Key limiting factors to

productivity and fruit quality of

apples

Stephen A. Hoying and Terence Robinson

Senior Extension Associate and Professor

Hudson Valley Lab and the NYSAES

Cornell University

XIVth Apple and Temperate Zone Fruit Tree

International Symposium

November 14, 2008

Thanks to Carlos Chavez and the

organizers for the invitation to speak to

you. I am sure I will learn a lot more

from you than you will from me. I want

to extend and invitation for all of you to

visit anytime and I will make sure your

trip is worthwhile.

Deep snows and frigid wintersAbundant year round water

Different Pest Complex

Low pH Soils

THE ORCHARD SYSTEMS

PUZZLE

THE ORCHARD

SYSTEMS PUZZLE

VARIETY AND

ROOTSTOCK

SITETREE QUALITY

SUPPORT

SYSTEM

TRAINING

AND

PRUNING

TREE

ARRANGEMENT

MANAGEMENT

SKILLS

• Site

•Rootstock and Variety

•Tree Quality

•Tree Arrangement

•Support System

•Training and Pruning

•Management Skills

After Barritt ‘75

Which are the critical

factors?• Variety

• Site Selection

• Preplant Land Preparation

– Lime and Fertilizer

– Drainage

• Tree Delivery and Planting Date

• Tree Quality

– Caliper/Height

– Root system

– Feathers

• Planting Systems

Selection

– rootstock, variety,

spacing, support

system,

• Planting Procedures

• Cultural Care

• Pest Control

Pre-plant Considerations

• Choosing a Planting Site

– Climate

– Soils

• The most important factor in maximizing

Yield and Fruit Quality. Once an orchard is

planted climate and soil cannot be changed!

Site Selection - Climate

Macro Climate

Micro Climate

Factors Determining Site

Suitability

Climatic Macro-Factors

• Geography, Elevation & Regional Climate

• 1000 – 1200 hours of chilling between 39-45 oF.

• 200 day growing season

• Moderate temperatures that minimize winter injury and summer sunburn yet promote optimal fruit coloring and improve firmness and soluble solids (Brix).

• Most of these sites in the world are identified – that is why we grow fruit where we do in NY and you in Mexico. And during hard economic times these area’s shrink to the very best of the best

Factors Determining Site

Suitability

Climatic Micro-Factors

These factors are within the orchardist’s control.

• Topography, Slope, Aspect and Location

– Influence possibility of Spring Frost, Hail, Fruit Maturity and

Soil Drainage, Orchard Spacing and Equipment Usage.

– The Best Frost Control Technique is Good Site Selection.

• Situate orchard to allow cold air drainage out of orchard.

• Take advantage of moderating effects of large bodies of

water if possible.

Effect of Air Drainage on Frost

Soils

• Deep - Root penetration and exploration for nutrients and water.

• Well Drained – Roots experience oxygenation, not asphyxiation. High water tables cause unwanted root-pruning.

• Reasonably Fertile – Good not excessive plant growth, low fertility has significant affect on Yield and high fertility has a significant effect on fruit quality

• Free of Pathogens - Phytothphora, Armillaria, others unknown

Soil Depth

• Bed Rock

• Restrictive Layers

– Fragipan

– Plow or Traffic Pan

• Water Table

– Seasonal

– Perched

Suitable for fruit. Deep

with excellent root

distribution and

penetration.

Batjer, 1930

Shallow soils limit rooting

depth and the tree’s ability

to overcome stresses from

drought and poor nutrition

Site

Preparation

Tree (and productivity)

losses will result in

permanent yield

reduction over the life

of the planting

Pre-plant Orchard Planning

• Select Variety and Rootstock

• Density and Spacing

– Tree Density and Light interception are the

keys to high yields

• Planting System

– A training and pruning scheme to achieve high

yields

Variety

The Variety contributes

to yield, precocity,

quality, marketability,

and product price. All

contribute to the

success of an Orchard

System.

Mistakes in Variety Selection that

May Result in Productivity Loss

• Planting too much of a low yield, low

price variety.

• Planting a variety that is unproven in a

region and turns out to be unsuitable

• Planting a variety before having an

established market.

PROFIT GENERATORS

• PRODUCT PRICE – FRUIT QUALITY

• VARIETY – Honeycrisp

• FRUIT SIZE – Gala

• FRUIT COLOR - McIntosh

• FRUIT CONDITION – Empire

• MARKET CONDITIONS – Macoun

• YIELD (Contribute to 50% of your profitability)

• PRECOCITY - TIME TO FIRST BEARING

• TIME TO MATURE YIELD

Rootstock

Rootstock determine tree

size and spacing,

influence fruit quality

(size), precocity, and

resistance to various

pest and diseases eg.

Novole – mice, G30 –

Fireblight.

Rootstock

• Too Strong for System

– Increased pruning

– Reduced yield

– Reduced fruit color and SS

– Increased Physiological Disorders such as

Bitterpit

Photo courtesy CB Watkins

Rootstock

To Weak for Systems:

• Significantly delayed bearing• Reduced Yield

• Reduced fruit size

• Exposure disorders like heat stress and sunburn

Selecting a Tree Density

• Rootstock vigor

• Variety vigor

• Soil Strength

• Climate

• Several models integrating the above factors are available for certain regions

– Cummins – NY

– Perry - Michigan

– Various Nursery Catalogues

0

200

400

600

8002

2 Y

ea

r C

um

ula

tiv

e Y

ield

(M

t/h

a)

0 500 1000 1500 2000

Tree Density (trees/ha)

Delicious

Empire

0

50

100

150

200

250

Cu

m Y

ield

(M

T/h

a)

0 1,000 2,000 3,000 4,000 5,000 6,000

Tree Density (trees/ha)

Effect of Tree Density on 7 Yr. Cumulative Yield

McIntosh

Gala

Fuji

Empire

Tree density had a highly significant negative effect on cumulative

yield per tree but a highly significant positive effect on yield per ha.

The cumulative yield per ha of the highest tree density was 3X

greater than the lowest density

Higher the density the better! Right?

• For increasing yield - RIGHT!

• For increasing profitability – WRONG!

When profitability was calculated

per unit land area with traditional

fruit prices, profitability over 20

years increased with increasing tree

density up to a density of 1,000

trees/acre (2,500 trees/ha).

0

2500

5000

7500

10000

12500

Net

Pre

sen

t V

alu

e ($

/Acr

e)

0 500 1,000 1,500 2,000 2,500

Trees Density (Trees/Acre)

Feathered Trees + Steel Tube Tree Stake

Inexpensive Feathered Trees + 4 Wire TrellisFeathered Tree + 4 Wire Trellis

When profitability was

calculated per $10,000 invested

then the optimum tree densities

was about 850 trees/acre (2100

trees/ha).

0

2500

5000

7500

10000

12500

Net

Pre

sen

t V

alu

e ($

/$1

0,0

00

in

ves

ted

)

0 500 1,000 1,500 2,000 2,500

Trees Density (Trees/Acre)

Inexpensive Feathered Trees + 4 Wire TrellisFeathered Trees + 4 Wire TrellisFeathered Tree + Steel Tube Tree Stake

B

Economic Results

Tree Arrangement

4 Wire Trellis

Triple Row

Y Trellis

Slender

Spindle

V Slender Sp

PLANTING

SYSTEMS

TRIALS

Vertical

Angled

Systems Trials have shown the most

successful plantings use:

• Size controlling and precocious Rootstocks preferably an appropriate clone of M.9 or CG.

• High Quality Large feathered nursery stock.

• Are planted in Single rows

• Have Planting densities of 800 – 1300 tree/Acre

• Trees are supported to 10 feet in height

• Are minimally pruned and appropriately trained.

• Are managed for a balance of growth and fruiting.

• Pest are managed for minimal effect on trees and fruit.

The Tall Spindle

System

• 0.90-1.20 m in-row spacing

(3-4’)

• 3.0-3.5 m between rows (10-

12’)

• 3 m tall (10’)

• no permanent branches

• highly feathered trees

• minimal pruning at planting

• feathers tied below

horizontal at planting.

Older Tall Spindle

Orchard

Tree Quality

0

20

40

60

80

100

120

140

% Yield

2nd Year 3rd Year 4th YearRobinson and Stiles 1994

1/4" Trees

5/8" Trees

7/8" Trees(2 yr old)

Effect of Tree Caliper on Yield

Quality Nursery trees!!!!!

Typical feathered trees in the USA have ~ 5 large feathers

These require some pruning and significant branch tying.

With wide spacing as

used with Vertical Axis

we suggested tipping

leader and feathers

With the Tall Spindle we suggest removing the 2

largest diameter feathers but leaving the leader and

feathers unheaded. All remaining feathers must be

tied down to prevent them from becoming large

branches.

• M.9

– Fire blight is a risk in NY and winter damage is a risk in colder areas.

– Use weaker clone of M.9 (T337) with vigorous scion varieties or with

vigorous or virgin soil.

– Use the vigorous clones (Nic29, Pajam2) with weak varieties or with

weak soils or on replant soils or in hot climates.

• B.9 – Is weaker than M.9 and must be spaced very close to achieve high

yields per acre. It may be too weak with weak scions.– More winter hardy than M.9.

– Has field resistance to fire blight.

– Very susceptible to apple replant disease.

• G.11, G.41, G.16

– Similar in vigor to M.9.

– As productive or more productive than M.9.

– Fire blight resistant.

Rootstocks Suggestions for Tall Spindle

Three Dwarfing Geneva® Rootstocks• G.11

• Tree size and productivity are similar to M.9.

• Large fruit size.

• It is fire blight resistant but is not immune.

• In European CG trial it has looked the best.

• Commercial sales in the US are strong.

• G.16• Tree size is similar to vigorous clones of M.9

• Large fruit size.

• It is fire blight immune.

• Good resistance to replant disease

• Requires virus free budwood.

• Currently available from most nurseries.

• G.41• Tree size is similar to M.9 but productivity is

better.

• It is resistant to fire blight and crown rot

• It is very winter hardy

• Good resistance to replant disease

• Will be available in 2-3 years.

Conclusions1) The tall spindle system appears to be the most profitable system for

New York growers.

2) Highly feathered trees are the key to the system

3) Branch angle management. Bending feathers below horizontal at planting induces early cropping and limits branch size.

4) Branch caliper management. Removal of large branches keeps trees manageable.

5) Restrict vegetative growth by partitioning a high proportion of photosynthates into apples.

Poor Support System can contribute to

either catastrophic tree loss or continuing

yield reduction.

Support System

Pest

Control

Poor pest control

can contribute to

tree loss, crop

loss, lack of

precocity, fruit

quality reduction

and on and on.

“Today’s fruit grower must have

a complete knowledge of all the

pieces of the puzzle and the

ability to put it together for a

productive and profitable

orchard!

Conclusion