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2. agriculture and forestry
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Our Goal:
to manage trees to achieve the
full genetic potential for fruit size
How to Produce Cherry
Fruit of Superior Size
Gregory Lang
Michigan State University
Our Strategy: to
optimize the
physiology of
the tree with
respect to water,
nutrients, and
carbon
(photosynthesis)
www.thewaywardecologist.com
Traditional Cherry Trees
Large, deep root
systems
Lower Investment, Longer
Time to Begin Profitability
7m
Intensive Orchards, Drip Irrigation
Reduced
Root Zone
Extensive area for extraction
of soil nutrients and water
More Limited Root-to-Shoot Ratio = A Challenge to
Provide Adequate Water and Nutrients at Critical Times for
Seasonal Growth Needs of the Tree Canopy and Fruit
2m
Photo by Yun Kong
Photo by Yun Kong
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Small Root Systems are Impacted More Quickly by
Weed Competition and Periods of Water Stress
0.45 m
Photo by Yun Kong
Effects of Weed Competition on Root-to-Shoot Ratio
Water & Nutrition Research
Gisela 12 Root System as % of Total Dry Weight
Weed Barrier Fabric 25%
Weed Competition 19%
Denise and Gerry Neilsen
Pacific Agri-Food Canada
Summerland, British Columbia
High frequency drip irrigation / fertigation
-
Short applications 4 times per day (03:00, 09:00,15:00, 21:00)
Replacement of ET (evapotranspiration of previous day)
8 weeks of nitrogen (CaNO3, 20 g/tree, beginning post-bloom)
4 weeks of K and B (KCl and Solubor, beginning pit-hardening)
High frequency irrigation / fertigation compensated for the reduced
root-to-shoot ratio, improving canopy growth ~80%, yield ~55%,
and fruit size ~4% (cumulative effects over 7 years of treatment)
Photos by
Yun Kong
Sweet Cherry Formation of Fruit
and Leaf Canopy “Units”
Year 1 - New shoot growth with single leaves
Managing the Carbon (Sugar) Supply to
Fruit
Year
2001
Leaf
population
Year 2 – Basal non-spur
fruiting sites, with formation
of future spurs
Fruiting spurs
13CO
2
2002
Non-fruiting spurs
13CO
2
2003
Current season
shoot
13CO
2
Year 3 –Fruiting spurs + basal fruiting sites + new shoot leaves
Ayala and Lang, 2004
Ayala and Lang, 2004
2
13CO
2
Research
Beginning of Stage III
(44 days after full
bloom)
Fruiting Spur Leaves are the Major C
Source for Fruit; New Shoot Leaves Also
Are Critical, Especially in Mid-Stage III
Carbon Sources and
Propostional
Distribution to Fruit
55%
29%
Marlene Ayala
16%
Fruit : 25% final size
Shoot: 16 leaves
Fruiting spur leaves Non-fruiting spur leaves
Shoot leaves
Ayala and Lang, 2004
Crop Load Effects on 13C Movement to Fruit
% 13C-Partitioned to Fruit
13CO
90
LowerFruit
Fruit
Distal
80
Upper Fruit
Proximal
Fruit
70
60
50
a
Growth Sensitivity of ‘Bing’ Sweet Cherry on
Gisela 5 Rootstock to Increasing Crop Load
Trunk expansion >
2
a
fruit soluble solids (Stage III) > New shoot leaves needed
ab
fruit growth (Stg. III) > New shoot leaves needed
bc
Leaf area/spur* > Late season C & N storage
40
30
ab
20
shoot elongation >
bc
10
0
140140
cm2/fruit
(Low)
75 cm
752/fruit
Crop Load
Leaf Area/Fruit
ratio (cm
fruit growth (Stg. I and II) >
40 cm
402/fruit
2
/fruit)
(Leaf Area per Fruit basis)
(High)
Leaf area/shoot
Balanced crop loads improve uniformity of quality fruit
Cherry Growth & Cropping Timeline, Part 1
Northern Latitude:
Southern Latitude:
May
(Nov)
Jun
(Dec)
Flower Bud
Stage of
Induction
Development: (# of flower
buds)
Physiological
Processes:
Important
Effects:
Whiting and Lang, 2004,
JASHS 129:407-415
Jul
(Jan)
Aug
(Feb)
Sept
(Mar)
Flower Organ
Differentiation
(# of flowers in
each bud)
Oct
(Apr)
Nov
(May)
*competition for reserves
Cherry Growth & Cropping Timeline, Part 1
Northern Latitude:
Southern Latitude:
Stage of Bud
Development:
May
(Nov)
Jun
(Dec)
Jul
(Jan)
Aug
(Feb)
Sept
(Mar)
Oct
(Apr)
Nov
(May)
Flower Organ
Differentiation
Photosynthesis
Soil Nitrogen Uptake
Fruit Development
New Shoot Growth
3
Sources of Nitrogen for, and Timing of,
Spur and Shoot Leaf Formation
Cherry Growth & Cropping Timeline, Part 1
Northern Latitude:
Southern Latitude:
May
(Nov)
Aug
(Feb)
Stage of
Development:
Flower Bud
Induction
Flower Organ
Differentiation
(# of flower
buds)
(# of flowers in
each bud)
Soil Nitrogen Uptake
Important
Effects:
Oct
(Apr)
Nov
(May)
Autumn
Leaf Fall
Building of Storage
Reserves for Spring
Growth; Cold
Acclimation
Fruit Development
New Shoot Growth
N movement into
the plant from the
soil solution:
Leaf Area: spurs and shoot
1000
Until new leaves
form and create
demand for water
due to
evapotranspiration,
very little N is
taken up from the
soil (fertilizers)
Fruiting spur
900
Non-fruiting spur
800
Carbon and Nitrogen
Mobilization to
Reserve Tissues
Photosynthesis
Physiological
Processes:
Sept
(Mar)
2
Jul
(Jan)
Total Leaf Area (cm )
Jun
(Dec)
Terminal shoot
700
600
500
400
300
200
100
0
0
10
20
Ayala, 2004
30
40
50
60
70
80
90
100
D ays After Full Bloom
Reserve N is
critical for spur leaf
formation
MSU Storage Nitrogen Studies
Autumn and Winter Nitrogen
Cycling (Michigan)
Hypothesis
Ouzounis and Lang
Leaf N declined 50% during the
month before leaf drop;
Sept (Mar)
fruiting spur N concomitantly
increased ~50%;
Oct (Apr)
Nov (May)
Experimental Series
premature defoliation decreased
spur N;
Pre-leaf drop (mid-Oct) foliar urea at ~20 to 49 kg/ha urea,
applied 1X to 3X times (best was 2X at 20 kg/ha each)
Fruiting spur N did not change
during winter
Results
Small trees on Gisela 5 rootstock
Ouzounis and Lang
Nov (May)
Winter
Dec/Jan/Feb
(Jun/Jul/Aug)
Stage of
Development:
Mar
(Sept)
Final Bud
Differentiation
Apr
(Oct)
Bloom
May
(Nov)
Physiological Chilling to Mobilization of C
Break
and N Reserves To
Processes:
Dormancy Growing Points
Important
Effects:
Strength
of Bloom
Jun
(Dec)
Fruit Cells
Dividing
Fruit Set
Fruit Cell #
Spur Leaf Size
- Dormant fruiting spur N levels were increased significantly
- Spring spur leaf size and total area was increased up to 20%
Apr (Oct)
Cherry Growth & Cropping Timeline, Part 2
Northern Latitude:
Southern Latitude:
Tree canopies with larger spur leaves will support:
a) a higher crop load, and/or
b) larger fruit
Dynamics of Fruit-to-Leaf Area Balance
Jul
(Jan)
Harvest
Elongating
Photosynthesis
Year 3:
Fruit populations: 1 spur (e.g., 75 total), 1 non-spur (e.g., 10 total)
Leaf populations: 2 spur (e.g., 120 total), 1 shoot (e.g., 10 x 2X)
Leaf-to-Fruit Ratio: 140 leaves / 85 fruit = 1.65
Soil N Uptake
Fruit Size,
Firmness, and
Sweetness
Year 4:
Fruit populations: 2 spur (e.g., 150 total), 1 non-spur (e.g., 10)
Leaf populations: 3 spur (e.g., 180 total), 1 shoot (e.g., 10 x 2X)
Leaf-to-Fruit Ratio: 1.25 (from Year 3 to Year 4, a 25% decrease)
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Basic Growth & Fruiting Units
Basic Growth & Fruiting Units
This heading cut
reduces future spur
fruit populations…..
Anticipation of the future
unbalanced cropping sites can
help in pre-emptive management
to better balance leaf-to-fruit
ratios and improve performance
A dormant heading cut to remove:
15 to 30% of last year’s shoot can remove
25 to 40% of the future crop density
Basic Growth & Fruiting Units
Basic Growth & Fruiting Units
This heading cut
reduces future spur
fruit populations…..
This heading cut
reduces future spur
fruit populations…..
and promotes new
shoot leaf
populations
Year 3:
Fruit populations: 1 spur (e.g., 40 total), 2 non-spur (e.g., 20 total)
Leaf populations: 3 spur (e.g., 166 total), 2 shoot (e.g., 20 x 2X)
Leaf-to-Fruit Ratio: 2.75
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8
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TSA Year 1
6
After bud
selection for
activation by
Promalin,
scoring, or bud
removal
5
All fruit produced on
Gisela 5 dwarf trees
on sandy soil!
4
3
2
1
2
3
4
5
6
7
5
9
9
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7
7
TSA Year 1
6
Spring shoot
growth from
activated buds
5
TSA Year 2
6
5
4
4
3
3
2
2
1
2
3
4
5
6
7
1
9
9
8
8
7
Tree canopy
prior to dormant
pruning, before
2nd growing
season in orchard
2
3
4
5
6
7
7
TSA Year 2
6
Dormant pruning
of the lateral
shoots that grew
in Year 1, to
increase leaf area
and balance the
future spur crop
in Year 3
5
4
3
2
1
TSA Year 2
6
Spring shoot
growth
5
4
3
2
2
3
4
5
6
7
1
9
9
8
8
7
2
3
4
5
6
7
7
TSA Year 2
6
Spring shoot
growth;
5
Fruiting at base
of last season’s
shoot growth and
on spurs on
portion of the
leader that grew
in the nursery
4
3
2
1
2
3
4
5
6
7
TSA Year 2
6
Summer shoot
extension growth
5
4
3
2
1
2
3
4
5
6
7
6
9
9
8
8
7
7
TSA Year 3
TSA Year 3
6
Tree canopy
prior to dormant
pruning, before
3rd growing
season in orchard
5
4
6
5
4
3
3
2
2
1
2
3
4
5
6
7
1
9
9
8
8
7
Dormant-prune
for: 1) future
crop load
management, and
2) to thin out any
overlapping
shoots (promote
good light
distribution)
2
3
4
5
6
7
7
TSA Year 3
TSA Year 3
6
Fruiting at base
of last season’s
shoot growth and
on spurs from
Year 1 shoot
growth
5
4
6
5
4
3
3
2
2
1
2
3
4
5
6
7
Superior Fruit Size
Summer-prune
overlapping
shoots to
minimize
shading of
developing
flower buds
1
2
3
4
5
6
7
MSU Tree Fruit Research
High frequency, short duration
irrigation / fertigation for efficient
supply of water and nutrients at
critical times of development for
fruit and shoot growth
Supplemental foliar feeding for
critical developmental stages and
building of storage reserves,
especially to optimize spur leaf size
Anticipate excessive crop loads or
limited leaf area and utilize pruning
to balance leaf area:fruit ratios
Training video clips at:
www.giselacherry.com
www.cherries.msu.edu
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