unfruitfulness in fruit crops

2. 2
What sort of tree is there which will not, if neglected, grow crooked and unfruitful; what but Will,
if rightly ordered, prove productive and bring its fruit to maturity ? What strength of body is there
which will not lose its vigor and fall to decay by laziness, nice usage, and debauchery ?
Plutarch

3. 3
PRESENTED BY,
Ch. Allaylay Devi
PhD. (Hort.) 1st Year
Dept. of FSc.

4. Seminar outline
4
Introduction
Unfruitfulness
Causes
Remedial measures
Brief review of research work
Conclusions

5.  Fruit growing is one of the most important and profitable venture in
horticulture.
 The art and science has now developed into one of the most deviled,
skillful and intensive forms of land utilization.
 Today the standard of living of different people of countries is
judged by the production and per capita consumption of fruits.

6. What is unfruitfulness ?
 ‘Fruitfulness’ refers to the state where a plant is not only capable of flowering and
bearing fruit, but also takes these fruits to maturity. The inability to do so is known
as ‘unfruitfulness’ or ‘barrenness’.
 It may be defined as the plant not only develop flowers, but set fruits and carries
them up to maturity. The conditions under which plants are unable to bloom or set
fruits or carry them upto maturity is called unfruitfulness.
 Unfruitfulness is one of the leading problems in many fruit crops which results in
huge loss to growers thus make fruit cultivation less profitable.
 Although tree produce adequate flowering, low initial fruit set and subsequently
higher fruit-let abscission leads to unfruitfulness.
 Besides any interference with the development of reproductive cells and organs
leads to unfruitfulness
Wani, et al., 2010

7. The causes of unfruitfulness in fruit plants have been broadly
classified into two categories:
(i) Internal factors and
(ii) External factors.
Wani, et al., 2010

8. Causes of unfruitfulness
 External factors
8
1. Environmental factors
i. Temperature
ii. Rainfall
iii. Wind
iv. Frost
v. Hailstorm
vi. Cloudy weather
vii. Light intensity
2. Disturbed water
relations
3. Nutrient supply
 Internal factors
1. Impotence
2. Incompatibility
3. Abortion
7. Locality
6. Age and vigour
of the plant
5. Pruning
4. Rootstocks
8. Seasonal
influence
9. Spraying fruit
plants during
flowering
10. Insect-pest
and diseases
11. Miscellaneous
factors
Wani, et al., 2010

9. Classification and explanation of unfruitfulness
 External factors
1. Environmental factors
i. Temperature
 It affects the flowering, pollination, fruit set, growth and development
of the plants.
 Every species requires certain optimum range of temperature for
growth, flowering and fruit set.
 Extreme temperature fluctuations and continuous high temperature
etc., are injurious to fertilization process.
9
Sharma, R. R. (2006). Fruit Production.

10. Examples
 The pollen of most of the fruit crops grown in temperate climate, like apple, pear,
cherry, plum, walnut, pecan nut etc., germinate freely at a temperature of 50 0F or
above, but the fertilization process is practically inhibited if the temperature falls
below 40 0F.
 Of the different climatic factors, temperature appears to have some relation with the
variability in the incidence of mango malformation.
 Higher temperature and dry atmosphere appear to be associated with the increased
production of pollen per anther in mango crop
 It have indirect influence on fruit set through its effect on the activity of pollen
carrying insects.
 Influence of temperature on fruit set has also been reported in papaya such as sex
reversing male plants
10
Cont..
Sharma, R. R. (2006). Fruit Production.

11. Rainfall
 It is necessary for proper growth and development of a plant, but rainfall at
blossoming is recognised as one of the most important factors limiting the
fruit set and ultimately the fruitfulness in fruit crops
 Rain at time of blossoming causes the loss of more fruits than any other
climatic agency.
 Rain washed off the pollens from the anthers.
Wind
 It is an important pollination agency in many fruit plants like walnut, pecan
nut, oak, hickory, hazelnut, coconut etc. (Anemophilous or Wind pollinated)
 In insect pollinated fruit plants, wind hinders rather than help in pollination,
because pollen carrying insects work more effectively in a still atmosphere
 It may also cause the stigmatic fluid to dry prematurely thus affecting the
pollen germination
Sharma, R. R. (2006). Fruit Production.

12. Frost
 This factors responsible for causing even a regular bearing cultivar or a
plant in an orchard to become an irregular bearer.
 Spring frost are harmful to the plants in temperate climate
 It may either kill the sexual organs of a flower or completely destroys the
blossoms, thereby influencing the fruit set and ultimately the fruitfulness
(mango, banana, guava, litchi, etc.)
Hail storm
 It has been found to be very harmful if it occurs at any time between
flowering and fruit development stages.
 In temperate fruit orchards, hail destroys all the flower buds and injuries
almost all the developing fruits.
 In hail-prone areas, anti-hail nets should be stretched over the orchards.
Sharma, R. R. (2006). Fruit Production.

13. Cloudy weather
 It also make unfruitfulness in many fruits plants by making conditions
favourable for development and spread of diseases.
 For example, powdery mildew, a most serious disease of many fruit crops,
usually appears immediately following cloudy weather which consequently
dry up and drop.
 It is most destructive during March-April, especially during cloudy weather.
Light intensity
 Light supply is also important in determining fruit-set in almost all the
deciduous fruit plants
 Effect of Light has been reported in strawberry, as the development of pistils
and stamens take place only when plants are exposed to certain light
intensity.
 Poor fruit set, yield and color development in high density mango orchards
have been mainly attributed to dense and overlapping tree canopy, rendering
poor light penetration, for which pruning is recommended.
Sharma, R. R. (2006). Fruit Production.

14. 2. Disturbed water relations
 For fruitful production, adequate supply of water is required, and
disturbance in water or moisture in soil may lead the formation of an
abscission layer, resulting in the dropping of the blossoms, leaves or
fruits, thereby affecting fruitfulness of the plant.
 Moisture deficit may be responsible for disturbance in C:N ratio and
composition of other chemicals, which are responsible for fruit drop.
 It is not true that moisture deficit is always responsible for drop of
flowers and fruits but excess moisture causes flower and fruit drop in
apples and olives.
 In general, avoid irrigating orchards during flowering as it may
sometime lead to complete shedding of flowers as reported in citrus.
Sharma, R. R. (2006). Fruit Production.

15. 3. Nutrient supply
 Balanced supply of nutrients is always desirable for realizing optimum fruit
production.
 However, it is often impossible to distinguish clearly between the influence
of nutritive conditions within the plant and the conditions without nutrient
supply on fruit set, fruitfulness and fertility.
 Excess supply of manures and fertilizers, though, may result in vigorous
growth of the plants, but it affects flowering and fruiting adversely.
 It is assumed that overfed plants have low C:N ratio, which is not desirable
for proper set in fruit plants.
Sharma, R. R. (2006). Fruit Production.

16.  Example: Jonathan apple Self sterile on rich land in Victoria
(Australia), becomes self-fruitful when grown on land of low
productivity.
 The Hope grape (perfect flower variety) and Muscadine group,
produce hermaphrodite flowers only when proper nutrient supply is
given. Under inadequate management practices, most of the flowers
produced by these varieties are staminate.
 Some cultivars of strawberry produce perfect flowers and are
productive when grown under ordinary management cultural
practices, but produce only little pollen for satisfactory crop when
grown on rich soils.
Sharma, R. R. (2006). Fruit Production.

17. 4. Rootstocks
 Rootstocks are known as the backbone of fruit industry
 Thus many rootstocks are used for inducing various desirable benefits on
the scion cultivar.
 In some instances, stocks exerts considerable influence on flowering and
fruit set of the scion cultivar.
 Example: Troyer Citrange (Citrus), Dogridge (Grapes), Pusa Srijan
(Guava), Khirni (Sapota), etc.
 Seedlings plants are relatively slow to come into bearing, but it can be
hastened by grafting on trees of some kind that are bearing.
 Thus, rootstocks, directly or indirectly influence the fruitfulness of the
plants
Sharma, R. R. (2006). Fruit Production.

18. 5. Pruning
 Pruning is very old horticultural practice in which undesirable parts of plant
are removed judiciously.
 It is a very important cultural practice to maintain the rhythm of fruiting in
deciduous fruit plants, but it is rarely done in evergreen fruit plants, though
they also respond favourably to pruning.
 Example: Cane-pruned grapevines produce flowers and fruits better than
the severe spur-pruned grapes.
 Heavy pruning has been on the change of sex, from staminate to pistillate or
to hermaphrodite in papaya.
 This is regarded as extreme illustration of influence of pruning practice on
flower formation, fruit setting and productivity. Sharma, R. R. (2006). Fruit Production.

19. 6. Age and vigour of the plant
 The effects of age and vigour on bearing behaviour of fruit plants are well
known.
 The age of the plant has been the factor, apparently associated with the
degree or percentage of fruit setting.
 Example: Young and vigorous plum trees are known to produce higher
proportion of defective pistils than older trees of the same variety.
 Young vigorous apple trees often fail to set fruits under controlled cross-
pollination, whereas old and less vigorous trees of the same variety set
freely.
 The problem of coulure is very serious disease in the initial years of
bearing in Muscat of Alexandria grape, but later it is less serious.
Sharma, R. R. (2006). Fruit Production.

20. 7. Locality
 Fruit setting on trees of the same variety is often much better in one locality
than in another.
 It is the only environmental complex, which influences the fruit set in a locality.
 Example: The American grape varieties have been found to be self sterile in
Columbia, although, perfectly self fertile in California, which is in the south
 The Jonathan apple is almost sterile in Victoria (Australia), although it is fertile
in USA.
 The Bose pear is self sterile in many localities, but becomes partially fertile in
New York (USA).
 The South Indian variety (Neelum and Baneshan) of mango don’t perform
better under North Indian conditions
Sharma, R. R. (2006). Fruit Production.

21. 8. Seasonal influence
 It is almost impossible to distinguish the influence of locality from
that of season, because the seasonal variations at a given place may
give rise to practically the same changes in environment which are
due to differences in localities in a single season.
 Example: Trees of some plum varieties have been found to be
greatly in fertility from season to season and a plum variety, which is
protandrous in one season, may be protogynous in the next season.
a) End season fertility (Grape varieties – Ideal)
b) Change of sex with season (Japanese Persimmon, Myrica
gale, Grapes Hybrid – Vitis riparia x Vitis Labrusca)
Sharma, R. R. (2006). Fruit Production.

22. 9. Spraying fruit plants during flowering
 Although, spraying of fruit trees with adequate insecticides and
fungicides may be an effective aid in preventing the attack of certain
insect-pests and disease, but it would seriously reduce fruit setting
and thereby affecting fruitfulness of the orchard.
 Example: Jhumka, the disorder has occurred in orchards due to
excessive spraying of insecticides, which result in decline in
pollination of pollinating insects.
 Arsenicals cause the greatest injury to the pollen and pollen carrying
insects, if they are sprayed on trees during flowerings.
Sharma, R. R. (2006). Fruit Production.

23. 10. Insect-pest and diseases
 At times insect are considered useful to the flowers as they are the chief
pollination agents and thereby they help in adequate fruit set
 Yet, the flowers of many fruits are attacked by numerous insect-pests,
fungal, viral and bacterial diseases, rendering them unfruitful too.
 Example: Houseflies strictly do pollination in mango, but mango hopper
may infest it blossoms in such a number as to blast off all the flowers on a
tree or even in the whole orchard.
 Among diseases blight is most serious diseases, which limits fruit setting in
pears considerably.
 Others like Scab (Apple and Pear), Powdery Mildew (Mango, Grape, Ber,
etc.)
Sharma, R. R. (2006). Fruit Production.

24. 11. Miscellaneous factors
 Management of orchard
 Presence of illuminating gases in the atmosphere (Black tip of
mango)
 Presence of high salt concentrations ( Chloride)
 Continuous spray of certain chemicals (Lime sulphur)
Sharma, R. R. (2006). Fruit Production.

25. Internal factors
 It is a common observation that some fruit plants even produce
abundant flowers, but usually fail to set adequate number of fruits
and sometimes they do not produce fruits at all.
 This failure of fruit set may be due to various reasons, like failure of
pollination, sterility or even nutritional deficiency.
 Stout and his co-workers in 1916 recognised that such type of
unfruitfulness is mainly due to the following three internal factors.
1. Sterility from impotence
2. Sterility from incompatibility and
3. Sterility from embryo abortion
Sharma, R. R. (2006). Fruit Production.

26. Impotence
 Sterility from impotence arises when one or both the sex organs fail to
develop the fruit properly.
 The impotence may be complete, in which either no flower or no sex organs
are formed, or it may be partial, in which either stamens or pistils are
abortive
Incompatibility
 Sterility from incompatibility arises, when, although the sex organs are
completely formed, they fail to function properly.
 The pollen grains are unable to germinate freely on stigma or stigma is not
compatible with the pollen.
 Thus in incompatibility, the properly developed gametes fail to unite
together, although the sex are organs are completely formed or functional
Sharma, R. R. (2006). Fruit Production.

27. Abortion
 In sterility due to abortion, even after the proper pollination and
fertilization, the abortion of the embryo takes place before reaching
the maturity.
 However, sterility associated with the internal factors are based upon
the following fundamental processes:
a) due to evolutionary tendencies
b) due to genetic influences and
c) due to physiological factors
Sharma, R. R. (2006). Fruit Production.

28. (A) Evolutionary tendencies
 Due to evolutionary tendencies, cross fertilization must be done in order to
maintain the vigor of the species. In these species, self fertilization is
difficult.
The evolutionary factors leading to unfruitfulness are:
 Imperfect/defective flowers-
a) Monoecious (Cashewnut, Annona, Aonla, Ber, Litchi,
Jackfruit)
b) Dioecious (Papaya, Date palm)
 Dichogamy
a) Protandrous (Ber, Passion fruit)
b) Protogynous (Sapota, Annona, Mango, Avocado)
Sharma, R. R. (2006). Fruit Production.

29.  Heterostyly: Difference in the length of style and stamens.
 Pin (Sapota, Pomegranate) and Thrum (Carambola) type flowers.
29Sharma, R. R. (2006). Fruit Production.

30.  Stigmatic receptivity
 Abortive flowers or aborted pistils or ovules
30
Fruit plant Causes of flower abortion
Grapes Degeneration of nucleus
Mandarin Abnormal pistil
Litchi Embryo abortion
Olive Pistil abortion
Kiwi fruits Pollen degeneration
Wani, et al., 2010.

31.  Impotence of pollen
• Unfruitfulness in Muscardine grape is due to defective pollen.
• In Ber Illaichi variety is male sterile.
• In Citrus Kagzi Lime and Eureka Lime are male sterile due to non-viable
pollen.
• Pollen sterility is common in many Olive cultivars.
31
Wani, et al., 2010.

32. (B) Genetic influences
i. Unfruitfulness due to incompatibility: Incompatibility between
pollen and ovule.
 Self incompatibility: In ability of a plant with functional pollen to
set fruits or seeds when self pollinated.
 In mango, self-incompatibilty is reported in cvs. Dashehari, Chausa
and Langra (Ram et al., 1976).
 In loquat varieties like Golden Yellow, Pale Yellow pollen tube
penetrate in to stylar canal up to 1/4th to 1/3rd of its length and did
not go further below, even after 72 hrs. of pollination (Singh and
Rajput, 1964).
32
Sharma, R. R. (2006). Fruit Production.

33. ii. Unfruitfulness due to hybridity: Generally, the wider the cross,
greater is the degree of sterility encountered.
 Waugh (1900) reported that a hybrid between ‘Troth Early’ peach
and ‘Wild Goose’ plum, which has been named as ‘Mule’ bears
flowers abundantly, but the flowers neither have petals nor pistils.
 The seedlessness of many commercial cultivars of banana and
pineapple is attributed to the hybrid nature of their ancestors i.e. due
to chromosome number.
 A number of hybrids between Vitis rotundifolia and Euvitis group
are almost sterile due to hybrid condition
33Sharma, R. R. (2006). Fruit Production.

34. iii. Inter-fruitfulness and inter-fertility: The ability of two plants or
two varieties to set fruits and develop seeds with each other’s pollen is
called as inter-fruitfulness or inter-fertility.
Example:
 Smyrna fig, Datepalm, some varieties of Grapes.
 Gardner (1913) reported in sweet type cherry, he found that leading
varieties of sweet cherries in many locations are inter-sterile or
inter-unfruitful. Similar type of inter sterility has been also reported
in other fruit crops like almond, plum, pear and some varieties of
filberts.
34Sharma, R. R. (2006). Fruit Production.

35.  iv. Reciprocal crossings
 In certain fruit species, it has been observed that, if a certain crossing proved
sterile, its reciprocal crosses were also sterile and if one variety proved to be
incompatible with the other, those two were likewise incompatible with each
other.
 However, in other, a certain set of crossing has been fruitful, but the reciprocal
crossing being sterile.
Example:
 Tragedy plum (European type) good pollinizer for several varieties of Japanese
type, but fail to set fruits when Japanese varieties is used for the Tragedy plum.
 Vitis Vinifera, V. labrusca and V. cordifolia species of grape set fruits freely
either with V. rotundifolia and V. munsoniana, but when V. rotundifolia and V.
munsoniana are used as pollen parents either for V. Vinifera, V. labrusca and V.
cordifolia, they never set fruits freely. 35
Sharma, R. R. (2006). Fruit Production.

36. (C) Physiological influences
i. Slow growth of the pollen tube (Clementine mandarin)
ii. Poor pollen germination
iii. Premature or delayed pollination (Kagzi Kalan)
iv. Nutritive condition of plant:
 Poor nutritive condition of the plant not only affects vegetative growth,
but also results in the production of defective pistils and poor pollen
production.
 One of the factors associated with alternate bearing in many fruit plants
has been the exhaustion of food reserves by heavy crop load in ‘on’ year,
leaving very little or no food reserves for flowering and fruiting in the
next year. 36Sharma, R. R. (2006). Fruit Production.

37. Remedial measures
Use of suitable rootstocks
Control of frost damage
Proper nutrition
Eg. Nitrogen application after terminal bud formation led to the development of
flower with enhanced embryo sac longevity (Jackson, 2003).
Control of pollination
Proper used of pollinzers
Application of plant growth regulators
Eg. Litchi application of TIBA and KNO3, Increase pollen fertility
(Sanyal et al., 1996)
Balancing vegetative and reproductive growth with proper pruning and thinning
37Wani, et al., 2010

38. 38

39. 39
Aim: To identify the suitable
rootstocks for Thompson
seedless .
S. Afr. J. Enol. Vitic.,. 31 (01), pp. 01- 08
Influence of Rootstocks on Growth Yield and Fruit
Composition of Thompson Seedless Grapes Grown in the
Pune Region of India
J. Satisha*, R.G. Somkuwar, J. Sharma, A.K. Upadhyay and P.G. Adsule
National Research Centre for Grapes, P.B. No. 3., Manjri Farm, Solapur Road,
Pune – 412 307, Maharashtra, India
Accepted January, 2010

40. Rootstocks Yield per vine (kg) Number of bunches per vine
2004 2005 2006 2007 Mean 2004 2005 2006 2007 Mean
Dog Ridge 4.5 6.3 6.4 8.7 7.2 36 37 38 38 35
110 R 4.6 6.4 6.3 13.5 9.0 38 38 37 59 45
1103 P 3.0 4.2 4.5 10.1 6.3 29 29 24 45 34
99 R 3.2 4.5 4.2 11.1 7.1 24 24 29 60 38
St. George 4.1 4.1 4.1 6.9 5.2 23 23 23 36 28
Own rooted 3.4 3.8 3.8 11.7 6.4 22 22 22 60 40
SEm ± 0.157 0.407 0.407 0.567 0.671 2.001 1.967 1.964 2.370 3.212
Level of sig. ** ** ** ** * ** ** ** ** NS
Table 1 : Influence of rootstock on yield components of Thompson Seedless
grape
* : Significant at P< 0.05
** : Significant at P< 0.01
Satisha et al. (2010)NRCG, Pune
40

41. 41
Aim: To study the influence of pre-harvest foliar application of
Calcium, Boron and sorbitol along with a control on pollination,
fruit set, fruit drop, fruit growth parameters and yield of mango cv.
Alphonso.
The Asian Journal of Horticulture, Volume 8 (2 ) December, 2013 | 635-640
Influence of pre-harvest foliar application of micronutrients
and sorbitol on pollination, fruit set, fruit drop and yield in
mango (Mangifera indica L.) cv. ALPHONSO
C. SANKAR, D. SARALA DEVI1 AND S. PARTHIBAN2
Department of Fruits Crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University,
COIMBATORE (T.N.) INDIA
Accepted 13th October, 2013

42.  The treatment were:
T1- Calcium nitrate - 0.06% (active ingredient 0.150 %),
T2- Boric acid 0.02% (active ingredient 0.114%),
T3- Sorbitol -2% (fine sorbitol),
T4- Calcium nitrate 0.06% + Boric acid 0.02%,
T5- Calcium nitrate 0.06% + Sorbitol -2%,
T6- Boric acid 0.02% + Sorbitol -2% and
T7- Control (water spray).
42

43. 43
Table 2: Effect of calcium, boron and sorbitol on pollen size, pollen viability,
pollen germination and pollen tube growth of mango cv. Alphonso
under in-vitro condition

44. 44
Aim: To evaluate the influence of foliar feeding
of micronutrients on plant growth, yield
and quality of papaya fruits.
The Asian Journal of Horticulture, Volume 5 (2 ) December, 2010,| 326-329
Influence of micronutrients on plant growth, yield and
quality of papaya fruit (Carica papaya L.) cv. WASHINGTON
CHANDRA SHEKHAR, A.L. YADAV, H.K. SINGH AND M.K. SINGH
Division of Horticulture, Narendra Deva University of Agriculture and Technology, Kumarganj,
FAIZABAD (U.P.) INDIA
Accepted: September, 2010

45. Treatments No.
Fruits/plt
Average fruit
weight (kg)
Fruit yield
(kg/plt)
T1 - Control 24.33 0.750 18.5
T2 - Copper sulphate 0.25% 25.00 0.925 24.57
T3 - Manganese sulphate 0.25% 25.00 0.758 18.86
T4 - Borax 0.1% 24.33 0.883 21.55
T5 - Copper sulphate 0.25% + Manganese
sulphate 0.25%
28.33 1.100 31.09
T6 - Copper sulphate 0.25% + Borax 0.1% 29.00 1.250 32.78
T7 - Manganese sulphate 0.25% + Borax 0.1% 26.00 1.025 27.77
T8 - Copper sulphate 0.25% + Manganese
sulphate 0.25% + Borax 0.1%
30.67 1.300 40.4
SEm ± 1.3 0.05 2.04
C.D (P= 0.05) 3.95 0.14 6.17
Table 3 : Yield attributing characters of papaya (Carica papaya L.) as
influenced by foliar spray of micronutrients
Shekhar et al. (2010)NDAU, Faizabad
 Applied time 60 and 90 days after
planting.

46. 46
Aim: To study the effect of PGR on
growth and yield of sapota cv.
Cricket Ball.
Indian J. Agric. Res., 42 (3) : 207 -211, 2008
Studies on the effect of plant growth regulators on growth
and yield of sapota cv. Cricket Ball
Shailendra Agrawal* and S.N. Dikshit
Department of Horticulture, Indira Gandhi Agricultural University, Raipur,
Chhattisgarh 492 006

47. Treatments Number of fruits per panicle Fruit yield (kg/tree)
FBD 2002-03 2003-04 pooled 2002-03 2003-04 pooled
CCC – 0 ppm 99.0 100.3 99.7 7.3 7.9 7.6
CCC – 200 ppm 149.0 152.4 150.7 12.1 13.1 12.6
CCC – 400 ppm 162.6 165.5 164.0 13.5 14.6 14.0
SE(m)± 1.0 0.9 0.8 0.06 0.07 0.05
CD(5%) 2.8 2.6 2.4 0.19 0.21 0.16
FLOWERING
GA/NAA – 0 ppm 99.0 101.0 100.0 7.3 7.9 7.6
GA – 50 ppm 149.6 152.3 150.9 12.2 13.2 12.7
NAA – 100 ppm 162.0 164.9 163.5 13.5 14.6 14.1
SE(m)± 1.0 0.9 0.8 0.06 0.07 0.05
CD(5%) 2.8 2.6 2.41 0.19 0.21 0.16
FRUIT DEVELOPMENT
GA – 50 ppm (P) 150.6 153.0 151.8 12.3 13.2 12.8
GA – 50 ppm (L) 119.2 120.9 120.0 9.2 9.9 9.5
NAA – 100 ppm (P) 154.8 157.6 156.2 12.7 13.7 13.2
NAA – 100 ppm (L) 122.9 126.2 124.5 9.5 10.4 10.0
SEm ± 1.1 1.0 0.9 0.07 0.08 0.06
CD(5%) 3.2 3.0 2.7 0.21 0.24 0.19
Table 4 : Effect of plant growth regulators (ppm) at different stages on yield attributes of sapota cv. Cricket Ball
Agrawal & Dikshit (2008)IGAU, Raipur 47

48. 48
Aim: To know its causes and adopting effective control measures for
obtaining economic orchards.
African Journal of Agricultural Research Vol. 5(25), pp. 3581-3589, December 2010
Unfruitfulness in fruit crops: Causes and remedies
Imtiyaz Ahmad Wani, M. Y. Bhat, Abid Ali Lone and Mohd. Younis Mir
Department of Pomology, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir,
Shalimar,
Srinagar 191121, India.
Accepted 28 December, 2010

49. 49
Table 5 : Percentage of fruit set in loquat varieties, ‘improved golden
yellow’ and ‘pale yellow’, by using different pollinizers.

50. 50
Aim: To know the information regarding the time and intensity of
pruning and sustainable production of mango cv. Amrapalli.
Annals of Horticulture, 2 (1) : 124-125 (2009)
Effect of pruning on panicle production and malformation
In mango cv. Amrapali under high density orcharding
Bhanu Pratap, S.T. Singh, H.K. Singh1 and Shashi Bala1
Division of FH. T., I.A.R.I., New Delhi

51. Treatment Total no. of
panicles per
plant
No. of normal
panicle/ plant
No. of
malformed/
panicle plant
Malformed
panicle/ plant (%)
1999-
2000
2000-
2001
1999-
2000
2000-
2001
1999-
2000
2000-
2001
1999-
2000
2000-
2001
Control 38.40 35.90 32.90 30.60 5.60 5.20 17.94
(25.03)
14.52
(22.38)
Light 42.40 40.60 39.60 37.60 2.80 3.00 6.60
(14.89)
7.38
(15.71)
Moderate 55.20 47.40 52.60 44.80 2.60 2.40 4.71
(12.50)
5.06
(13.15)
Severe 35.70 36.60 32.50 33.40 3.20 3.40 8.98
(17.36)
9.28
(17.69)
Mean 42.92 40.05 39.37 35.50 3.55 3.50 9.55
(17.98)
9.06
(17.46)
Table 6 : Effect of pruning on panicle production (number) and
malformation (%) in mango cv. Amrapali
Pratap et al. (2009)IARI, New Delhi 51

52. 52
Aim: To assess the effect of Paclobutrazol and Ethephon on fruit
retention per cent of guava cv. Allahabad safeda .
J. Hortl. Sci. Vol. 5 (2): 128-133, 2010
Role of Paclobutrazol and Ethephon in reproductive growth
of ‘Allahabad Safeda’ guava (Psidium guajava L.) plants at
different spacing
J.S. Brarand J.S. Bal
Regional Research Station, Punjab Agricultural University Bathinda – 151 001 (Punjab), India

53. Treatments
Spacing
(m)
Spacing (m)
Rainy season Winter season
6X2 6X3 6X4 6X5 Mean 6X2 6X3 6X4 6X5 Mean
Pachlobutrazol
500 ppm
39.12 38.63 40.37 40.37 39.62 54.23 51.96 52.92 55.80 53.73
Pachlobutrazol
1000 ppm
38.11 39.52 41.40 41.00 40.01 51.96 51.80 54.70 57.62 54.02
Ethephon 500
ppm
46.38 47.40 49.23 47.63 47.66 59.86 62.05 63.01 65.30 62.56
Ethephon 1000
ppm
43.21 43.59 45.97 44.65 44.36 58.00 59.25 58.34 63.13 59.68
Control 41.37 41.25 40.54 41.73 41.22 51.81 54.11 55.33 53.71 53.74
Mean 41.64 42.08 43.50 43.08 42.57 55.17 55.86 56.86 59.11 56.74
Table 7 : Effect of Paclobutrazol and Ethephon on per cent fruit retention of
Allahabad Safeda guava planted at different spacing
Brar and Bal (2010)PAU, Ludhiana
CD at 5% - Pruning level (A) : 3.10 Pruning level (A) : 1.34
Spacing (B) : NS Spacing (B) : 1.50
Interaction : A x B : NS Interaction : A x B : 1.90
53

54. Conclusion
From the foregoing discussion and research results of various scientists, it can
be concluded that fruiting of a tree is influenced by many factors. So, it is necessary
to adopt corrective measures which should begin from planning level and extends to
an established orchard.
Compatible, disease resistant, high yielding rootstocks should be selected.
To maintain healthy condition of the tree as well as to get profitable yield it should
be supplemented with ample quantity of nutrition.
Different varieties should be cultivated and the introduction of effective pollinizer
varieties as well as pollinators were essential.
Thinning and crop regulation should be practiced to maintain balance between
vegetative and reproductive phase.
So proper planning in initial establishment of orchard must be done for
effective encounter of arising problems that may leads to unfruitfulness.
54

55. 55