food safety

INSV Infections Low to Start Season, But Concerns Remain with Drying Conditions

Brian German Field & Row Crops, Industry, Leafy Greens

Issues with Impatiens Necrotic Spot Virus (INSV) appear to be lower than what was seen in 2022. Last year’s disease pressures created a host of issues related to loss of yield and limited product availability. The Grower Shipper Association’s INSV Task Force reports that lower INSV infections in the early growing season may be due to weather conditions.

INSV Infections

“We’re looking for reports over one percent on a weekly basis and we haven’t had any reports above one percent. I know in-house we feel that we’ve approached one percent but not yet exceeded it. I think that unfortunately, it will probably start to pick up a little bit here as the hills continue to dry down,” said Eric Morgan, VP of Environmental Science and Resources at Braga Fresh, and member of the INSV Task Force.

The wet weather has kept areas of the Salinas Valley greener much further into late spring than average. Morgan said there were still flowers in May. However, warming temperatures is typically when pest pressures become more problematic. Morgan said that they have been starting to see lygus populations showing up, which can be an indicator of thrip presence and potential for INSV issues.

“There tends to be a correlation between the lygus moving in and the thrips moving in,” Morgan explained. “They always kind of seem to start to show up in the same 30-day period of time or so. But generally, we’ve always attributed that to the native ranges that we have on both sides of the valley. They start to dry down and we see the influx of pests from the hills.”

INSV infections were “catastrophic” for many growers last year. Efforts to look for methods of mitigating damage from INSV in the future include a variety of projects and approaches. One significant aspect of the effort is better understanding thrips and how they can spread infection.

“This is a multi-pronged problem and there’s probably not going to be one solution by the time it’s done,” said Morgan. “I think we need to be looking at habitat. We need to be looking at breeding and we need to be looking at population dynamics. We need to be looking at what biological controls can help reduce the population.”

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Brian German

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Ag News Director, AgNet West