September 2020 - 28

CONTROLLED ENVIRONMENT AGRICULTURE
Based on the models generated from our results, the Topt
for fresh
mass, where production was greatest, is at 74.8, 77.4, 79.2 and
79.9° F for arugula, pac choi, kale, and Swiss chard, respectively.
It is interesting to note these Topt
,
the leaf area continues to expand and leads to a net increase in
photosynthesis when the entire canopy is considered.
MANAGING AIR
TEMPERATURE
Traditionally, cool air temperatures
for fresh weight compared were
higher than those for photosynthesis for all species. However, even
if photosynthesis decreases as temperatures increase above Topt
For commercial
(~60 to 64° F) have been
recommended for these species.
Our research certainly supports
that these species all can grow at
cooler temperatures due to their
low temperature tolerance. However,
the results of this work also show
that these species can grow at air
temperatures warmer than these
traditionally recommended cooler
temperatures based on the Topt
for fresh mass. By using warmer temperatures than traditional
cool temperature recommendations, specialty leafy greens can be
finished more quickly and increases productivity by allowing for
more crop cycles.
It is common for leafy green growers to have several different
species in production, and when a number of different species is
grown, grouping crops in different sections based on air temperature
requirements is an effective strategy for temperature management.
Again, arugula, kale, pac choi and Swiss chard can all be grouped
with cool-growing crops based on their cold-temperature tolerance.
However, they can and should be grouped with other crops that are
grown at warmer air temperatures, since arugula, kale, pac choi and
Swiss chard will all be more productive,
with respect to yields, when grown in
the upper 60s and low- to mid-70s.
greenhouse and controlled
environment food crop
producers, yield is the
most important aspect of
production.
TAKE HOME
Air temperatures have a strong
influence on the rate of plant specialty
green growth and development.
Arugula, kale, pac choi and Swiss chard
have been traditionally considered
cool-growing crops. However,
our research demonstrates these
species can all be grown at warmer
temperatures, which can increase
yields and the bottom line.
Christopher Currey (ccurrey@iastate.edu) is an associate professor and
Christopher Imler is a graduate research assistant in the Department of
Horticulture at Iowa State University.
CREATING AN ENVIRONMENT FOR SUCCESS
MANUFAC TURERS OF PROVEN GREENHOUSE DES IGNS
At Atlas Greenhouse, we make hydroponics easy. Our greenhouses are
designed with fully integrated components for the perfect plant
environment. Let us partner with you to help design, plan and
implement your next greenhouse project. We know how important your
business is to you - and that's why your greenhouse is important to us.
Let's grow together.
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September 2020

Table of Contents for the Digital Edition of September 2020
