Light and Plant Health header

Plant pathogens and light. Pathogens evolved amidst natural cycles of light and darkness. Electric lighting is a relatively new phenomenon in our world, and especially in theirs. Pathogens sense, interpret and use light to direct their development. In the case of UV radiation, pathogens have evolved defense mechanisms that are regulated by visible light. We seek to exploit these evolved relationships as a novel and effective means to suppress plant diseases and promote plant health.

We work as a diverse international group to promote this research area and its applications, and to act as a resource to train others. The group includes Rensselaer Polytechnic Institute's Lighting Research Center (RPI/LRC), Norway's Institute of Bioeconomy Research (NIBIO), the Norwegian University of Life Sciences (NMBU), the University of Florida Gulf Coast Research and Education Center (UFL/GCREC), and Cornell University's Geneva Experiment Station (Cornell/Geneva). The work spans disciplines from plant growth and photobiology to physics and lighting technology.

Support for research. Our work has been generously supported by grants from the USDA Organic Research and Extension Initiative (OREI), the Specialty Crops Research Program (SCRI), The Research Council of Norway (RCN), and the New York Farm Viability Institute, as well as by assistance from the lighting companies OSRAM, Ushio, Cree, and the Asahi Glass Company.

What is the problem?

What have we discovered?

Research greenhouse in Geneva, NY
Research and demonstration greenhouses at Cornell's Experiment Station and at the USDA Grape Genetic Research Unit in Geneva, NY. These automated night-operated lighting systems employ both UVB lamps and specific LEDs to suppress powdery mildews, photosensitive downy mildews, and arthropod pests such as spider mites. (Click for larger image.)

What is the basic science?

Powdery mildew colony
Microscopic view of a powdery mildew colony on a strawberry leaf. The pathogen grows externally on plant surfaces, sending absorptive structures into the epidermal cells. It's niche makes it especially vulnerable to targeted light treatments. (Click for larger image.)

What are the existing technologies?

UV-C video clip
Video clip of mobile UV-C array drawn by tractor. (Click to download .mov video.)

What are the present applications and implications for the future?

Clear tunnels
Plastic tunnels for strawberry culture at the University of Florida. These tunnels are constructed of a special fluorocarbon plastic that uniquely transmits nearly 100% of incoming UV light. This greatly reduces severity of powdery mildew, which has historically plagued tunnel production systems for many crops. (Click for larger image.)