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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). These outbreaks were associated with proximity of fields to foothills and unusually hot, dry, and windy spring weather conditions, possibly by altering migrations of the beet leafhopper (BLH) vector from locations with BCTV-SpCT reservoirs. Support for this hypothesis came from the failure to observe CTD outbreaks and BLH migrations in 2023, when spring weather conditions were cool and wet. Our results show the climate-induced emergence of a rare plant virus strain to cause an economically important disease in a new crop and location. • Curly top disease (CTD) in the western US is caused by beet curly top virus (BCTV). • CTD affects processing tomato production economically in central and southern California, historically sparing the north. • Unprecedented CTD emerged in northern California in 2021 and 2022, involving a rare BCTV spinach curly top strain. • The lack of CTD in 2023 with cool, wet spring weather conditions highlight climate's role in virus emergence. [ABSTRACT FROM AUTHOR]

Abstract Describing baseline microbiota associated with agricultural commodities in the field is an important step towards improving our understanding of a wide range of important objectives from plant pathology and horticultural sustainability, to food safety. Environmental pressures on plants (wind, dust, drought, water, temperature) vary by geography and characterizing the impact of these variable pressures on phyllosphere microbiota will contribute to improved stewardship of fresh produce for both plant and human health. A higher resolution understanding of the incidence of human pathogens on food plants and co-occurring phytobiota using metagenomic approaches (metagenome tracking) may contribute to improved source attribution and risk assessment in cases where human pathogens become introduced to agro-ecologies. Between 1990 and 2007, as many as 1990 culture-confirmed Salmonella illnesses were linked to tomatoes from as many as 12 multistate outbreaks (Bell et al., 2012; Bell et al., 2015; Bennett et al., 2014; CDC, 2004; CDC, 2007; Greene et al., 2005a; Gruszynski et al., 2014). When possible, source attribution for these incidents revealed a biogeographic trend, most events were associated with eastern growing regions. To improve our understanding of potential biogeographically linked trends in contamination of tomatoes by Salmonella , we profiled microbiota from the surfaces of tomatoes from Virginia, Maryland, North Carolina and California. Bacterial profiles from California tomatoes were completely different than those of Maryland, Virginia and North Carolina (which were highly similar to each other). A statistically significant enrichment of Firmicutes taxa was observed in California phytobiota compared to the three eastern states. Rhizobiaceae, Sphingobacteriaceae and Xanthobacteraceae were the most abundant bacterial families associated with tomatoes grown in eastern states. These baseline metagenomic profiles of phyllosphere microbiota may contribute to improved understanding of how certain ecologies provide supportive resources for human pathogens on plants and how components of certain agro-ecologies may play a role in the introduction of human pathogens to plants. Highlights • At the time measured, bacterial profiles from the phyllosphere of California tomatoes were completely different than those of Maryland, Virginia and North Carolina (which were highly similar to each other). • As environmental pressures on plants (wind, dust, drought, water, temperature) vary by geography, it appears that risk factors for introduction of human pathogens to plants may also vary. • Describing baseline microbiota associated with agricultural commodities in the field is an important step towards improving our understanding of a wide range of important objectives from plant pathology and horticultural sustainability, to food safety. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carotenoid and sugar profiles of melons grown at five locations were reported. • Total sugar content was higher in honeydew HD-150 grown in Georgia. • Tuscan type (DaVinci) grown in Texas had significantly higher β-carotene content. • Three ζ-carotene isomers were identified in cantaloupe cultivars. • Cultivar and location significantly influenced the phytochemical composition. The sensory and functional quality attributes of muskmelons (Cucumis melo L.), such as flavor, sweetness, color, and texture, determine consumer preferences. Genetic makeup primarily regulates these traits, but environmental factors such as soil type, irrigation, and temperature affects yields and quality. Here, we investigated variation in quality traits of diverse melon cultigens (advanced breeding lines or cultigen) grown in multiple locations (California, Texas, Georgia, Arizona, and North Carolina) across the United States. Mesocarp sugar and carotenoid concentrations varied significantly as a function of production location and cultigen. Multivariate analyses revealed significant cultigen, location, and interactive effects on fruit quality. The highest sugar content was found in a honeydew melon cultigen (HD-150; 83.1 ± 2.36 mg/g) grown in Georgia and the Western Shipper type cantaloupe (F-39; 70.8 ± 2.85 mg/g) grown in North Carolina compared to the other cultigens. The Tuscan type (Da Vinci) grown in Texas and Georgia had the highest β-carotene contents (29.1 ± 3.37 and 33.6 ± 1.73 μg/g, respectively) compared to the other cultigens. These findings suggest that cultivar and location significantly influenced melon phytochemical composition, will help melon breeding programs improve the sensory and functional qualities of melons and identify suitable cultivars for specific environments to maximize fruit quality. [ABSTRACT FROM AUTHOR]