What is in this article?:
- Higher product development costs are causing chemical companies to reinvent older herbicides introduced up to 50 years ago.
- Chemical companies are developing new uses for older herbicides, plus generating new product formulations and application techniques.
- Formulation changes are largely in response to environmental safety concerns.
Despite fewer herbicides on the market, specialty crop growers rely heavily on herbicides. Produce buyers expect fields to be absent of weeds and damage from pests and diseases. Accordingly, growers utilize pesticides to grow near-perfect fields to ensure crop salability at a good price.
“One weed will not reduce the yield or quality of the crop, but one weed can change the attitude of a shipper about a particular field and grower,” Tickes said. “Disease- or insect-caused spots on spinach, for example, can result in a major price discount to the grower. Occasionally, a field with a very low level of injury is not harvested.”
Some herbicides applied on more traditional crops are now finding a good weed control fit in specialty crops.
For example, the herbicide Stinger (clopyralid), registered more than three decades old, was developed to control weeds in grain crops. In recent years, Stinger was approved for cole crops with positive results.
In one of Tickes’ herbicide field trials, Stinger was applied in broccoli to measure product effectiveness.
“Stinger has a good fit with excellent crop safety,” Tickes said. “Stinger did a remarkable job of saving the broccoli crop.”
Another example is the herbicide Sandia (halosulfuron), originally developed for nutsedge control in turf. Sandia was acquired by the Gowan Company in Yuma to develop a fit in specialty crops. Tickes’ test drove Sandia in a trial on the weed purslane in 10 different types of melons. Sandia performed well when the product was applied prior to weed emergence.
In Tickes’ spinach trial, the product Far-Go (trialate) did a good job controlling winter annual grasses.
In California, Tickes said UCCE farm advisors and weed specialists Richard Smith and Steve Fennimore have tested low rates of the herbicide Lorox applied as a pre-emergent in spinach to control annual broadleaf weeds.
“The overall crop safety is not real good, but they haven’t given up on it,” Tickes explained. “They believe they’ll find a rate that will be safe and effective.”
The herbicide Prowl, originally registered in the 1970s, is primarily used today on legumes, cotton, alfalfa, trees, and vines. Tickes says Prowl performed well on nettleleaf goosefoot and canarygrass in a broccoli trial.