In recent years, there has been an increase in crown rot/vine decline problems in processing tomatoes. Many tolerant, as well as several susceptible tomato cultivars, have been identified from previous efforts funded by CTRI. The number of fields in the Sacramento Valley with confirmed Fusarium falciforme vine decline has been increasing each year. In 2022, eight new tomato fields were diagnosed in Sutter and Colusa counties, for a total of 20 fields since 2019. In 2021 and 2022, we worked with AgSeeds and evaluated processing tomato varieties in field trials for their tolerance or susceptibility to Fusarium falciforme by rating disease severity and sending diagnostic samples to the Swett lab at UC Davis for confirmations. Unfortunately, in 2021, we were unable to confirm F. falciforme in the particular fields we evaluated, however, in 2022, all three fields in Sutter County where we evaluated trials were positive for F. falciforme, along with Fusarium crown and root rot in 2/3 fields. We evaluated fields for advanced decline and whole plant collapse. Yield data was provided by AgSeeds. Below is a table with the average number of declined plants at our three field sites in Sutter County. The table also includes percent decline and yield for two of the fields. Also worth noting, field #2 was evaluated the day before harvest, whereas field #1 was evaluated a couple weeks before harvest and field # 3 was not harvested due to September rain events in 2022.
The varieties with the highest decline are similar to results we have seen at other sites over the years and a more comprehensive table (developed by UCCE Vegetable Crops Advisor, Brenna Aegerter, in San Joaquin County) which can be found in my December 2022 newsletter. If you are interested in more results and information from other regions of the state, you can see Brenna’s article on pages 4-5 in the UCCE San Joaquin County Field Notes newsletter from February 2023. — By Brenna Aegerter, UCCE San Joaquin; Co-PIs: Tom Turini, UCCE Fresno; Amber Vinchesi-Vahl, UCCE Colusa/Sutter/Yuba; Cassandra Swett, UC Davis Extension Pathology Specialist; Collaborators: AgSeeds (Funded by California Tomato Research Institute)