The effectiveness of UVC treatment on dollar spot
To investigate the effectiveness of treating dollar spot with UVC technology, an independent study was conducted using the SGL UVC180. The aim was to see if there was a (significant) difference in treatment results between UVC technology, fungicide treatment and a control condition. The research was conducted in cooperation with AB Kristianstads Golfbana, the FEGGA and SGL.
Research background
The golf industry faces numerous challenges, one major challenge is climate change. Climate change is bringing about a shift in global temperatures, causing some areas that used to be cold, such as the south of Sweden, to become hotter, and in some areas, it has become either drier or wetter. This change brings about new challenges such as new grass diseases that have not been present before. The increasing climate has allowed for dollar spot to become a more frequent phenomenon. This calls for actions that need to be taken that may have not been relied on in the past. Therefore, it is necessary to adapt to these new challenges and find ways, especially sustainable methods, to deal with these new upcoming challenges.
Another challenge is the EU Pesticide ban, which will take effect in the coming years. There are, however, some golf courses that are chemical and pesticide-free, and we can learn from them through knowledge sharing. Therefore, running trials, and incorporating it into the FEGGA Scholarship as a project could give insight into what alternatives are to be considered and where improvements can be made.
About FEGGA
FEGGA, the Federation of European Golf Greenkeepers Associations, serves as an umbrella organisation representing and supporting national greenkeeping associations across Europe. Its mission is to promote best practices in golf course management, offer educational opportunities for greenkeepers, and advocate for the interests of its member associations within the golf industry.
AB Kristianstads Golfbana (KGK) hosts the FEGGA Scholarship programme annually, spanning from April to October. The scholarship programme is designed to educate and support both aspiring and experienced greenkeepers, providing them with opportunities to enter and advance within the industry. Each participant is assigned projects tailored to their expertise and interests.
In 2023, one of the focal projects centered on chemical-free Integrated Pest Management (IPM) and sustainable course maintenance. Collaborating with SGL, KGK introduced the UVC unit UVC180 as part of this initiative. The project aimed not only to educate FEGGA students on chemical and pesticide-free maintenance practices but also to explore alternative sustainable methods for disease management and prevention, with a particular emphasis on combating dollar spot disease. This endeavor gains further significance in light of impending EU regulations banning pesticides and chemical usage within the industry.
Methods and materials
AB Kristianstads Golfbana, located in Åhus, Sweden, served as the testing ground for SGL in partnership with the FEGGA scholarship programme held on-site each season. The golf course provided an ideal setting for conducting trials with the UVC180, a sustainable alternative to chemical treatments for preventing and managing dollar spot (Sclerotinia homoeocarpa) on greens. The trial took place on the 2nd green of the West course, spanning from September to November 2023. This green, meticulously crafted to USGA specifications, boasts a blend of Poa annua and Festuca rubra, maintained at a precise height of 2.8 mm throughout the season.
This study aimed to compare two different dosages of UVC radiation by using the UVC unit SGL UVC180, to two non-UVC radiated sites namely a control area (no treatment) and an area treated with a fungicide:
- Control: No treatment
- Fungicide: Treatment with Syngenta – Instrata fungicides
- UVC1: Treatment with the UVC180: three times a week, one round
- UVC2: Treatment with the UVC180: three times a week, two rounds
Within the four different conditions, fixed sample positions were made. This was done to ensure we have the same sample area weekly. The samples were taken using a grid, which was 1m². The blocks of the wire were 2cm². The grid was divided into 4 quadrants and labelled A, B, C, and D. The grid was placed on a fixed position, and a picture, approximately 1m high from the ground, was taken of each quadrant.
For each trial there were 16 pictures, in total there were 64 sample pictures taken, once a week from week 35 to week 41. The sample pictures were sorted into their different trial folders and sent to SGL for analysis. Throughout the trial, the infection rate in each treatment section was monitored weekly, by counting the number of squares in each quadrant infected with dollar spot. A decrease or increase in the number of infected squares gave an indication of the effectiveness of each treatment method.
Statistical analysis was used to determine the effectiveness of each treatment.
Results
The results of the research are shown in the chart.
- In week 39, there was a significant difference between fungicide and untreated, but the UVC treatments were not significantly different from the previously mentioned treatments.
- In week 40, all three treatments were significantly different from untreated, but not significantly different from each other.
- In week 41, the untreated treatment is significantly different from the UVC and fungicide treatment. There is a higher infection rate in the untreated section than in the rest.
Upon completion of the two-month trial, the statistical analysis determined there was a significant difference in the number of squares infected with dollar spot between the three treatment trials and the control trial.
It was also noted that in the last week of the trial, there was a significant difference between the UVC treatment trials and the fungicide trial.
Conclusion
In conclusion, untreated greens exhibited a notably higher rate of infection compared to those subjected to treatment trials. Among these trials, the application of fungicide proved most effective in mitigating dollar spot infection. Nevertheless, it’s imperative to acknowledge the tightening regulations surrounding fungicide usage, highlighting the urgency for a more sustainable strategy. Such an approach should entail the adoption of effective, plant-friendly alternatives, complemented by sound cultural practices, to uphold a resilient and environmentally sustainable playing surface.
