Mold Control in Horticulture with UVB+A Light

UV in general, and 285 nm in particular, is a highly effective wavelength for controlling mold and mildew (Fig. 4a, b) by reducing spore germination and mycelial growth. The magic of 285nm is that it is deep enough on the UV scale to act as a sterilizing wavelength while gentle enough to be applied directly to plants. Given that UV’s effects are dose dependent - with the right exposure time, 285 nm penetrates through the cell wall and disrupts the structure of DNA molecules (Fig. 5), prohibiting reproduction, effectively preventing mold colony growth, drastically reducing the need for human and/or chemical interventions.

As mold is a result of unwanted moisture and stagnant air in facility systems, employing UV mold control directly in the plant’s immediate environment allows facilities to operate with a greater margin of safety, reducing intervention costs, and, in some cases, avoiding the need to replace poorly designed HVAC systems.

Not only does 285 nm prevent microbes from reproducing, but can also produce a double-pronged effect by triggering the UVR8 chemical pathway that produces more naturally occurring antimicrobial compounds.

Mold CFu/g

The bar graph entitled Mold CFu/g represents an estimated number of viable bacteria or fungal cells in samples from a test between a deep UV exposed grow and a non-UV. Samples were grown in rooms with identical environmental conditions and identical independent HVAC systems.

Curing can benefit from the effects of growing with a UVB lighting strategy.

Many of the aromatic compounds (or terpenes) that give each strain its unique smell and flavour are quite volatile. They can degrade at temperatures as low as 21°C (70°F). With drastically reduced mold spores, curing Cannabis can be done more slowly at low temperatures, which preserves these terpenes better.

A long cure allows enzymes and aerobic bacteria to break down leftover minerals and the undesirable sugars produced by the decomposition of chlorophyll.

The MetaRail UVB+A
Lighting Instrument

The AgricUltra MetaRail UVA+B, Multi-Channel, Dimmable Lighting Instrument. Learn More

Simply Put

UV lighting allows facilities to operate with a greater margin of safety, reducing intervention costs, and, in some cases, avoiding the need to replace poorly designed HVAC systems.

UV extended curing times allow growers to elevate the art of Cannabis curing to the same level as a coveted cigar, or a well-aged cask.

UVB+A lighting instruments can help sterilize equipment when cleaning a grow room.

AgricUltra UVB+A lights also help purify grow room air.

Fig 4a Strawberries after 9 days in cold, dark storage control — **Fig 4a** Strawberries after 9 days in cold, dark storage control

Fig 4b UVB treated strawberries after 9 days in cold, dark storage — **Fig 4b** UVB treated strawberries after 9 days in cold, dark storage

Fig. 5 UV DNA Damage — **Fig. 5** UV DNA Damage