UC Davis Walnut Improvement Program

Department of Plant Sciences

Sac-Solano-Yolo Walnut Day

Feb 23rd, 2016

New Walnut Varieties

Scion BreedingStandard cultivarsBlackline resistanceGenomics/DNA markers

Rootstock ImprovementRootstock BreedingTissue cultureClonal rootstocks

Walnut Improvement Program

• Yield– Precocity, Lateral flowering, No PFA

• Kernel color• Early harvest dates• Kernel halves• Nut traits

– Size, fill, shell and seal strength• Reduced input costs

– Disease/insect resistance– Reduced water use

Scion Breeding Goals

What do we want in new varieties?

Breeding Process

Nuts from crosses are flagged

Plants ready for field planting

Seed collected

Germinated in greenhouse

Planting and Field Evaluation

• PhenologyLeafing dateFlowering datesHarvest date

• Precocity• Lateral bearing• Yield• Tree form• PFA• Blight resistance

Nut and Kernel Evaluation

SealThicknessColorTexture

Shell traits

ColorWeightKernel percentFill ShrivelPlumpnessEase of halves

Kernel traits

Nut weight

Grower Field Trials and Input

This year we generated 3,546 seed from crosses.We continue evaluating 3,900 seedlings and 94 selections for cultivar development

Year CrossesOriginal

seedlings SelectionsUnder

Evaluation(n) (n) (n) (n)

1990 15 591 - -1991 18 493 - -1992 15 243 - -1993 14 116 1 11994 15 587 - -1995 15 758 1 11996 7 333 - -1997 13 611 - -1998 5 1759 - -1999 1 993 - -2000 12 2503 - -2001 16 210 - -2002 5 1200 1 12003 11 4608 9 142004 7 6000 3 72005 9 3332 12 242006 22 954 15 322007 27 1045 21 462008 33 929 7 402009 32 1187 18 1312010 32 1081 6 2892011 37 761 - 3632012 60 758 - 6862013 83 1550 - 15312014 58 787 - 7872015 25 3546* -Total 587 33389 94 3953

Seed collected from 2015 crosses for 2016 germination.

Male Parent

Female Parent Ivan

hoe

PI 1

5956

8

56-2

24

00-0

06-2

27

03-0

01-1

938

03-0

01-2

357

06-0

05-3

1

Chandler 214Ivanhoe 37 109Cheinovo sd. 117PI 159568 51Pedro 12 16576-080 16391-090-41 25791-096-3 162 393-028-20 19495-007-13 17300-006-227 29302-005-870 3203-001-1372 30303-001-1938 44003-001-2357 37703-001-2440 10905-001-94 2006-005-31 7907-002-5 11007-019-9 121

Parents chosen for:Color Blight resistanceHarvest date

Ivanhoe x 03-001-977 Cross

UC Davis Breeding ProgramGene Serr & Harold Forde

1948 - 1979

Lateral Bearing

Variety Date of

Cross Date

Released Midland 1948 1968 Vina 1948 1968 Pioneer 1950 1968 Gustine 1951 1968 Lompoc 1951 1968 Pedro 1952 1968 Amigo 1955 1968 Chico 1955 1968 Tehama 1957 1968 Serr 1958 1968 Chandler 1963 1979 Howard 1963 1979 Sunland 1965 1979

French Introductions

Gene Serr

Harold Forde

Franquette

Payne

Walnut Breeding Program 1982-2009

Cultivar Released Cisco 1990 Tulare 1993 R. Livermore 2001 Sexton 2004 Gillet 2004 Forde 2004 Ivanhoe 2010 Solano 2013

Durham 2016

Gale McGranahan

Large, oval, smooth, attractive nuts

Solid shells with good seals

55% kernel weight

8.3 g kernels - consistently light , plump

Tulare or earlier harvest

Leafs a few days before Chandler

Has had very little blight

Mid-season in-shell competitor with Hartley

Durham(93-028-20)

Chandler x PI159568

Pedigree of Walnut Varieties

Durham

Durham

Davis Chico

Kearney

Durham

Durham

Chandler

Howard

Tulare

Solano

Hartley

Leafing date 3/30

4/5

4/4

4/1

3/25

4/4

Days after Payne 11

17

15

14

6

16

Days after Chandler -6

0

-2

-4

-11

-1 Peak pollen 4/4

4/13

4/10

4/13

4/3

4/13

Peak female bloom 4/18

4/23

4/21

4/19

4/14

4/23 Harvest date 9/25

10/8

9/29

9/27

9/22

10/4

Days after Payne 10

23

12

12

7

18

Days after Chandler -15

-2

-11

-12

-17

-6

Durham Phenology

Durham Nut and Kernel Traits

Durham

Chandler

Howard

Tulare

Solano

Hartley

Inshell weight 15.1

12.9

14.0

14.0

16.0

14.1

Kernel weight 8.3

6.4

7.1

7.5

7.9

6.4

Percent kernel 55.1

49.6

50.9

53.9

53.8

45.7

Fill 5.4

4.5

5.0

4.9

5.5

4.3

Plumpness 7.0

4.2

5.0

5.0

5.3

4.2

Ease of Removal 4.2

3.9

4.7

4.6

4.6

5.0

% Extra light 43.0

50.1

17.0

7.0

37.7

9.4

% Light 53.1

42.4

61.5

74.8

55.8

68.9

% Tip shrivel 12.6

29.8

3.5

6.0

8.9

0.0

% Veins 4.0

15.9

28.8

13.2

10.6

13.1

Ser

r

Ser

r

Har

tley

Har

tley

Cha

ndle

r

Cha

ndle

r

Cha

ndle

r

How

ard

How

ard

76-8

0

Sola

no

Sola

no

Dur

ham

Dur

ham

91-0

90-4

1

91-0

90-4

1

91-0

96-3

95-0

07-1

3

95-0

07-1

3

96-0

14-1

2

Durham

Tulare harvest date or earlier Leafs a few days before Chandler 55% kernel 8.3 g kernels consistent light color, plump Low blight Large, oval, smooth nuts – attractive appearance Very solid shells with good seals Mid-season in-shell replacement for Hartley

DurhamChandler x PI159568

Solano Early harvest (Vina time)Precocious strong yield54 % kernel, 7.9 g nutsLight colorSolid uniform shellsUpright growth habitStandard tree sizeLeafing later than Ivanhoe

Solano

UC67-13

Tehama

Serr

Payne

Waterloo

Payne

PI159568

ChicoSharkey

Marchetti

UC 95-011-16

SolanoPhenology Camparisons

Trait Payne Solano Vina Chandler

Leafing date 3/18 3/25 3/25 4/05

Peak female 4/7 4/13 4/13 4/23

Peak male 4/1 4/03 4/5 4/13

Harvest 9/15 9/22 9/23 10/08

SolanoNut and Kernel Comparisons

Trait Vina Solano Chandler

In shell wt. (g) 12.8 14.7 g 13.4 g

Kernel wt (g) 6.3 g 7.9 g 6.6 g

Percent kernel 49% 54 % 49 %

% Extra light 3% 38 % 50 %

% Light 43% 56 % 42 %

Solano Solano

Solano DurhamIvanhoeChandler

Ivanhoe Very early harvest date High yield, precocityExcellent color57% kernel, 7.4 g, easy halvesSmaller treeBlight susceptibleReleased for South Valley in 2010

UC 67-13 x Chico

Femalesbloom first

Chandler IvanhoeIvanhoeKernels

Varie

ty

Nut

wt

Ker

nel w

t

% k

erne

l

Ex L

ight

Ligh

t

Leaf

Dat

e

Har

vest

da

te

Ivanhoe 12.9 7.4 57 45 47 3/20 9/12

Serr 14.6 8.3 57 10 65 3/19 9/18

Solano 14.7 7.9 54 38 56 3/25 9/22

Vina 12.8 6.3 49 3 43 3/25 9/22

Durham 15.1 8.3 55 43 53 3/30 9/25

Tulare 14.0 7.6 54 7 75 4/1 9/27

Howard 14.1 7.1 51 17 62 4/4 9/29

Chandler 13.4 6.6 49 50 42 4/5 10/8

Comparing Varieties

03-001-2357 (Chandler x Phase II)

Outstanding color and yieldHarvests a week before Chandler, better yield and fillLeafs a week after Payne8.5 g kernels, easy halves, 60% kernel Hulls split well and still hold nuts in tree

03-001-1938 (Chandler x Phase II)

Mid-season harvest similar to TulareExcellent color and yield7.9 g kernels, 58% kernelEasy removal of halves

In the Future ?

CiscoLeafs and harvests after Chandler6.5 g kernels, 45% kernel, 7% ExLite

00-006-227Harvests with VinaLeafs a few days before Chandler7.9 g kernels, 60% kernel, 56% ExLiteVery good yield, shells are thin but sufficiently strong

03-001-977Harvests with TulareLeafs a few day before Chandler8.1 g kernels, 58% kernel, 20% ExLiteSolid shells and seals, low blight

04-003-143Harvests a week before ChandlerLeafs a week before Chandler9.1 g plump kernels, 55% kernel, 36% ExLiteGood yield, large smooth nuts with easy removal

Pollenizers for Chandler with Inverse Bloom Habit

00-006-227(76-80 x O.P)

00-006-227 Serr

Suggested Pollenizers for Recent Releases

Ivanhoe Serr, Payne

Solano Chandler, Tulare, Howard

Durham Chandler

Robert Livermore

Tulare Fall Leaf Drop