Category Archives: Research

Activity in the TPDDL that include or require some research activity

New treatment for the management of Cotton Root Rot on winegrapes

Dr. David Appel, Extension Plant Pathologist with the Texas A&M AgriLife Extension Service contributed this article that describes a new treatment for one of the most devastating diseases of Texas winegrapes. This was research conducted by Dr. Appel and our own TPDDL diagnostician, Sheila McBride. -KO This disease, cotton root rot, occurs on winegrapes in the calcareous soils of Central, South, and West Texas where soil pH is well above 7. The most common symptom of CRR in grapes is a sudden wilt and death of the infected… Read More →

Leaf Gall Diagnostics

Ever wonder about how some diseases are diagnosed in a plant disease diagnostic lab.  You would be surprised that there are similarities to an ER in the hospital. When a sample arrives at the Plant Clinic, it has to be accompanied with a submission form where there are a bunch of question trying to get some history leading to the incidence or current situation.  Then the samples are triaged within 24-48 hours of receipt (dependent on diagnostician availability).  Decisions are made how to proceed based on history information… Read More →

Rose rosette

Recently there was quite a bit of “chatter” about rose rosette.  This year, we have heard of reports from parts of Texas, Ohio, Michigan, Indiana, Tennessee and some other states.  It seems that this disease is becoming more prevalent especially on knockout roses. But is it because that more folks are planting roses, in particular knock-out roses? Nonetheless, this is quite an interesting disease that we know little about. Anyhow, what is rose rosette?   This is a disease of roses that was described in the 1940s and… Read More →

Date Palm Decline or Cold Damage?

My colleague and collaborator, Dr. Greta Schuster at  Texas A&M – Kingsville took me around the campus to show me some of the plants where samples were taken from for our detection assay for palm phytoplasmas.  In South Texas, there has been a rash of palm trees dying.  Usually when the palms start to decline, one of the symptoms are yellowing leaves.  In fact, there are 2 related types of phytoplasmas that are well known to affect palms.  One is called Lethal Yellowing –  a common problem on coconuts in… Read More →

Sweet Orange Scab in Texas

The Plant Clinic is always abuzz with activity.  Recently (late July 2010) Sweet Orange Scab (a disease caused by the fungus Elsinoe australis) was confirmed by USDA-APHIS from a sample in the greater Houston area in Texas.  Since then, confirmed findings of the pathogen were recorded for various places in Texas and Louisiana.  Most recent was the detection of this pathogen in the valley – where the Texas citrus production industry is concentrated.  The first report of this disease was made in 1937 (Bittancourt & Jenkins) but it was… Read More →