- Author: Karey Windbiel-Rojas
- Author: Akif Eskalen
[From the August 2015 issue of the UC IPM Green Bulletin]
Declining coast live oak (Quercus agrifolia) trees have recently been found throughout urban landscapes in Los Angeles, Orange, Riverside, Santa Barbara, Ventura and Monterey counties. A fungus associated with a specific beetle is causing the decline by spreading what is known as “foamy bark canker disease” (Figures 1 and 2).
The fungal species, Geosmithia pallida, was recovered from symptomatic plant tissues in association with the western oak bark beetle...
/span>Although most fruit trees are pruned during the dormant season, in areas with wet winters, apricots and cherries should be pruned in late summer to allow time for the pruning wounds to close. Pruning apricots and cherries during the rainy season could lead to detrimental canker diseases.
Cherries, apricots, and a few related species are particularly susceptible to fungal and bacterial canker diseases, including Eutypa dieback, Botryosphaeria canker, and bacterial canker. Pathogens can be spread by rain or tree wounds – such as pruning wounds – during wet weather; subsequent infections spread through the wood for several years and may eventually kill the tree.
Late summer is the best time to do final...
- Author: Chuck Ingels, UCCE Sacramento
Most people think about pruning fruit trees during the winter since the branch structure is most visible and winter is considered the traditional time to prune deciduous trees. Actually, pruning fruit trees mainly during the growing season is a good practice and with some species such as apricots and cherries, pruning between September and March in northern California could lead to detrimental canker diseases.
Cherries, apricots, and a few related species are particularly susceptible to fungal and bacterial canker diseases, including Eutypa dieback, Botryosphaeria canker, and bacterial canker. Pathogens can be spread by rain or tree wounds – such as pruning wounds – during wet weather; subsequent infections spread...