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Peanut Yields and Cobra + 2,4D-B

Because of crop rotation concerns, resistance concerns, or just personal preference, some growers are choosing to use Cobra (or Ultra Blazer) and 2,4-DB in their Peanut Herbicide programs in place of Cadre.

Dr. Eric Prostko, UGA Extension Weed Scientist, has provided the following information regarding the use of these products in relation to peanut yields:

Frequently, peanut growers get concerned when they make herbicide applications that “burn” their crop.  One of the herbicides that can cause this type of injury is Cobra (Figure 1).   Recent results from tests conducted in Florida reconfirm that the injury caused by Cobra or Cobra + 2,4-DB is cosmetic in nature and does not negatively impact peanut yields (Figure 2).  In these tests, Cobra or Cobra + 2,4-DB treated plots yielded 97-105% of the non-treated check plots. Cobra or Ultra Blazer + 2,4-DB is recommended for the control of Palmer amaranth in peanut fields when Cadre is not a viable option due to ALS-resistance or crop rotation concerns (page 460 of 2014 UGA Pest Control Handbook).


Figure 1.  Peanut leaf burn caused by Cobra.COBRA2