New last year, Chateau WDG herbicide has proven to be a very effective weed control product in tree fruit, as well as tree fruit orchards in the Okanagan. A Group 14 product that represented new chemistry when it was introduced, Chateau WDG provides seasonal residual control of many broadleaf weeds. In fact, Okanagan growers discovered and enjoyed the extraordinarily long residual effects because of the low rainfall and low organic matter soils. They soon found that Chateau WDG is very effective, forming a “barrier”, activated by rain or irrigation of at least ½ cm of water. They also found it does not affect established weeds, but can be mixed with glyphosate to control existing weeds. It must not come in contact with crop fruit, green bark or foliage, and should not be used on very young plants. The active ingredient flumioxazin is a photosynthesis inhibitor, preventing target plants from making chlorophyll by inhibiting an essential enzyme (the enzyme is called protoporphyrinogen oxidase, for those interested in unpronounceable names). It can be used effectively on coarse and medium textured soils, but will be less effective on soils with very fine texture or high organic matter.