are you growing puny plants?
require moisture for germination. Since high
humidity is equal to high moisture, fungal
diseases are more likely to develop. Lastly
and most importantly is the effect of stomata
opening with high humidity. One research
study has shown the vase life of cut roses is
significantly reduced when the plants are
grown in greenhouses under high (>85%)
humidity. The plants responded to their
environment and became acclimated
to these humid conditions, resulting
in a lack of functionality of the
stomata. The cut flowers became
insensitive to the cues that usually
helped reduce water loss.
I use this point to illustrate the
impetus of this article: your
growing conditions can and will
dictate the type of plants you
produce. Make them lazy in
their environment and they
will be ill-prepared for the
real world. At the very least,
growers should invest in
a cheap hygrometer and
try to maintain RH at
76
Maximum Yield USA | February 2014
50 to 80%, avoiding situations where RH exceeds
90%. The lack of water uptake by growing plants
in a humid environment would directly reduce
nutrient uptake, leading to reduced growth and
nutrient deficiencies over time.
To correct high RH, simple ventilation may be
effective at decreasing th H[