I’ve been getting a lot of questions on whether or not to use the typical gramoxone burn down treatment on dryland peanuts under the current dry conditions. Obviously, the drier it is the greater the chance of injury and yield loss. The old saying, “if it don’t rain it don’t matter” applies here.
Below are some peanut herbicide considerations from Dr. Prostko:
- If you have started clean, used a strong residual herbicide program that includes Prowl or Sonalan + Valor, and that residual program was activated with a timely rainfall or irrigation event, there is a VERY strong chance that there will be no need for a “cracking” application of paraquat. I see no need to torch a peanut field if weeds are not present.
- Applications of paraquat alone should be applied at 5.5 oz/A (3 lb ai/gal) or 8 oz/A (2 lb ai/gal) up until 14 days after cracking (DAC). Include a NIS @ 0.25% v/v (1 qt/100 gal).
- When applied at higher rates, later than 14 DAC, and/or in combination with a residual herbicide (Dual Magnum, Warrant, or Zidua), use a safener (Basagran or Storm). Safeners have 2 functions. They slightly reduce the foliar injury caused by paraquat and help improve the control of other weeds, especially smallflower morningglory (Figure 2).
- UGA recommended use rates for tank-mixtures are as follows: Paraquat @ 8 oz/A (3 lb ai/A) or 12 oz/A (2 lb ai/A) + Dual Magnum @ 16 oz/A or Warrant @ 48 oz/A or Zidua @ 1.5 oz/A (dry)/2.5 oz/A (liquid) + Basagran @ 8 oz/A or Storm @ 16 oz/A. When using Warrant or Zidua include a NIS @ 0.25% v/v (1 qt/100 gal) (Figure 3).
- Apply paraquat mixtures in 15 GPA, use pressure/nozzle combinations that result in the delivery of medium droplets (236-340 microns), and slower tractor speeds. With medium size droplets, spray coverage is improved at slower tractor speeds. Additionally, slower tractor speeds will reduce the formation of dust which can adversely influence the performance of paraquat.
- Avoid paraquat applications after 28 days after cracking.