1
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Unpublished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