September 2023 - 12

technically speaking
BY ERIK RUNKLE
The Importance of
Transpiration
Transpiration is the
process of water movement
from the roots to the
shoots of plants. Just
like photosynthesis and
respiration, it is a requisite
function for plant growth.
In this article, the specific
functions of transpiration
are discussed, as well as
the different cultural and
environmental factors in
controlled environments
that can influence the
process. As boring
as transpiration may
sound, understanding
the process can provide
fundamental insights into
successful crop production.
Erik Runkle is
professor and
floriculture
Extension specialist
in the Department
of Horticulture at
Michigan State
University. He
can be reached at
runkleer@msu.edu.
WATER AND
NUTRIENT UPTAKE
Water is absorbed as a
liquid by roots, moves through
the stems and leaves, and is
lost as a vapor through very
tiny openings on leaves called
stomata. This transpiration
process is passive, meaning
it doesn't require energy.
Instead, the driving force for
water movement is from the
difference in water potential
between the root zone and the
atmosphere. The evaporation
of water from leaves has the
greatest impact on the rate of
water uptake and movement
through the plant.
Minerals are dissolved in
water and together, they move
12
SEPTEMBER 2023 GPNMAG.COM
from the roots to the shoots.
Therefore, nutrient uptake
relies upon water uptake,
which relies upon a healthy
root system and a driving
force for evaporation. When
water uptake is slowed, such
as from insufficient water in
the substrate, a poor root
system, or high humidity
(low vapor-pressure deficit,
or VPD), nutrient uptake is
simultaneously decreased.
EVAPORATIVE
COOLING
There are similarities
between transpiration in
plants and respiration, or
sweating, in people. Just
like people lose water
through their bodies to cool
themselves, plants " sweat "
to cool their leaves. We sweat
more, or lose more water,
when the air is dry - high
VPD - and when it's sunny.
Plants are the same; they
lose more water as the VPD
increases and as the amount
of energy incident upon a
leaf - from the sun or electric
lamps - increases. If a
plant or plant part does not
adequately transpire water, it
can overheat under high light
and kill plant tissues.
IMPORTANCE OF
TRANSPIRATION
The process of transpiration
controls water and nutrient
uptake as well as leaf and
plant temperature. When
water loss through the leaves
begins to exceed what the
roots can supply, plants
respond by closing their
As boring as
transpiration may
sound, understanding
the process can provide
fundamental insights
into successful crop
production.

http://www.GPNMAG.COM

September 2023

Table of Contents for the Digital Edition of September 2023

Table of Contents
Editor's Report | Beauty is a Gift
40 Under 40 Perspectives | Using Digital Technology Effectively
Dr. Bugs | How Does Growing Medium Affect Nematodes?
Technically Speaking | The Importance of Transpiration
Management | Supply Chain Challenges
Marketing | 5 Floral Trends for 2023
Great Lakes EXPO | Emerging Technology in the Ag Industry
Culture Report | Senetti Pericallis
Vaughn's View | Bountiful and Durable Recipe Combinations — Part 2
Product Marketplace
Classifieds/Ad Index
Chat Room
September 2023 - 1
September 2023 - 2
September 2023 - Table of Contents
September 2023 - Editor's Report | Beauty is a Gift
September 2023 - 5
September 2023 - 6
September 2023 - 7
September 2023 - 40 Under 40 Perspectives | Using Digital Technology Effectively
September 2023 - 9
September 2023 - Dr. Bugs | How Does Growing Medium Affect Nematodes?
September 2023 - 11
September 2023 - Technically Speaking | The Importance of Transpiration
September 2023 - 13
September 2023 - 14
September 2023 - 15
September 2023 - Management | Supply Chain Challenges
September 2023 - 17
September 2023 - 18
September 2023 - 19
September 2023 - 20
September 2023 - 21
September 2023 - Marketing | 5 Floral Trends for 2023
September 2023 - 23
September 2023 - 24
September 2023 - 25
September 2023 - 26
September 2023 - 27
September 2023 - 28
September 2023 - 29
September 2023 - Great Lakes EXPO | Emerging Technology in the Ag Industry
September 2023 - 31
September 2023 - 32
September 2023 - 33
September 2023 - Culture Report | Senetti Pericallis
September 2023 - 35
September 2023 - 36
September 2023 - 37
September 2023 - 38
September 2023 - 39
September 2023 - Vaughn's View | Bountiful and Durable Recipe Combinations — Part 2
September 2023 - 41
September 2023 - 42
September 2023 - 43
September 2023 - 44
September 2023 - 45
September 2023 - 46
September 2023 - 47
September 2023 - 48
September 2023 - 49
September 2023 - Product Marketplace
September 2023 - 51
September 2023 - 52
September 2023 - 53
September 2023 - 54
September 2023 - 55
September 2023 - 56
September 2023 - Classifieds/Ad Index
September 2023 - Chat Room
September 2023 - 59
September 2023 - 60
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https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2023
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https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2023
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https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-april-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/cannabisguide-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/hempguide-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/newvarieties-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2022
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2022
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https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-march-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/cannabisguide-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/hempguide-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/newvarieties-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-january-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/january-2021
https://www.nxtbook.com/greatamericanmediaservices/GPN/december-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-november-2020
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https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-september-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/september-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/august-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-july-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/july-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/june-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/may-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/april-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/californiaspringtrials-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/big-grower-march-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/march-2020
https://www.nxtbook.com/greatamericanmediaservices/GPN/february-2020
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