Unusual outbreaks of curly top disease in processing tomato fields in northern California in 2021 and 2022 were caused by a rare strain of beet curly top virus and facilitated by extreme weather events.

In the western United States, curly top disease (CTD) is caused by beet curly top virus (BCTV). In California, CTD causes economic loss to processing tomato production in central and southern areas but, historically, not in the north. Here, we document unusual CTD outbreaks in processing tomato fields in the northern production area in 2021 and 2022, and show that these were caused by the rare spinach curly top strain (BCTV-SpCT).

First Report of Watermelon Mosaic Virus Naturally Infecting Coriander () and causing a leaf mottling disease in California.

(WMV, genus Potyvirus, family Potyviridae) is a species of considerable economic importance to cucurbit crops worldwide (Keinath et al. 2017). This virus has a wide host range that includes more than 170 plant species from 27 families (Dong et al.