Herbicide Resistant Horseweed in New York and Possible Implications
Mike Basedow, Tree Fruit Specialist
Eastern New York Commercial Horticulture
Horseweed (also called marestail) is a frequently occurring species in New York. It can be found growing in a variety of habitats, including along roadsides, in field crop and vegetable operations, and in berries, grapes, and tree fruit. Often considered a winter annual, horseweed has a wide germination window and seedlings can emerge in the spring, summer, and fall. Herbicide resistance, particularly to glyphosate, is widespread in the US and has recently been identified in New York (see the 2022 summer issue of Fruit Quarterly https://nyshs.org/fruit-quarterly/). Many of these populations were collected from soybean systems where glyphosate is frequently used for managing unwanted vegetation. Two New York populations, collected from a vineyard and an apple orchard in the Finger Lakes Region, were found to be susceptible to glyphosate but resistant to labeled rates of paraquat. Paraquat resistance in horseweed has been formally confirmed previously in Belgium (nurseries), Canada (peaches), Japan (orchards, grapes, roadsides, railways), California (almonds), Delaware (soybeans) and Mississippi (soybeans) (https://weedscience.org/Home.a... ).
Herbicide Resistant Horseweed in New York and Possible Implications (pdf; 1849KB)
Upcoming Events
What is my vine trying to tell me?
May 15, 2024 : What is my vine trying to tell me?
Plattsburgh, NY
Are your grapevines showing signs of discoloration or stunted growth? Don't ignore these warning signs! Join us on May 15th at the Clinton County CCE office to learn about the essential nutrients that grapevines require to thrive, identify the symptoms of nutrient deficiencies, and how to fix them. Don't miss out on this opportunity to improve your grapevine cultivation skills! Attendance is free, but registration is required.
How man's best friend can help find Spotted Lanternfly
May 21, 2024
Millbrook, NY
Come and join us at the Dutchess County CCE office on May 21st for a special demonstration by Jennifer Fimbel, the Agriculture and Horticulture Program Leader with Dutchess County CCE. You will get to see her SLF K9 Cole in action as they demonstrate how man's best friend can be used to detect the Spotted Lanternfly. Attendance is free, but registration is required
What is my vine trying to tell me?
May 22, 2024 : What is my vine trying to tell me?
Greenwich, NY
Are your grapevines showing signs of discoloration or stunted growth? Don't ignore these warning signs! Join us on May 22nd at the Washington County Fair Grounds to learn about the essential nutrients that grapevines require to thrive, identify the symptoms of nutrient deficiencies, and how to fix them. Don't miss out on this opportunity to improve your grapevine cultivation skills! Attendance is free, but registration is required.