Timing Fall Herbicides on Berry Crops

Kristen Obeid, OMAFRA Weed Management Program Lead – Horticulture

Berry Growers – If You’re Thinking of Spraying Your Fall/Winter Herbicides this Week – Don’t!  (November 04, 2015)

 We are hitting record temperatures this week, so it might be tempting to apply your fall/winter herbicides, but don’t waste your time or money.  It is simply too warm.

What will happen if you apply some common herbicides now:

Casoron, dichlobenil (Group 20) – dichlobenil volatilizes under warm conditions. Applications should be made under cool weather conditions in late fall / winter, as long as the ground is not frozen. Also, herbicide breakdown by microorganisms is slower in low temperatures, increasing herbicide longevity and, thus, the length of weed control. Rain and falling snow help incorporate applied pre-emergence herbicides. Further, due to cooler temperatures, the need for immediate rainfall or irrigation for incorporation can be less critical than it is in summer.

Chateau, flumioxazin (Group 14) – Crops are definitely not dormant now and unacceptable crop injury, including yield loss, may occur if this product comes into contact with non-dormant strawberries or blueberries.

Goal, oxyflurafen (Group 14) – oxyflurafen can cause damage if warm weather occurs in late winter while the soil is wet.  Under these conditions, oxyflurafen can evaporate from the soil surface and cause burning to the crop.