I was recently asked how to control relatively large common cocklebur. 2,4-DB alone is very effective on this weed. The PHI is 45 days. One challenge is concern over residues by one sheller as they work toward maintaining international markets. This company has asked their growers not to apply 2,4-DB after July 1. Theoretically and I suspect in practice, this can reduce the probability that residues from 2,4-DB will be found in peanuts. The EU and US regulatory agencies use different approaches to pesticide registrations and residues in raw and processed foods.

It is legal to apply 2,4-DB up to 45 days prior to harvest for the domestic market in US and for some international markets. However, peanuts cannot be reasonably segregated at the buying point and shelling plant. To maintain as many markets as possible, we are restricted to use patterns of pesticides with the most restrictive restrictions. This is a challenge that is not going away. It creates an uncomfortable dilemma for grower and sheller alike. No one wants to restrict the tools we have.

With respect to options for cocklebur, Basagran is the next best option. It may not control a big cocklebur as well as 2,4-DB, but it is a good option and the best one we have. Unfortunately, the PHI for Basagran is 75 days. If applied now, that puts harvest into mid-October.