New Sandea herbicide label for cucumbers
Preharvest interval reduced to 21 days for Sandea on cucumbers for improved yellow nutsedge and broadleaf weed control.
The U.S. EPA has approved a 24c SLN label for Sandea75 W herbicide on cucumbers with a preharvest interval (PHI) of 21 days. Previously, the PHI was 30 days, which limited the effectiveness of Sandea against yellow nutsedge and broadleaf weeds in machine-harvested cucumbers. Machine-harvested cucumbers are harvested 40 to 50 days after planting. With a 30-day PHI, Sandea was applied post-emergence when the cucumber plants were small and few weeds had emerged. Sandea may now be applied up to 21 days before harvest, which is a more effective time to kill broadleaf weeds and yellow nutsedge.
The Sandea label allows two applications per crop at 0.5 to 1.0 ounce of product (0.023 to 0.047 lbs active ingredient) per acre. There is a maximum of 2 ounces of product per crop cycle and per acre per year. For yellow nutsedge control, Sandea should be applied preemergence and again post-emergence no later than 21 days before harvest. On light soils, use the 0.5-ounce rate to avoid crop injury. Cucumbers usually tolerate Sandea quite well, but there may be some leaf discoloration.
Sandea is active against yellow nutsedge, most broadleaves, and a few grasses. It is weak against eastern black and hairy nightshades. It controls common lambsquarters preemergence, but does not control it post-emergence. If annual grasses have emerged, add a post-emergence grass herbicide to the tank-mix. Application of a grass herbicide with Sandea may cause some cucumber phytotoxicity.
Addition of a nonionic surfactant at 0.25 percent v/v (1 quart in 100 gallons) will improve Sandea activity against yellow nutsedge and broadleaf weeds, but also may increase cucumber plant discoloration. Cucumbers normally grow out of any phytotoxicity and there is no adverse effect on yield.
If yellow nutsedge emerges in spots in a field, it may be more effective and less expensive to treat the spots and not apply Sandea over the whole field. It normally takes several years to kill a nutsedge infestation.
The new printed Sandea label should be available from chemical dealers soon.
Dr. Zandstra’s work is funded in part by MSU‘s AgBioResearch.