Disinfectants useful to manage the emerging tomato brown rugose fruit virus in greenhouse tomato production

Authors: Ling, Kai-Shu; Gilliard, Andrea; ZIA, BAZGHA - Clemson University

Submitted to: Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2022
Publication Date: 12/14/2022
Citation: Ling, K., Gilliard, A.C., Zia, B. 2022. Disinfectants useful to manage the emerging tomato brown rugose fruit virus in greenhouse tomato production. Horticulturae. 8: 1193. https://doi.org/10.3390/horticulturae8121193.
DOI: https://doi.org/10.3390/horticulturae8121193

Interpretive Summary: Tomato is one of the most important vegetables grown worldwide. The U.S. with over $2 billion annual farm gate value in tomato production, is one of the world’s top tomato producing countries. In the last few years, world tomato production is facing a serious threat from an emerging tobamovirus, tomato brown rugose fruit virus (ToBRFV). This emerging virus, first identified in the Middle East in 2014, has caused outbreaks on tomato crops in over 30 countries from four continents (Asia, Africa, Europe and North America). Due to its ease of mechanical transmission, contaminated seeds can serve as a pathway for virus spread. In the U.S., the first outbreak of ToBRFV was identified on greenhouse tomato in southern California in 2018, and another reported case on tomato plants in a community garden in Florida in 2021. The emerging ToBRFV has caused serious concerns to the tomato industry due to its ability to break the Tm-2.2 resistance gene in tomato. No commercial tomato cultivar is resistant to ToBRFV. This highly contagious virus can be easily transmitted through plant handling and spread quickly without proper intervention. In the present study, ARS scientists in Charleston, SC evaluated 11 disinfectants and determined the optimum concentration and proper exposure time. Overall, 1% Virocid, 2% Virkon S, 5% Clorox bleach solution and 2.5% trisodium phosphate achieved complete deactivation of ToBRFV with 15 min exposure. The results in the present study offer growers some practical solutions to manage this emerging disease in tomato production.

Technical Abstract: Tomato brown rugose fruit virus (ToBRFV) is an emerging tobamovirus infecting tomato and pepper crops. First identified in 2014 in Mid-East, ToBRFV has spread rapidly around the world. Being a seed-borne and ease in mechanical transmission, ToBRFV can spread quickly in a greenhouse through plant handling. Thus, selecting an effective disinfectant that is capable of deactivating virus infectivity is important. Our earlier study identified several disinfectants that are effective in deactivating virus infectivity on two common tobamoviruses. However, for practical application to manage ToBRFV in a greenhouse, further improvements would be necessary. A useful disinfectant is not only effective but should also not cause major phytotoxic effect on the test plants. In this study, using 11 disinfectants at various concentrations to treat ToBRFV and assess their efficacy on tomato plants that were pretreated with or without SP2700, we observed a delay in symptom expression for 2-3 weeks on SP2700-treated plants. Overall, 1% Virocid, 2% Virkon S, 5% Clorox bleach solution and 2.5% trisodium phosphate (TSP) achieved complete deactivation of ToBRFV with 15 min exposure. However, TSP had a serious phytotoxicity on test tomato plants. Our results offered practical solutions to manage this emerging disease on tomato plants in a greenhouse.