Evaluation of Ultraviolet Light as a Sustainable Disease Management Strategy for Southeastern Onion Production

Commodities

Practices

This project aims to move southeastern onion production towards more sustainable management practices. To accomplish this goal, evidence-based recommendations are needed to increase onion production while minimizing disease concerns. Our project will evaluate the efficacy of ultraviolet light (UV) as an alternative disease management approach at the University of Georgia (UGA)'s research farms and/or cooperating growers' fields. The findings of this research will be disseminated primarily through training, workshops, and on-farm demonstrations across the state of Georgia targeting onion crop growers, stakeholders, and county agents.

Diseases are the primary yield-limiting factors of onion crops. Chemical treatments are widely used management practices to mitigate disease spread and yield loss. These chemical applications not only increase production costs but also contaminate the environment, which is hazardous for humans and ecosystems. Reducing production costs and environmental contamination are vital pillars of sustainability that can be achieved through non-chemical crop disease management and improved crop production. Applying UV from ultraviolet lamps, in particular, UV-C (200-280 nm wavelength), can be an alternative aspect of disease management. The germicidal effect of UV-C for surface sterilization in the food industry is well established, and more recently, the application of this technology has been studied extensively for disease control in strawberry, cucumber, squash, tree fruit, and vine production, where commercial field-use solutions have been developed. However, less is known about how this UV-C may positively or negatively affect onion production. The exposure levels (e.g., low, medium, and high) of UV-C application play an important role in disease management and can vary from one crop to another. The proposed study will evaluate the efficacy of night-time UV-C application at different exposure levels in onion fields to determine the effective exposure level. The wavelength of light is another important parameter responsible for the quality of disease management. The study will employ a wavelength of 254 nm, which has demonstrated effectiveness in various cropping systems. This wavelength will be used to evaluate its impact on the management of onion diseases. Recommendations will be made based on the results of our 3-year trials. This project will also evaluate the impact of UV-C treatments on crop growth and yield to assess the positive and/or negative effects of UV-C treatments on onions.

The ultimate success of this project is associated with the producer's adoption of this technology. This project will educate producers and stakeholders on how to use this technology, its associated expenses, and how to better manage their crops against diseases. A survey will be conducted at the beginning of the project to understand the level of growers' knowledge about this type of technology. We will prepare education materials based on survey results and organize training and workshops to effectively educate them on time. The adoption of this technology will introduce a sustainable disease management approach to the vegetable industry to increase profitability.

The main goal of this research is to enhance sustainability in southeastern onion production by using a non-chemical UV-C-based disease management approach. This research will be focusing on the following three objectives:

Obj. 1: Evaluate the efficacy of UV-C treatments for onion crop disease management

Obj. 2: Assess the impact of UV-C treatments on the growth and yield of onion crops and economic analysis

Obj. 3: Conduct outreach and evaluation of growers/stakeholder interest in the adoption of UV-C technology