Purple Top

Leaves of infected plants turn purple and curl. Infected plants may die early.

General Information:

Symptoms of purple top include curled and discolored leaves, axial bud growth resulting in a bushy plant, swollen nodes, and sometimes aerial tubers.

Causal Agent:

The Columbia Basin Purple Top Phytoplasma (a.k.a. BLTVA).


The purple top phytoplasma lives inside its beet leafhopper insect vector and can infect many plant species including potato, tomato, and various weeds. Early-season transmission is most likely to impact yield and/or crop quality.


Monitor beet leafhopper populations in your area (see below and this page for more details on insect trapping). In areas of high risk, the only clear management strategy is well-timed insecticide applications aimed at migrating beet leafhoppers.

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Insects, Diseases, Nematodes, & Beneficial Organisms

Find out more information about insects, diseases, nematodes, and beneficial organisms for Potatoes.

About The Northwest Potato Research Consortium

In February 2012 the state potato commissions in Washington, Idaho, and Oregon officially launched a new cooperative effort in research. The aim of this initiative is to increase cooperation and efficiency of the research programs funded by the three potato commissions that total about $1.5 million annually. It will also work toward comprehensive research results reporting process that aims to get useful information to the growers and industry members who need it. This website is a big part of that effort. Research results, integrated pest management guidance, and production information of many kinds will be presented here. For feedback or suggestions on this site, please contact Raina Spence, Manager of the Consortium.

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A useful and resourceful research library available with a wealth of knowledge and insight into potato data from in field experience.

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