Valor Injury or The Sky Is Falling (Prostko)

My right ear is currently bleeding due to the numerous telephone calls that I have received over the last few days about Valor injury in peanuts.  Peanuts that were planted approximately 10 days ago or so were in a great place to get hammered from Valor because of the recent rainfall events (Figure 1).   Everyone seems to be panicking as though this was a surprise??????  If it rains on Valor treated peanuts when they are cracking and small (~2 weeks after cracking), injury will occur.  Peanuts typically recover from this injury without a yield penalty.  Check out Figures 2 and 3 from some of my research back in 2009.  In this trial, more than 5" of rainfall occurred in the 30 day period after peanut planting.  Peanut injury was significant but yields were not reduced even at a 2X rate.  Not sure what else I can say or do at this point???

Zidua Peanut Label (Prostko)

On Friday afternoon, May 19, I received word from BASF that Zidua (pyroxasulfone) was labeled for use in peanut.  I have been conducting peanut research with pyroxasulfone for more than 10 years (over 47 field trials).  In a nutshell (no pun intended), Zidua will compete with Dual Magnum or Warrant in our POST peanut herbicide programs for the residual control of Palmer amaranth and a few other weeds (Figure 1). Some advantages for Zidua include its lower use rate (1.5 oz/A-2.1 oz/A) and improved control of other broadleaf weeds such as Florida beggarweed.  Generally, I have observed no real differences in performance/yield between Zidua, Dual Magnum, and Warrant when used in a complete peanut weed control program (Table 1). A copy of the supplmental peanut label can be obtained at the following web-address: http://www.cdms.net/ldat/ldAMK017.pdf

Figure 1.  Zidua vs. Dual Magnum Programs in Peanut - 2016.

Table 1.  Dual Magnum/Warrant/Zidua Peanut Weed Control Programs - 2014.

Common Cocklebur in Peanut (Prostko)

Chris Tyson (Tattnall County) recently sent me a picture of a common cocklebur seedling (Figure 1).  In 2016, Brian Hayes (Grady County) had a peanut grower with a very serious cocklebur problem (Figure 2).  In fact, that peanut field in Grady County was probably the first time that I ever made a recommendation just for that specific weed.  At one time though, cocklebur used to be a more widespread weed problem but sorta disappeared during the "glyphosate era".   Peanut herbicides with good to excellent activity on cocklebur include the following: 2,4-DB, Basagran, Cadre, Cobra, Gramoxone (paraquat), Pursuit, Storm, Strongarm, and Ultra Blazer.  On the downside, Valor is not very effective on this weed so don't be surprised if you see cocklebur in a Valor treated field. The fruiting structure of cocklebur (i.e. the big bur that sticks to your favorite shirt or hunting dog) contains 2 seeds, one for now and one for later.   

Figure 1.  Common cocklebur seedling (Source: Chris Tyson)

Figure 2.  Common cocklebur infestation in a Grady County peanut field, 2016.

Peanut Injury Likely (Prostko)

Rainfall events today will likely result in the development of Valor injury on peanut, especially in fields where the peanut plants are just beginning to emerge/crack.  In preparation for any upcoming questions, please refer to my Weed Science Blog on May 20, 2014.  This should help refresh your memory.  No need to re-invent the wheel.

http://ugaweedscience.blogspot.com/2014/05/peanut-injury-update-prostko.html