Plant and Insect Diagnostic Clinic Update - February 4, 2009

News Article

Diseases

Rhizoctonia solani foliar infection was found on Cyclamen submitted to the Plant and Insect Diagnostic clinic. Rhizoctonia spp., most commonly found at the soil line (root rots), can attack stems and leaves as well when plants are grown close together and kept under moist conditions. Entire stock beds or flats can be lost to Rhizoctonia in very short periods of time. Rhizoctonia root rot can be common in begonia, ferns, holly, impatiens, juniper and many others herbaceous and woody ornamentals.

Phytophthora root rot fungus was detected on roots of Norway Spruce young trees maintained in pots that were showing needle browning and drop. The disease occurs on soils that are poorly drained or receive excessive irrigation. Spores of this fungus are carried by water and the disease can spread very quickly from plant to plant. To manage the disease, do not place the pots directly above plastic, create raised beds or provide sub-surface drainage. Treat plants (drench) with approved fungicide for managing Phytophthora. For more information about Phytophthora root rot and collar rot of landscape plants see this article.

Insects

We received a sample of snowfleas, one of the few insects active in Iowa at this time of the year.  Snow fleas are actually not related to fleas, but they can jump like fleas.  Snowfleas are in a group of insects called springtails.  Snow fleas are a species of springtail that contain antifreeze proteins that allow them to be active at low temeperatures.  Click here for some pictures and information from the University of Minnesota.

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