Atrazine and Hexazinone (Forest Mix WDH*) incident that killed 100 old growth redgum trees at Rosedale between 2000 and 2002.
Friends Block (now owned by Grand Ridge Plantations (GRP) is located approximately 6km south of Rosedale. The district has a long grazing history. The site receives roughly 700mm of rain per year and is about 50m ASL. The landform is gently undulating to flat, with locally dissected drainage ways, or on flatter parts, shallow irregularly scattered depressions. The parent material is unconsolidated alluvial deposits of the late Pliocene age. The soils are a yellow duplex textured soil, with a loamy sand surface horizon over a yellow-brown mottled and generally dense clay. The block is about 450ha in size.
In 2000, the Friends Block was site prepared and planted in Pinus radiata by Australian Paper Plantations. The site had in excess of 100 old Red Gum trees on site, which were deliberately protected and left intact at time of site preparation and planting. A different herbicide was used to that used normally, which was believed to have a lesser effect on native trees. No herbicide was sprayed around the native trees but this appears to have been inadequate protection. On this block we applied “Forest Mix WDH*” @ 7.2Kg/Ha. Apparently, following herbicide application a strong rain event occurred, resulting in water from the general establishment area pooling around the base of the native trees. The water was slow to get away due to the duplex nature of the soil.