WHAT ARE GROWTH REGULATORS? A growth regulator is An organic compound, Can be natural or synthetic, It modifies or controls one or more specific physiological processes within a plant but the sites of action and production are different. If the compound is produced within the plant, it is called a plant hormone. Both internal plant hormones and lab-created hormones are called plant growth regulators The ‘Plant Hormones’ are natural and ‘Plant Growth Regulators’ are synthetic in nature.

1. Use of growth regulators in
seed production of Vegetable
Submitted to :
Dr Rajinder Singh
Senior Scientist ( Vegetable Seeds)
Department of Vegetable Science
Punjab Agricultural University
Ludhiana
Submitted by :
Simranpreet kaur
L_2018_A_165_M
MSc Student

2. WHAT ARE GROWTH REGULATORS?
 A growth regulator is
◦ An organic compound,
◦ Can be natural or synthetic,
◦ It modifies or controls one or more specific physiological
processes within a plant but the sites of action and
production are different.
 If the compound is produced within the plant, it is
called a plant hormone.
 Both internal plant hormones and lab-created
hormones are called plant growth regulators
 The ‘Plant Hormones’ are natural and ‘Plant
Growth Regulators’ are synthetic in nature.

3. History of Growth Regulators
 “Hormone” is a Greek word derived from “hormao”
which means to stimulate. (Beylis & Starling, 1902)
 Thimann in 1948 was coined the term ‘Phytohormone’ as
an organic substance that produces naturally in plants.
 Growth hormone defined as the substances which are
synthesized in particular cells and are transferred to other
cells, wherein extremely small quantities influence the
developmental process. (Phillip 1971)
 Auxin was the first hormone to be discovered in plant and
at one time considered to be only naturally occurring plant
growth hormone. (Charles Darwin 1880)
 Three types of plant hormones Auxins, Gibberellins and
Cytokinins, these were discovered in the early decades of
the twentieth century, in 1930s and in 1960s respectively.
(Thomas, 1956)

4. CLASSIFICATION OF PGR’S
Sr.No GROWTH REGULATOR EXAMPLE
1. Auxins IAA, IBA, NAA, 2,4-D
2. Gibberellins Gibberellic acid
3. Cytokinins Kinetin, Zeatin
4. Ethylene Ethylene
5. Dormins Abscisic Acid
6. Flowering hormones Florigen, Anthesin, Vernalin
7. Synthetic growth retardants CCC, Phosphon-D, Maleic
hydrazide (MH) etc.

5.  AUXIN: Charles Darwing in 1880 was the first who
proposed the existence of auxin. It was the first class
growth regulator that was discovered.
 Auxins are those compounds that give a positive effect on
the formation of bud, enlargement of cell and root initiation
and they are also helpful for the formation of other growth
hormones.
 IAA is a naturally occurring hormone while NAA, IBA,
2-4D etc. are synthetic in nature.
 GIBBERELLIN: Kurosava in 1926 was a Japanese
scientist who discovered gibberellins. It is the second
growth regulator.
 It was extracted from the fungus ‘Gibberella fujikuroi’
which is the causal organism of “foolish seedling of rice”.
 Gibberellins are designated as GA1, GA2 and so on and the
most common gibberellic acid is GA3.
 GA stimulates germination of seed and maturation of flower
and fruit.

6.  CYTOKININS: Skoog in 1995 experimented that when pith tissues of
‘Nicotiana tabaccum’ were separated from the vascular tissues they grew
without division of cell.
 There are so many different synthetic cytokinins such as 6-benzylamino
purine (BAP), kinetin, 6-(benzyl-amino)-9-(2-tetrahydropyranyl)-9H-
purine (PBA), 1,3-diphenylurea, thidiazuron (TDZ), etc.
 ETHYLENE: Neljubow (1901) a Russian plant physiologist was the first
to show the importance of ethylene present in the illuminating gas as a
growth regulator of plants.
 This hormone is synthesized from methionine and it is synthesized in all
organs of the plant.
 ABSCISIC ACID: It was for the first time identified by Wareing (1965)
in Acer pseudoplatanus leaves and buds who gave the name dormin to it.
 It is also called plant stress hormone. It act as inhibitory chemical
compound that gives direct effect on growth of bud, seed and dormancy of
bud.
 It has inhibitory effect and occurs naturally in plants. It inhibit mRNA and
synthesis of protein.

7. Other Plant Growth Regulators
 BRASSINOSTEROIDS : Brassinosteroids have been
recognized as the sixth class of plant hormones.
 Brassinolide was the first identified brassinosteroid and
was isolated from extracts of rapeseed (Brassica napus)
pollen in 1979.
 It stimulates cell elongation and division, resistance to
stresses and inhibits root growth and leaf abscission.
 MORPHACTINS: they are the group of substances
which act on morphogenesis and modulate the
expression of plants.
 Seed germination- inhibition, Growth of seedlings-
inhibit and Stem elongation- dwarfing effect.

8. EFFECT OF PLANT GROWTH REGULATORS ON SEED YIELD AND
ITS PARAMETERS IN TOMATO (Solanum lycopersicon L.)
 A field experiment was carried out during Kharif season of the
year 2015 of tomato variety, “Gujarat Tomato 3” at J.A.U.
Junagadh.
 Total 16 treatment combinations comprising four levels of
plant growth regulators viz., G0 = Control, G1 = GA3-50
ppm G2 =NAA-50 ppm and G3= Cycocel-500 ppm were
included in the study.
 The observation on different growth parameters was recorded
including Seed weight per fruit (g) and Seed yield per
plant in field level were recorded in the laboratory of Seed
Science and Technology.
 Statistical analysis of the data was worked out using
Randomized Block Design and Completely Randomized
Block Design for each character and treatment were compared
by a critical difference at 5% and 1% levels of significance.

9. EFFECT OF PLANT GROWTH REGULATORS ON NUMBER OF
SEEDS PER FRUIT, SEED WEIGHT PER FRUIT (g) AND SEED
YIELD PER PLANT (g) IN TOMATO.
Treatment Number of
seeds per
fruit
Seed weight
per fruit (g)
Seed yield per
plant (g)
G0 = Control 117.51 0.34 15.40
G1 = 50 ppmGA3 118.14 0.16 18.94
G2 = 50 ppm
NAA
126.43 0.39 16.64
G3 = 500 ppm
Cycocel
118.47 0.25 16.68
Mean 120.14 0.28 16.91
S.Em. ± 1.97 0.01 0.31
C.D. at 5 % 5.68 0.03 0.89
ChauhanShitalA.,etal.,
(2017)

10. Results and Discussions
 Number of seeds per fruit: The effect of plant growth regulators was
significant on number of seeds per fruit. The application of NAA 50 ppm
(G2) retained the first position by producing significantly the highest
number of seed per fruit (126.43) and significantly the lowest number of
seed per fruit was recorded in control (Go) (117.51) in tomato.
 Seed weight per fruit (g): The effect of plant growth regulators was found
significant for seed weight per fruit. Among the plant growth regulators
treatments, NAA 50 ppm (G2) registered the first position by producing
significantly the highest seed weight per fruit (0.39g). The minimum
seed weight per fruit was observed in GA3 50 ppm (G1) (0.16g) in
tomato.
 Seed yield per plant (g): The effect of plant growth regulators was
significant for seed yield per plant. Application of GA3 @ 50 ppm (G1)
produced significantly the highest seed yield per plant (18.94 g).
Significantly the minimum seed yield per plant was recorded in control
(Go) (15.40g) in tomato.

11. EFFECT OF PLANT GROWTH REGULATORS
ON SEED YIELD OF CARROT
 The experiment was conducted at the Banga Bandhu Sheikh Mujibur Rahman
Agricultural University, Gazipur, Bangladesh during the period from October 2006
to May 2007.
 The carrot genotype Bejo Sheetal was used as planting material. The experiment
was laid out in a randomized complete block design with three replications.
 The treatments included spray of (i) NAA 100 ppm, (ii) Ethrel 100 ppm,(iii) GA3
50 ppm, (iv) GA3 100 ppm, (v) GA3 150 ppm, (vi) GA3 200 ppm, and (vii)
Control.
 Ten plants were selected randomly from each plot and data on different seed yield
parameters were collected on individual plant basis from the selected plants. Seed
carrot was harvested when seeds in umbel were matured and turn to light yellow and
straw colour.
 The data on various parameters including the number of seeds per umbel, 1000
seed weight, seed yield, seed germination on blotting paper method etc. were
recorded and statistically analyzed.
 Analysis of variance was done according to Gomez and Gomez (1984). The means
were compared using Duncan’s Multiple Range Test (DMRT).

12. Effect of plant growth regulators on Number of seeds
per umbel,1000 seed weight, seed yield per plant, and
seed yield per hectare in carrot.
Treatments Number of
seeds per
umbel
1000 seed
weight (g)
Seed yield
per plant (g)
Seed yield
(kg ha-1)
NAA 100 ppm 3828.12 1.18 3.13 139.42
Ethrel 100 ppm 4238.21 1.12 3.44 152.73
GA3 50 ppm 5229.25 1.25 4.37 194.45
GA3 100 ppm 5663.31 1.50 4.90 214.61
GA3 150 ppm 6038.50 1.56 5.13 228.13
GA3200 ppm 6569.62 1.68 5.78 256.90
Control 3237.16 0.91 2.20 102.42
CV(%) 8.31 9.99 6.10 12.32
MohantaH.C.etal(2015)

13. Results and Discussion
 Number of seeds per umbel: There were significant
variations among the treatments. The highest number of
seeds per umbel (6569.62) was obtained in plants treated with
GA3 200 ppm which was statistically different from rest of
the treatments. The lowest number of seeds per umbel
(3237.16) was found in plants of untreated control.
 1000 seed weight: There had significant variation among the
treatments. The highest 1000 seed weight (1.68 g) was
obtained by GA3 200 ppm which was statistically different
from other treatments. The lowest seed weight (0.91 g) was
obtained from control.
 Ghonameet al. (2004) found similar results by the application
of GA3 at 200 ppm and recorded the highest 1000seed weight
of carrot seeds.

14. Cont….
 Seed yield: There was significant variation in seed
yield per plant. The maximum seed yield per plant
(5.78 g) was obtained from the plants treated with GA3
200 ppm which was statistically different from GA3
150 ppm(5.13 g), GA3 at 50 ppm (4.37 g) and NAA
100 ppm (3.13 g). The minimum seed yield per plant
(2.20 g) was obtained in plants of untreated control.
 From this result, it might be concluded that the
application of GA3 200 ppm ensured the highest seed
yield than the other treatments of plant growth
regulators.
 A similar observation was reported by Jacobsohn and
Globerson (1980) who found the highest seed yield of
carrot per plant (5.7 g) by application of 200 ppm GA3.

15. EFFECT OF GIBBERELLIC ACID ON SEED
PRODUCTION OF RADISH CV. PUSA HIMANI
 The present investigation was carried out at Regional Research Station,
Bajaura in Kullu valley during the year 1994-95 and 1995-96.
 The treatments included spray of three GA3 concentrations i.e. 50, 100 and
150 ppm (symbolized T1, T2 and T3) at three different stages i.e. 30 days
after transplanting of stecklings (30 DAT, at flowering and both at 30 DAT
and at flowering stage with one untreated control (symbolized S1 S2 and S3).
 The ten treatment combinations were tested in three replications in
randomized block design.
 The stecklings of radish of cv. Pusa Himani was transplanted in plots.
 The observations were recorded on direct component of seed yield viz.
number of branches per plant, number of flowers per branch, number of
siliqua per branch, number of seeds per siliqua, seed yield (q/ha),1000 seed
weight and seed germination, because the growth regulator was sprayed
when the vegetative phase was complete.

16. Effect of gibberellic acid on seed
production components of radish
Treatment No. of flower
per branch
No. of siliqua
per branch
No. of seed per
siliqua
Seed yield
q/ ha
Control 32.9 23.1 5.9 5.5
S1T1 42.6 26.9 6.3 6.7
S1T2 44.2 28.1 6.5 6.2
S1T3 42.0 31.4 6.8 6.5
S2T1 41.2 28.8 6.5 6.1
S2T2 41.6 30.7 6.9 6.8
S2T3 43.6 32.0 6.9 7.1
S3T1 44.4 32.3 7.0 6.9
S3T2 46.3 32.9 7.0 8.0
S3T3 47.8 34.7 7.3 8.7
CD at 5% 5.0 2.9 0.8 0.6
Malhotra S.K.et al (2001)

17. Results and Discussion
 The GA3 spray at different concentrations and stages have shown significant
increase in all of the characters under study except 1000 seed weight and seed
germination.
 Among the nine treatment combinations the treatment S3 T3.i.e: spray of
GA3,150 ppm twice at 30 DAT and at flowering exhibited significantly the highest
number of flowers per branch (47.8), number of siliqua per branch (34.7) and
number of seeds per siliqua (8.4) when compared with control.
 The second best treatment was S3 T2, wherein 100ppm GA3 was sprayed twice at
30 DAT and at flowering stage produced high number of flowers per branch
(46.3), number of siliqua per branch (32.9) and number of seeds per
siliqua(7.0).
 The S3.T3 and S3 T2 treatments showing an encouraging effect on the above
direct components of seed yield contributed, significantly towards high seed yield
of 8.7 and 8.0 q/ha, respectively.
 The higher seed yield might have happened due to metabolic changes brought out
by GA3 application at curd mature stage and flowering.
 The earlier worker Sharma (1995) reported increased seed yield of radish when
GA 100 ppm was sprayed once at bolting stage, whereas in the present studies the
spray of GA3-150 ppm, twice, at 30 DAT and flowering proved to be the best for
getting the higher seed yield of radish var. Pusa Himani under Kullu conditions.

18. Effect of Soaked Allium Cepa L. Bulbs in Growth
Regulators on their Growth and Seeds Production
 Onion bulbs of variety Giza 20 used in this experiment were obtained
from Onion Research Section, Agricultural Research Center, Giza.
 Two experiments were established to evaluate the treatments with GA3
and Cycocel on onion vegetative growth, earliness of flowering, seed
quantity and seed quality in seasons of 2013/2014 and 2014/2015.
 In the first experiment: the bulbs were treated with gibberellic acid
(GA3) in contrast to tap water treatment as a control. GA3 used at the
concentration of 250, 500, 1000 ppm and bulbs were soaked in these
concentrations in polyethene bags for 36 hours then cultivated directly in
experimental filed plots.
 In the second experiment: the bulbs were treated with the growth
regulator Cycocel in addition to tap water as a control. Cycocel used at the
concentration of 50, 100, 150 ppm and the bulbs were soaked in these
concentrations in polyethene bags.
 All experiments were statistically analyzed in a complete randomized
design with three replicates. The analysis of variance procedure and
means were compared by L.S.D. method at 5% level of significant.

19. EFFECT OF SOAKED BULBS IN GA3
CONCENTRATIONS ON SEED OF ONION C.V GIZA 20
DURING SEASONS OF 2013/2014 AND 2014/2015.
Characters Seed Yield/Plot (g) Average Weight of
1000 Seeds (g)
Seed Germination
Percentage
Treatments 2013/
2014
2014/
2015
2013/
2014
2014/
2015
2013/
2014
2014/
2015
Control 583.15 550.5 4.41 4.19 86.32 84.29
250 ppm 621.83 556.21 4.9 4.44 90.11 87.13
500 ppm 614.76 571.74 4.98 4.64 90.49 88.2
1000 ppm 643.1 595.16 5.31 4.82 92.58 89.47
L.S.D at
5%
17.08 17.19 0.21 0.28 2.59 3.51
Helaly A.A. et al (2016)

20. EFFECT OF SOAKED BULBS IN CCC
CONCENTRATIONS ON SEED YIELD OF ONION C.V
GIZA 20 DURING SEASONS OF 2013/2014 AND 2014/2015.
Characters Seed Yield/Plot
(g)
Average Weight of
1000 Seeds (g)
Seed Germination
Percentage
Treatments 2013/
2014
2014/
2015
2013/
2014
2014/
2015
2013/
2014
2014/
2015
Control 555.67 533.3 4.7 4.04 85.42 87.08
50 ppm 586.67 573.33 4.45 4.61 84.04 89.61
100 ppm 542.67 534.33 4.88 4.98 88.08 90.43
150 ppm 566.33 533.3 4.53 4.62 85.95 86.43
L.S.D at 5% 14.1 33.92 N.S 0.34 1.34 N.S

21. Results and Discussions
 Effect of soaked bulbs in GA3 on onion seed production: The result
showed that the highest values were obtained with the treatment of GA3 at
1000 ppm level and significantly increased during the two experimental
seasons.
 Rabinowitch et al. (1991) found that the application of GA3 at 500 to
1000 ppm enhanced flowering of normal genotypes and improved seed
yields in onion plants.
 Lovato et al. (2000) reported that foliage spraying with 20 ppm GA3
before bolting induced a slight earliness in seed maturity and increased
seed yield.
 Here, cytokinins are thought to be essential for cell division whereas IAA
and gibberellins functions are important to cell enlargement in the growing
pod.
 These results may be due to the effect of GA3 on cell elongation, cell
division which turn resulted in increasing the growth parameter of onion
umbel and seed production.

22. Results and Discussions
 Effect of soaked bulbs in GA3 on onion seed production:
The obtained results showed that a significant increment in
onion total seed yield with cycocel treatment at 50 ppm,
average weight of 1000 seeds and seed germination
percentage at 100 ppm during both experimental seasons.
 The superiority of CCC might be own to its effect on the seed
yield, seed weight and seed germination percentage or its
effect on the appearance of flowering scapes and consequently
the period of flowering.
 The study concluded that the favourable growth regulators
level to produce high seed yield with best quality was
obtained from GA3 at 1000 ppm and CCC at 50 ppm. GA3
and CCC application significantly varied the scape length,
umbel diameter, seed yield per plant, weight of thousand seeds
and germination % of onion.

23. EFFECT OF PLANT GROWTH REGULATORS ON
GROWTH CURD YIELD AND SEED PRODUCTION OF
CAULIFLOWER
 The research work was carried out at the Horticulture Research Center,
Bangladesh Agricultural Research Institute, Joydebpur, Gazipur during the
period from October 2004 to March 2005.
 The cauliflower genotype BARI Fulkapi-1 (Brassica oleracea var. botrytis
L.) used in this research.
 Two experiments were conducted and both were laid out in a randomized
complete block design (RCBD) with three replications.
 Evaluate the treatments with Gibberellic acid in different concentrations
viz. 50, 75, 100, 125, 150, 300, 350 and 400 ppm and Ethrel in different
concentrations viz. 50, 75, 100 ppm.
 Data were statistically analyzed following F-test and (DMRT) Duncan’s
New Multiple Range Test (DMRT) at 5% level of significance (Gomez
and Gomez, 1984).

24. EFFECT OF (GA3 & ETHREL) ON SEED YIELD AND
YIELD OF CAULIFOWER
Treatment Seed yield per
plant (g)
1000 seed weight
(g)
Seed
Germination %
Go = Control 26.50 2.95 89.25
G1 = GA3 300 ppm 36.24 4.72 91.00
G2 = GA3 350 ppm 38.53 4.97 97.50
G3 = GA3 400 ppm 31.12 4.00 94.35
E1 = Ethrel 50 ppm 28.42 2.86 92.17
E2 = Ethrel 75 ppm 30.47 3.45 93.33
E3 = Ethrel 100 ppm 32.98 3.90 94.50
CV (%) 6.47 7.61
KHAN ZIA, & MALIMUDUL ISLAM
(2008)

25. EFFECT OF GA3 & ETHREL ON SEED
YIELD OF CAULIFLOWER
•Marked variation was found in seed
yield (t/ha) due to varied levels of
plant growth regulators i.e. GA3 and
Ethrel (Figure 2).
•Seed yield was found to be
maximum (1.57 t/ha) in plants treated
with GA2 350 ppm and the lowest
(0.87 t/ha) in control which was
identical to Ethrel 50 ppm.
•It might be due to higher number of
pods and seed yield per plant.
•Mongal el a/., (1980) reported that
GA3 at 50-250 ppm improved seed
yield.

26. Results and Discussions
 Seed yield per plant: Remarkable variation was observed in seed yield per
plant due to varied levels of PGR i.e. GA.i and Ethrel. GA3 350 ppm
treated plants produced the highest (38.53 g) seeds per plant followed by
GA3 300 ppm and the lowest (26.5 g) in control. It might be due to higher
to pods per plant which consequently conferred higher seed weight/plant.
 1000 seed weight (g): Analysis of variance revealed a significant variation
as regards to the 1000 seed weight. The maximum 1000 seed weight (4.97
g) was obtained from GA3 350 ppm which was also identical to GA3 300
ppm and the minimum 1000 seed weight (2.86 g) was recorded from
Ethrel 50 ppm which was identical to control treatment (2.95 g).
 Percentage of seed germination (%): Analysis of variance revealed
significant variation regards to percentage of germination of the seeds of
cauliflower due to the different concentrations of Gibberellic acid and
Ethrel. It was also observed that the quality of seed was the highest in
GA3 350 ppm while it was the lowest in control treatments. The
germination percentage of seeds in cauliflower was about more than 90%.

27. EFFECT OF PLANT GROWTH REGULATORS ON GROWTH, YIELD
AND QUALITY OF OKRA (ABELMOSCHUS ESCULENTUS)
 An experiment was carried out at Instructional Farm, Uttar Banga Krishi
Viswavidyalaya, Pundibari, Cooch Behar during rainy season of 2015-2016.
 Seeds of okra cv. ‘Arka Abhay’ were sown at the spacing of 60 cm x 45 cm
with a net plot size of 4.5 m2.
 The experiment was laid out in R.B.D. with three replications having ten
treatments including controls (T1- without spray and T2-with water spray).
 The treatments comprised of the combination of four concentrations of each
plant growth regulators. The plant growth regulators used were GA3 @ T3-
25, T4-50, T5-100 and T6-150 (ppm) and IBA @ T7-25, T8-50, T9-100
and T10-150 (ppm).
 The observations were recorded on five randomly selected plants from
each treatment. The data on parameters including yield (g)/plant, number
of seeds/fruit, 100 seed weight (g), were recorded.
 Analysis of variance was performed following the statistical method and
significance of differences among treatment means were calculated at 5%
level of significance.

28. EFFECT OF GA3 & IBA ON GROWTH AND YIELD
ATTRIBUTES OF OKRA
Treatment Yield /plant
(g)
Number of
seeds / fruit
100 seed
weight (g)
T1 control 213.90 45.80 3.85
T2 control (water
spray)
222.94 46.10 3.95
T3 GA3-25 ppm 284.66 52.40 4.68
T4 GA3 -50 ppm 294.93 52.55 4.75
T5 GA3-100 ppm 314.17 52.85 4.95
T6 GA3 -150 ppm 324.87 53.10 5.10
T7 IBA – 25 ppm 264.87 48.75 4.25
T8 IBA – 50 ppm 270.27 48.95 4.38
T9 IBA – 100 ppm 275.37 49.35 4.52
T10 IBA -150 ppm 279.18 49.75 4.58
SEM (±) 2.824 2.046 0.095
CD (p < 0.05) 4.993 4.250 0.915
MaityU.etal(2016)

29. Results and Discussions
 In this investigation it was found that growth regulators application had
increased the yield (g) / plant, the number of seeds per fruits and 1000 seed
weight (g) in okra as compared to control.
 Comparisons between two growth regulators revealed that GA3 treatments
had a more positive influence on growth and yield parameters than IBA.
 It was obvious from the results that T6 (GA3 @150 ppm) recorded the
best performance towards growth and yield attributes among all other
treatments.
 The results of better performance of okra under growth regulator
treatments might be due to the consequence of growth regulators on cell
elongation, stimulated RNA and protein synthesis, and better diversion of
food material towards flowering and fruiting thereby leading to enhanced
growth and development.
 It may be concluded that plant growth regulators i.e. gibberellic acid and
IBA have a significant effect in increasing growth & development and
yield of okra with increasing concentration of both. However, GA3 is
found to be a superior growth regulator as compared to respective doses of
IBA.

30. Influence of Growth Regulators on Fruit, Seed Yield and
Quality of Pumpkin cv. Arka Chandan
 The field experiment was conducted at Main Agricultural Research Station,
Saidapur Farm, University of Agricultural Sciences, Dharwad during
Kharif season 2005 and the laboratory studies were made in the
Department of Seed Science and Technology, University of Agricultural
Sciences, Dharwad, Karnataka (India).
 The breeder seeds of pumpkin cv. Arka Chandan was obtained from
Breeder Seed production unit, IIHR, Hessarghata, Bangalore.
 The field experiment consist of three growth regulator sprays viz:
G1:Ethrel 200 ppm,G2: 25 ppm G3:NAA 100ppm and control (water
spray).
 The field experiment was conducted in the split-plot design and replicated
three times. The growth regulator spray was given at 2-4 leaf stage (22-25
days after sowing) and water was sprayed on the vines as control at the
same time.
 The observations on the number of fruits per vine, number of seeds per
fruit, seed yield per fruit, seed yield per vine, seed yield per plot, seed
yield per ha, and seed quality parameters such as 100 seed weight (g)
seed germination and field emergence were recorded.

31. EFFECT GROWTH REGULATORS ON SEED YIELD
AND SEED QUALITY IN PUMPKIN CV.ARKA CHANDAN
Treatment Seed yield /
ha(Kg)
100 Seed weight
(g)
Seed
germination(%)
Go-water spray
G1-Ethereal
200ppm
524.00 7.78 91
G2-Gibberlin 25
ppm
346.00 8.72 92
G3-NAA 100
ppm
471.00 9.42 91
Mean 402.0 8.45 91(72.3)
CD at 5% 42.9 0.35 0.73
Manjunath Prasad CT et al
(2010)

32. Results and Discussions
 In this investigation it was found that growth regulators
application had increased the yield (g) / plant, the number of seeds
per fruits and 1000 seed weight (g) in pumpkin as compared to
control.
 Foliar spray with ethrel (200 ppm) recorded significantly higher
seed yield of 524.0 kg per ha followed by NAA at 100 ppm
(471.0 kg per ha) and lowest yield at control (265.0 kg per ha).
This could be due to more number of fruits (2.87 per vine).
 The auxins are known to cause physiological modifications in
plants mainly on flowering behaviour, sex ratio, increased fruit
set, enlargement and development of fruits, source-sink relation
and growth regulators bring certain changes in metabolism during
fruit and seed development due to which there would be a greater
accumulation of food reserves resulting in higher seed yield.

33. IN CUCURBITS WE REQIURE GROWTH
REGULATOR FOR FOLLOWNING PURPOSE ?
 Sex modification in cucurbits
 Increase male and female flowers for hybrid
seed production.
 Early flowering in bittergourd, muskmelon,
pumpkin etc.
 Maintain the gynoecious line in cucumber,
muskmelon and other cucurbits.
 Maintainence of male sterility

37. USE OF GROWTH REGULATORS IN CUCURBITS FOR
HYBRID SEED PRODUCTION:
 Use of ethephon has been used for producing temporary female lines in
some cucurbits.
 In cucumber, GA3 at 1500-2000 ppm sprays have been made to induce
staminate flowers in gynoecious lines (Peterson and Andher 1960).
 It has been reported that Silver nitrate at 500 mg/L as effective as GA3 in
inducing male flowers on gynoecious lines of cucumber (Beyer, 1976).
 In muskmelon foliar sprays of Silver thiosulphate at 400 mg/l was found
best for induction of male flower on gynoecious lines.
 Ethrel and MH have been used for inducing the pistillate flower in bottle
gourd, pumpkin and squash.
 NAA, etheral, Boron or Molybdenum can suppress the number of male
flowers and increases the number of female flowers, fruit set & ultimate
yield.
 Pundir and Singh (1965) reported a considerable percentage of pollen
sterility when muskmelon plants were sprayed with Mendok @ 0.4 per
cent.

38. Conclusion
 Plant growth regulators are a group of chemicals for controlling and
enhancing the natural plant growth processes to better meet the
requirements of food supply in general.
 Use of plant growth regulator in vegetables has been found beneficial for
improve yield, quality, synchronization in flowering, earliness, cold and
high temperature fruit setting, sex modification, increases post-harvest
life, and develop resistance to biotic and abiotic stresses and also very
effective for induction of male sterility in vegetable crops.
 The use of Plant Growth Regulators may be beneficial for short
imperatives. Plant growth regulators provide an immediate impact on crop
improvement programs and are less time consuming.
 Applications of Plant growth regulators must lead to quantifiable
advantages for the user plant growth regulators must be specific in their
action and toxicologically and environmentally safe.
 There is need for some plant growth regulators which can inhibit
photorespiration in plants. More research is needed to develop simple,
economical and technical viable production systems of Plant growth
regulators.