New detection tools for curly top virus offer opportunity for improved understanding of the disease and its management strategies. PCR tests can quickly detect the virus in plants. The CDFA can also sample leafhoppers for the virus.

Gilbertson said researchers have determined that leafhopper population numbers and the presence of the virus can be determining predictors in whether BCTV will be a significant issue in the following growing season.

For instance, in March and April of 2013 the CDFA was collecting five times more leafhoppers than they normally collect in the foothills. That was the first bad sign, Gilbertson said.

Tomatoes with curly top symptoms began showing up in late March of last year. Losses were the highest in Fresno, Kern and Kings Counties. Yields losses appeared far beyond the western foothills, and even into San Joaquin County.

“This was very unusual in that regard because we were seeing curly top in areas where we typically don’t see it,” Gilbertson said.

Gilbertson noted that the disease was not widespread, but affected different areas to varying degrees. While particularly bad in counties such as Kern, Kings and Fresno, it was seen to a lesser degree in the rest of the San Joaquin Valley. The virus was not seen in the Sacramento Valley.

“To illustrate just how bad it was for curly top last year, we saw it in cucurbits, which we never see,” Gilbertson continued. “I’ve been working here over 20 years and this was the first year I’ve seen this develop in crops like cantaloupe and honeydew.”