Fruit set, growth & developmental stages of various fruits

1. Fruit set, growth & developmental stages of various fruits
Mandeep Kaur
Ph.D. Fruit Science

2.  FRUIT SET occurs after pollen is released from male flower parts (anthers), lands on receptive female
flower parts (stigmas), produces a tube that grows to the ovules, and fertilizes eggs contained in them.
 Fertilized eggs form seeds, which induce surrounding (pericarp) tissues to grow and form a fruit.
 The final form of the fruit is dependent upon the contributing number and type of floral organ components,
the position of the contributing organs, and how the different tissues within them grow and differentiate.

3. Pomegranate
Guava
Strawberry
Banana
Mango
Pear

4. Plum Apple
Kiwi

5. Fruit set in Grapes
Figure: (a) Flowers with caps attached, (b) bloom, (c) berries formed at fruit set, (d) berries after fruit set
Source: https://psuwineandgrapes.wordpress.com/2015/08/07/fruit-set-in-grapevines-101/

6. Regulation & Manipulation of Flowering & Fruit setting
 Post-blossom thinning of apples (NAA or Carbaryl) @ 10 and 25 DFFB (Childers,1983).
 Enhancement of fruit-set and retention- Fruit set is suboptimal in apple, pear, plum & cherry.This can
be increased by tipping growing shoots to reduce competition.
 Mixture of GA3 with an auxin induces fruit-set of cherries. GA4+7 is generally more effective than GA3 on
apples (Modlibowska, 1975).
 Reduction in crop load: By pruning, usually involves selective removal of thin shoots with weak fruit-buds.
 Maintenance of proper soil moisture- Excessive moisture or water stress causes flower and fruit drop.
 Heavy irrigation during flowering resulted in flower dropping in guava and aonla. Irrigation at 20% or 40%
soil moisture depletion gave maximum fruit set and yield in mango (Chandel and Singh, 2002).
 Remedial measures for inadequate winter chilling- At high altitudes in tropics & sub tropics &
temperate zones, temperature may be low enough to induce dormancy, but do not sufficiently low to satisfy
chilling requirements. In brazil, a combination of 2% thiourea & 10% potassium nitrate, followed by 4%
mineral oil & 0.12% DNOC has been approved in Apple.

7.  Use of pollinator varieties. E.g. In kiwi, male to female tree ratio is 1:9.
 Use of bees - Managed bee pollination is very limited & available bee hives during bloom hardy
meet 2-3% of the demand. This leads to poor fruit set in Delicious (Gautam et al., 1990).
 Control of frost damage- Fruit buds become more sensitive to frost towards full-bloom partly
as the result of the increase in water content. Late flowering varieties offer effective control
(Jones, 1985).

8. Frost damage to Stone fruit
(apricots, cherries, peaches and plums)
A. This cherry flower was not damaged by a freeze the day before.
B. The pistil of this cherry flower was killed by a freeze the day before and has shriveled and turned black.
 Stone fruit have a very simple flower structure.
 The flower contains a single pistil, that is exposed inside a cup formed by the sepals and petals of the flower.
 If the pistil is brown or black after a freeze, that flower will not develop into a cherry because the pistil has been
killed.
A B
*Source: https://www.canr.msu.edu/news/assessing_frost_and_freeze_damage_to_flowers_and_buds_of_fruit_trees

9. Frost damage to Apple & Pears
 Apples and pears are very different than stone fruit.
 In apples, the fruit buds are really small shoots with both flowers and leaves.
 In apples, the flower in the center of the flower cluster is the oldest and most developed and will be the first flower to
bloom.This central flower is called the king bloom and has the potential to be the largest fruit.
A. The king bloom of the apple flower cluster has opened, but the side blooms are still closed. The king bloom is more
susceptible to freeze injury at all stages of the apple bud development in the spring and is often the first flower killed
in the cluster.
B. The dark brown center of this apple flower indicates it was killed by a freeze.
C. The dark brown centers and signed appearance of the petals indicate that both king and side blooms were killed in a
freeze. The king bloom in the center of the cluster has lost its petals.
*Source: https://www.canr.msu.edu/news/assessing_frost_and_freeze_damage_to_flowers_and_buds_of_fruit_trees
A B C

10. Regulation & Manipulation of Flowering & Fruit setting
(By application of Plant Growth Regulators)
Fruit Growth regulators Response Reference
Apple NAA (at full bloom stage) Decrease fruit set & increase yield Komzik, 2004
GA +NAA (at petal fall)₃ Increase initiation & final set Jackson et al., 1983
Ethephon (for thinning) Decrease fruit set & increase size of fruit Metz, 2005
Litchi TIBA & KNO₃ Increase pollen fertility Sanyal et al., 1996
NAA @ 200 ppm Increase size, quality & retain bloom Cuello et al., 1992
Grapes GA₃ Increase fruit set Hyatt et al., 1994
CCC @ 2000 mg/l Increased fruit set & inhibited shoot growth Todic , 2004
CPPU @ 10 ppm 14 days after bloom Increase fruit retention, yield and quality Notodimedjo, 2000

11. Fruit Growth regulators Response Reference
Citrus GA₃ Increase fruit retention Turnball, 1989
2,4-D @10 ppm Increase fruit retention Daulta et al., 1986
Paclobutrazol @ 2.5 g/l Increase fruit set Walstenholme et al., 1990
Ethephon Increase fruit yield Dumer & Gianfaguo,1992
Pear GA @ 50 ppm₃ Increase fruit set & retention, parthenocarpy Yuda et al., 1993
1-MCP @ 0.75 µ/l during pre-
pollination
Increase fruit set Franco et al., 2005
GA3 @ 10 g/ha Increase fruit set Decker et al., 2000
Peach Paclobutrazol & KNO₃ Increase fruit set George and Nissan, 1993
Regulation & Manipulation of Flowering & Fruit setting
(By application of Plant Growth Regulators)

12. Auxins in Fruit setting

13. Boron in Fruit setting

14. Factors Affecting Fruit Set
Light
 Affects fruitfulness by its effect on photosynthesis.
 Low light intensity or its duration reduces the carbohydrates reserves in the trees.
 Poor light conditions promote fruit abscission.
 Shaded plants (overlapping tree canopies) hardly differentiate into flower buds (lesser cell division).
Temperature
 Affects the activity of bees (below 15 degree).
 Also affects the growth rate of pollen tubes, pollen viability and fertility.
 The optimum temperature for pollination, pollen germination and fruit setting is 18 to 22 C. It has
been established that the flowers are killed below 22 C in apples.
High temperature
 Accelerate anthesis and shorten the bloom period (Lovatt et al., 1984).
 Above 32 C, desiccation of the stigmatic surface & more deterioration of embryo sac occurs. It
adversely affects pollen germination percentage.
 Reduced fruit set due to both pollen and stigmatic damage from heat stress found in annona fruits
(Higuchi et al., 1998).

15. 4.4 C or lower
Check the blooming, fertilization
and fruit set in plum, cherry, apple
and pear (Jindal et al., 2004).

17. Effect of soil moisture status and locality on fruit set
 Soil moisture stress caused pollen abortion in pecan, reduced fruit set (Polla et al., 1993).
 Fruit setting on trees of the same variety is often much better in one locality than in another.
 Some examples are:
 Jonathan apple is almost sterile inVictoria (Australia), although it is fertile in USA.
 Bosc pear is self fertile in many localities, but becomes partially fertile in New York (USA) and
develops parthenocarpic fruits regularly in South Africa.
 The commercial mango varieties of south India (e.g. Neelum and Baneshan) usually don’t
perform better under northern Indian conditions.

18. Chemicals and pesticides
 Can kill bees.
 Some can be toxic to delicate flowers, causing abortion and loss of fruit.
 Sprays effect receptive stigmatic surface, showed varying degree of injury and range from
minor surface wrinkling to degeneration of stigma papillae.

19. Nutrition
• An adequate and balanced supply of all mineral
nutrients is critical for optimum fruit set.
• However, certain mineral nutrients, including
phosphorus, boron, zinc, and molybdenum,
effect fruit set directly because they have
various roles in pollen development, pollen
viability, pollen germination, and pollen
tube growth.
• Fruit retention was significantly improved by
the application of ZnSO4 in Kinnow (Daulta
et al., 1986). Fig. Phoshorus deficiency
induces fruit set reduction.
Source: Progressive Viticulture, LLC

20. Tree factors affecting fruit set other than pollination
 Self-fruitful cultivars tend to set more heavily.
 As bloom density increases the percentage of fruit set decreases. The carbohydrate
ratio and growth regulator substances manufactured by the plant usually only satisfy
less than 20% of the growing fruit lets. (Apple: only 10% develop into fruits)
 Trees on semi-dwarf and dwarfing rootstocks tend to set more fruits than
seedling rootstock.
 Ringing - can improve fruit set (done 7 DFFB). E.g. - Grapes.
 Branch bending - can increase flower bud formation and fruit set. E.g. - Guava.

21. • Dichogamy: Prevention of natural self- pollination in an individual perfect flower.
Heterodichogamy: Walnut, Pistachio nut.
Protogynous Diurnal Synchronous Dichogamy: Avocado.
• Stigmatic receptivity: Ability of the stigma to support pollen germination.
Limits Effective Pollination Period (EPP).
Fruit set in kiwifruit high (80%) when hand pollination is done within 4 days after anthesis.
Fruit set was 36% 5 days after anthesis and almost nil 7 days after anthesis. Thus, EPP was
limited to first four days and the stigmatic receptive averaged 84% and sharply reduced to nil
after 7 days (Gonazelez et al., 2004).
Conti…

22. • Non viable pollen: E.g. Muscadine grape.
• Sterility: Occurs due to failure to obtain normal development of pollen, embryo sac, embryo
and endosperm.
Morphological sterility is due to rudimentary pistil or abortion of sex organs ovule
degeneration.
Pollen sterility is common in peach cv. J.H.Hale and many olive cultivars also.
The proportion of sterile ovules varies between 22% in apricot and 98% in avocado (Verma
and Jindal, 1997).

23. • Abortive flowers or aborted pistils or ovules: This occurs in the developing flowers, pistils
and stigmas. Interference either in the development of the flower or in the full development of
sex elements and their function may lead to unfruitfulness.
• Table: Various causes of fruit abortion in different fruit crops.

24. Genetic influences
• Unfruitfulness due to sterile hybrids
Peach plum hybrids known as ‘Blackman’ or ‘Mule’ are completely sterile.
Barren flowers and are also present in ‘Kamdesa’, which is a hybrid between peach
and sour cherry.
The popular tangelo are seedless or they produce seeds only with nuclear embryos.
• Incompatibility
Failure of viable pollen to grow down the style of flower of the same variety (self
incompatibility).
Common in fruit crops like apple, pear, sweet cherry, almond, avocado, fig, mango,
citrus, olive, etc.

25. Fruit Growth and DevelopmentFruit Growth and Development

26. cell enlargement
Ripening
Fruit Development Stages

27. Fruit Development Stages
• The pollinated flower develop to a fruit and the fertilized ovules grow to seeds.
• Cell division
 Started after bloom.
 Smaller fruited crops generally have a shorter period of cell division.
 Can be extended to some extent by blossom thinning.
• Pit hardening (stone fruit only)
 Lignification of endocarp.
• Cell enlargement
 Predominates later in fruit development (and after pit hardening in stone fruit).
• Fruit maturation
 Final weeks (days) of fruit development.

28. Stone Fruit
• Usually one carpel & seed.
• Fruit derived from ovary.
• Usually 5 carpels & 10 seeds.
• Fruit derived from thalamus.
Pome Fruit

29. Apple
fruit development
 Apple fruit at various stages of
development.
 A, 0 DAA
 B, 14 DAA
 C, 35 DAA
 D, 60 DAA
 E, 87 DAA
 F, 132 DAA
 G, 146 DAA
 H, diagram of fruit development showing
the timing of major physiological events.
 Ripening is shown as a solid and dashed red,
solid from the time of the climacteric and
dashed for events prior to the climacteric.
Bar = 1 cm.
*Source: http://www.biomedcentral.com/1471-2229/8/16

30. Fruit development of the diploid kiwifruit, Actinidia chinensis ’Hort 16A’
 Development of Actinidia chinensis ’Hort
16A’ fruit from open flower (0 days
after anthesis, DAA) to over ripe fruit
(286 DAA) in Season 1.
 The physiological changes have been
scaled to 100 arbitrary units based on
maximum values.
 Based on fresh weight (g), seed colour
(% black), flesh colour (°h) and firmness
(N), a BBCH scale has been aligned.
 A-E Photographs from different growth
stages in Season 3 fruit with BBCH
stages for each picture shown.
*Source: https://www.researchgate.net/publication/51954771

31. Fruit growth & development stages of Date palm

32. Fruit growth & development stages of strawberry fruit
 SG: small green fruit
 MG: middle green fruit
 LG: large green fruit
 W: white fruit
 IR: initial reddening
 FR: full reddening
*Source: https://doi.org/10.1104/pp.114.251314

33. Fruit growth & development stages of Mango
The growth and development stages and peel colour of mango fruits cv.
Jinhwang harvested at 50, 80, 110 and 140 days after anthesis (DAA).
*Source: http://dx.doi.org/10.1016/j.njas.2014.10.001

34. Fruit Growth Curves
The combined growth resulting from cell division, cell enlargement and
air space formation results in a general sigmoidal (S-shaped) curve.

35. Sigmoid Curve
Sigmoid/Single sigmoid curve
•Fruit undergoes slow enlargement at the
early (a) and last stages of growth (c).
•While growth is considerably faster
during the middle development stage
(b).
•Examples: Apple, pear, pineapple,
banana, avocado, almond, loquat, date
palm, papaya, mango, lemon &
strawberry.
a
b
c

36. Double Sigmoid Curve
Three stages are seen
I.Ovary, nucellus an integuments of the seed grow
rapidly, but the embryo and endosperm grow little.
II.Embryo and endosperm grow rapidly, but the ovary
does not increase much in size, sclerification of the pit
also begins and embryo achieve full size by the end
and the amount of endosperm material increases
greatly.
III.A new surge of ovary growth begins and continues
to fruit ripening.
Examples: Peach, plum, apricot, ber, raspberries, fig,
blackberry, blueberry, cherry, persimmon, guava,
grapes, olives, etc.

37. a
b
d
c
e
Time
Growth
Triple Sigmoid Curve
Five stages are seen
a)Initial rapid growth, seeds reaching full size (0-9 weeks).
b)Slow growth, seeds hardens and start to colour, first very
large respiratory response to ethylene (9-12 weeks).
c)Rapid growth, seeds become dark brown, response to
ethylene increases (12-17 weeks).
d)Very little growth, seeds dark brown, softening starts, soluble
solids starts to increases, respiratory response to ethylene
rises to a maximum and then decreases (17-21 weeks).
e)A smaller, but significant growth increase to approximately
final size. The fruit matures, the seeds becoming very dark
brown and free in the tissues.
Example: Kiwi fruit.

38. Pre-bloom factors affecting fruit size
• Post-harvest defoliation
Reduction in Fruit size in following year.
• Spur size & position
Larger spurs bear larger fruits.“King bloom” of apple produces largest fruit.
• Age of bearing wood
Larger fruit on 2-year-old spurs than 1-year-old spurs.
• Pre-blossom temperature

39. Post-bloom factors affecting fruit size
• Seeds
Fruit size dependent for first 7 weeks.
Aborted seeds alter fruit shape.
• Light & carbohydrates
Controls supply of CHOs - competition between fruit & shoot growth & between fruits.
Most important source of within tree variation in fruit growth.
• Temperature
• Water stress
• Fruit thinning

40. Apple growth stages

41. Fruit growth & development stages of Cherry
*Source:
https://www.nature.com/articles/sdata2016108

42. Nectarine fruit development

43. Regulation and manipulation of fruit development
 Climatic factors like late spring frosts, precipitation, rainy days have been
found to cause poor development of fruit (Grabowsky, 2000).
 The stage II of fruit growth has been identified, as an appropriate period at
which fruit growth is minimal and not affected by drought. In early cultivars,
this period is very short, the main shoot growth occurs after harvest, and
thus may be ideal time for drought.
 Heavy irrigation during critical period i.e. end March to End April in
early cv. Partap, Florda Prince and end April to mid May in late cv. Under
subtropical conditions, resulted in higher fruit weight and quality in peaches.
 Nutrient sprays

44. Effect of Auxin on fruit set and development
Fruit crop PGR Concentration Stage of application Response/effect Reference
Apple NAA + BA 7.5+75 ppm At full bloom • Good thinning
• Good increase in fruit size
Robinson, 2006
Guava cv.
L-49
NAA 10 ppm At blooming • Greatest fruit diameter (5.03 cm),
fruit weight (88.9 g), flesh weight
(83.6 g), number of fruits per tree
(666) and fruit yield (56.9 kg)
Yadav, 2002
Japanese
Plum
2,4- D +
NAA
25+30 ppm Before pit hardening • Increase in fruit size
• No negative effect on fruit quality
Stern et al., 2007
Cherry 2,4-D +
NAA
25+30 ppm Before pit hardening • Increase in fruit size
• No negative effect on fruit quality
Stern et al., 2007
Pear • NAA
• IBA
• 20 ppm
• 30 ppm
Young Fruit period • Enhance fruit growth
• Improved final fruit size
Chen et al., 2012
Mango cv.
Bombai
NAA 40 ppm After fruit set • Maximum fruit retention Gupta and
Brahmachari, 2004
*Source: https://doi.org/10.20546/ijcmas.2018.705.159

45. Effect of Gibberellins on fruit set and development
Fruit crop PBR Concentration Stage of
application
Response/effect Reference
Mango cv.
Amrapali
GA3 100 and 200
ppm
At full bloom • Maximum fruit retention,
growth, yield and quality
Rani and
Brahmachari (2004)
Pear GA4+7
or GA3
10 to 25 ppm At full bloom • Improve cropping of pears --
Pear GA3 11 ppm At blooming • Induced fruit development but
led to the production of small
fruits due to heavy fruit set
Knight and
Browning (1986)
Pear • GA4+7
• GA3
• 3%
• 2.7%
Young Fruit
period
• Enhance fruit growth
• Improved final fruit size
Chen et al., (2012)
Blueberry GA3 0.4 mM At full bloom • Increased fruit set
• Decrease fruit mass
Cano- Medrano and
Darnell (1998)
*Source: https://doi.org/10.20546/ijcmas.2018.705.159

46. Effect of Growth retardant on fruit set and development
Fruit crop PBR Concentration Stage of
application
Response/effect Reference
Mango cv.
Banganapalli
Paclobutrazol 5 ml/tree (twice) Before bud
break
• Maximum number of fruits per
panicle at harvesting stage
• More number of fruits/tree
Singh and Ranganath
(2006)
Apple PCa+TDZ 330+12 ppm Petal fall
stage
• Increase fruit set and no of
fruit/tree
Leite et al., (2010)
Pear Daminozide 2000 ppm • Increase fruit set Costa et al., (2006)
Pear CPPU 6-BA 10 ppm
30 ppm
Young fruit
period
• Enhance fruit growth
• Improved final fruit size
Chen et al., (2012)
*Source: https://doi.org/10.20546/ijcmas.2018.705.159

47. Effect of plant growth regulators on fruit set, fruit retention and yield
efficiency of apple cv. Scarlet Spur II (Sharma and Sharma 2018)
Treatments
Fruit set (%) Fruit retention (%) Yield efficiency (kg/cm2
)
2017 2018 Pooled 2017 2018 Pooled 2017 2018 Pooled
Promalin (GA4+7+BA) @ 1ppm 38.82 47.53 43.17 66.00 73.24 69.62 0.25 0.29 0.27
Promalin (GA4+7+BA) @ 1 ppm 40.35 50.41 45.38 72.62 76.10 74.36 0.27 0.32 0.30
Promalin (GA4+7+BA) @ 2.5 ppm 43.66 55.45 49.55 75.72 82.75 79.24 0.32 0.37 0.35
Promalin (GA4+7+BA) @ 2.5 ppm 41.34 51.19 46.26 83.27 85.18 84.22 0.36 0.43 0.40
Promalin (GA4+7+BA) @ 5 ppm 42.31 55.48 48.90 73.17 80.12 76.64 0.34 0.38 0.36
Promalin (GA4+7+BA) @ 5 ppm 50.35 59.98 55.16 82.64 88.54 85.59 0.42 0.43 0.42
CPPU @ 2.5 ppm 51.94 60.33 56.14 77.76 86.03 81.89 0.43 0.45 0.44
CPPU @ 5 ppm 49.90 61.16 55.53 82.15 88.23 85.19 0.45 0.49 0.47
CPPU @ 10 ppm 57.41 65.14 61.28 83.59 91.34 87.47 0.49 0.54 0.51
Control (no spray) 26.13 31.89 29.01 50.87 66.13 58.50 0.22 0.25 0.24
CD0.05
7.21 5.44 4.21 6.74 6.47 4.95 0.10 0.09 0.08
* Source: https://www.researchgate.net/publication/331089391

48. Improved fruit retention, yield and fruit quality in mango cv. Himsagar
with exogenous application of polyamines (Dutta et al., 2018)
Treatments Fruit retention
(%)
Numbers of fruits
per tree
Fruit weight
(g)
Fruit yield
(kg/tree)
Water spray 0. 87 134.65 214.50 28.882
Spermidine
0.5 mM 1.34 167.2 244.42 40.867
1mM 1.00 156.4 234.64 36.698
1.5 mM 0.93 151.0 227.88 34.410
Putrescine
0.5 mM 1.61 168.0 250.22 42.037
1mM 1.48 163.1 242.63 39.573
1.5 mM 1.32 158.4 222.56 35.254
C.D. (p=0.05) 0.03 2.00 2.40 0.52

49. Effect of bio regulators and application stages on
‘Bunch circumference (cm)’ and ‘Yield per vine (kg)’ in grape cv. Italia
(Senthilkumar et al., 2018)
Treatments
‘Bunch circumference (cm)’ ‘Yield per vine (kg)’
S1 S2 S3 MEAN S1 S2 S3 MEAN
C 32.78 33.02 32.45 32.75 8.50 8.75 8.36 8.54
B1 34.52 35.76 34.14 34.81 9.68 9.91 9.89 9.83
B2 36.70 36.43 37.04 36.72 10.38 10.51 9.54 10.14
B3 33.45 33.24 32.96 33.22 10.55 11.01 10.42 10.66
B4 36.90 37.17 36.49 36.85 8.10 10.30 9.65 9.35
B5 34.98 35.46 34.73 35.06 9.35 12.70 11.02 11.02
B6 35.65 35.52 36.36 35.84 9.89 10.24 10.23 10.12
MEAN 35.00 35.23 34.88 35.04 9.49 10.49 9.87 9.95
*Source: https://doi.org/10.20546/ijcmas.2018.704.040

50. Effect of plant growth regulators on yield and quality of
guava (Psidium guajava L.) cv. Allahabad Safeda (Lal and Das, 2017)
Treatments Yield/
plant
Pulp
weight
(g)
Juice
content
(cc)
Seed
weight
(g)
TSS
(%)
Total
sugar
(%)
Ascorbic
acid
(mg/100g)
Titrable acidity
(%)
Control 12.17 75.40 25.23 4.50 7.90 6.30 64.27 0.34
2,4-D-10 ppm 19.73 85.20 29.50 4.73 11.50 9.50 115.27 0.18
2,4-D-20 ppm 16.23 104.9 37.63 4.20 9.40 8.00 84.47 0.27
NAA-50 ppm 25.97 103.0 39.33 5.67 11.20 9.20 104.40 0.19
NAA-100 ppm 15.70 104.6 39.17 3.60 10.10 8.50 89.73 0.25
GA3-50 ppm 37.13 173.0 63.17 6.67 12.50 10.30 135.30 0.16
GA3-100 ppm 28.93 140.1 50.83 4.50 10.40 8.70 92.33 0.24
Ethrel-50 ppm 23.10 124.3 46.23 4.87 9.90 8.20 88.40 0.27
Ethrel-100 ppm 26.50 102.0 34.77 4.00 8.80 7.10 73.83 0.30
CCC-500 ppm 24.23 113.3 47.33 4.20 10.70 8.90 98.43 0.22
CCC-1000 ppm 32.53 101.1 34.27 4.23 10.40 8.70 92.37 0.24
S.Ed. ± 0.472 0.84 1.13 0.23 0.19 0.19 2.48 0.01
CD (5%) 0.984 2.48 2.35 0.49 0.40 0.40 5.19 0.3
*Source: https://doi.org/10.20546/ijcmas.2017.605.096

51. Effects of plant growth regulators on fruit set and yield
of pomegranate cv. Bhagwa (Anawal et al., 2016)
Treatments Days taken
for fruit set
Yield Fruit characteristics
Number Kg/plant Kg/ha Length
(cm)
Diameter
(cm)
Weigh
t (g)
Volume
(ml)
T1-Control (Water spray) 40.66 45.00 8.14 7540.73 4.48 5.01 181.00 178.32
T2-NAA 40 ppm 37.55 62.44 16.45 15232.70 8.66 8.71 262.23 255.44
T3-NAA 50 ppm 38.22 60.11 15.06 13942.47 8.42 8.46 250.43 249.85
T4-NAA 60 ppm 38.55 50.55 11.90 11022.49 8.37 8.45 235.57 234.74
T5-GA3 40 ppm 39.66 50.44 11.25 10417.50 6.91 7.22 223.10 217.44
T6-GA3 50 ppm 39.44 47.33 9.91 9173.57 6.73 7.24 209.57 211.37
T7-GA3 60 ppm 39.89 50.66 11.23 10395.89 7.64 7.54 221.67 218.48
S.E m ± 2.64 2.76 0.77 713.56 0.36 0.37 3.78 6.86
C.D. @ 5% 8.14 8.51 2.37 2198.68 1.11 1.14 11.64 21.12

52. Improving fruit set, yield and fruit quality of date palm (Phoenix dactylifera,
l. cv. Mnifi) through bunch spray with boron and zinc (Omar et al., 2015)
Treatments Fruit set (%) Yield (kg/tree) Fruit weight (g) Flesh weight (g)
2011 2012 2011 2012 2011 2012 2011 2012
1500 ppm B 92.87 88.62 126.67 149.90 14.75 12.78 13.15 11.45
2500 ppm B 79.04 79.80 146.67 136.17 16.89 13.85 15.43 10.36
300 ppm Zn 74.74 85.24 130.0 126.27 15.43 10.94 14.04 9.51
600 ppm Zn 70.93 83.47 130.0 133.17 15.05 11.60 13.79 10.41
1500 ppm B + 300 ppm Zn 65.66 86.75 166.67 183.33 17.53 15.21 16.07 13.98
1500 ppm B + 600 ppm Zn 64.51 79.00 123.33 171.67 14.40 13.85 12.95 12.40
2500 ppm B + 300 ppm Zn 61.95 74.80 116.67 150.23 14.02 13.39 12.72 12.13
2500 ppm B + 600 ppm Zn 51.94 72.88 113.33 143.37 13.24 12.31 11.93 11.03
Control 41.35 49.16 110.0 118.13 12.47 9.22 11.17 8.04
*Source: https://www.researchgate.net/publication/274292393

53. Treatment Fruit set (%) Fruit drop (%) Fruit retention (%)
Full
bloom
Petal fall Mean Full
bloom
Petal fall Mean Full
bloom
Petal fall Mean
GA3 10 ppm 5.31 4.26 4.78 34. 74 39.38 37.01 65.22 60.60 62.91
GA3 20 ppm 7.51 5.61 6.56 27. 94 32.17 30.05 72.04 67.84 69.94
GA3 30 ppm 6.68 5.01 5.85 38. 39 34.40 36.40 61.67 65.68 63.67
Sucrose 5% 5.20 4.98 5.09 51. 26 45.92 48.59 48.64 54.09 51.37
Sucrose 10% 6.12 5.83 5.97 41. 49 40.41 40.95 58.51 59.62 59.06
Sucrose 15 % 7.36 7.22 7.29 40. 82 31.20 35.99 59.24 68.85 64.04
Boric acid 100 ppm 6.82 5.39 6.10 42. 48 42.06 42.27 57.47 57.44 57.46
Boric acid 200 ppm 5.16 5.16 5.16 44. 38 43.46 43.92 58.57 56.47 57.52
Boric acid 300 ppm 4.62 4.59 4.61 42. 99 45.96 44.47 57.02 54.14 55.58
Control 3.13 3.13 3.13 61. 75 61.45 61.6 38.40 38.25 38.32
Mean 5.79 5.16 - 42.62 41.64 - 57.68 58.30 -
Effect of chemicals sprayed at different flowering stages of semi-soft
pear cultivar 'Punjab Beauty' on fruit set, fruit drop & fruit retention
(Dhillon et al., 2012)
*Source: https://www.researchgate.net/publication/289221439

54. Cultivars Treatments Fruit set
(%)
Fruit weight
(g)
Fuji Control - -
2,4-D - -
CPPU - -
GA₃ 6.7 197
GA₃ + 2,4-D 21.1 177
GA₃ + CPPU 50.0 291
GA₃ + 2,4-D +
CPPU
40.0 367
Pollination 76.0 232
Effects of plant growth regulators on fruit set and fruit shape of
parthenocarpic apple fruits (Watanabe 2008)
Cultivars Treatments Fruit set
(%)
Fruit weight
(g)
Ohrin Control 24.1 167
2,4-D 31.0 168
CPPU 64.3 225
GA₃ 60.0 189
GA₃ + 2,4-D 69.0 205
GA₃ + CPPU 86.7 313
GA₃ + 2,4-D +
CPPU
89.3 314
Pollination 64.3 209
*Source: https://www.researchgate.net/publication/47439571

55. Thank You