Etiology, epidemiology, and control of diseases of potatoes caused by viruses, phytoplasmas, and bacteria.

Introduction

 

Potatoes are only surpassed by wheat and rice as a direct source of nutrition in the human diet.  Over one million acres of potatoes are annually grown in the United States alone.  There are a number of diseases of potatoes that reduce both the yield and quality of the potato crop.  Among the most important of these are diseases caused by viruses, phytoplasmas, and bacteria.

 

My professional goal is to develop improved methods to detect, identify, and characterize virus and virus-like pathogens that cause economic damage to potatoes.  A secondary goal is to study the biology of the insects that transmit these viruses, phytoplasmas, and bacteria.  An important responsibility of my position is research into new and emerging diseases of potato.  Information obtained by this research is utilized in the development of effective disease control strategies.  Current research efforts are focused on:

 

·         Effects of various strains of potato virus Y (PVY) on potato varieties grown in the Pacific Northwest.  PVY causes a reduction in potato yield and some strains of the virus also cause severe symptoms in potato tubers, which also reduces quality of the crop.

·         Soil-borne virus problems including potato mop top virus (PMTV) and tobacco rattle virus (TRV).  PMTV is transmitted by a soil fungus and TRV by soil-inhabiting nematodes.  Therefore, these organisms are being studied as well.

·         Phytoplasma diseases of potatoes and some vegetable crops.  The phytoplasmas are transmitted by leafhoppers, so the population biology of these insects is being studied.

·         The emerging potato “zebra chip” disease, which appeared for the first time in the Pacific Northwest in 2011.  This disease is caused by a bacterium transmitted to potatoes by the potato psyllid, a small insect similar to an aphid.  There is ongoing research into the population biology of the potato psyllid in the Pacific Northwest.

 

 

Major Collaborators:

 

ARS:  Joseph Munyaneza, Yakima Agricultural Research Laboratory, Wapato, WA

Chuck Brown, Vegetable and Forage Crops Research Unit, Prosser, WA

Jonathan Whitworth, Aberdeen Research and Extension Center, Aberdeen, ID

Non-ARS:  Phil Hamm, Oregon State University, Hermiston, OR

Silvia Rondon, Oregon State University, Hermiston, OR

Alex Karasev, University of Idaho

 

Research Support:

Launa Hamlin, Biological Science Research Technician