A new crop disease has hit the Salinas Valley, the area that accounts for more than half of the country’s lettuce, more than $1 billion in value, according to the East Bay Times. As of now, pesticides have shown only limited success in killing the bugs that carry the disease, and organic crops can’t use chemical sprays by law.
The disease is known as Impatiens necrotic spot virus or INSV, and it is spread mostly by an insect known as a thrip. These millimeter-long creatures migrate from already infected host plants to other crops and spread the disease, according to the Grower-Shipper Association of Central California, which warned about INSV back in November.
According to the association, plants that become infected with INSV show dark spotting and yellowing, which resembles the natural effects of sunburn on the leaves. Another crop disease, Pythium wilt, usually accompanies INSV infections and causes the plants to wilt or collapse completely.
“In 2022, disease pressure was exacerbated by unseasonably warm weather stretches which caused prolonged stress on the plant, making the lettuce more susceptible to disease impacts,” the association wrote. Richard Smith, a vegetable researcher with the University of California Cooperative Extension in Monterey County, echoed these sentiments.
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