Author Archives: ashley.brake

Are Lichens Killing Your Trees?

         One of the most common mutualistic relationships in the plant world is that of lichens. Made up of one part filamentous fungi and one part algae or blue-green bacteria, lichens are not considered a “true species.” The unique combination results in a very hardy, weather-tolerant, and genetically diverse group of Nitrogen fixers that is practically self-sufficient. The fungal partner cannot survive alone, but instead thrives on the availability of photosynthetic products provided by the algae or bacteria. Lichens are common pioneers on trees, shrubs, soil, and even… Read More →

Cladoptosis: An interesting phenomenon

Cladoptosis is a process in which trees shed their branches or “self-prune” as part of their normal physiology or in response to stress through the formation of an abcission layer at the branch base. Sources of stress which may contribute to this shedding include drought, soil and root compaction, or presence of disease. In the case of certain tree species, however, none of these factors need be present in order for Cladoptosis to occur. For some tree species, including larches, pines, poplars, willows, maples, walnut, ashes, bald cypress, and oaks,… Read More →

Tomato Russet Mite

    Last week a tomato sample was diagnosed with tomato russet mites (Aculops lycopersici). These conical-shaped insects, usually translucent and yellowish, cannot be seen without the aid of a 14X hand lens. Russet mites cause damage by feeding on leaves and stems, giving them a greasy or bronze appearance. Infestation normally begins at the base of the plant and progresses upwards as lower leaves dry out. Left alone, these mites can kill plants. Fortunately, they can be controlled with miticides or sulfur. Hosts include tomato, potato, eggplant, petunia, tomatillo,… Read More →

Perfect conditions for Cercospora

Be on the lookout for Cercospora leaf spot in your landscape plants! Recent weather conditions around the state like cool temperatures and high humidity seem to trigger an increase in Cercospora activity. Check your colorful fall annual bedding plants, including zinnias, hydrangeas, snapdragons and azaleas, for necrotic or purplish, angular leaf spots. A: Cercospora symptoms on a recent Pansy sample B: Conidiophores on leaf edge C: Cluster of Cercospora conidiophores