A recently concluded Northeast SARE Partnership Grant project shined a light on an effective strategy for increasing greenhouse growers' yields by controlling a destructive fungal disease.
In ONE22-413, Application of Ultraviolet Light and MilStop to Restrict Powdery Mildew Infestation in Vegetable Greenhouses, project leader Dr. Arash Ghalehgolabbehbahani of the Rodale Institute in Pennsylvania, worked in partnership with greenhouse farmers to measure the effectiveness of using ultraviolet light and bicarbonate salts as an alternative to chemical pesticides for controlling powdery mildew on green vegetables.
Powdery mildew is a destructive fungal disease in greenhouses that affects several species of vegetable crops. This disease appears as small white to gray powdery spots on the vegetable seedlings’ foliage and can easily spread to the entire greenhouse after transplanting.
The project team build a custom UV light chamber fitted with UV-C and UV-B lamps to expose lettuce seedlings to UV radiation. The seedlings were inoculated with powdery mildew spore to asses the effectiveness of treatments. The test included four groups: Plants exposed to UV-C light, plants exposed to UV-B light, plants exposed to both lights, and untreated plants exposed to neither lights.
“The results of this research demonstrate that integrating UV light treatments with potassium bicarbonate applications can increase crop productivity by approximately 50% while significantly reducing powdery mildew spores on leaves, enhancing marketability. This promising impact could encourage growers to adopt this methodology in their agroecosystems. However, while the interaction between these treatments shows potential, further research is needed to optimize this disease suppression strategy.
Our findings highlight that innovative disease management methods can improve crop yield without affecting mineral composition or vitamin content. The observed increase in amino acid content, coupled with improved management of microbial diseases, underscores the efficacy of environmentally sound treatments. In regenerative organic agriculture, where chemical pesticide use is prohibited, developing integrated pest and disease management approaches is critical to linking soil and environmental health with food and human health.”