Plant Architectural Engineering in fruit crops: Physiology and Prospects

1. 1
Presented by:
Mandeep Kaur
PhD Fruit Science
4th Sem
Plant Architectural Engineering in fruit crops:
Physiology and Prospects
Presented to:
Dr H S Dhaliwal
Dr K S Gill
Dr Monika Gupta
CREDIT SEMINAR

2. • Introduction
• Components of fruit tree architecture
• Manipulation of fruit tree architecture
– Training
– Pruning
– Plant growth regulators
– Biological agents
– Biotechnological interventions
• Conclusion

3. INTRODUCTION
• Plant architecturalengineering
• The geometric arrangement of shoots & leaves which provide
linkage with ecological & environment processes required for
survival growth & reproduction is referred to as plant
architectural engineering.
• It determines the development of form of trees based on the
position of the flowers, orientation of branches and cycle of
growth.
Peter and Arnold (2013)

4. NEED FOR PLANT ARCHITECTURAL ENGINEERING … ?
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5. Objectives of Plant Architectural Engineering
1. To obtain specific form of the plant
2. To maintain balance between vegetative & reproductive growth
3. To maintain root/shoot ratio
4. To increase photosynthetic efficiency
5. To maintain production of fruit quality

6. Light Interception
• Light is critical to growth & development of trees & their fruits.
• Light interception: It is the sunlight intercepted by tree canopy
relative to total incoming sunlight.
• Better light distribution into the tree canopy improves tree
growth, productivity, yield and fruit quality.
• Plants intercept direct and diffuse sunlight.
• Photosynthesis – 400-700 nm of electro-magnetic radiation
• Interception can be increased by :
• Increasing tree density per area of land
• Reducing distance between rows
• Orienting rows in north-south direction
• Increasing height of the trees

7. Treatments Light interception %
below canopy
Light interception %
upper canopy
Photosynthetic rate
(μ mol/m2/sec)
Fruit Yield
(kg/plant)
TSS of fruit
(0Brix)
2x2 m 47.80 84.52 1.70 3.65 18.15
3x3m 57.92 88.25 2.17 6.10 19.15
4x4m 72.97 90.05 3.87 14.05 19.00
5x5m 73.82 93.62 4.92 20.97 20.19
6x6m 76.97 94.02 6.35 40.12 20.73
8x8m (control) 80.22 96.88 8.32 50.05 20.19
C.D. at 5% 4.748 3.631 0.898 1 1.207
SE(m) 1.561 1.194 0.295 0.329 0.397
Effect of different planting density on light interception (%)
and photosynthetic rate of litchi cv. Shahi
Int.J.Curr.Microbiol.App.Sci (2020) 9(9):170
Singh et al (2020)
ICAR-NRC, Muzaffarpur, Bihar

8. Poor canopy architecture leads to….
• Larger tree height
• Higher cost of management
• High pest and disease incidence
• Low photosynthetic efficiency
• Low productivity

9. Features of an ideal canopy
1. Canopy size – dwarf and open
2. Adequate number of fruiting units
3. Allow sufficient light and ventilation
4. Avoid overlapping of foliage

10. Components of fruit tree architecture
IDENTIFYING SHOOT TYPES
ANALYSING BRANCHING
DESCRIBING INTRA SPECIES VARIABILITY
OF FRUIT TREE ARCHITECTURE
1.
2.
3.

11. 1. IDENTIFYING SHOOT TYPES
Champagnat (1996)
Mesoblast
Auxilblast
SHORT
SHOOTS
LONG
SHOOTS
SHOOT
TYPES

12. 2. ANALYSING BRANCHING
Branching
pattern

13. 13

14. Bearing habit of fruit trees
Bearing habit Growth
habit
Examples
Stem or branch bearing Jackfruit, durian & cocoa
Spur bearing Grapes, Apple, pear, plum, cherry, apricot
Shoot
bearing
Terminal bearing New shoots Loquat & Bael
Old shoots Mango & Litchi
Lateral/axillary bearing New shoots Guava, ber, aonla, phalsa,
karonda, grape
Old shoots Apple, pear, peach, plum,
apricot, walnut

15. Acrotonic
Basitonic
Mesotonic
Branching
Position

16. 3. Describing intra-species variability of
fruit tree architecture
Fig: Four ideotypes of apple tree architecture

17. Rootstock
 Rootstock: Used to propagate scion of preferred cultivars.
 How rootstocks manage canopy … ?
1. Low root: shoot ratio: Water supply restrictions to the scion induced by
anatomical characteristics of rootstock ( Aykinson et al., 2003).
2. High phloem to xylem ratio: Reduction of solutes transported to the
scion through the rootstock (Bukovac et al., 1958; Jones, 1976).
3. Higher bark to wood ratio.
4. Hormone imbalance
5. Carbohydrate metabolism
6. Phenolics compounds (coumarin) – oxidative decarboxylation of IAA.
 Sucker free rootstocks

18. Dwarfing rootstocks in various fruit crops
18
Crop Dwarfing rootstocks
Apple M-9, M-27, MM 106 & 111
Pear Quince C
Plum Pixy
Citrus Troyer citrange
Trifoliate orange cv. Fly Dragon
Mango Vellaikolumban (Alphonso)
Olour (Himsagar, Langra)
Guava Pusa Srijan (Allahabad Safeda)
Chinese guava
Ber Z. rotundifolia
Z. nummularia
Rootstock Speciality Height
M 27 Ultra dwarf 1.5 – 2.0 m
M 9 Dwarf 2.4 – 3.0 m
M 26 Semi dwarf 3.0 – 4.5 m
MM 106 Mod. vigorous 3.6 – 5.5 m
M 25 Vigorous 9.0 – 12.0 m
Relative size of apple trees on various rootstocks Hartmann et al (2002)

19. Scientia Horticulturae 97 (2003) 95–108
Reddy et al (2003) IIHR
Long term effects of rootstocks on canopy
volume of mango cv. ‘Alphonso’

20. J. AMER. SOC. HORT. SCI. 136(2):93–102. 2011.
Hoojdonk et al (2011)
New Zealand
Influence of rootstocks on scion architecture and root
growth of newly grafted apple trees cv. ‘Royal Gala’

21. Influence of planting density and size-controlling
rootstocks on performance of Tart Cherry
Spacing 4.5*4
(556 tree/ha)
4.5*3
(741 tree/ha)
4.5*1.5
(1481 trees/ha)
HDP
Size
control
Yield
(t/ha)
P. mahaleb
(control)
No mortiality No mortiality Reduced tree
size by 20%
Vigorous
tree
17
Weiroot 13 No mortiality 14% shorter
than control
No mortiality 43% than
control
24.3
Krymsk 6 50%
mortiality
50% mortiality 50% mortiality similar 25.3
Krymsk 7 50%
mortiality
50% mortiality 50% mortiality similar 20.4
Gisela 6 No mortiality No mortiality No mortiality 16% 28.8
Cline (2019)
Gulf, Canada
Scientia Horticulturae 97 (2019) 95–108

22. Genetically dwarf scion cultivars
Crop Genetically dwarf scion cultivars
Apple Spur varieties like Golden Delicious, Red Delicious, Red Chief, Oregon Spur
Peach Red Heaven
Cherry Compact Lambert, Meteor and North Star
Mango Amarpali
Banana Pusa Nanha
Papaya Dwarf Cavendish (AAA)
Use of partial incompatible rootstocks
Use of interstocks

23. Effect of EM-9 interstock on yield of
apple cv. ‘Imperial Gala’
Rev. Ceres, Viçosa, v. 66, n.3, p. 178-183,
Fiho et al (2019)
Brazil

24. MANIPULATION OF FRUIT TREE ARCHITECTURE
1. Training
2. Pruning
3. Plant growth regulators
4. Biological agents
5. Biotechnological Interventions
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25. 1. Training

26. Physiology of training
• Increased leaf surface exposure to solar radiation.
• Under low PAR interception - low cellular respiration and
carbon partitioning.
• Training - High partitioning of carbon to the fruit rather than
vegetative characters
• Improved balance between assimilation and respiration
• Physiological processes of plants like photosynthesis
efficiency, water use efficiency and carboxylation efficiency
get improved.
• Fruit colour, total soluble solids (TSS) and fruit firmness also
depended upon light distribution in plant canopies.
Campbell et al (2015)

27. Methods of Training
Conventional methods
Open center
Central leader
Modified leader
Training methods for dwarf trees
Tall spindle
Super spindle
Slender spindle
Dwarf pyramid
Y trellis
V system
Tatura trellis
Espalier system

28. Conventional methods
Central Leader Modified Central Leader
Open centre
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29. Slender Spindle
Super Spindle
Tall Spindle Dwarf Pyramid
Y trellis system V - system Tatura trellis Espalier system
Training methods for dwarf trees

30. Effect of planting distances and training systems on light interception (%)
in high density plantings of peach cv. ‘Shan-i-Punjab’
Training system Planting distance
(No. of trees per hectare)
Light interception (%)
Part of the canopy
Upper Middle Lower Total
‘Y’ shaped structure 6 x 1.5 m (1111) 52.5 12.9 9.7 75.1
3 solid rows (6 m gap after 3 rows) 3 x 3 m (800) 49.7 9.9 6.3 65.9
Modified leader system 6 x 6 m (289) 50.4 10.9 7.3 68.6
Mean 50.8 11.3 7.7
C.D.0.05 Planting distances 0.5
Part of canopy 0.8
Planting distance x Part of the canopy 0.9
Acta Hort 662, ISHS 2004
Singh and Kanwar (2004)
Y shaped structure
Light interception - > 75%

31. Effect of light interception and penetration at different levels of fruit
tree canopy on quality of peach cv. ‘Shan-i-Punjab’
31
CURRENT SC 1562 IENCE, VOL. 115, NO. 8
Espailer system and V trellis had better light distribution within the tree canopy as compared to others.
Sharma et al (2018)
PAU, Ludhiana

32. Effect of different training systems on yield of apple
Open centre system Modified Leader system
Planting density 625 plants/ha (4x4 m spacing) 625 plants/ha (4x4 m spacing)
Rootstock MM-111 & MM-106 MM-111 & MM-106
Yield t/ha 20-40 t/ha on 8-10 year old trees 20-45 t/ha on 8-10 year old trees
Cordon system Espalier system
Planting density 8888 plants/ha
(1.5 x 0.75 m spacing)
2222 plants/ha
(1.5 x 3.0 m spacing)
Varieties tested Granny Smith, Spartan (p) and
Coe Red Fuji
Granny Smith, Spartan (p) and
Coe Red Fuji
Rootstock M9 M9
Yield t/ha 12-15 t/ha on 5 year old plant 43-95 t/ha on 5 year old plant
Mir (2019)
ICAR - CITH, Srinagar

33. Adv. Hort. Sci., 2019 33(3): 313-320
Dadashpour et al (2019) Iran
T 1 : V-system
( 0.9 × 3.7 m)
3000 trees/ha
T 2 : Y-trellis
( 1.6 × 3.7 m)
1680 trees/ha
Y trellis
TCSA - > 40%
Yield - > 70%
Influence of two training systems on TCSA (cm²) and yield
of four apple cultivars grafted onto ‘M 9’ rootstock

34. Gill et al (2011)
PAU
Treatment Stem girth
(cm)
Tree height
(m)
Canopy spread (m) Tree volume
(m³)
E-W N-S
Bush 22.11 3.24 3.56 3.43 19.30
15 cm 45.78 3.25 3.43 3.30 18.70
30 cm 43.11 3.26 3.15 3.02 17.33
45 cm 36.78 3.22 3.07 3.02 16.66
CD at 5% 6.3 NS 0.18 0.17 1.8
Effect of training systems on vegetative growth
of pomegranate cv. ‘Kandhari’
Acta Hort. 890, ISHS 2011

35. Training methods for grape vines
• 6 cane system
• Vines grow @ 1.5-1.6 m
• Superior to kniffin system
• 4 cane system
• 2 Wires @ 1 m and 1.65 m
• 2 horizontal lines
1. Kniffin system 2. Telephone system 3. Bower system

36. Effect of two training on production variables
of grapes cv. ‘Niagara’
Trellis
systems
Number of
shoots
(vine)
Number
of
bunches
(shoot)
Number
of berries
(bunch)
Mass of
bunch (g)
Yield
(kg/vine)
Yield
( ton/ha )
Overhead 25.8 1.81 62.64 266.28 10.7 28.8
VSP 10.9 1.56 57.09 222.33 3.1 15.5
• Overhead system
• VSP- Vertically shoot-positioned (VSP) trellis systems
Scientia Horticulturae 261 (2020) 109043
Rodriguez et al (2020)
Brazil

37. 2. Pruning
• Judicious removal of plant parts to have good and qualitative
yield is known as pruning.
• Methods of pruning

38. Physiology of pruning
• Removal of apical dominance.
• Increased light penetration - photosynthetically active leaf
area per fruit increased.
• Pruning increases respiration & rate of photosynthesis.
• The flower bud development, growth, fruit color & content
of soluble solids in fruits also enhanced.
• Pruning changes total dry weight partitioning.
• Pruning change the hormonal pattern of fruit trees.
• Ringing increases the assimilate supply in shoots.
(Lauzike et al, 2020)

39. Effect of pruning on yield and fruit quality of guava trees
Ali et al (2014) Lucknow

40. HortFlora Research Spectrum, 4(3): 200-203
Heading back Percent reduction in tree canopy volume
1.5 m < 50 %
2.0 m < 40 %
2.5 m < 30 %
Brar et al (2015)
RRS, Abohar, PAU
Effect of heading back at different heights on tree
canopy (m³) of guava cv. ‘Allahabad Safeda’

41. Effect of pruning intensity on fruitfulness and anthocyanin
content of grape hybrid ‘H-516’ trained on bower system
Journal of Applied Horticulture, 16(2): 122-125.
Singh et al (2015)
Fruit orchard, PAU
41/69

42. https://doi.org/10.11118/actaun201765041241
Treatment TCSA (cm²) Cumulative yield
(kg/tree)
Yield efficiency per TCSA
(kg/cm²)
SS-WP 26.70 69.06 2.813
SS-WP+SP 29.26 72.99 2.661
SS*-WP 29.23 67.11 2.461
SS*-WP+SP 29.25 65.88 2.423
Effect of different time of pruning on apple cv. ‘Topaz’
Martin et al (2017)
Czech Republic
SS- slender spindle
SS*- super spindle
WP- winter pruning
SP- summer pruning
Slender Spindle - WP+SP
• TCSA and yield - > 8%
Slendle spindle + WP
• Yield effi./ TCSA - > 13%

43. Treatments Average
biomass
(kg/tree)
Average
yield
(kg/tree)
Percent of
Lemons (diameter
> 58 mm
Manual pruning (control) 42 289 75
Mechanical (skirt, top and two sides) in even years +
Manual pruning in odd years
41 325 82
Mechanical (skirt and top)
Plus manual follow-up of all the tree
21 285 65
Mechanical (skirt, top and one side)
Plus manual pruning of the other side of the tree.
24 276 70
Mechanical pruning (skirt, top and one side) +
North side was pruned in even years +
South side in odd years.
9.5 357 71
Scientia Horticulturae 275 (2020) 109700
Gorriz et al (2020)
Spain
Response of lemon trees cv. ‘Fino 95’ to different
long-term mechanical and manual pruning practices

44. Effect of different pruning intensities on
fruit quality of ber cv. ‘Sanaur-2’
Pruning
intensity
Days taken
for
sprouting
Number of shoots
emerged/branch
Fruit set
(%)
Fruit
retention
(%)
Fruit
length
(mm)
Fruit
breadth
(mm)
Fruit yield
(kg/tree)
Control 36.21 25.31 45.94 30.24 3.90 2.97 36.23
T1 25.34 27.15 51.23 38.28 4.31 3.34 47.12
T2 21.52 29.34 59.62 42.21 4.87 3.89 56.14
T3 19.34 28.21 56.34 40.28 4.49 3.53 50.37
Control - No pruning
T1 - 25% removal of vegetative growth
T2 - 50% removal of vegetative growth
T3 - 75% removal of vegetative growth
Bangladesh J. Bot. 49(1): 65-70, 2020
Khokhar (2020)
RRS, PAU

45. Branch Bending
Fastens breeding cycle – Helpful in early evaluation of hybrids

46. Nasr et al (2015)
Giza, Egypt
Middle East J. Appl. Sci., 5(4): 1115-1127,
Effect of horticultural treatments on fruit set (%)
and yield (%) of pear trees cv. ‘Le-Conte’

47. Canopy management in HDP of Apple
Starkrimson Silver Spur Red Fuji

48. Canopy management in Pear, Peach and Plum
Pear Peach Plum
Training
system
Modified leader
system
Modified leader
system
Modified leader
system
Bearing
habit
Spurs 1 year old shoots 1 year old shoots +
short spurs
Pruning Thinning out
and heading
back of laterals
40% of 1 year old
branched - Thinning
Light annual
pruning & removal
of water suckers

49. Canopy management in Meadow orcharding of Guava
Planting distance: 2.0 x 1.0m Heading back @ 30 to 40 cm New growths after pruning
Growth after 2nd pruning Growth after 3rd pruning Flowering after 3rd pruning

50. Canopy management in Mango
Development of primary (A), secondary (B) and tertiary (C) branches in 2 years.

52. Canopy management in Litchi

53. • Skirting and light hedging
• Canopy structure improvement
• Window pruning to remove Weak Bearing Branch Units (WBBU)
Canopy management in Citrus

54. Canopy management in Grape vines
Planting density 3 * 3
Training system Bower system
Number of canes per vine 60-80
Number of buds per cane 4

55. Canopy management in Ber
Acta Hortic. 1116, 99-104
• Light annual pruning
• Time of pruning - April to May
• The cultivar 'Umran' pruned by retaining 6 buds & 'Sanaur-2' cultivar by
heading back at 8 buds at dormant condition proved beneficial.
• Rejuvenation - Heading back @ 30 cm during 2nd fortnight of May.
Bal and Gill (2016)

56. 3. Plant growth regulators
Hormones Precursor Site of synthesis Role in plants
Auxin Tryptophan Shoot tips, root
tips, young
growing leaves
Promotes apical growth
Inhibits lateral shoot growth
Root growth of callus in vitro
Gibberellines Terpenoids Young leaves Internode elongation
Break bud dormancy
Prevention of genetic &
physiological dwarfism
Cytokinins Isopentyl
group
Root tips Cell division & enlargement
Juvenile hormone – stimulates
lateral bud development
ABA Mevalonic
acid
All organs Closes stomata, induction &
maintenance of dormancy
Ethylene Methionine Ripening fruits,
flowers, leaves,
nodes of stem
Primary hormone responsible for
leaf & fruit abscission

57. Plant growth retardants
• Plant growth retardants are synthetic compounds which reduce tree
growth by interfering with the action of natural plant hormones.
• Growth retardants restrict growth by three basic mechanism :
Fruit crop Growth
retardant
Effect Reference
Peach Paclobutrazol Minimum trunk growth,
height and spread
Chanana and
Gill, 2007
Pear Paclobutrazol Reduced the tree height Gupta and
Bisht, 2005
1. Inhibition of apical meristematic activity: MH
2. Reduction of apical control: TIBA.
3. Inhibition of internode elongation without disrupting meristematic
functions: PBZ, CCC, UCZ.

58. Not Sci Biol 2 (3) 2010, 110-113
Brar (2010) PAU
• Guava ‘Allahabad Safeda’ raised on ‘L-49’ rootstock
• Foliar spray - March before onset of flowering
Treatments Planting density
6 × 2 m 6 × 3 m 6 × 4 m 6 × 5 m Mean
PBZ 500 36.72 38.11 37.75 44.09 39.17
PBZ 1000 38.33 41.82 50.17 44.42 43.69
Ethephon 500 41.80 45.28 36.76 40.46 41.05
Ethephon 1000 40.85 40.76 38.24 48.80 42.16
Control 46.79 54.87 55.23 58.35 53.81
Mean 40.90 44.17 43.61 47.22 43.98
CD (p-0.05) Spacing (A): 1.23 Treatments (B): 1.37 A × B:2.75
Results
PBZ 500
Canopy vol. - < 27%
Influence of Paclobutrazol and Ethephon on canopy
volume (m³) of guava cv. ‘Allahabad Safeda’

59. Effect of Uniconazole on branch length and
branch diameter of mango cv. ‘Palmer’
Lima et al (2016) Brazil
UCZ dose
(g a.i./tree)
Spray schedule
(30-day interval)
1.0 0.0, 1.0
2.0 1.0+1.0
3.0 1.0+1.0+1.0
4.0 1.0+1.0+2.0
RESULTS
B Length - < 80%
B Diamter - < 27%
CR-2015-0940.R2

60. Effect of plant bio-regulators on shoot length
of pear trained on Y-trellis system
Journal of Agrometeorology 22 (2) : 140-147
Kaur et al (2020) PAU
Shoot
length
(cm)
• Foliar applications
• Prohexadione calcium (Pro-Ca) (100, 200, 400 mg/L)
• Paclobutrazol (PBZ) (100, 250, 500 mg/L)
• @ 10 DAFB
RESULTS
Pro-Ca 400 mg/L
Shoot length - < 31.11%

61. Effect of pruning and PBZ on morphological and
reproductive parameters of acid lime cv. ‘Balaji’
Treatments combinations Plant
height (m)
Canopy
volume (m3)
Total number
of
flowers/shoot
Fruit retention
percentage
(at harvest)
T1 - Control 0.560 0.400 9.22 29.22
T2 - No pruning + PBZ 2.5 ml/m canopy 0.540 0.380 10.60 31.82
T3 - No pruning + PBZ 5 ml/m canopy 0.520 0.380 11.53 33.27
T4 - Light pruning 0.500 0.350 12.44 36.40
T5 – Light pruning + PBZ 2.5 ml/m canopy 0.410 0.270 15.16 47.28
T6 - Light pruning + PBZ 5 ml/m canopy 0.370 0.260 15.76 49.56
T7 - Medium pruning 0.490 0.350 13.30 38.55
T8 - Medium pruning + PBZ 2.5 ml/m canopy 0.340 0.200 16.10 51.53
T9 - Medium pruning + PBZ 5 ml/m canopy 0.310 0.180 16.76 55.34
T10 - Heavy pruning 0.470 0.330 13.65 39.32
T11 - Heavy pruning + PBZ 2.5 ml/m canopy 0.470 0.310 14.16 39.89
T12 - Heavy pruning + PBZ 5 ml/m canopy 0.430 0.300 14.89 46.80
S. Em (±) 0.0039 0.0072 0.2479 0.8666
C.D. (5%) 0.0109 0.0204 0.7022 2.4552
• Light pruning - 25 cm from apex
• Medium pruning – 50 cm from apex
• Heavy pruning – 75 cm from apex
International Journal of Chemical Studies 2020; 8(4): 201-206
Kondle et al (2020) West Bengal, India

62. 4. Biological agents
• Dwarfism produced by viroid can be considered as disorder.
• Mode of action
• Interrupting protein transport
• Viroids affect peroxidase/IAA oxidase
• Viroids interfere with mRNA splicing
• Competition for RNA polymerase
• Extent of dwarfism response depends upon –
• Earlier it is done, greater will be dwarfing response
• Infected bud or bark from the inoculated stick
• Bark shield is preferred
• Double bud is preferred over single

63. Ann Appl Biol 158 (2011) 204–217
Vidalakis et al (2011) CA, USA
Treatment Planting density Height (m) Spread (m) Canopy volume (m³)
Control Standard
(6 m × 6.7 m)
2.30 2.62 8.54
TsnRNA-IIIb Standard
(6 m × 6.7 m)
1.87 2.13 4.70
TsnRNA-IIIb HDP
(3 m × 6.7 m)
1.83 2.00 3.97
• Navel organge scion on Poncirus trifoliata rootstocks were grafted with two blind buds
having TsnRNA-IIIb.
• Transmissible small nuclear RNA-IIIb (TsnRNA-IIIb)
• After 13 years, canopy volume of rootstock reduced by -
• Standard density - < 45%
• HDP – < 53.5%
Effect of Citrus dwarfing viroid (TsnRNA-IIIb) on tree size of
Poncirus trifoliata rootstocks for high density planting

64. 5. Biotechnological interventions
- It aims at developing a designer trees/model plants with balanced shoot
and root growth for maximizing productivity
- Through gene transfer/breeding
Golden Scentinel
“Characteristics of a Model Plant”
1. Small and more leaves
2. Short inter-node length
3. Maximum lateral branch
4. Maximum rooting ability
5. Better anchorage
6. Reduction in juvenile period
7. High yield and good fruit quality

65. Genes involved in modifying tree architecture
rolB :
rolC :
rolD :
Gene Role Reference
rolA Modification of plant morphology
Enhancement of root growth
Welander et al. (1997)
rolB Increase auxin sensitivity &
promoting rooting
Rugini et al. (1997)
rolC Reduces internode length White et al. (1985)
rolD Dwarfing and early flowering -
aux1 & aux2 Auxin synthesis genes Rugini et al (1997)
GA2 oxidase Control production of GA
Dwarfing trees in apple
James & Massiah (2000)
Co In apple - compact and columnar
habit.
Lapins and Watkins (1973)

66. Plant Science 163 (2002) 463/473
Phenotypic variation of apple transformants with
pBIN19rolC1 and pBIN19rolC2
Igarashi et al (2002)
Fig: Shoot morphology
1 - control (pIG121Hm)
2 - rolC gene expressing in shoots
Line Plant height
(cm)
Growth
(cm)
Internode length
(cm)
Leaf length
(cm)
Leaf width
(cm)
Control
(PIG121Hm)
76.6 36.0 1.08 6.3 4.1
pBIN19rolC1 60.1 23.6 0.66 4.5 3.1
pBIN19rolC2 70.3 32.2 0.82 5.7 3.9

67. Future Prospects
67/69
• Uniform trees – Individual tree effect will get over.
• Exploring the possibilities of farm mechanization.
• Precision farming applied to canopy architecture – VRT & Robotics.

68. Conclusion
• Plant architecture is a combination of main five variables
namely variety, rootstock, spacing, training and pruning.
• With help of canopy architecture, every individual tree in the
orchard is subject to proper care for development of ideal
architecture and outward spread of canopy to facilitate more
light penetration.
• Higher yields & superior quality fruits can be obtained with
good light distribution within the canopy.
• Besides, tree growth is regulated to manageable height.
• Hence, canopy architecture needs greater attention.