Comments From Dr Anco Clemson Peanut Notes No. 126 2020
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Question came up about whether the residual on some Cobra herbicide labels is something we benefit from for palmer management. Dr. Marshall and Valent reps agree, for practical purposes Cobra does not have appreciable residual activity for us.
Control from earlier residuals tapering out with palmer near 5 inches from recent rains. Cultivation helped some but still have palmer standing, would 24 oz 2,4-DB be too hot? Yes that rate would likely hurt the peanuts pretty good, Dr. Marshall recommends 12.5 oz Cobra + 16 oz 2,4-DB + Dual (dual serves crop oil function for Cobra; between the two crop oil may be a better oil additive than Dual, but in doing so would also contribute more burning). This should be followed up in 10 to 14 days (with fungicide app) with a second 16-oz 2,4-DB as needed to help limit palmer seed production. Select can be added if grass control is also needed at that 2nd app time (crop oil needed for the select).
Is a surfactant needed for Miravis/Elatus combination? Not so much, combination is highly effective as-is, and there is a chance surfactant could interfere with Elatus’ washoff for targeted soil activity.
If Miravis/Elatus got washed off before dried completely, is there a need to respray for leaf spot? Syngenta indicated rainfast time is 1 hour (chart with additional products below). If it was rained off less than 30 minutes after application (45 min more conservative), it would be a safe approach to respray (e.g., bravo).
Which to spray as first application if rain delayed access of 40-45 day spray to 50 days, Aproach Prima + Bravo + teb or Provost Silver? Provost Silver has provided better control in my experience.
If I spray Lucento, will I get 3 or 4 weeks of leaf spot control? I do not have the data to recommend that length; I would anticipate activity closer to the standard 14 days.
Attached are some recent peanut pictures (LCB was a little older from this year but was the lone ranger found in the field so as not to sound the alarm).