Plant and Insect Diagnostic Clinic Update - March 23, 2017

The following are highlights and updates about samples and questions recently received in the Plant and Insect Diagnostic Clinic. Visit the PIDC's Facebook page to ask questions and for updates and more pictures. For more information on a particular disease or insect problem listed, follow the article cited.


Plant Diseases



structures (Stigmina signs) observed under microscope magnification.
 Photo caption:  note fungal bodies (signs) on spruce needles (top). Microscopic

pathogen structures (Stigmina signs) observed under microscope magnification.

One of the biggest challenges in plant diagnostics is obtaining and working with a representative sample. We as diagnosticians want to make sure we get a full scenario of where the plants have been developing and what you see in your plant. Unfortunately, incomplete or insufficient information or sample may lead to an inaccurate diagnosis.


Digital photos that accompany a sample give very important clues. See our tips on taking digital photos at http://bit.ly/PIDCphotoguidelines


We also have added pictures to our Plant Problem Sample Submission page to show examples of good and bad samples submitted to the Clinic. Check out our new pictures at  https://www.ipm.iastate.edu/ipm/info/submit/plant


Broadleaf Trees


            Environmental Stress and Bot canker on Oak


Coniferous Trees


            Diplodia Tip Blight in spruce


            Rhizosphaera needle cast on Spruce


            Stigmina needle cast in Spruce 


 


Perennials and Annuals


            Acidovorax bacterial spot - Petunia     


            Root rots- of Geranium and Coleus


Vegetables


            Environmental disorders in transplants (light, temperatures, watering and nutrients)


            Damping off and root rots


 


 

Authors: 

Lina Rodriguez Salamanca Extension Plant Pathologist and Diagnostician

Dr. Lina Rodriguez-Salamanca is an extension plant pathologist and diagnostician with the Iowa State University Plant and Insect Diagnostic Clinic  (clinic.ipm.iastate.edu), a member of the National Plant Diagnostic Network (NPDN,&nbsp...

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on March 23, 2017. The information contained within may not be the most current and accurate depending on when it is accessed.