- Author: Ben Faber
So rain is great………as long as it doesn't cause problems like increased iron chlorosis, root rot, snails, erosion, too many weeds, etc., etc., etc, And now we are seeing more anthracnose. This disease is not normally much of a problem in dry California. Colletotrichum gloeosporioides, the causal fungus of the disease, is widespread in avocado and citrus groves. We see it frequently on small stems and branches, but It is normally of little importance on fruit because unusually large numbers of spores are required to produce damaging infections.
Disease on stems
Disease on leaves
Low humidity and no rain during much of the...
- Author: Belinda Messenger-Sikes
After years of drought, we welcome rain in California. But we also recognize that rain can help spread a number of plant diseases. Rain and wind can splash bacteria and fungi from infected leaves, branches, and blossoms to uninfected parts of the tree. The fungal diseases anthracnose, peach leaf curl, scab, shot hole blight, and the bacterial disease fire blight can all be spread by rain splash. This ability to spread by water makes these diseases more common after a wet spring. With 2023 bringing quite a bit of rainfall and 2024 looking similarly wet, we want to focus on some common rain-dispersed diseases.
Anthracnose
Anthracnose affects many trees including almond, citrus, Chinese elm, and...
/h2>- Author: Belinda Messenger-Sikes
Have you been seeing a lot of defoliated sycamore trees recently? Sparse foliage and early leaf drop on sycamore trees might be due to anthracnose. The cool, wet spring in many parts of California provided the perfect conditions for this disease. Anthracnose is a common fungal disease sometimes called leaf, shoot, or twig blight. It can cause twisted, distorted branches in American sycamore, some varieties of London plane trees, and California sycamore trees. Sycamore anthracnose is primarily an aesthetic concern since it usually doesn't kill established trees.
Symptoms
Take a close look at the fallen leaves for the characteristic irregular blotches caused by this disease. Anthracnose can...
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by Penny Pawl, U.C. Master Gardener of Napa County
I recently discovered bunchberry (Cornus canadensis) and could not resist.I admit I am a plant collector but that is another story. The bunchberry is a ground-hugging member of the dogwood family.The leaves resemble the leaves on bigger dogwoods but are much smaller. It only grows about eight inches high but has the same showy white blossoms
When I looked for information on this little guy, I discovered that the dogwood family is quite large. Dogwoods are found within the temperate zones of the Northern Hemisphere. Some are native to the West Coast. The bunchberry also is found in Greenland.
The...
Anthracnose is a group of fungal diseases that infect many trees and shrubs, causing dark lesions on leaves and cankers on twigs and stems. In some areas of California, vegetables and turfgrass can also be infected with anthracnose.
Symptoms of anthracnose vary by plant host and weather conditions. High humidity and dense canopies can exacerbate this common disease. Management relies on planting resistant cultivars of landscape plants along with careful maintenance of susceptible cultivars, such as pruning and removal of fallen leaves and twigs.
Authors Jim Downer (UCCE Ventura County), Steven Swain (UCCE Marin County), and Amanda Crump (UC Davis Plant Sciences) recently revised