Over the last several years, many county agents have asked about carryover concerns of Cadre applied in a peanut
crop to sweet potato the following season.
The Cadre label restricts planting potatoes to 40 months after a Cadre
application but the label does not specifically mention sweet potato. Many have wondered is it really this serious?
According to the 2014 edition of the WSSA's Herbicide Handbook (page 256), the half-life of
Cadre or the time in which about half of the Cadre would be gone is
approximately 120 days. In theory then, a June
application of Cadre at 4 oz/A in peanut should be down to a rate somewhere between ½-1 oz/A approximately 8-12 months later when one would plant sweet potato.
During 2015, a study was conducted where we applied ½ and 1 oz/A of
Cadre prior to transplanting sweet potato.
Cadre at ½ oz/A caused 55% visual injury (stunting and discoloration)
and reduced U.S. Number 1 fruit yield by 59%.
For Cadre at 1 oz/A, sweet potato injury reached 77% and reduced U.S.
Number 1 fruit by 96%. Simply, applications of Cadre in peanut should be avoided if you plan to rotate to sweet potato!!!!!.
