Subscriptions - Maximum Yield Cannabis USA November/December 2020 | Page 53

Speculation aside, mold presents an extremely troublesome
pathogen for all cannabis growers, from personal gardens to
commercial grows. Whether growing indoors, outdoors, or in
a greenhouse, bud rot or botrytis is by far and away the most
troublesome mold in cultivation circles. Known as a pathogenic
fungus by professional horticulturists, botrytis exists
throughout the natural world and thrives in humid conditions.
The mold is spread by microscopic spores that are easily
dispersed through both air and water, as well as the clothes
and tools of the careless gardener. Unfortunately for cannabis
cultivators, prized flowers offer a prime breeding ground for
botrytis — this notion is heightened with irregularities in cultivation
environments related to humidity and airflow.
HUMIDITY AND MOLD
When diagnosing botrytis outbreaks in a cannabis grow,
excess humidity is almost always the growth catalyst
for this troublesome pathogen. Since cannabis thrives in
environments with less than 50 percent humidity, spikes in
moisture levels make plants susceptible to pathogens.
These atmospheric irregularities come about from a
variety of sources, some of which are caused by
growers themselves. For indoor growers,
the number one cause of humidity
spikes and subsequent bud
rot is poor air flow. As such, with an improperly working
exhaust or AC system, or dead pockets of air in the canopy,
botrytis spores can easily find a susceptible niche to
populate. Looking to outdoor gardens, mold almost always
comes with rainy or humid weather. In hotbeds of outdoor
cultivation like Northern California, moist fall weather
patterns are notorious for causing excessive molding
shortly before harvest. Finally, as greenhouse growers
enjoy the spoils of both indoor and outdoor cannabis
cultivation, they also face botrytis challenges seen in
both schools of thought. Therefore, fluctuations
in outdoor moisture levels or inefficient
airflow in a greenhouse can easily
seal the deal with rampant bud
rot in a greenhouse grow.
“
For indoor growers,
the number one cause of humidity spikes and
subsequent bud rot is poor air flow.”
Maximum Yield 53