2,4-DB can be applied according to current labels.

Figure 2.  Summary of 2,4-DB labels for use in peanuts.

3) On more than 1 occasion this year, growers have accidently applied 2,4-D amine rather than 2,4-DB to peanut plants.  Fortunately, we have a good idea what could happen to peanut yields when this occurs (not that bad depending upon rate and peanut stage of growth).  Check out the following UGA Extension publication:

http://extension.uga.edu/publications/files/pdf/C%201036_1.PDF

"Not a rocket scientist for sure but I am thinking that is a great idea to read and check the label (or at least look at it) of any pesticide jug before dumping it into a spray tank.  As my father once told me, fast and ready sets the pace but slow and steady wins the race!"

4) I will be on vacation from July 4-11.  If you need to contact me, please send me an e-mail or text.  I will respond to e-mails and texts from 9 am-10 am during my vacation.  

5) From July 13-17, I will be attending the annual APRES Meeting in Charleston and will respond to any phone calls, texts, or e-mails as usual.

6) Now that my busy spray season is almost over, I would like to remind any county extension agent (seasoned or un-seasoned) that I would be more than happy to spend a day in your county just walking and talking.  All you need to do is call.  

Peanut Weed Control Update (Prostko)

It has been awhile since I had a chance to write a blog.  I have been very busy spraying plots, answering phone calls/e-mails/texts, and trouble-shooting.  Here a few things to consider based upon your questions and my experiences over the past few weeks:

1) Generally, Cadre almost always looks better after an EPOST (i.e. at-crack) application of paraquat + Basagran or Storm and this would be my preferred recommendation in most cases (Figure 1). With that said, there are some exceptions when paraquat + Basagran or Storm may not be justified including the following:

a) Irrigated fields that have been treated with a Prowl or Sonalan + Valor (+/- Strongarm) and these residuals are working well.

b) The only weed present is nutsedge.  

2) Peanut tolerance to Cadre is excellent at any stage of growth.   Crop injury has never really been an issue with this herbicide. 

3) You will note from the above figure that the average control of sicklepod with Cadre is 86% (~50 trials).  Thus, 100% control of sicklepod with Cadre is unrealistic but its the best we have.

4) Generally, I have no preference between Dual Magnum or Warrant when used in a complete peanut weed control program.  However, I have observed faster breakdown with Warrant  (i.e. does not last as long) in some of my research plots over the last few years (100% irrigated).  Culpepper has data to suggest that Warrant might be a better choice than Dual Magnum in dryland fields.  If a grower has a preference, I would not try to talk him/her out of it.