Darren Robinson, Weed Researcher, Ridgetown Campus – University of Guelph
Sandea and Permit are Group 2 herbicides that are taken up by roots and shoots and are systemic in the plant. The herbicides will translocate to the new growing tissues, and if applied to a sensitive crop or weed, it will cause stunting, chlorosis (yellowing) and may even delay maturity of sensitive species. These herbicides are particularly useful for control of preemergence control of common lamb’s-quarters and postemergence control of yellow nutsedge. They have also provided good control of common ragweed and redroot pigweed. The labels should be consulted before use in all cases, and are available at:
Tomatoes: Sandea is particularly useful for control of common lamb’s-quarters when applied prior to transplanting and before emergence of the weed. Its efficacy on common lamb’s-quarters is significantly reduced when applied postemergence. Though it can be applied postemergence to tomatoes, temporary injury (ie. chlorosis) is possible when applied in hot, humid weather.
Vine Crops: Sandea can be applied both preemergence and postemergence, though growers are cautioned to consult the label for product rates, as they vary depending on crop species and application timing. Best results have been obtained when Sandea is applied in a tank mix with Command, prior to crop emergence, followed by a postemergence application of Sandea alone later in season.
Sweet Corn: Permit can be applied postemergence in sweet corn, and is particularly useful for control of yellow nutsedge. Growers should consult the label for information on rates, variety sensitivity, and corn leaf stage.
Peppers: Care should be taken when applying Sandea to peppers. The label indicates that Sandea should be applied as a directed-postemergence application between pepper rows. Injury may be possible with certain pepper varieties.