Can I use Yates Anti Rot to treat what I think is cercospora on Grevilleas?
It is affecting the inner leaves, turns them bronze - more so on the edges, with tiny brown spore like spots underneath, some turn dark grey. The plants get the western sun and are on a slope but have had lots of rain.It is affecting several similar grevilleas.
Anti Rot does not have registration for the control of Cercospora leaf spot. Spraying with a copper spray may have some effect in controlling the spread of this disease. The disease appears first on the oldest leaves of the plant and seems to be worst when temperatures are high and conditions are damp. To stop the spread of the disease, remove all the infected leaves, if that is possible and dispose of them. Check the drainage and make sure water is able to flow away. Ensure plenty of aeration around the infected plant. Unfortunately I think a lot of native plants have been affected by the enormous amount of rain we have experienced in the last few months. Most native plants like good drainage, so I am sure you will be able to save your plants once the weather improves.
Answered: 10 Mar, 2012