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Quality of Organically and Conventionally Grown Apples and StrawberriesPreston K. Andrews

Horticulture & LandscapeArchitecture

John P. ReganoldCrop & Soil Sciences

Fruit quality• Depends on stakeholder

fruit growersgraders/processorsmarketersconsumers

• Scientists - specific quantifiable measurespriorities of consumers, growers, grading and processing enterprises, wholesale & retail marketers

Definition of fruit quality• Composite of attributes

productivityripeness (maturity)storage capacity, including “shelf-life”sensorynutritive valuehealth benefits

• The standards of excellence of a product that distinguishes it as superior

Food quality issues• Farm-worker rights• Land ownership• Farm profitability• Resource utilization• Environmental quality• Globalization• Pesticide risks• Affordability• Food attitudes

Crop qualitySoil qualityFarm profitabilityEnvironmental risks of agrochemicalsEnergy efficiency

Recent publications:GM Peck, PK Andrews, JP Reganold & JK Fellman. 2006. Apple orchard productivity and fruit quality under organic, conventional, and integrated management. HortScience 41:99

SB Kramer, JP Reganold, JD Glover, BJM Bohannan & HA Mooney. 2006. Reduced nitrate leaching and enhanced denitrifier activity and efficiency in organicallyfertilized soils. PNAS USA. In Press

Sustainability of three appleproduction systemsJP Reganold, JD Glover, PK Andrews & HR HinmanNature 410: 926, 2001

Apple field study• Yakima County,

Washington• Replicated, on-farm

ORG & CON• Soil & topography

identical• Cultivars

‘Golden Delicious’‘Gala’

• Grower/scientist managed

2

Strawberry field study• Monterey & Santa Cruz

Counties, California• Paired ORG/CON farms

5 pairs in 20048 pairs in 2005

• Soils & topographiesmatched for each pair• Cultivars

‘Diamante’‘San Juan’‘Lanai’

Crop yieldsApples

0

50

100

150

200

250

300

350

CON ORG

Yiel

d (M

g/ha

) 2003200219991998199719961995

Nature (2001) & HortScience (2006)

Fruit sizeApples

0255075

100125150175200225250

1995 1996 1997 1998 1999 2002 2003

Mea

n w

eigh

t (g)

CON ORGNS

NS NS

**

* *

*Pr<0.05

Nature (2001) & HortScience (2006)

Fruit sizeStrawberries

0

5

10

15

20

25

30

Wei

ght (

g)

CON ORG

Pr<0.001

Unpublished

Fruit firmnessApples

0102030405060708090

Harvest Storage Harvest Storage Harvest Storage Harvest Storage

Forc

e (N

)

CON ORG

‘Golden Delicious’ ‘Gala’

1998 1999 2002 2003

NS

NS

NS

* * *

**Pr<0.05 *

Nature (2001) & HortScience (2006)

Antioxidant ActivityApples

0

5

10

15

20

25

30

35

2002 2003 2002 2003

Tota

l act

ivity

(_m

ol/g

FW

)

CON ORG

Harvest CA storage 3-month

NS

NS *Pr<0.05

* *

HortScience (2006)

3

PhytochemicalsStrawberries

HCl-methanolPelargonidyn-3-glucoside

350 A319 BAnthocyanins(µmol)

HCl-methanol15.6 A14.0 BFlavonoids(Abs 325 nm)

Folin-Ciocalteu1.37 A1.22 BPolyphenols(mg gallic acid)

MethodORGCON(units per g FW)

Unpublished

PolyphenolsStrawberries

0

10

20

30

40

50

60

70

CON ORG

Con

cent

ratio

n (m

g/10

0 g

FW)

0

1

2

3

4

5

6

7

8

9

10

CON ORG CON ORG

Glycoside Aglycone

Ellagic acid Quercetin Phloridzin/Phloretin

NS NS

NS*

*Pr=0.014

Unpublished

Consumer taste panelApples

0

1

2

3

45

6

7

8

9

Overallacceptance

Texture Flavor Firmness Tartness

Rat

ing

CON ORG

* * **

NS

*Pr<0.05 2003 storage/shelf-life

IntensityLike

HortScience (2006)

Consumer taste panelStrawberries

0123456789

Sweetness Appearance Overall Acceptance

Rat

ing

CON ORG

Pr=0.04

Pr=0.096Pr=0.062

SweeterLike

Unpublished

Conclusions & Future• ORG apple yields were often lower and fruit

size was smaller• ORG apples were as firm or firmer and ORG

strawberries were sweeter• ORG apples had higher antioxidant activity

and ORG strawberries had higher polyphenol content• ORG apples stored better• ORG fruit were generally preferred by

consumers

Acknowledgements• Funding

USDA National Research InitiativeWashington Tree Fruit Research CommissionOrganic Farming Research Foundation

• Graduate studentsJennifer ReeveJaime YañezGreg PeckJerry GloverJeffrey ClarkSasha Kramer

• Post-docsCanming XiaoCarolina Torres

• ScientistsLynne Carpenter-BoggsNeal DaviesCarolyn RossMarc EvansHerb HinmanJohn FellmanRich AldridgeHarold MooneyBrendan Bohannan

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