Apr 13, 2016Broadworks herbicide available for use on stone fruit
New this spring is the herbicide Broadworks from Syngenta. It is a new chemistry for use in tree fruits with the active ingredient being mesotrione. The chemical family is triketone with an HRAC of Group 27.
It acts as a bleaching agent by inhibiting carotenoid biosynthesis resulting in damage to the chloroplast. If you have been growing vegetables, blueberries, cane berries or field crops you may have used it in those crops under the trade name of Callisto. Broadworks is primarily labeled for broadleaf weeds and does not control annual grasses. It has both preemergence activity and post-emergent effectiveness. The post-emergent effectiveness will vary by weed species and weed height. In most cases for post-emergent burn down weeds should be ≤ to 5 inches. Potential target weeds it may work more effectively on include common lambsquarters, marestail, black nightshade, pigweeds and other broadleaf species.
At present it is only labeled for stone fruit orchards that have been established at least 12 months. There is a 12 hour REI and 1 hour rainfast period and a 30 day PHI. Application of Broadworks can be done post-emergent and provide residual control of the weed species listed below. To avoid crop injury do not allow spray to contact crop foliage, stems or fruit. Damage to crop foliage may appear as a bleaching of the foliage. Do not apply more than 12 fluid ounces/acre (0.376 lb ai/A) or 3 applications in a 12 month period. Do not exceed 6 fluid ounces/acre in the first application. Include either a crop oil concentrate (COC) or non-ionic surfactant (NIS).
Sequential applications are recommended for best results with the first application being a minimum of 6 fluid ounces/acre. The addition of a post-emergent burn down material such as glyphosate, paraquat, carfentrazone, glufosinate etc should be used if weed species present exceed 5 inches.
Potential application program, rates and intervals
Application Rate (fl. oz./A)
Weed susceptibility to Broadworks
(Scale 1-10 with 10 being best)
*Grasses: Barnyard grass, crabgrass, fall panicum, foxtails, johnsongrass seedling, johnsongrass rhizome quackgrass, shattercane, wirestem muhly, yellow nutsedge, respectively. ** Suppresion only
Broadleaves: burcucumber, cocklebur, jimsonweed, lambsquarters, annual morning glory, eastern black nightshade, pigweed, triazine resistant pigweed, common rageweed, giant ragweed, prickly sida, smartwee, velvetleaf, respectively.
— Robert Crassweller, Penn State University
Source: Penn State Extension