Effects of Temperature Roberto Lopez, Purdue Univ.
Plant Responses to
Temperature
Effects of Temperature
on Greenhouse Crops
• Temperature has a large influence on
plant development:
• Plants are primarily affected by:
1) Average daily temperature (ADT)
Roberto Lopez
2) Difference between day and night
temperature (DIF)
3) Extreme temperatures
Plant Development
• Development refers to changes in the
meristematic tissues (shoot tips and leaf
axils) where leaves and flowers initiate and
develop
• Average daily temperature (ADT) is the
primary environmental factor that controls
how slow or fast a plant develops towards
marketability
ADT can Influence
− Flower size
− Root growth and development
− Flower color − Time to flower
− Time to unfold a leaf
− Leaf size
57
63
68
73 ºF
• Growth (plant size and yields) is primarily
affected by light, water, and nutrients
Zygopetalum Redvale ‘Fire Kiss’
Zygopetalum Redvale ‘Fire Kiss’
Flower development 21 days after placement at:
57
63
68
73
79 °F
57
63
68
73
79 °F
20 weeks after transfer to environmental chamber
1
Effects of Temperature Roberto Lopez, Purdue Univ.
Calculating ADT
Bud meters have been developed for different crops
to predict the time to flower based on current bud
size and greenhouse temperatures
Average daily temperature (ADT) is the
24-hour average air temperature in a
greenhouse =
(12 hours) × (75 °F day) + (12 hours) × (65 °F night)
= 70 °F
24 hours
ADT
77 + 75 + 70 + 77 + 74 + 75 + 76 + 75 + 77 + 74 + 75 + 75 (day)
+ 66 + 65 + 67 + 64 + 61 + 65 + 65 + 66 + 62 + 66 + 68 + 65 (night) = 70 °F
ADT
24 hours
Base Temperature
• The base temperature (or min. temperature) is a
species-specific, low temperature at which
plant development stops
• At or below the base temperature, plants no
longer develop leaves and progress towards
flowering ceases
• As temperature increases above the base
temperature, plants develop faster
• The temperature at which plant development is
most rapid is the optimum temperature
Base Temperature
• Cold-sensitive greenhouse crops:
base temperature of 46 °F or higher
• Cold-temperate greenhouse crops:
base temperature between 40 and
45 °F
• Cold-tolerant greenhouse crops:
base temperature of 39 °F or lower
Cold-Sensitive
Greenhouse Crops
Base Temperature
• Time to flower of cold-sensitive crops is
substantially delayed by low
temperatures, plants should be grown
at warm temperatures (> 65 ºF).
• Time to flower of cold-tolerant crops is
less influenced by low temperatures.
Greenhouse Crop
Base Temperature (°F)
Vinca Viper series
53
Poinsettia
50
Angelonia Serena series
50
Celosia Gloria series
50
Pentas Graffiti series
49
Blue salvia Victoria series
Portulaca Margarita series
49
48
Browallia Bell series
48
Zinnia Dreamland series
46
Ageratum High Tide series
46
Matt Blanchard & Erik Runkle, Michigan State Univ.
2
Effects of Temperature Roberto Lopez, Purdue Univ.
Vinca is a Cold-Sensitive Annual
Cold-Temperate
Greenhouse Crops
Effects of Temperature on Development
Base Temperature ≈53 °F
Base
Temperature (°F)
Greenhouse Crop
59
68
77
86
95 (°F)
Erik Runkle, Michigan State Univ.
Cosmos sulphureus Cosmic series
45
Salvia splendens Vista series
45
Verbena Obsession series
44
Wax begonia Sprint series
43
Impatiens (seed) Accent series
Petunia (Spreading) Wave series
43
42
Matt Blanchard & Erik Runkle, Michigan State Univ.
Rate of Development
of Cosmos
Rate
(time to flower)
0.5
Optimum
temperature
Linear range
0.4
0.3
0.2
Base
temperature
0.1
0.0
30
40
45
Petunia (Spreading) Easy wave series
50
60
70
80
90
Cold-Temperate
Greenhouse Crops
Base
Temperature (°F)
Greenhouse Crop
Dahlia Figaro series
42
Gazania Daybreak series
41
Geranium (seed) Florever series
Lobelia Riviera series
41
41
Verbena Quartz series
41
Marigold (African) Antigua series
40
Rudbeckia (annual) Becky series
40
100 110 (°F)
Temperature
Matt Blanchard & Erik Runkle, Michigan State Univ.
Cold-Tolerant
Greenhouse Crops
Greenhouse Crop
Base
Temperature (°F)
Viola Sorbet series
39
Dianthus Super Parfait series
39
Marigold (African) Moonstruck series
37
Petunia (Grandiflora) Dreams series
37
Petunia (Milliflora) Fantasy series
Snapdragon Montego series
37
36
Osteospermum Passion series
35
Marigold (French) Janie series
34
Matt Blanchard & Erik Runkle, Michigan State Univ.
Petunia is a Cold-Tolerant Annual
Effects of Temperature on Development
Base Temperature ≈37 °F
54 °F
61 °F
68 °F
75 ° F
John Erwin, Univ. of Minnesota
3
Effects of Temperature Roberto Lopez, Purdue Univ.
Effect of Decreasing
Temperature on Days to Flower
Crop
Nemesia ‘Sunsatia Peach’
57
62
68
73
79
(°F)
Cold-Tolerant Crop
Delay in Crop Timing
when Temperature is
Reduced by 1°F
Phaleonopsis
6.8 days
Petunia ‘Purple Wave’
3.3 days
Miltoniopsis ‘Augres Trinity’
3.1 days
Petunia ‘Avalanche Pink’
2.5 days
Zygopetalum Redvale ‘Fire Kiss’
2.0 days
Impatiens ‘Super Elfin Lipstick’
1.8 days
Pansy ‘Delta Pure White’
1.6 days
Viola ‘Sorbet Blackberry Cream’
1.1 days
Erik Runkle, Michigan State Univ.
New Guinea Impatiens ‘Grenada’
57
63
68
73
79
84 (°F)
Cold-Sensitive Crop
Erik Runkle and Ryan Warner, Michigan State Univ.
DIF
DIF
DIF = DIFference between day and night
temperature (Day Temp. – Night Temp.)
• Is the concept of regulating plant height by
monitoring the difference between day and
night temperature
– 76 °F day - 64 °F night = +12 °F DIF
(ADT = 70 °F)
– 70 °F day - 70 °F night = 0 °F DIF
(ADT = 70 °F)
– 64 °F day - 76 °F night = -12 °F DIF
(ADT = 70 °F)
• Under “positive DIF” (higher day temperature
than night temperature) stem elongation
INCREASES
• Under “negative DIF” (lower day temperatures
than night temperature) less stem elongation
• A “zero DIF” occurs when day temperatures
equal night temperatures (ex. constant 70 °F)
DIF
• Most Cucurbitaceae and spring bulbs such
as: hyacinths, tulips and daffodils do NOT
respond to DIF
• A large percentage of stem elongation
occurs early in the day just after sunrise
• Therefore growers can reduce the
temperature early in the morning
-DIF
+DIF
4
Effects of Temperature Roberto Lopez, Purdue Univ.
Chilling Injury
Temperature Stresses
• Symptoms of temperature stress are most
often observed when environmental
conditions in a greenhouse are beyond the
control of the grower.
− Power outages/ mechanical
failure
− Abnormal/ extreme outdoor
temperatures
− Production in structures that do
not have environmental control
− Sudden temperature fluctuations
− Shipping
Chilling Injury
and Edema
• Symptoms occur in plant tissues of sensitive
species (ex. tropical and subtropical) when
exposed to temperatures above 32 °F:
− Slowed growth
− Leave discoloration/
lesions
− Water-soaked
appearance
− Wilting
Preventing
Chilling Injury
Phalaenopsis are tropical
plants, they should not be
exposed to temperatures
below 50 °F or large and rapid
fluctuations in temperature, as
they can suffer from chilling
injury or edema
Matt Blanchard & Erik Runkle, Michigan State Univ. and Yin-Tung Wang
Freezing Injury
Symptoms of freezing injury/ frost damage
occur to plant tissues when exposed to
temperatures below 32 °F
Even a cold-tolerant
Osteospermum crop can
exhibit freezing injury after
consecutive
temperatures below 32 °F.
if not acclimated.
High Temperature
Stress
• Most greenhouse crops exhibit symptoms of
injury or die when exposed to temperatures
above 110 ºF
• The deleterious effects of high temperatures
are primarily seen in terms of reduced
photosynthetic function
• High temperatures can delay crops, cause
flower bud abortion, leaf deformation, etc.
5
Effects of Temperature Roberto Lopez, Purdue Univ.
Flowering Delay of Diascia due
to High Temperatures
57
68
Night Temperatures above 74 °F can
Cause Heat Delay in Poinsettia
79 ºF
DT 84
DT 79
DT 73
DT 68
DT 63
DT 57
NT 84
Ryan Warner, Michigan State Univ.
NT 79
NT 73
NT 68
NT 63
NT 57
Royal Heins, Michigan State Univ.
Flower Bud Abortion
Leaf Distortions
•
•
Changes in temperature
and humidity as plants
are moved from
propagation to finishing
can lead to leaf
distortions
High temperatures in
early August can also
lead to distortions
Heat Stress on Ivy
Geraniums
Flower bud abortion
can be caused by
ethylene, root rot,
low light, water
stress, or high
temperatures
Poinsettia Lateral Brach Development
is affected by High Temperatures
Whitening of young,
developing ivy
geranium leaves is
caused by high air
temperatures
(heat stress)
Blind Leaf Axil
Healthy Bud
Dead Bud
Royal Heins, Michigan State Univ.
6
Effects of Temperature Roberto Lopez, Purdue Univ.
High night temperatures during flower
initiation can cause uneven flowering, heat
delay and crown buds of garden mums
Take Home Message
• Temperature influences the rate of
plant development
• Crops can be categorized: coldsensitive, cold-temperate, or coldtolerant
• DIF can be used to increase or reduce
stem elongation
Take Home Message
• Excessively high or low temperatures
can result in symptoms of injury and
the potential damage is influenced
by both the magnitude, duration of
exposure and acclimatization of the
crop
7