Supplementary Information
This document contains supporting material for the manuscript: Quantifying Variety-specific
Heat Resistance and the Potential for Adaptation under Warming
Supplementary Tables S1-S8
Supplementary Figures S1-S25
Table S1. Characteristics of study sites in Kansas: location and observations included in sample
Site
38.86°N/99.27°W
Number
of Years
25
Min/Max of
Years
1985/2013
Number of
Varieties
173
Number of
Clusters
30
37.94°N/100.72°W
23
1985/2013
156
30
624
Abbreviation
Latitude/longitude
Hays, Ellis County
ELD
Garden City, Finney County
FND
Observations
717
Ottawa, Franklin County
FRD
38.83°N/94.89°W
23
1985/2013
111
27
432
Tribune, Greeley County
GRD
38.07°N/102.68°W
23
1986/2013
169
30
685
Hesston, Harvey County
HVD
38.05°N/97.29°W
25
1985/2009
106
27
527
Parsons, Labette County
LBD
37.30°N/95.5°W
27
1985/2013
114
27
498
Manhattan, Riley County
RLD
39.16°N/96.67°W
17
1985/2011
102
27
359
Hutchinson, Reno County
RND
38.08°N/97.87°W
20
1989/2012
108
27
433
Belleville, Republic County
RPD
39.55°N/97.65°W
23
1985/2009
128
28
612
St. John, Stafford County
STD
37.70°N/98.75°W
15
1985/2004
107
28
390
Colby, Thomas County
THD
39.42°N/101.01°W
25
1985/2013
175
30
743
--
--
29
1985/2013
197
30
6,020
Totals
Table S2. Characteristics of study sites in Kansas: means of yield, temperature, and precipitation
Tmin(°C)
Site
Tmax(°C)
Cumulative Precip (in)
Yield (bu/acre)
Fall
Winter
Spring
Fall
Winter
Spring
Fall
Winter
Spring
ELD
56.7
5.2
-7.1
4.6
20.2
7.2
19.9
4.1
1.4
5.9
FND
37.3
4.8
-7.1
3.9
20.4
8.1
19.7
3.3
1.3
5.1
FRD
50.5
7.0
-5.4
6.4
20.2
6.3
19.3
9.3
4.0
10.1
GRD
44.0
3.0
-8.1
2.2
19.4
7.2
18.9
2.7
1.0
3.6
HVD
40.8
7.3
-5.1
6.5
20.2
6.7
19.3
6.4
2.5
9.0
LBD
47.1
8.0
-3.7
7.8
20.7
7.8
20.0
8.1
4.4
10.6
RLD
51.3
6.8
-6.1
6.2
19.6
6.0
19.5
7.2
2.3
9.1
RND
44.5
6.7
-5.1
6.2
20.7
7.8
19.6
4.8
2.2
7.4
RPD
65.3
4.9
-7.7
4.5
19.1
5.3
18.4
4.9
1.9
8.3
STD
48.4
6.5
-5.4
6.2
19.9
7.5
19.6
4.9
2.4
7.8
THD
57.9
3.4
-8.1
2.6
19.2
6.7
18.5
3.5
0.9
5.4
Notes: Values were calculated across all years and seasons (Fall, Winter, and Spring) in the sample. Values for temperature and
precipitation are shown by season. Seasons are September-November (Fall), December-February (Winter), and March-May (Spring).
Table S3. Regression results: impacts of temperature on log wheat yield (bu/acre)
Variables
(1)
(2)
(3)
(4)
-0.0924***
[0.0221]
-0.0324*
[0.0173]
-0.0358**
[0.0154]
-0.0109***
[0.00306]
0.00683**
[0.00290]
-0.00169*
[0.000972]
-0.0138**
[0.00581]
0.0144**
[0.00544]
-0.00656**
[0.00288]
-0.00172**
[0.000695]
0.00307***
[0.000966]
-0.0773***
[0.0132]
-0.0945***
[0.0226]
-0.0389*
[0.0192]
-0.0355**
[0.0159]
-0.0112***
[0.00309]
0.00733**
[0.00293]
-0.00188*
[0.00101]
-0.0157**
[0.00641]
0.0151**
[0.00570]
-0.00650**
[0.00285]
-0.00154**
[0.000744]
0.00282**
[0.00103]
-0.0773***
[0.0147]
-0.0652***
[0.0218]
-0.0537***
[0.0172]
-0.0357*
[0.0208]
-0.00970***
[0.00262]
0.00787**
[0.00285]
-0.00218*
[0.00111]
-0.0192***
[0.00563]
0.0146**
[0.00581]
-0.00454
[0.00312]
-0.000886
[0.00100]
0.00150
[0.00101]
-0.0730***
[0.0172]
-0.0942***
[0.0226]
-0.0390*
[0.0191]
-0.0357**
[0.0160]
-0.0111***
[0.00310]
0.00722**
[0.00294]
-0.00183*
[0.00101]
-0.0158**
[0.00638]
0.0152**
[0.00570]
-0.00652**
[0.00285]
-0.00155**
[0.000747]
0.00284**
[0.00105]
a
-0.0866***
[0.0161]
Field Trial
Field Trial
Farm
Field Trial
Trial Location Fixed Effects
Y
Y
N
Y
Variety Fixed Effects
Y
N
N
N
Cluster Fixed Effects
N
Y
N
Y
County Fixed Effects
N
N
Y
N
Heterogeneous High Spring DD effect
N
N
N
Y
R-squared
0.470
0.431
0.429
0.433
Observations
Freeze Days: Fall
Freeze Days: Wint
Freeze Days: Spring
Degree Days Low: Fall
Degree Days Med: Fall
Degree Days High: Fall
Degree Days Low: Winter
Degree Days Med: Winter
Degree Days High: Winter
Degree Days Low: Spring
Degree Days Med: Spring
Degree Days High: Spring
Source of Yield Measure
6020
6020
217
6020
Num Locations
11
11
11
11
Num Varieties
197
197
--
197
Num Clusters
--
24
--
24
Years
29
29
28
29
Notes: All models include a quadratic trend over time and Fall, Winter, and Spring precipitation and precipitation squared
variables. Spatial and heteroskedasticity robust standard errors are reported in square brackets. Farm yields are countylevel yields from the National Agricultural Statistics Service. *, **, and *** denote statistical significance at the 10, 5,
and 1 percent levels. a the estimate and standard error are reported for the average of the 24 cluster-specific parameter
estimates for the effect of high degree days in the Spring.
Table S4. Characteristics of the 24 genetic clusters included in the sample
1
Number of
Locations
11
Number of
Years
26
Min/Max
of Years
1988/2013
Number of
Varieties
5
2
11
27
1987/2013
17
511
3
11
12
1987/2013
5
88
4
11
24
1988/2013
8
228
5
11
18
1995/2012
5
192
6
11
26
1987/2013
11
219
7
11
26
1985/2010
19
519
8
11
28
1985/2013
21
557
Cluster
Observations
323
9
11
26
1985/2013
11
266
10
11
29
1985/2013
8
348
11
11
29
1985/2013
8
281
12
11
24
1985/2012
8
346
13
11
24
1987/2013
8
187
14
11
11
2003/2013
8
229
15
11
15
1996/2013
6
107
16
4
5
2005/2009
1
14
17
11
24
1985/2008
8
293
18
5
3
2003/2005
1
12
19
11
9
1985/2004
9
99
20
11
18
1993/2013
3
171
21
11
16
1998/2013
6
173
22
11
28
1985/2012
11
503
23
11
20
1994/2013
5
195
24
11
19
1985/2010
5
159
Total
11
29
1985/2013
197
6020
Table S5. Clusters, release dates, traits, and pedigrees of included varieties
Variety
Release Source
Year
Special Pedigree
Traits
Cluster 1
2137
2154
2163
Everest
TAM 302
1995
1986
1989
2009
1999
Kan. State U.
Pioneer
Pioneer
Kan. State U.
Texas A & M
none
none
none
none
none
Cluster 2
2145
Abilene
Antero
Avalanche
Clara CL
Danby
Mesa
NuGrain
Nuplains
Ogallala
Rio Blanco
Robidoux
RonL
Thunderbolt
Trailblazer
Trego
Venango
2001
1988
2013
2001
2012
2005
1988
2006
1999
1992
1989
2010
2006
1999
1985
1999
2000
Kan. State U.
AgriPro
Col. State U.
Colo. State U.
Kan. State U.
Kan. State U.
AgriPro
AgriPro
USDA, U. Neb.
AgriPro
AgriPro
U. Nebraka
Kan. State U.
AgriPro
AgriPro
Kan. State U.
Goertzen
none
Abilene, Pioneer experimentals
none
Payne sib (Triumph type), Scout sibs
white TAM 111, Trego/Betty sib
white Rio Blanco, TAM 107 sib
whi., CL RonL sib, Clearfield
white Trego, Jagger sib
none
Payne sib (Triumph type), Scout sibs
white AgriPro experimentals, Platte
white Abilene, Kan. State U. experimentals
none
TAM 200 sib, Abilene
white Sister to Mesa, Abilene
none
Wahoo, Cody, Scout66, same genetic family as Millineum
white Trego, Colorado expt.
none
Abilene, modified TAM 107
none
Sister to Mesa and Abilene
white Rio Blanco, modified TAM 107
none
Pioneer experimental
Cluster 3
2157
2158
Billings
Duster
Iba
1983
1991
2009
2006
2012
Pioneer
Okla. State U.
Okla. State U.
Okla. State U.
Okla. State U.
none
none
none
none
none
Cluster 4
2172
2180
Endurance
Gallagher
NuFrontier
Ok101
TAM 109
TAM 304
1985
1988
2004
2012
2000
2001
1991
2007
Pioneer
Pioneer
Okla. State U.
Okla. State U.
AgriPro
Okla. State U.
Texas A & M
Texas A & M
none
TAM 101, Mexican Cimmyt experimentals
none
TAM 101, Mexican Cimmyt experimentals
none
2180, Siouxland, TAM 105, experimentals
none
Duster, Oklahoma Expt. That includes 2180
white Improved Centurk type
none
2180, Chisholm sib, Mesa
no beard TAM 107, Texas experimentals
none
Pioneer germplasm, Arkan, experimentals
Cluster 5
2174
Centerfield
Custer
Keota
Ok102
1997
2006
1994
2005
2002
Okla. State U.
Okla. State U.
Okla. State U.
Westbred
Okla. State U.
none
CL
none
none
none
2163, Experimental lines
TAM 101, Mexican Cimmyt experimentals
Mexican Cimmyt wheats. Related to 2180, without TAM 101
Pioneer experimentals, Betty
ProBrand 812, Caldwell, TAM 106, experimentals
Sturdy, Tascosa
2157 selection
Pioneer experimentals, Ukranian line
Pioneer experimentals, Texas expt., Nebraska expt.
Duster, Oklahoma expt. That includes Karl 92, Tomahawk
2165, PL145, Illinois experimental
2174, Above sib
Chisholm, TAM 105, Romanian variety
Jagger, Custer
2174, Cimarron
Table S5 continued.
Variety
Release Source
Year
Special Pedigree
Traits
Cluster 6
7805
Akron
Ankor
Brawl CL Plus
Byrd
Ruby Lee
Stanton
T153
T154
TAM 112
Thunder CL
1988
1994
2001
2011
2011
2011
2000
2011
2010
2005
2008
Agseco
Col. State U.
Col. State U.
Col. State U.
Col. State U.
Okla. State U.
Kan. State U.
Trio Research
Trio Research
Texas A & M
Col. State U
none
none
none
none
none
none
none
none
none
none
white
Probrand 817, TAM 105
TAM 107, Hail
TAM 107, Hail, RWA-resistant germplasm
Above, Canadian spring Clearfield wheat, experimentals
TAM 112, Ike, Halt
Endurance (Pioneer genetics), USDA experimental
Modified TAM 107, TAM 200, experimentals,
T136, T81, experimental line also used in T158
T811 (selection from T81), 2180, T88
TAM 110, TAM 200, WGRC experimental
Kansas experiment line, Colorado experimental line, half Halt
Cluster 7
7833
Alliance
Arapahoe
Brule
Culver
Harry
HR64
Jules
Millennium
Mustang
Niobrara
Overland
Rawhide
Redland
Siouxland
Siouxland 89
Vista
Wahoo
Wrangler
1988
1994
1988
1982
1999
2002
1983
1994
2000
1983
1994
2007
1991
1988
1984
1989
1992
2001
1983
AGSECO
Agseco
U. Nebraska
U. Nebraska
U. Nebraska
U. Nebraska
Garst
Col. State U.
U. Nebraska
AgriPro
U. Nebraska
U. Nebraska
U. Nebraska
U. Nebraska
U. Nebraska
U. Nebraska
U. Nebraska
U. Nebraska
AgriPro
none
none
none
none
none
none
none
none
none
none
none
none
none
none
none
none
none
none
none
Olesen/Omaha/Homestead
Arkan, Chisholm, Colt
Brule, Agent, Parker 76, Lancer, Russian variety
Gage, Nebraska experimentals
Arapahoe, Scout, Buckskin, experimentals
Newton, Brule,
N/A
Hawk, NE7666
Arapahoe, Abilene, Colt, Warrior, Agent, Kavkaz
Colorado experimentals, Warrior, Sonora, Trapper
Brule, TAM 107 sib
Millineum, Seward, Archer, experimentals
N/A
Brule selection
Warrior, Agent, Kavkaz
Warrior, Agent, Kavkaz
Centurk, Brule, Warrior, Ottawa, Atlas 66, Cheyenne,
Arapahoe, Abilene
Mustang sib
Table S5 continued.
Variety
Release Source
Year
Special Pedigree
Traits
Cluster 8
7837
Denali
Dumas
Hondo
Karl
LCH08-80
Longhorn
Neosho
Norkan
Oro Blanco
Pony
Rowdy
Stallion
T111
T83
TAM 108
TAM 111
Thunderbird
Tonkawa
Triumph 64
WB-Cedar
1988
2011
2000
1998
1988
2013
1990
2005
1986
1994
1985
1994
1985
2000
1995
1984
2003
1985
1994
1964
2011
AGSECO
Col. State U.
AgriPro
AgriPro
Kan. State U.
Limagrain
AgriPro
AgriPro
Kan. State U.
AgriPro
Rohm & Haas
AgriPro
AgriPro
Trio
Trio
Texas A & M
AgriPro, TA&M
AgriPro
Okla. State U.
Danne
Westbred
none
Trison/Prosper
none
TAM 111, experimental that is half Yumar
none
AgriPro experimentals
none
AgriPro experimentals
none
Plainsman V, Kaw, Atlas 50, Parker, Agent
none
Pioneer germplasm
no beard Thunderbird
none
Victory, Thunderbird, Heyne sib
none
Scout, Plainsman V, Larned, Sage, Eagle
white Rio Blanco, Colorado experimental related to Hawk
none
Scout, Sturdy
none
Mesa sib, AgriPro experimental
none
Bulk Selection
none
T67, Tecumseh, Plainsman V
none
TAM 107, TAM 108, Lancota
none
Sturdy sib, Triumph, Centurk
none
TAM 107, Centurk 78, Texas experimentals
none
Bulk selection
none
Chisholm, TAM 105, Romanian variety
none
Triumph, Blackhull, Kanred
none
TAM 302, experimentals with 2180 in pedigree
Cluster 9
7846
Bill Brown
Colby 94
Hatcher
Lamar
Sierra
Vona
1988
2007
1994
2005
1988
1990
1976
Agseco
Col. State U.
Agseco
Col. State U.
Col. State U.
AgriPro
Col. State U.
none
none
none
none
none
none
none
Windstar
Wings
Yuma
Yumar
1997
1977
1991
1997
U. Nebraksa
AgriPro
Col. State U.
Col. State U.
none
none
none
none
Vona, Centurk, Sturdy, Agent
Yumar, Arlin
N/A
Yumar, Vista, Kansas experimental
Vona, Wings, Colorado experimental
Century, Scout, Payne, Mexican spring wheat, English wheat
Kaw, Sonora 64, Tacuari, Warrior, Kenya 58, Newthatch,
Cheyenne, Tenmarq, Mediterranean, Hope, Parker, Lancer,
Norin
Siouxland, Brule, Caldwell,
Vona sib
Vona, Yugoslavian wheats
Yuma, RWA-resistant germplasm
Cluster 10
Above
Halt
Prairie Red
Ripper
T158
TAM 105
TAM 107
TAM 110
2001
1994
1999
2007
2009
1979
1984
1996
Col. State U.
Col. State U.
Col. State U.
Col. State U.
Trio Research
Texas A & M
Texas A & M
Agseco, T A&M
CL
none
none
none
none
none
none
none
TAM 110, French variety
TAM 107, Sumner, RWA-resistant genetics
TAM 107, RWA-resistant germplasm
Prairie Red, experimentals
T81, KS93U206 exptl.
Scout, short wheats
TAM 105, Amigo
TAM 107, Largo
Table S5 continued.
Variety
Release Source
Year
Special Pedigree
Traits
Cluster 11
Arkan
Coronado
Garrison
Pecos
Settler CL
Voyager
Wesley
Winterhawk
1982
1994
2011
1991
2008
1994
1999
2007
Kan. State U.
AgriPro
Okla. State U.
AgriPro
U. Nebraska
Goertzen
USDA, U. Neb.
WestBred
none
none
none
none
none
none
none
none
Sage, Arthur
Mustang, experimentals, some spring wheat
Betty, Hickok, Oklahoma experimental that is half 2180
Arkan, AgriPro experimental
Millennium, Wesley, Above sibs
N/A
Plainsman V, Colt, Cody, Russian experimental
WestBred experimentals
Cluster 12
Arlin
Camelot
Dodge
Lakin
Newton
1992
2008
1986
2000
1978
Kan. State U.
U. Nebraska
Kan. State U.
Kan. State U.
Kan. State U.
white
none
none
white
none
NuHorizon
Snowmass
Tiger
2000
2009
2010
General Mills
Col. State U.
Kan. State U.
white
white
white
Selection from hard red winter and hard red spring wheat
Arlin sib, Redland, Experimetnals
Arkan sib, Newton sib
Arlin, experimentals
Scout, Sonora 64, Pitic, Kenya 58, Newthatch, Thatcher,
Frontana, Klein Rendidor
Arlin, AgriPro experimentals
Trego and experimentals, with some Arlin
Experimentals, including some Ike
Cluster 13
Armour
Guymon
Hickok
Intrada
Spartan
TAM 113
TAM 200
TAM 202
2008
2005
1994
2000
2008
2010
1986
1991
Westbred
Okla. State U.
AgriPro
Okla. State U.
Westbred
Texas A & M
Texas A & M
Texas A & M
none
white
none
white
none
none
none
none
Westbred experimentals
Intrada, Platte, AgriPro experimental
TAM 200 sib, AgriPro experimental
Rio Blanco, TAM 200
2180, Experimentals
TAM 200 sib, TAM 105 sib, TAM 202, TAM 200
Amigo, Scout types
Amigo gene, Siouxland outcross
Cluster 14
Art
Fuller
Jackpot
OK Bullet
Overley
Postrock
Tarkio
WB-Stout
2007
2006
2008
2005
2003
2006
2006
2010
AgriPro
Kan. State U.
Agripro
Okla. State U.
Kan. State U.
Agripro
WestBred
WestBred
none
none
none
none
none
none
none
none
Jagger, AgriPro experimentals
Jagger, experimentals
W98-232 and WGRC experimetnal
Jagger, KS96WGRC39 experimental
Jagger, Heyne, modified TAM 107
Jagger, Ogallala, Kansas experimental
Jagger, Snow White, Oklahoma expt.
Jagger, Santa Fe sib, experimentals
Cluster 15
Big Dawg
Hitch
Santa Fe
SY Wolf
TAM 203
W99-194
1996
2008
2003
2011
2007
2004
AgriPro
WestBred
WestBred
Agripro
Texas A & M
U. Nebraska
none
none
none
none
none
none
Bulk selection
Abilene, karl 92, Jagger, Kansas experimentals
Jagger, G1878
Agripro experimentals
Romanian variety, experimentals
N/A
Cluster 16
Bond CL
2005
Col. State U.
CL
Above sib, Yumar
Table S5 continued.
Variety
Release Source
Year
Special Pedigree
Traits
Cluster 17
Bronco
Century
Chisholm
Cimarron
Discovery
Enhancer
Onaga
Payne
1989
1996
1983
1990
1995
1998
1998
1977
AgriPro
Okla. State U
Okla. State U.
Okla. State U.
Goertzn
Goertzen
Agseco
Okla. State U.
none
none
none
none
none
none
none
none
Payne, half-parent of Hawk
Payne, TAM 101, Amigo
Sturdy sib, Triumph, Oro, Tenmarq
Payne, Wings (Vona sib)
N/A
Includes Pioneer genetics
Pioneer genetics
Sturdy, Triumph 64
Cluster 18
Burchett
2003
Farmer Direct
white
AgriPro experimentals
Cluster 19
Carson
Centura
Centurk 78
1986
1983
1978
Col. State U.
U. Nebraska
U. Nebraska
none
none
none
Cody
Goodstreak
1986
2002
U. Nebraska
U. Nebraska
none
none
Hawk
Parker 76
Ram
Sandy
1981
1977
1983
1981
AgriPro
Kan. State U.
AgriPro
Col. State U.
none
none
none
none
Centurk, Scout, Anza
Centurk 78, Warrior, Agent
Turkey, Cheyenne, Parker, Newthatch (HRS), Kenya 58
(HRS), Hope (HRS)
Centurk 78, Agent
Len, Butte, Agent, Waldron, Bluebird, Dular, Eagle, Cheney,
Larned, TAM107, Colt, Patrizanka
Baca, Colorado experimentals
Parker*5/Agent
Hawk sib
Centurk, Mexican varieties
Cluster 20
Cisco
Deliver
Karl 92
2003
2004
1992
Goertzen
Okla. State U.
Kan. State U.
none
Karl 92, Bounty experimentals
no beard Karl, Chisholm, experimentals
none
Plainsman V, Kaw, Atlas 50, Parker, Agent
Cluster 21
CJ
Cutter
Heyne
Jagalene
SY Southwind
2010
2001
1998
2001
2012
Agripro
AgriPro
Kan. State U.
AgriPro
Agripro
none
none
white
none
none
WB-Grainfield
2012
Westbred
none
Cluster 22
Colt
Eagle
Hallam
Ike
Infinity CL
Larned
McGill
Nekota
Scout 66
1984
1971
2005
1993
2005
1976
2010
1994
1967
U. Nebraska
Kan. State U.
U. Nebraska
Kan. State U.
U. Nebraska
Kan. State U.
U. Nebraska
U. Nebraska
U. Nebraska
none
none
none
none
CL
none
none
none
none
T163
Tut
2010
1989
Triio Research
Pharaoh
none
none
Agripro experimentals
Jagger, TAM 200, W81-296
Experimentals, including some Plainsman V
Jagger, Abilene
Agripro experimentals
experimentals
Westbred and Kan. State U. experimentals
Related to Vona.
Nebred, Hope, Turkey, Cheyenne, Ponca
Niobrara, Brule, Bennett
Dular, Eagle, Cheney, Larned, Colt
Windstar, Millennium sib, Above sib
Scout, Ottawa
Ike, Redland, Chisholm, Vona, and Plainsman
TAM 107, Bennett
Scout, Nebred, Hope (HRS), Pawnee, Marquillo (HRS),
Kawvale
T811 (selection from T81), 93WGRC27 experimental
Field selection of soil-borne resistant Scout type
Table S5 continued.
Variety
Release Source
Year
Special Pedigree
Traits
Cluster 23
Greer
Jagger
Shocker
Smoky Hill
TAM 401
2010
1994
2006
2006
2008
Agripro
Kan. State U.
WestBred
WestBred
Texas A&M
none
Experimentals, including Pioneer genetics
none
Karl sib, Stephens (SWW)
none
Jagger, Tomahawk, Freedom (soft)
none
Bulk selection
no beard Jagger, Mason
Cluster 24
Hawken
NuDakota
Ponderosa
Tomahawk
Victory
2007
2006
1992
1990
1985
AgriPro
AgriPro
AgriPro
AgriPro
AgriPro
none
white
none
none
none
AgriPro experimentals
Jagger, Romanian variety
Thunderbird, W81-133
Related to Victory
Bulk selection
Table S6. Estimated heat effects and average yields for the 24 genetic clusters included in the sample
Cluster
Stand Err
Avg Yield
1
-0.082***
Estimate
0.0182
52.9
Varieties
2
-0.071***
0.0202
51.7
3
-0.099***
0.0166
49.9
2145,ABILENE,ANTERO,AVALANCHE,CLARA CL,DANBY,MESA,NUGRAIN,NUPLAINS,OGALLALA,RIO
BLANCO,ROBIDOUX,RONL,THUNDERBOLT,TRAILBLAZER,TREGO,VENANGO
2157,2158,BILLINGS,DUSTER,IBA
4
-0.095***
0.0189
50.4
2172,2180,ENDURANCE,GALLAGHER,NUFRONTIER,OK101,TAM 109,TAM 304
5
-0.067***
0.0203
52.0
2174,CENTERFIELD,CUSTER,KEOTA,OK102
6
-0.087***
0.0177
51.9
7805,AKRON,ANKOR,BRAWL CL PLUS,BYRD,RUBY LEE,STANTON,T153,T154,TAM 112,THUNDER CL
7
-0.075***
0.0143
52.3
8
-0.089***
0.0128
50.4
9
-0.086***
0.0150
53.5
7846,BILL BROWN,COLBY 94,HATCHER,LAMAR,SIERRA,VONA,WINDSTAR,WINGS,YUMA,YUMAR
10
-0.065***
0.0165
51.6
ABOVE,HALT,PRAIRIE RED,RIPPER,T158,TAM 105,TAM 107,TAM 110
11
-0.087***
0.0276
48.9
ARKAN,CORONADO,GARRISON,PECOS,SETTLER CL,VOYAGER,WESLEY,WINTERHAWK
12
-0.063***
0.0171
46.6
ARLIN,CAMELOT,DODGE,LAKIN,NEWTON,NUHORIZON,SNOWMASS,TIGER
13
-0.091***
0.0255
49.3
ARMOUR,GUYMON,HICKOK,INTRADA,SPARTAN,TAM 113,TAM 200,TAM 202
14
-0.086**
0.0343
53.0
ART,FULLER,JACKPOT,OK BULLET,OVERLEY,POSTROCK,TARKIO,WB-STOUT
15
-0.113**
0.0421
53.5
BIG DAWG,HITCH,SANTA FE,SY WOLF,TAM 203,W99-194
16
-0.154***
0.0374
58.8
BOND CL
17
-0.080***
0.0177
50.6
BRONCO,CENTURY,CHISHOLM,CIMARRON,DISCOVERY,ENHANCER,ONAGA,PAYNE
18
-0.075**
0.0296
54.8
BURCHETT
19
-0.133***
0.0230
50.0
CARSON,CENTURA,CENTURK 78,CODY,GOODSTREAK,HAWK,PARKER 76,RAM,SANDY
20
-0.109***
0.0307
50.4
CISCO,DELIVER,KARL 92
21
-0.077***
0.0247
53.0
CJ,CUTTER,HEYNE,JAGALENE,SY SOUTHWIND,WB-GRAINFIELD
22
-0.043**
0.0182
48.8
COLT,EAGLE,HALLAM,IKE,INFINITY CL,LARNED,MCGILL,NEKOTA,SCOUT 66,T163,TUT
23
-0.089***
0.0296
52.5
GREER,JAGGER,SHOCKER,SMOKY HILL,TAM 401
24
-0.064***
0.0160
51.8
HAWKEN,NUDAKOTA,PONDEROSA,TOMAHAWK,VICTORY
2137,2154,2163,EVEREST,TAM 302
7833,ALLIANCE,ARAPAHOE,BRULE,CULVER,HARRY,HR 64,JULES,MILLENNIUM,MUSTANG,NIOBRARA,
OVERLAND,RAWHIDE,REDLAND,SIOUXLAND,SIOUXLAND 84,VISTA,WAHOO,WRANGLER
7837,DENALI,DUMAS,HONDO,KARL,LCH08-80,LONGHORN,NEOSHO,NORKAN,ORO
BLANCO,PONY,ROWDY,STALLION,T111,T83,TAM 108,TAM 111,THUNDERBIRD,TONKAWA,TRIUMPH 64,WB-CEDAR
Notes: Highest and lowest heat effects are in italics. Estimates are from the preferred model (Table S3, Col 4). Average yields (bu/acre) are predicted using this specification, with yield replacing log yield as the
dependent variable. The model is re-estimated and predictions are made at the sample average of covariates, with the exception that the trend variable is held at its 2013 value to reflect modern practices.
Table S7. Joint hypothesis tests for regression parameters
Null Hypothesis
P-value
Equality of Spring DD high effect across genetic clusters
0.000
Precipitation Effects Jointly Zero
0.055
Trend Parameters Jointly Zero
0.006
Equality of Fixed Effects
All location effects equal
0.000
All cluster effects equal
0.000
Notes: Hypotheses were tested using F-tests with spatial and heteroskedasticity robust
standard errors. *, **, and *** denote statistical significance at the 10, 5, and 1 percent
levels.
Table S8. Prediction accuracy for alternative models
Model
rmse
Preferred
0.3274
All spring temperature effects heterogeneous
0.3277
All temperature effects heterogeneous
0.3702
Notes: We consider models with varying degrees of heterogeneity in the temperature
coefficients. The preferred model allows the effect of extreme heat in the spring to
vary across genetic clusters. The second model allows the effect of all spring
temperatures to vary, and the third allows the effect of all temperature variables to
vary. Each model is estimated 1000 times, randomly choosing 80 percent of the 6,020
observations. Parameter estimates are then used to predict yields for the omitted 20
percent in each subsample. Root-mean-squared-errors (rmse) are reported for these
predictions. The smaller the rmse, the better the performance of the model.
150
100
50
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
1985
0
Figure S1 Spatial and temporal variation of yields. We observe yields across varieties at the
location-year level, and construct boxplots for each year. Each box is defined by the upper and
lower quartile, with the median depicted as a horizontal line within the box. The endpoints for
the whiskers are the upper and lower adjacent values, which are defined as the relevant quartile
+/- three-halves of the interquartile range, and circles represent data points outside of the
adjacent values.
Fall
Wint
Avg Min Temp (°C)
-2
10
8
6
4
-6
-8
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
-10
2
15
-4
Spri
10
5
0
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
Avg Min Temp (°C)
Avg Min Temp (°C)
12
Figure S2 Seasonal average daily minimum temperature by year. We average observed daily
minumimum temperaure within each season for each location-year. Seasons are SeptemberNovember (Fall), December-February (Winter), and March-May (Spring). The location specific
measures are then used to construct boxplots for each year. Each box is defined by the upper and
lower quartile, with the median depicted as a horizontal line within the box. The endpoints for
the whiskers are the upper and lower adjacent values, which are defined as the relevant quartile
+/- three-halves of the interquartile range, and circles represent data points outside of the
adjacent values.
Fall
Avg Max Temp (°C)
12
22
20
18
16
Wint
10
8
6
4
2
24
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
14
Spri
22
20
18
16
14
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
Avg Max Temp (°C)
Avg Max Temp (°C)
24
Figure S3. Seasonal average daily maximum temperature by year. We average observed
daily maximum temperaure within each season for each location-year. Seasons are SeptemberNovember (Fall), December-February (Winter), and March-May (Spring). The location specific
measures are then used to construct boxplots for each year. Each box is defined by the upper and
lower quartile, with the median depicted as a horizontal line within the box. The endpoints for
the whiskers are the upper and lower adjacent values, which are defined as the relevant quartile
+/- three-halves of the interquartile range, and circles represent data points outside of the
adjacent values.
Fall
10
Cumulative Precip (in)
20
15
10
5
25
8
6
4
2
0
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
0
Wint
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
25
Spri
20
15
10
5
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
0
Figure S4. Seasonal cumulative precipitation by year. We sum observed daily precipitation
within each season for each location-year. Seasons are September-November (Fall), DecemberFebruary (Winter), and March-May (Spring). The location specific measures are then used to
construct boxplots for each year. Each box is defined by the upper and lower quartile, with the
median depicted as a horizontal line within the box. The endpoints for the whiskers are the upper
and lower adjacent values, which are defined as the relevant quartile +/- three-halves of the
interquartile range, and circles represent data points outside of the adjacent values.
60
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
10
20
30
40
50
Wint
Spri
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
0
5
10
15
20
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
Freeze Exposure (24 hours)
20
0
5
10
15
Fall
Figure S5. Seasonal freeze days. Cumulative exposure to below 0°C temperatures within each
day are constructed using a sinusoidal interpolation of temperature exposure. Daily values are
summed within each season for each location-year. Seasons are September-November (Fall),
December-February (Winter), and March-May (Spring). The location specific measures are then
used to construct boxplots for each year. Each box is defined by the upper and lower quartile,
with the median depicted as a horizontal line within the box. The endpoints for the whiskers are
the upper and lower adjacent values, which are defined as the relevant quartile +/- three-halves of
the interquartile range, and circles represent data points outside of the adjacent values.
1,800
200
300
400
500
Wint
2010
2005
2010
2010
2000
2005
2005
1995
2000
2000
1990
1995
1995
1985
1990
1990
1,000 1,200 1,400 1,600 1,800
1985
100
1,000
1,200
1,400
1,600
DD above 0 (24 hours)
600
Fall
1985
800
Spri
Figure S6. Seasonal degree days above 0°C. Degree days for each day are constructed using a
sinusoidal interpolation of temperature exposure. Daily values are summed within each season
for each location-year. Seasons are September-November (Fall), December-February (Winter),
and March-May (Spring). The location specific measures are then used to construct boxplots for
each year. Each box is defined by the upper and lower quartile, with the median depicted as a
horizontal line within the box. The endpoints for the whiskers are the upper and lower adjacent
values, which are defined as the relevant quartile +/- three-halves of the interquartile range, and
circles represent data points outside of the adjacent values.
-5
5
0
-5
Wint_DD0
-10
5
Spri_DD0
0
-5
-10
ALL
ELD
FND
FRD
GRD
HVD
LBD
RLD
RND
RPD
STD
THD
-10
0
-10
Trend (% of mean)
-5
Trend (% of mean)
0
Fall_DD0
Spri_FR
ALL
ELD
FND
FRD
GRD
HVD
LBD
RLD
RND
RPD
STD
THD
-10
ALL
ELD
FND
FRD
GRD
HVD
LBD
RLD
RND
RPD
STD
THD
Trend (% of mean)
5
5
Trend (% of mean)
-5
ALL
ELD
FND
FRD
GRD
HVD
LBD
RLD
RND
RPD
STD
THD
-10
0
Wint_FR
ALL
ELD
FND
FRD
GRD
HVD
LBD
RLD
RND
RPD
STD
THD
-5
5
ALL
ELD
FND
FRD
GRD
HVD
LBD
RLD
RND
RPD
STD
THD
0
Fall_FR
Trend (% of mean)
Trend (% of mean)
5
Figure S7. Trends in freeze days (FR) and degree days above 0°C (DD0) over time. Each bar
corresponds to the estimated trend coefficient in a model that regresses the weather variable
against time. The estimates are normalized to a percentage of the sample mean for that variable.
The term, “ALL” refers to a pooled model across all locations, the others denote a regression
using only that locations data. Bars show 95% confidence intervals.
0
A
15
B
-.05
Number of varieties
10
-.1
5
-.15
1960
1970
1980 1990 2000
Release year
2010
0
1960
1970
1980 1990 2000
Release year
2010
Figure S8. Effect of extreme heat across seed variety release years. (A) Degree days above
34°C are interacted with polynomials of release year in the regression model. Lines measure the
estimated marginal effect of an additional degree day above 34°C. The horizontal line is the
constant effect in absence of the interactions. (B) The number of varieties by release year
A. Varieties Ranked by Observed Trial Years in Data
Number of Years
30
20
10
0
1
Varieties
197
B. Clusters Ranked by Observed Trial Years in Data
Number of Years
30
20
10
0
1
Clusters
24
Figure S9. Number of observed years for seed varieties and clusters of varieties. Bars report
the total number of trial years that each variety or cluster appeared in.
2
1
0
-1
0
50
100
150
Varieties, ranked by effect size
200
Figure S10. Effect of extreme heat across seed varieties. Degree days above 34°C are
interacted with a dummy (indicator) variable for each seed variety. Droplines report estimated
marginal effects of an additional degree day above 34°C for each variety.
-.15
-.2
-.25
-.3
-.35
15
16
17
18
19
20
21 22 23 24 25
Number of clusters
26
27
28
29
30
Figure S11. Optimal number of genetic clusters to include in the regression model. We
consider models with 15-30 genetic clusters, and interact dummy (indicator) variables for these
clusters with degree days above 34°C. Root mean squared errors (Rmse) are reported as a
percentage reduction relative to the baseline model that does not interact degree days above 34°C
with genetic clusters. Each of the 30 models is estimated 1000 times, randomly choosing 80
percent of the 6,020 observations. Parameter estimates are then used to predict yields for the
omitted 20 percent in each subsample. The larger the reduction the better the performance of the
model.
N=15
N=16
N=17
N=18
N=19
N=20
N=21
N=22
N=23
N=24
N=25
N=26
N=27
N=28
N=29
N=30
0
-.05
-.1
-.15
0
-.05
-.1
-.15
0
-.05
-.1
-.15
0
-.05
-.1
-.15
0
10
20
30
0
10
20
30
0
10
20
30
0
10
20
30
Clusters, ranked by effect size
Graphs by Num
Figure S12. Heterogeneous effect of extreme heat across various groupings of genetic
similarity. We consider models with 15-30 categories of genetic clusters. For example, when
N=15 each variety is classified into one of fifteen groups, when N=30 each variety is classified
into one of thirty groups. A separate heat effect is estimated for each cluster by interacting the
categorical variable with degree days above 34°C. The Droplines report estimated marginal
effect of an additional degree day above 34°C for each cluster.
HR 64
MUSTANG
NIOBRARA
WAHOO
OE
ARAPAH M
NNIU
MILLE
CISCO
ER
DELIVL 92
KAR LIN
AR
GE
DOD T
ELO
CAMRIZON
R
HO TIGE S
NU
S
MA IN
OW AK
L
SN
ON
WT TT
NE CHE AN
K S
R
BU AR CO L
PE R C EY
LE L K
TT ES AW N
SE W H ISO O
R
D
TE R A
IN GAR ON
R
O
C
W
TE
R
FI
EL
O 217 D
K1 4
21 02
BI
L 21 57
DU LIN 58
ST GS
ER
OR
H
O B ON IBA
LA DO
RO NCO
TA WDY
M
THU STAL 108
NDE LIO
N
LON RBIR
GHO D
NEO RN
SHO
DEN
A
TAM LI
1
LCH08 11
WB-CED -80
AR
TRIUMPH
64
PONY
TONKAWA
KARL
EN
C
76 78
K R
W KE RK
HA AR TU RA
P EN TU
C EN Y
C OD Y
K
C ND ON REA
SA RS ST
CA OD A
GOERR
SI MAR 94
LA LBY
CO 6
R
784 DSTA
WIN CHER
HAT A
M
YU AR
YUM S
WING
VONA OWN
R
BILL B L
BOND C
OSA
PONDER
HAWKEN
ORY
VICT
TOMAHAWK
NUDAKOTA
SY SOUTHWIND
CJ
HEYNE
WB-GRAI
NFIELD
CUTTER
JAGALE
OVER NE
L
E
Y
FULL
STO ER
TAR UT
OK KIO
JAC BULLE
PO KPOT T
AR STRO
CK
SA T
HI NTA
TA TCH FE
W M2
S 99- 03
B Y W 194
S IG OL
SH MO DAW F
G O KY G
TA RE CK HI
M ER ER LL
40
1
ER N
US
G O
PL
G NT
JA TA 5
CL
L
S 0
78 RAWOR
B NK N
A KRO
A 54
T1 53 LEE
T1 BY 2
RU M 11
L
TA RD ER C
BY UND
TH 8
T15 PER
RIP T
HAL 107
TAM 105
TAM IE RED
PRAIR 10
TAM 1
ABOVE
DUMAS
7837
T83
NORKAN
T111
VO
EV YA
ER GE
E R
21 ST
21 37
TA 21 63
M 54
3
TA 21 02
M 72
10
9
2
EN
OK 180
D
GA URA 101
NU LLAG NCE
FRO HE
R
N
TAM TIER
ARM 304
GUY OUR
M
INTR ON
AD
TAM 1 A
1
TAM 20 3
0
TAM 20
2
HICKOK
SPARTAN
AVALANCHE
CLARA CL
TREGO
ANTERO
DANBY
RONL
RBOLT
DE
THUN
NCO
RIO BLA ZER
BLA
TRAIL LLALA
A
G
O
X
IDOU
ROB NGO
A
VEN 2145
AIN
GR
NU LAINS
E
P
NU ILEN A
AB MES
CO
ON LM
R
B HO RY
IS TU N
H
C EN RO E
C AR YN
M PA ER
CI
NC RY
HA VE GA
EN CO NA TER A
S O S T
I
D
O
CU KE
WRANGLER
OVERLAND
7833
REDLAND
BRULE
ALLIAN
VISTA CE
HAR
R
CUL Y
JUL VER
SIO ES
U
SIO XLAN
RA UXLA D
T1 WHID ND 89
E
INF 63
NE INIT
HA KOT Y CL
A
L
LA LA
EA RN M
S GL ED
TU COU E
IK T T
66
C E
M OL
R CG T
AM IL
L
Dendrogram of 197 wheat lines
Figure S13. Dendrogram for the clustered wheat varieties.
25
frequency
20
15
10
5
0
-.15
-.1
-.05
Effect of extreme heat
Figure S14. Heterogeneity of heat sensitivity across genetic clusters. Figure provides a kernel
density plot for the 24 heat effects estimated under our preferred model. The underlying effects
are provided in Table S6.
.1
0
-.1
-.2
-.3
-.4
-.5
-.6
-.7
0
10
20
Spring temperature (°C)
30
40
Figure S15. Heterogeneous effect of temperatures above 34°C across genetic clusters. Graph
displays changes in log yield if the crop is exposed for one day to a particular 1°C temperature
interval. Solid black line reports the average effect, other colors correspond to the 24 genetic
clusters under our preferred model.
0
-20
-40
-60
-80
Most resilient cluster
Least resilient cluster
Average across clusters
+1°C
+2°C
+3°C
Warming scenario
+4°C
+5°C
Figure S16. Replication of Figure 3 for an alternative model using 22 genetic clusters. The
alternative model is same as the preferred model except it uses the grouping scheme with 22
clusters instead of 24. Bars show 95% confidence intervals.
0
-20
-40
-60
-80
Most resilient cluster
Least resilient cluster
Average across clusters
+1°C
+2°C
+3°C
Warming scenario
+4°C
+5°C
Figure S17. Replication of Figure 3 for an alternative model using 30 genetic clusters. The
alternative model is same as the preferred model except it uses the grouping scheme with 30
clusters instead of 24. Bars show 95% confidence intervals.
0
-20
-40
-60
-80
-100
Most resilient cluster
Least resilient cluster
Average across clusters
+1°C
+2°C
+3°C
Warming scenario
+4°C
+5°C
Figure S18. Replication of Figure 3 for an alternative model using location specific trend
variables. The alternative model is same as the preferred model except it includes separate
quadratic trends for each location. Bars show 95% confidence intervals.
-28
-27
-26
-25
1995 2005 2015
Harvest Year
+3°C Warming
1985
1995 2005 2015
Harvest Year
1985
1995 2005 2015
Harvest Year
-56
-57
-58
+4°C Warming
-55
-54
-53
1985
-29
Yield impact (%)
-14.5
-15
-15.5
Yield impact (%)
Yield impact (%)
-40
-41
-42
-43
-44
Yield impact (%)
+2°C Warming
1995 2005 2015
Harvest Year
-39
1985
-14
-13.5
-4.4
-4.6
-4.8
-5
Yield impact (%)
-5.2
+1°C Warming
+5°C Warming
1985
1995 2005 2015
Harvest Year
Figure S19. Replication of Figure 4 for an alternative model using 22 genetic clusters. The
alternative model is same as the preferred model except it uses the grouping scheme with 22
clusters instead of 24.
-28
-27
-26
-25
1995 2005 2015
Harvest Year
+3°C Warming
1985
1995 2005 2015
Harvest Year
-54
-56
-42
-41
Yield impact (%)
-40
-39
-52
1985
-29
Yield impact (%)
-14
-14.5
-15
+2°C Warming
1995 2005 2015
Harvest Year
+4°C Warming
1985
1995 2005 2015
Harvest Year
-58
-43
-44
Yield impact (%)
-15.5
Yield impact (%)
1985
-13.5
-13
-4.4
-4.6
-4.8
-5
-5.2
Yield impact (%)
-5.4
+1°C Warming
+5°C Warming
1985
1995 2005 2015
Harvest Year
Figure S20. Replication of Figure 4 for an alternative model using 30 genetic clusters. The
alternative model is same as the preferred model except it uses the grouping scheme with 30
clusters instead of 24.
-25
-26
-27
-28
+3°C Warming
1985 1995 2005 2015
Harvest Year
+4°C Warming
1985 1995 2005 2015
Harvest Year
-58
-56
-54
-52
-50
-29
Yield impact (%)
+2°C Warming
1985 1995 2005 2015
Harvest Year
-60
Yield impact (%)
-38
-40
-42
-44
Yield impact (%)
-36
1985 1995 2005 2015
Harvest Year
-24
-12
-13
-14
-15
Yield impact (%)
-4
-4.5
-5
Yield impact (%)
-5.5
+1°C Warming
+5°C Warming
1985 1995 2005 2015
Harvest Year
Figure S21. Replication of Figure 4 for an alternative model using location specific trend
variables. The alternative model is same as the preferred model except it includes separate
quadratic trends for each location.
0
-20
-40
-60
-80
2014 planted varieties
Recently released varieties
Most resilient varieties
+1°C
+2°C
+3°C
Warming scenario
+4°C
+5°C
Figure S22. Replication of Figure 5 for an alternative model using 22 genetic clusters. The
alternative model is same as the preferred model except it uses the grouping scheme with 22
clusters instead of 24. Bars show 95% confidence intervals.
0
-20
-40
-60
-80
2014 planted varieties
Recently released varieties
Most resilient varieties
+1°C
+2°C
+3°C
Warming scenario
+4°C
+5°C
Figure S23. Replication of Figure 5 for an alternative model using 30 genetic clusters. The
alternative model is same as the preferred model except it uses the grouping scheme with 30
clusters instead of 24. Bars show 95% confidence intervals.
0
-20
-40
-60
-80
2014 planted varieties
Recently released varieties
Most resilient varieties
+1°C
+2°C
+3°C
Warming scenario
+4°C
+5°C
Figure S24. Replication of Figure 5 for an alternative model using location specific trend
variables. The alternative model is same as the preferred model except it includes separate
quadratic trends for each location. Bars show 95% confidence intervals.
B. 1°C warming
A. Baseline
C. 2°C warming
Most
Most
Most
Avg
Avg
Avg
Least
Least
Least
D. 3°C warming
E. 4°C warming
F. 5°C warming
Most
Most
Most
Avg
Avg
Avg
Least
Least
Least
0
10
20
30
40
50
0
10
20
30
40
50
0
10
20
30
40
50
Average yield (bu/acre)
Figure S25. Yield predictions for least, average, and most heat resistant varieties across
warming scenarios. Yields are predicted under the preferred model at the cluster level. Trend
variables are set to their highest observed value in the data to reflect current production practices.
“Most” combines the three most heat resistant clusters, “Least” combines the three least
resistant, and all others are combined in “Average”.