Why was it so bad?

Gilbertson suspects a combination of favorable conditions for the leafhopper and hosts for the virus in the foothills. There are also hypotheses of new, more virulent strains of BCTV that have a wider host range or are able to be transmitted more effectively.

“The state’s spray program was certainly not enough to manage the disease,” he said.

There are limitations on the spray program, which could have helped leafhopper populations thrive.

“The spray program is being constrained now by certain farmers who want to do organic production in the foothills,” he said.

A comprehensive research program to address these issues has been initiated with the goal of applying new approaches and technologies to develop an effective integrated pest management program for curly top.

One such thought is the possible development of a spray that will act as a deterrent to keep leafhoppers from landing on tomatoes and feeding upon them.

Gilbertson is cautiously optimistic that the coming growing season won’t be as bad as last year’s.

“Clearly it’s been very dry,” he said. “There are not a lot of green plants out there for these leafhoppers to feed on to survive the winter and lay the brood for the coming season.”

State tests for the curly top virus in leafhoppers and host plants are coming back negative so far.

“I would say that it is looking promising that the pressure of curly top this year does not look like it’s going to be anything like it was in 2013,” he said. “Things can change in terms of the weather.”

Historically the BCTV was a severe problem in sugar beets until the sugar beet industry developed resistant beets, he said.

“When we had a major sugar beet industry here in the early 1900s through the mid-1900s curly top was one of the most devastating diseases of sugar beets,” he said. “One of the reasons for that is Beet leafhoppers love sugar beets. They really don’t like tomatoes.”

Most thought that the incidents of curly top diminish as sugar beet production declined, but curly top did not disappear.


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