At-cracking sprays are an effective tool in managing weeds in peanuts. New pre-plant incorporate (PPI) or pre emergence (PRE) herbicides provide an excellent residual barrier in a weed program. But many fields will need an at-cracking herbicide(s). Consider the following tips when making at-crack applications with paraquat in peanuts:
**If the main weed problems are FL beggarweed, TX panicum, or sicklepod, then Firestorm/Parazone @ 5.4 oz/a, or Gramoxone Inteon @ 8.0 oz/a + surfactant at 1 qt/100 gal can be used for control. Apply up to 14 days after ground cracking if using paraquat without a tank mix partner. When used alone, paraquat is not effective on smallflower morningglory, prickly sida, wild radish, or tropic croton.
**Add 0.5 pt/A of Basagran to the parquat product (Firestorm/Parazone @ 8.0 oz/a, or Gramoxone Inteon @ 12.0 oz/a) if small flower morning glory is a problem or to reduce peanut foliar burn . Add 1.0 pt/A of Basagran if control of weeds such as bristly starbur or prickly sida is necessary. Apply anytime up to 28 days after ground crack. Include surfactant at 1qt/100 gallon spray with all paraquat treatments.
**Add 1.5 pt/A of Storm to the parquat product (Firestorm/Parazone @ 8.0 oz/a, or Gramoxone Inteon @ 12.0 oz/a) if copperleaf, tropic croton, Palmer amaranth or other morning glories (Ipomoea spp.) are present. Apply anytime up to 28 days after ground crack. Include surfactant at 1qt/100 gallon spray with all paraquat treatments.
**If paraquat is applied alone and growers are concerned about the burn, consider tankmixing Basagran or Storm regardless of weed spectrum.
**Apply at crack treatments as early as possible. Weeds will be smaller and easier to control and the peanut plant will have more time to recover from the paraquat injury.
**To improve the success of “at-crack” applications, apply Gramoxone/ Basagran/Storm in at least 15 GPA, use flat fan nozzle tips, decrease ground speed and lower sprayer pressures (30 PSI).
**Research indicates no adverse effects of adding chlorothalonil products with paraquat tank mixes where fungicide treatments are needed.
**Warrant, Dual Magnum or generic metolachlor can be used in combination with the cracking sprays to provide residual control of pigweed and tropical spiderwort. NIS is not recommended if Dual Magnum or generic metolachlors are used with paraquat + Storm or Basagran.
Information for this post comes from the 2016 UGA Pest Control Handbook. The University of Georgia Cooperative Extension does not endorse of guarantee the performance of any products mentioned in this information.