Commercial Plant growht regulators used in india

Commercial Phyto-hormones, Plant growth
regulators and other Bio-stimulants available in
India & their uses.
Dr. Subhomay Sinha
Asstt Dir. Of Agriculture (Training)
Murshidabad, West Bengal, India

PGRs also called Biostimulats or Bioinhibitors, act inside plant cells to
STIMULATE or INHIBIT specific enzymes or enzymes systems and help to
regulate plant metabolism.
NATURALLY OCCURRING PLANT GROWTH REGULATORS / Phyto-
hormones falls into five classes: Auxin, Gibberellins, Cytokinin, Abscicic
Acid (ABA) & Ethylene.
A PLANT HORMONE / PHYTO-HORMONE is a NATURALLY PRODUCED
CHEMICAL synthesized in one part of the plant and then TRAVELS to
another part where it effects growth & development processes and active in
minute amounts.
PLANT GROWTH REGULATORS (PGR) INCLUDES MAN-MADE SYNTHTETIC
CHEMICALS AS WELL AS NATURALLY OCCURING CHEMICALS APPLIED TO
PLANTS TO PRODUCE A DESIRED EFFECT.
A problem with this definition is that in all cases plant hormones are not
necessarily translocate. A prime example of such a case is the hormone
ETHYLENE which may bring about changes in the same tissue or even the
same cell in which it is synthesized.

Role of Plant Growth Regulators in Crop Production:
A. Plant growth regulators are used to
including horticultural crops.
B. Plant growth regulators can be used as , as a direct
replacement for hand labor in horticultural crop production other
than harvesting.
C. Plant growth regulators can be used for
in a wide range of crops.
D. Application of growth regulator allowed the proper
and use of mechanical harvesting equipment in
orchard / field crop.
E. Plant growth regulators MODIFY chemical composition of plant &
color of fruits.
F. They initiate or terminate DORMANCY of seeds, buds and tubers.
G. PROMOTES ROOTING and thus useful in plant propagation.

Role of Plant Growth Regulators in Crop Production (contd.) :
H. PROMOTES, DELAYS OR PREVENT flowering.
I. They can INDUCE or PREVENT leaf and fruit drop.
J. Plant growth regulators CONTROL FRUIT SET AND FRUIT DEVELOPMENT.
K. influence MINERAL UPTAKE OF PLANT FROM SOIL.
L. They can MODIFY timing of crop development / crop maturity.
M. INCREASE PLANT RESISTANCE to pests, diseases & adverse
environmental factors like Temperature, draught, frost etc.
N. Plant growth regulators helps to PREVENT POST – HARVEST
SPOILAGE.
O. Plant growth regulators used to SUPPRESS the sprouting of potato and
onion in storage.

Auxins
Auxins are a group of phyto-hormones produced in the shoot and root apices
and germinating seeds. They migrate from the apex to the zone of
elongation. Auxin promote the growth along the longitudinal axis of the
plant. At low concentration, auxin stimulate growth while at high
concentration it retard growth and act as herbicides.
Indole – 3 - Acetic Acid (IAA) is the only naturally occurring auxin in plants.
Indole – 3 – butyric acid (IBA) was also found in some extent.
They are characterized by causing CELL ENLARGEMENT and STEM
ELONGATION in plants. They are also associated with APICAL
DOMINANCE. It also initiates ROOT DEVELOPMENT in stem cuttings. Auxin
delays SENESCENCE OF LEAVES and INDUCE FRUIT SETTINGS. At higher
concentration auxin STIMULATES PRODUCTION OF ETHYLENE.
The plant growth regulators or phyto-hormones which have CATALYTICAL
effect, i.e. take a vital role in PROMOTING plant growth are called Growth
Promoter e.g. AUXINS, GIBBERELLINS and CYTOKININS.

Auxin induces the formation &
organization of phloem and xylem.
When the plant is wounded, the auxin
may induce the cell differentiation and
regeneration of the vascular tissues.
Auxin induces both growth of
pre-existing roots and
adventitious root formation,
i.e., branching of the roots.
Auxin INDUCES SHOOT APICAL
DOMINANCE; the axillary buds are
suppressed by auxin, as a high
concentration of auxin directly
stimulates ethylene synthesis in
axillary buds, causing inhibition of
their growth and potentiation of
apical dominance.
Auxin is concentrated in the part of
the plant facing away from the
light, where it promotes cell
elongation,
Auxin is required for fruit growth
and development & delays fruit
senescence. Auxin encourages
parthenocarpy, i.e. seedless fruit
production.
In low concentrations, it can delay the senescence of
flowers. High concentration of Auxin can induce
femaleness of flowers in some species.
Role of Auxin in plant

The auxin produced & supplied
from the apical bud suppresses
growth of lateral buds : APICAL
DOMINANCE
The auxins stimulate adventitious
root development by inducing root
initials that differentiate from cells
of the young secondary phloem,
cambium, and pith tissue.
Application of auxin to flowers
could promote the process of
fruit set.
Secondary root initiation is
normally controlled by auxin
supplied by the Shoot.
Prevents dropping of un-ripe fruits
Helps to modify male – female
flowering ratio in cucurbit
crops
Auxin can induce the
formation of parthenocarpic
fruits (fruit formation without
pollination and fertilization).
Auxin stimulates
production of ethylene
Involved in the initiation of roots in
stem cuttings.

Apical dominance is the
inhibition of the
development of some or all
of the lateral buds by the
terminal (apical) bud of
shoot.
.
In pineapple, auxin initiates
the production of flowering.

Phototrophism effect of Auxin in plant

Apical Dominance effect of Auxin in plant

Although naturally occurring, Indole –
3 - Acetic Acid (IAA) is not
commonly used in propagation because
it breaks down quickly in the plant.
Indole - 3 - butyric acid (IBA) is also
naturally occurring, but at very low
abundance. It is comparatively stable
against Auxin degrading enzyme system.
It works by being converted to IAA by
the plant.
It favours root development
IT IS COMMONLY FOUND IN
COMMERCIAL ROOTING COMPOUNDS.
Different types of Auxin : Natural auxins
All auxins are compounds with
aromatic ring and a carboxylic acid
group:

α-Naphthalene acetic acid (NAA) is a
purely SYNTHETIC AUXIN.
It is chemically similar to IAA in
structure but is a more effective in
promoting rooting.
It is commonly found in commercial
rooting compounds and is often
combined with IBA.
Different types of Auxin : Synthetic Auxins
NAA is used in chemical thinning
of tender fruits of apple and pear.
NAA is applied @ 2 – 5 ppm, 7 – 20
days after full bloom.
For preventing pre-mature fruit
drops, Auxin like NAA can be
applied during the mid-stages
of fruit growth @ 10 – 25 ppm
NAA

The potassium salt form of IBA and
NAA have the advantage of being water
soluble and not needing a solvent.
In some cases, IBA or NAA treated
cuttings can be damaged by the effects
of the solvent used to dissolve them.
In these cases, the water soluble K- IBA
and K-NAA salts can be a very useful
alternative.
Different types of Auxin : Synthetic AuxinsDifferent types of Auxin : Synthetic Auxins

Auxins are toxic to plants at higher
concentrations; they are most toxic to
Dicots and less toxic to Monocots.
Because of this property, synthetic
auxin herbicides, including 2,4-D &
2,4,5-T, have been developed and used
for weed control.
2, 4-D, an auxin based herbicide
2,4,5-T, an auxin based herbicide
Different types of Auxin : Herbicides
Both 2, 4 – D and 2, 4, 5 – T are synthetic auxin
Actually at higher concentration, Auxin
stimulates excessive, uncontrolled growth
in broadleaf plants for which it is used as
a herbicide.

Structure of some common synthetic auxins
Different types of Synthetic Auxins : - Used as Herbicide

Commercial formulation of Auxins
Alpha Naphthyl Acetic Acid 4.5% SL ( Na salt)
NAA
Recommended doses per hectare
For induce Flowering and uniform growth: 1 mL in 4.5 L water (10 ppm),
To increase fruit size: 10 mL in 4.5 L water (100 ppm),
To delay maturity: 10 mL in 4.5 L water (100 ppm).
It is used for INDUCING
FLOWERING, PREVENTING
SHEDDING / DROPPING OF
FLOWER BUDS & UNRIPE
FRUITS. It helps in enlarging
fruit size, increasing /
improving the quality and
yield of fruits.
Standard solution :
1 ml 4.5 %
formulation in 4.5 L
of water = 10 ppm

Use of Commercial formulation of Auxins
Used in tomato and chilli
against flower and fruit drop.
1st spray during flowering &
2nd spray 20 - 30 days later @
10 ppm dose.
Used in Mango : used against flower
and fruit drop.
1st spray when tender fruits are of pea
size. 2nd spray when fruits are of marble
size (about 2 cm diameter) @ 2 mL / 4.5 L
of water (20 ppm)
Used in Grapes : To increase
size & weight of Berriers. 1st
spray during pruning and 2nd
spray during flowering shoot
appearance @ 10 ppm (10 mL in
45 L of water).
Used in Pineapple : To induce
flowering and uniform growth 10
ppm solution strength @ 30 - 40 ml is
to be poured into head of each plant.
When applied two weeks before
harvest @ 100 ppm as spray, it
delays matuirity.

Use of Commercial formulation of Auxins

Indole - 3 - butyric acid (IBA) 0.1 %
These are mainly used as ROOTING HORMONE.
Powdered forms of rooting hormones are generally less
effective than liquid formulations applied at the same
concentration.

GIBBERELLINS
Gibberellins are responsible for internode elongation, seed germination and
leaf expansion. They are produced in young tissues of shoot and seeds. Most
important Gibberellins in plant is GA1. its transport occurs thorugh xylem,
phloem and through cell to cell.
1. Stimulate stem elongation by stimulating cell division and elongation.
2. Stimulates bolting /flowering in response to long days.
3. Enhance Seed Germination. It breaks seed dormancy in some plants which
require stratification or light to induce germination.
4. Stimulates enzyme production (α-amylase) in germinating cereal grains for
mobilization of seed reserves.
5. Induces maleness in dioecious flowers (sex expression) & female flower in
maize.
6. Can cause parthenocarpic (seedless) fruit development.
7. Can delay senescence in leaves and citrus fruits.
Function of Gibberellins in plant

There are about 120 gibberellins found in both higher plants and
the Gibberella fungus, although only two products are
commercially available, viz. GA3 and a mixture of GA4 and GA7..

Gibberellins helps to Overcome dormancy in seeds

GA is used extensively on seedless grape varieties to increase the
size and quality of the fruit. Application of GA3 during the late
bloom to early fruit set period will increase berry size. It has been
suggested that this later application of GA increases the
mobilization of carbohydrates to the developing fruit
Application of GA3 @ 15 – 30 ppm can induce parthenocarpic
(seedless) fruit set in Grape.
Agricultural Application of GIBBERELLINS
GA application in Sugarcane is used to overcome the reduced
growth rate of sugarcane during the cooler winter season.
Gibberellic Acid (GAs) is a growth regulator that acts by
stimulating rapid stem and root growth, induces mitotic division in
the leaves of some plants and increase seed germination rate.
GA can move into phloem sap of plants, and that it aids growth and
development of the plants, as well as their flowering.

Application of GIBBERELLINS in Plants
Gibberellins helps to break seed dormancy

Used in Grapes : Two
directed spray 1st at full
bloom & 2nd at fruit set
stages @ 100 ppm. It
prevents fruit drop and
enhance fruit size.
Used in Brinjal: Seedlings
are dipped in GA solution @
10 ppm before sowing.
When plant is 4 week old,
foliar spray @ 50 ppm
Used in Banana: Three
sprays, 1st at 3 month age,
2nd at 5 month and 3rd
during fruit formation.
Used in Tomato / Potato /
Cabbage / Cauliflower: Two
directed spray 1st at 45
DAS & 2nd at 65 DAS @ 10
ppm.
Application of GIBBERELLINS in Plants
Used in Onion: single spray
at 25 – 30 DAT, @ 10 – 15
PPM enhance growth.

Citrus
• Increases fruit set and yield.
• Delays rind aging.
• Reduces physiological disorders.
• Delays maturity for a more
orderly harvest.
Bananas
• Post-harvest treatment extend green life.
• Improves fruit size, quality and overall yield.
• Stimulates early growth in new plantations.
Pineapples
• Increases fruit size, quality and overall yield
• Improves pack-out
• Post-harvest treatment to extend crown life
Role of Gibberellic Acid in
crop growth

Difference between Auxin and Gibberellin.
The most important differences between auxin and gibberellin are that auxin promotes
the growth of shoot whereas gibberellin is involved in the elongation of the stem,
flowering and seed germination. Auxin plays a major role in apical dominance whereas
gibberellin has no role in apical dominance.
How do gibberellins initiate seed germination?
Gibberellins synthesize and produce hydrolases such as amylase which helps in
the germination of seeds. The hydrolases breaks the macromolecules in the
endosperm to provide nutrients to the embryo. Thus they directly stimulate the
growth of the embryo and enhance seed germination.
How do gibberellins promote flowering?
Gibberellins promote flowering by activating the LEAFY promoter. Severe
reduction in gibberellins delays flowering during long days and prevents
flowering during short days.
How do gibberellins initiate cell elongation?
Gibberellins alter the rheological properties of the cell wall. As a result, the water
potential of the cell is lowered that allows the uptake of water and facilitates
germination.

Commercial formulation of Gibberellic Acid (GA = 0.001 % L)
Commercial formulations have 0.001 % GA3 in Liquid formulation.
It is recommended for use in Paddy, Cotton, Sugarcane, Groundnut,
Brinjal, Bhendi, Grapes, Banana, Tomato, Potato, Cabbage,
Cauliflower, Tea, Mulberry etc.
Used as root stimulant for agricultural crops. It stimulates root
growth and enhances nutrient uptake.

Commercial formulation of Gibberellic Acid (GA = 0.001 % L)

Commercial formulation of Gibberellic Acid (GA = 0.186 % SP)
This formulation is highly effective to improve fiber quality in Cotton.

Commercial formulation of Gibberellic Acid (GA = 0.186 % SP)
Gibberelic Acid is used to increase size
and quality of fruits, vegetables and
other crops. It is essential for optimum
growth and development and plays a
role in the regulation of other plant
processes such as flowering, seed
germination, dormancy and
senescence.
It should not be applied when the
temperature is below 7°C or above 32°C.
GAs should only be applied in warm
weather, or they will not work to
stimulate growth
Gibberellic acid should not be used with
alkaline products, but it can be used
along with natural fertilizers and
pesticides.

Gibberellic Acid 40% WSG
It increases
flowering and
improves quality
of fruits
Dose : 2.5 gm / 200
l of Water
It can be applied to RICE at 20 – 25 DAT & at Panicle emergence stage @ 20 – 25 ppm

CytokininsCytokinins
The word for cytokinins is a generic name for all naturally occurring
substances that are known to promote cell division. They are also known to
delay senescence. The first naturally occurring cytokinin was found in corn
and is known as Zeatin.
The natural cytokinin appears to be made primarily in apical root meristem,
inflorescences and developing fruits.
Cytokinins are also involved in stimulation of organ formation e.g. formation
of leaf, fruit, buds and branches. They tend to overcome apical dominance
and break dormancy. They also enhance seed germination and uniform
flowering. Cytokinins are also useful in the preservation of flowers, fruits
and leafy vegetables.
There are two types of cytokinins: 1. Adenine type cytokinins
represented by Kinetin, Zeatin, and 6-benzylaminopurine,
2. Phenyl-urea type cytokinins like Diphenylurea and Thidiazuron.
Phenyl urea type of Cytokinins are not produced inside the plants.
They are produced in the roots and transported throughout the plant via the xylem.

Cytokinins are a group of plant growth regulators which are primarily
involved in performing cell division in plant root & shoot system. This
hormone helps in promoting the cell’s growth, development,
differentiation, affecting apical dominance, leaf senescence, and
axillary bud formation.

Function of Cytokinins
1. Stimulates cell division.
2. Stimulates morphogenesis (shoot initiation /
bud formation) in tissue culture.
3. Stimulates the growth of lateral buds.
4. Stimulates leaf expansion resulting from cell enlargement.
5. May enhance stomatal opening in some species.
6. Promotes the conversion of etioplasts into chloroplasts via
stimulation of chlorophyll synthesis. Thus helps the plant to
remain green for a long period.
7. Cytokinins delays leaf senescence.

Cytokinin
promotes
lateral bud
growth.
Cytokinin
counteracts
apical
dominance

Treated with
Cytokininc
Control
Cytokinins delays senescence
Doses : 1 mL formulation / L of water

Cytokinins stimulate photosynthesis and thereby enhance the yield & size of fruits.
Control
Treated

Relationship between auxin and cytokinins
Depending on the
relative concentration
of each, root
meristems
(high auxin: low
cytokinin) or shoot
meristems (low auxin:
high cytokinin) may be
initiated

Basipetal = Towards the base

Some commercial
formulations of
Cytokinin available in
India

Phytohormones as Growth inhibitors
The plant bio-regulators which selectively interfere with normal hormonal
process of growth are called Growth Inhibitor e.g. Abscisic acid and
Ethylene.
Abscisic acid (ABA)
These were previously called Dormin or Abscisin. This hormone is
widespread in higher plants and is found in many different organs
and tissues (both old and young) of plants. ABA INDUCES
ABSCISSION OF THE LEAVES OF A WIDE VARIETY OF PLANTS
AND FRUITS OF SOME PLANTS. ABA also prevents or DELAYS
SEED GERMINATION.
ABA RETARDS THE GROWTH of a large variety of plant tissues and
organs including leaves, coleoptiles, stems, hypocotyls and roots. IT
PROMOTES SENESCENCE through leaf abscission, degeneration of
excised leaves and acceleration of decomposition of chlorophyll.

Effects of ABA in plant
 Induces stomatal closure, decreasing transpiration to prevent water loss.
 Inhibits fruit ripening.
 Responsible for seed dormancy by inhibiting cell growth – inhibits seed
germination – Dormancy inducer.
 Inhibits the synthesis of Kinetin nucleotide.
 Regulates enzymes needed for photosynthesis.
 Acts on endodermis to prevent growth of roots when exposed to salty
conditions
 Delays cell division.
 Enhance senescence of leaves, flowers & fruits.
Abscisic acid (ABA)
ABA induces dormancy, prevents
seeds from germinating and
causes abscission of leaves,
fruits, and flowers.

Abscisic acid (ABA)
 ABA can be synthetized in all parts of plants, i.e. roots, leaves,
seeds, flowers etc.
 it is mobile within leaves and translocate through xylem.
 it produce in response to environmental stress.
 ABA helps to build up draught resistance in plants.
 Elevated ABA level in plants is associated with increased
freezing resistance.

Ethylene
This is a simple gas that is produced in small quantities by many plant
tissues and they serve as a very powerful regulator of growth and
development. They are found very prominently in physiologically matured
fruits undergoing ripening.
Ethylene is a small hydrocarbon, a colourless flammable gas which is denoted
by a formula C2H4 or H2C=CH2. It has a “sweet and musky” odour when it is
pure. It is the simplest alkene and also the second simplest unsaturated
hydrocarbon after C2H2.
In fruits, ethylene causes breakdown of cell walls to soften the fruit,
conversion of starch into sugar to sweeten it, and loss of chlorophyll to
reveal other colors which signals “ripe”.
Ethylene promotes abscission, which breaks the connection between the plant
and the fruit’s stem, so that the fruit falls to the ground.
In addition to ripening fruit, ethylene speeds aging and dropping of
deciduous leaves.
Ethylene can affect the cells in which it is synthesized as well as cells to
which it is translocate. So classical definition of “ Plant Hormone” is not
applicable for Ethylene.

Ethylene can affect the cells in
which it is synthesized as well
as in cells to which it
translocates.
Ethylene is known to affect the following plant processes:
1. Stimulates dormancy.
2. Stimulates shoot and root growth and differentiation.
3. May have a role in adventitious root formation.
4. Stimulates leaf and fruit abscission.
5. Induction of femaleness in dioecious flowers.
6. Stimulates flower opening.
7. Stimulates flower and leaf senescence.
8. It acts as ripening agent of fruits like tomato, banana, avocado,
melons etc
Ethylene is synthesized in tissues
undergoing senescence or
ripening.
Ethylene is a de-greening agent, which can turn the peel from green to perfect
yellow (in the case of bananas) and maintain the sweetness and aroma of the
fruit, thus value addition in the fruit is possible as it looks more appealing.

Commercial formulation of Ethylene / Ethylene releasing
agents.
Ethephon is a systemic plant growth regulator
belonging to the phosphonate family. It is readily
absorbed by the plant and releases ethylene inside
the plant cell. Ethylene is a natural plant hormone.
Ethylene directly influences several physiological
processes of plant (ripening, maturation etc.) and
stimulates the production of endogenous ethylene.
Ethephon is mainly formulated as a soluble
concentrate (SL) and sold under several trade
names corresponding to specific uses.
EthephonEthephon – An ethylene releasing agent.
This is used for Inducing flowering, Enlarging Fruit
size, Increasing the yield of the crop and Inducing
ripening in the fruits of Mango, Pineapple, Tomato,
Coffee, Rubber, etc. Ethylene is usefiul in Breaking
Alternate Bearing in Mango and it encourages
Flowering.

Some Commercial formulation of Ethephon 39 SL

Rubber Plant : For stimulating latex flow in
Rubber, without affecting economic life of the
trees, Ethephon can be applied. Four
applications in a year @ 1000 ppm during the
month of March, August, September &
November. Application during heavy rain
should be avoided.
Apple : To promote flower initiation on
young, non-bearing tree, spray 500 ppm
Ethephon solutions 2-4 weeks after full
bloom period. To hasten ripening and
improves colour and taste, spray 750
ppm solution. 10 days before harvest.
Pineapple : For flower induction
one spray of Ethephon 39 % SL, @
100 ppm at 30 - 37 leaves on the
plant [10 - 12 months age]
Tomato : For uniform
ripening post harvest dip
of harvested fruits on
2500 ppm solution.
Cucumber : Sex
modification, i.e. for
increasing female flower
by applying Ethephon 39
% formulation @ 125
ppm at 5 leaf stage
Application of Ethephon 39 % SL on Crop Plants

For inducing flowering, increasing
yield and breaking alternate bearing,
use Ethephon @ 200 ppm solution
[Dissolve 5 ml formulation of 39 % SL
formulation in 10 litres of water]. Spray
the trees Four - five times at
fortnightly intervals, first application
late September or early October.
Application of Ethephon in MANGO :
For flower induction in
juvenile mango tree, a total of
5 sprays of Ethephon at
weekly interval @ 1000 ppm
commencing from early
November. For this dissolve 26
mL of Ethephon 39 % SL
formulation in 10 L of water.
Ethephon 39 % SL can be used
for Post harvest treatment for
uniform ripening of mango.
Single dip treatment in 500
ppm solution or spraying on
physiologically matured fruits
gives significant result.

Some other plant hormones, specific to
plant species.
Salicylates : Salicylates have been known to be present in willow
bark. They have been recognized as potential growth regulators.
Salicylates are reported to enhance longevity of flower.
Jasmonate: it was isolated from Jasmine plant. They play the
following roles in plant:
1. Inhibition of many processes such as growth and germination.
2. Promotion of senescence, abscission, tuber formation, fruit
ripening, pigment formation, and tendril coiling.
3. They appear to have important roles in plant defense by inducing
proteinase synthesis.

Brassinosteroids (BRs) are a class of polyhydroxysteroids that have
been recognized as a sixth class of plant hormone. They are steroid
hormone.
BRs have been shown to be involved in numerous plant processes:
 Promotion of cell expansion and cell elongation.
 Promotion of vascular differentiation in plant.
 Is necessary for pollen elongation for pollen tube formation.
 Can provide some protection to plants during chilling and drought stress.
 They decrease fruit abortion and fruit fall.
 They acts very similar to Auxin.

Synthetic Plant Growth RegulatorsSynthetic Plant Growth Regulators
1. Growth Retardants

GROWTH RETARDANTS
These are the synthetic organic compounds causing retardation of cell division
by INHIBITING BIOSYNTHESIS OF PLANT HORMONES without causing
substantial growth distortions. e.g. onium compounds, pyrimidines, trizoles,
tetcyclacis, morphactins, maleic hydrazide etc.
Growth retardants which inhibit Gibberelic acid (GA) biosynthesis :
They are of three types.
1. Onium compounds such as CHLORMEQUAT CHLORIDE (CCC), MEPIQUAT
CHLORIDE and CHLORPHONIUM CHLORIDE.
2. The second class consists of nitrogen containing heterocyclic compounds, such
as ANCYMIDOL (pyrimidine), TETCYCLACIS (norbornanodiazetine) and trizole type
compounds (e.g. PACLOBUTRAZOL, UNICONAZOLE).
3. The third class consists of ACYL-CYCLOHEXANEDIONE compounds.
Growth retardants
Inhibit GA bio - synthesis Influence Auxin Metabolism

Growth retardants which NOT INHIBITS Gibberelic acid (GA)
biosynthesis
 These compounds may exert their effect by influencing the
plant‘s auxin metabolism, thus causing alterations in hormonal
balance and resulting loss of apical dominance.
 These compounds are useful to control the growth of woody
plants, but they have been known to cause foliar distortions,
retardation of stem elongation and breaking of axillary bud.
 It also stimulate abscission of flowers and fruits because the
firmness of attachment of fruit to the plant can be
decreased by application of MORPHACTIN type of chemical,
they may become useful aids in the mechanical harvesting of
grapes and tree fruits. e.g. MALEIC HYDRAZIDE: It is a
general inhibitor of meristematic activity, it retards stem
elongation and prevents leaf and flower initiation, as well as
fruit set and enlargement.

CHLORMEQUAT CHLORIDE : It acts by inhibiting Gibberelin Bio-synthesis.
it inhibits cell elongation, resulting in thicker stalks, which are sturdier, facilitating
harvesting of cereal crops.
It is a growth retardants, used in agriculture to increase crop yields. IT ACTS BY
RETARDING THE UNWANTED / EXCESSIVE VEGETATIVE GROWTH OF THE
PLANT AND THUS DIVERTING THE ENERGY OF THE VEGETATIVE GROWTH
TOWARDS THE DEVELOPMENT OF FLOWERS AND FRUITS /GRAINS.
Its dose is : 1 ml - 1.5 ml/ L
 It increases chlorophyll content resulting higher photosynthesis rate.
 Causing extensive root development, strengthening of the shoot,
 Induce early and uniform ripening and prevention of fruits and flower drop.
 Increases the efficacy of plant protection measures in many crops.
 Treated plants turns dark green in colour.
 Helps crops to effectively cope with environmental stresses such as drought,
flood and heavy wind.
It is used in Cotton, Wheat (as seed dressing agent), Soybean, Sugarcane, Onion,
Garlic, Paddy (Basmati Variety-Spray after 40 days of transplanting), Pulses,
Potato, Oilseeds, Mango, Chikoo, Grapes, Citrus, Tomatoes, Cucumber, Chilies
and Other vegetables.
GROWTH RETARDANTS

Commercial formulations of Chlormequat Chloride (50 % SL)

It inhibits the biosynthesis of gibberellic acid, and leads to a deeper green leaf
colour after 3-6 days. Its dose is 2.0 – 3.0 mL per liter of water.
It is used on Cotton to reduce vegetative growth and to advance maturation of
the bolls. Also used in potato for tuber maturation and vegetative growth
control. It is also used in combination with Ethephon to prevent lodging in cereal
and flax. It is formulated as 5 % Aqueous Solution.
MEPIQUAT CHLORIDE GROWTH RETARDANTS

 Paclobutrazol (PBZ) is a plant growth retardant (Cell elongation inhibitor). It
acts by inhibiting gibberellin biosynthesis, reducing internode growth to give
stouter stems, excessive root growth and causing early fruit set.
 Paclobutrazol reduce canopy growth & re-direct the nutrients and
carbohydrates synthesized in the leaves into fruit and seed production, rather
than into non-productive leaves and stems. Thus, the vegetative growth
reduces and the assimilates are transferred to reproductive organs and the
yield potential increases. It best performs on Mango.
 It is available in 23 % and 25 % SC formulation.
 In Mango, application of small amount of paclobutrazol in the soil, after
harvest of Mango, significantly promotes flowering and fruiting in the following
year. It can be applied upto january, but foliar spray is ineffective
Paclobutrazol
Dosage of Paclobutrazol 25% SC to
Different Age Of Mango Tree:
7-15 Year => 15ml / Tree
16-25 Year => 20ml / Tree
> 25 Year => 25-40ml/ Tree
Recommended quantity of
Paclobutrazole 25% SC to be diluted in
clean water of 5-10 liters & applies in
a furrow of 5 cm deep about 2 to 3
feet away from the trunk (collar
drench method). Then the trench
should be fill up with soil after
application.
GROWTH RETARDANTS

Mode of action of Paclobutrazol
GROWTH RETARDANTS

Mode of action of Paclobutrazol

Paclobutrazol 25 % SC formulation

Paclobutrazol 23 % SC formulation

Prohexadione - calciumProhexadione - calcium
 It is taken up by plant through FOLIAGE and transported within the
plant, both acropetally and basipetally.
 This is a growth retardant, regulate late stage of gibberelin bio
synthesis. Thus inhibit foliage growth.
 In case of fruit crops, it reduces canopy growth and diverts the
photosynthates towards fruit development. This effect of
suppression of vegetative growth lasts for 2 – 5 weeks after each
application.
It is a growth – retardant.

Prohexadione – calciumProhexadione – calcium
+
Mepiquat Chloride
 Increase the root plate spread for
better anchorage and water/nutrient
uptake.
 Balance and strengthen tillers,
creating an even crop with uniform
leaf emergence to assist in more
accurate fungicide timings for leaf 3
applications (T1).
 Thicken and strengthen the 1st
internode as it develops.
 It helps the plants against LODGING.
It has a positive effect on stem cell
wall structure by increasing stem dry
matter and lignin content, giving
plants a higher tensile strength
.
A growth – retardant.

Chlorpropham 50% HN
It is used as Anti-sprouting agent for stocked potatoes under cold
storage condition

Ancymidol (Commercial names: Abide and A-Rest) Ancymidol readily moves through the plant
and is usually used on crops where other chemicals aren’t effective (most notably in bulb crops) or
on very high-value crops. Ancymidol is non – phytotoxic.
Some other plant growth retardants, not registered in India
Daminozide (Commercial names: Dazide and B-Nine) This material is applied only as a foliar
spray because it’s rapidly broken down when applied to the substrate. It’s highly mobile in the plant
and will rapidly move from the point of application to all parts of the plant. Daminozide is effective
on most crops except lilies. It is most effective in cooler climates.
Ethephon phosphonic acid (Commercial names: Collate and Florel) This material is
absorbed by the plant tissue, and due to a change in pH once absorbed into the plant cells, they
releases ethylene.
Flurprimidol (Commercial name: Topflor) is chemically closely related to ancymidol, but it has a
greater degree of activity. Flurprimidol is also one of the most cost-effective growth retardants to
use as a drench, with recommended use rates in a range similar to uniconazole on most plants.
Uniconazole (Commercial names: Concise and Sumagic) Uniconazole is applied as a foliar
spray, or as substrate drench method. This chemical is commonly used on perennials because it’s
highly effective on a very broad range of plant species.
Benzyladenine (Commercial name: Configure) : Benzyladenine (BA) is used to
promote branching and increase flower set.

Other types of synthetic plant growth regulators
Biostimulants

“A plant bio-stimulant is any substance or microorganism applied to
plants with the aim to enhance nutrition efficiency, abiotic stress
tolerance and/ or crop quality traits, regardless of its nutrients
content”.
Plant Bio-stimulant
Bio-stimulants have no direct action against pests,
and therefore they do not fall within the regulatory
framework of pesticides”.
Bio stimulants stimulate natural processes to ENHANCE
NUTRIENT UPTAKE, NUTRIENT USE EFFICIENCY, TOLERANCE TO
ABIOTIC STRESS, and IMPROVEMENT IN CROP QUALITY.

Biostimulants THEY ENHANCE NATURAL PLANT GROWTH
& its DEFENSE MECHANISMS
Bio-stimulant naturally increases the vigour and vitality of crops. It STIMULATE
the natural processes of the plant such as growth and pathogen resistance.
Bio stimulants improve the absorption of nutrients, their mobility and
effectiveness within the plants. It enhance plant tolerance to stress such as
adverse climate, herbicide application etc.
This is achieved by supplying nutrients in the form of amino acids, long chain
sugars and / or supplying natural hormone-like components, which induces
immunity.
Bio-stimulant are not a fertilizer, nutrient, pesticide or soil conditioner /
improver. But they can promote Plant growth in minute quantities.
Plant bio stimulants can be classified into following major groups.
These are:
1. Humic Substances, like humic acid, fulvic acid.
2. Hormone containing products, like Seaweed extract.
3. Amino Acid containing products & protein hydrolysate.
4. Chitosan and Other bio-polymers.
5. Plant growth promoting micro-organisms.
6. Synthetic organic / inorganic compounds.

Role of Bio-stimulants in Nutrient Metabolism.

Bio-stimulants beneficial effects on plants

Plant bio-stimulants contain substance(s) and /or micro-organisms,
whose function when applied to plants or the rhizosphere is to
stimulate natural processes to enhance nutrient uptake, nutrient use
efficiency, tolerance to abiotic stress, and improvement of crop quality.

Biostimulants
Classification of Bio stimulants :
1. Humic Substances including Humic and Fulvic Acid & their salts.
2. Sea weed extracts.
3. Protein hydrolysate and Amino acids.
4. Plant Growth Promoting Micro – Organisms.
5. Chitosans and other bio-polymars.
6. Synthetic compounds

Natural components, used as bio-stimulants, includes Phenols,
Salicylic Acid, Humic & Fulvic Acids, & Protein Hydrolases.
Popular micro-organism used as biostimulants (as Plant Growth Promoting
Micro-organisms) are Glomus intraradices, Trichoderma spp., Heteroconium
chaetospira, Arthrobacter spp., Enterobacter spp., Acinetobacter spp.,
Pseudomonas spp., Ochrobactrum spp., Bacillus spp., and Rhodococcus spp.
Biostimulants
Bio-stimulants contribute to sustainable agriculture by:
 Improving plant tolerance to abiotic stress on plants, including drought,
extreme temperatures (cold, frost, and heat), and salinity.
 Enhancing uptake and efficient use of nutrients, both freshly applied and
existing.
 Improving soil health by enhancing beneficial soil microorganisms.
 Enhancing crop quality through plant health and vigor.
 Increasing harvestable yields

Humic substancesHumic substances
Humic substances (HSs): They include humic acids, fulvic acids and
humins. HSs are natural constituents of soil organic matter, resulting from the
decomposition processes of plants, animals, and microbial residues, but also
from the metabolic activity of soil microbes.
It has been observed that treatments with humic substances STIMULATE
PLANTS ROOT GROWTH AND DEVELOPMENT. This is reflected in a better
uptake of nutrients and water, and ENHANCED TOLERANCE TO
ENVIRONMENTAL STRESSES.
Humic acid maximize the availability of nutrients whether applied directly to
the crop or already present in the soil. It stimulates the activity of growth
promoting factors. It is also beneficial as a seed treating agent and can also used
as seedling root dipping medium, prior to transplantation.
Applied as a foliar treatment, Humic acid enhances the translocation of nutrients
throughout the plant by increasing cell wall permeability. Applied as a seed
dressing medium, it improves germination rates.

Humic acid and fulvic acid stimulate plant growth in terms of increasing
plant height and as well as enhancing nutrient uptake. Thus improves
overall plant development.
Humic substances enhance the water holding capacity of soil by many-
folds. This is ideal for sandy soil.
Root proliferation is a benefit from applications of humic and fulvic acids at low
concentrations. These stimulatory effects also have been directly correlated with
enhanced uptake of nitrogen, phosphorus, sulfur, zinc and iron
Humic acid helps the plant to TOLERATE OSMOTIC STRESS and helps the plants
to WITHSTAND EXTREME WEATHER CONDITION like DROUGHT.
Humic acid STIMULATE SEED GERMINATION. It increases the microbial activity in
the soil, making it an excellent root stimulator. Thus help to promote better plant
health and growth.
It also helps to AERATE THE SOIL from the inside. It will also help to lower the pH
of the soil to a more neutral level and will flush high levels of salts out of the root
zone.
Advantages of using Humic Substances

Removal of toxicants from soil environment : Humic acids chelates harmful
toxins in the soil, thus preventing them from entering the plant. This is
particularly important in today’s soil environments, where countless toxicants
have been introduced over many years like heavy metals and pesticides. These
toxic molecules are captured by humic molecules and locked up.
Advantages of using Humic Substances
Increases Soil microbial population: One of the most noticeable and impactful
benefits of humic acids is their positive impact on microbial populations on soil.
Facilitates nutrient availability: Humic acids are extremely important as a medium
for transporting nutrients from the soil to the plant because they can hold ionized
nutrients, preventing them from leaching away. As humic acid is being attracted
by plant root and absorbed, this captured nutrient ion along with it also enters
into plant system.
Humic acid has been used to promote the soil-less growth of seedlings.
Cucumber and tomato seedlings have been found to be especially responsive to
growth in aquatic media that contain appreciable amounts of humic acid.
Humic acid acts as a buffer to neutralize alkaline or acidic soils. It helps in
stabilizing nitrogen release and facilitate plants to absorb micro nutrients.

Method of application of humic
substances
Doses
Foliar spray and drenching
Foliar spray - 750 to 1500 ml per hectare
(300 to 600 ml per acre)
5 mL per liter of water
Drenching or drip irrigation - up to 2500 ml
per hectare (1000 ml per acre)
Seed Dressing
Mix 5 ml of Humic substances
formulation with 1 kg of seed
thoroughly and sow.
During flowering and fruit
formation stages
Apply Humic Substance formulation at
2 ml per litre of water as a spray
(Shake the container before use).
Soil Application
Mix 4 mL of liquid formulation in 1
litres of water. Apply the mixture while
ploughing /seeding along with the
application of fertilizer

Humic acid (12 %) formulations.

Humic acid (20%) formulation.: Applied as foliar spray as well as fertigation.
 Increase soil fertility through its influence
on the water holding capacity.
 Increase humus contents & effectively form
chelates with nutrient ions to make them
available to plants.
 Increase the soil cation exchange capacity,
enhance soil phosphate availability.
 Increase root penetration and improve soil
drainage.
 Conserves top soil, converts unproductive
clay soils and turns into loam type. Humic
acid buffer soil pH.
 Increase soil micro-organisms’ metabolic
activity. Stabilizes soil structure through the
formation of micro-aggregates.
 Increases the sugar (brix) level of the plants,
which strengthens the plant and helps
plants to resist both from diseases and
insect attack.

Humic acid Granule formulation.: Applied as Soil Conditioner.
It can be directly broadcasted in soil.

Humic acid Granule formulations.

CHEMICAL BENEFITS of using Humic acid Granule:
 Increases buffering properties of soil
 It is rich in both organic and mineral substances essential to plant
growth
 Retains water soluble fertilizers in the root zones and releases them
to plants when needed
 Has an extremely high CEC (cation exchange capacity)
 Promotes the conversion of insoluble nutrients into forms available
to plants
 Reduces or eliminates many soil-related phenomenon, such as dry
spots on golf greens.
PHYSICAL BENEFITS of Humic acid granules:
 Makes soil more friable and crumbly
 Improves soil workability
 Increases aeration of soil
 Reduces thatch build-up in turfgrasses
 Increases water holding capacity
 Improves thermal coloring of soil
Humic acid Granule formulations.

Commercial formulations of Humic acid + Fulvic acid.
Fulvic acids have a higher cation
exchange capacity than Humic acid.
Therefore have a higher chemical
interaction with fertilizers and are
able to form soluble chelates with
trace metals. So, it can be mixed
with most traditional fertilizers.
Has better Efficacy

Potassium Salts of Humic Acid & Fulvic Acid

Advantages of using Potassium humate
Potassium humate is the salt of humic acid and completely soluble in
water, where as humic acid is a comparatively large molecule and
insoluble in water.
It has similar advantages of humic acid formulation, plus has added
advantage of providing available potassium to the plant.
Advantages of using Potassium fulvate
Potassium fulvate is 100% water soluble. It can work as anti-drought and
anti-frost agent, as well as it can detoxify pesticide residues from soil.
These chemicals are responsible for Loosening soil and making more air
and water availability in root zone.
It also reduces soil acidity and alkalinity. It is non – toxic and safe to the
environment. It is compatible with
These two chemicals are widely used in agriculture as a soil
conditioner to improve soil structure and a fertilizer additive to
increase the efficiency of fertilizers especially nitrogen and
phosphorus-based fertilizer inputs.

Commercial formulations containing Potassium humate and Potassium fulvate.
This product are100% water soluble and comprises around 50% humic
acid, 12% potassium and 30% fulvic acid. It can work as anti-drought
and anti-frost agent, as well as it can detoxify pesticide residues from
soil. These are also used as flowering agent.
Beneficial effects of K – Humate and K – Fulvate on soil is increase in
total organic carbon, increased pH, improved cation exchange
capacity, water permeability and soil aggregate stability.

Potassium Humate &
Humic Acid stimulate
the plant to produce its
own beneficial
hormones naturally.
Super potassium humate : - They contains up to 95 % of active ingredient.
It is an organic potashIt is an organic potash
fertilizer, with soil
available potassium,
it could reduce the
loss and fixation of
potassium, increase
the uptake of
nutrients and
utilization of
potassium by plants.

Different types of Humic Acid / K – Humate formulations

Potassium humate based formulation. (15 % K – Humate) :
Applied as foliar spray as well as fertigation.
Formulation is water-soluble,
containing potassium humate 15%
& fulvic acid 3%. This product is
suitable for all crops.

Potassium humate based formulation. (85 % K – Humate, 13 %
Fulvic acid) : Available in solid formulation
 For drip & sprinkler irrigation mix 1 - 2 kg
formulation in sufficient quantum of water
for one Acre of crop land.
 For seeding root dipping & drenching mix
10 - 20 gram formulation per Liter of water.
 For spray Mix 1 - 1.5 gram product per
Liter of water during high growth and
reproductive stage plant.
 For seed treatment Mix 50 gram
formulation per kg of seed in sufficient
quantum of water.

Humic Acid (K – Humate) 98%
 Enhance root development, increase stem thickness, increase nutrient uptake. Increase
crop yield.
 Improve soil fertility & soil structure, increase water retention, improve microbial
growth in soil.

Seaweed extracts:
 Seaweeds are a vast group of macroscopic, multicellular marine algae that can
be brown, red, and green. They are an important source of organic matter and
plant nutrients. Seaweed extracts have been used in agriculture as SOIL
CONDITIONERS & PLANT GROWTH STIMULATORS. They are applied as foliar
spray and are able to enhance plant growth, increase abiotic stresses
tolerance, photosynthetic activity, resistance to harmful fungi, bacteria and
virus.
 Sea weed extracts also IMPROVING yield & productivity of several crops. It also
improve plant’s tolerance to salinity, heat, and drought.
 Seaweeds used for plant bio-stimulant contain cytokinins, auxins and other
hormone-like substances. They also contain many active mineral and organic
compounds, including complex polysaccharides such as laminarin, fucoidan,
alginates etc, which contribute to plant growth.
 Seaweed extracts enhance uptake of Cu, Ca, K and Mg from soil. It also
stimulate water uptake by plant roots.
 It enhance anti-oxidant activity within the plant. Delays senescence and reduce
transpiration rate. Enhance resistance to extreme climatic condition, insect and
disease attack. Build resistance against soil nematodes.

Seaweed extracts (contd…) :
 It extends the SHELF LIFE of fruits and vegetables if applied 10
days before harvesting.
 It enhance the shelf - life of cut flowers if they are sprayed with it a
day or two before cutting.
 Seaweed extract also boosts crop yields, improves resistance of
plants to frost and disease, increases uptake of inorganic
constituents from the soil, bolsters resistance to stress conditions
and reduces storage losses of fruit.
 Seaweed extracts contain almost every micro-nutrient in a fully
chelated (immediately available) form. The algae is also full of
carbohydrates, which plants use as a building block. Numerous
beneficial microorganisms also use carbohydrates as a food
source.
 Liquid seaweed extracts (especially the alginates in the seaweed)
act as soil conditioners. The alginates react with metals in the soil
and form long, cross-linked polymers in the soil. These polymers
improve the crumbling in the soil and swell up when they get wet.
They also retain moisture for a long time.

Mode of Action of Sea Weed Extracts as Plant Bio-stimulator
These are of three major divisions of Sea weeds. These are :
BROWN ALGAE (Phaeophyta), RED ALGAE (Rhodophyta) and
GREEN ALGAE (Chlorophyta).

Ascophyllum nodosum is a seaweed, extract of which is used for
promotes nutrient uptake, vegetative growth, early flowering, flower
and fruit setting and fruit quality (size, hardness, taste, weight, colour
and shelf life).
Its natural composition includes phyto-regulator precursors
(cytokinins, auxins and gibberellins), amino acids, carbohydrates,
betains and many nutritive elements (N, P, K, Ca, Fe, Mn, Zn, S, B, Mo
and Cu).
Seaweed extract : Ascophyllum nodosumSeaweed extract : Ascophyllum nodosum
Sea weed extracts improve plant resistance to frost & drought and
increase crop yields. Plants sprayed with the seaweed extracts
showing higher resistance to pests & diseases and are becoming
more efficient in consumption of nutrients from soils. Seaweed
extracts contribute to the recovery of damages caused by insects
and bacterial / fungal diseases.
Sea weeds can be applied as :
1. Seed Treatment. – Stimulate seed germination.
2. Foliar application. – Enhance plant growth.
3. Soil Application. – broadcasted on soil for overall development of
plants.

The bio-stimulant present in seaweed extract increase the vegetative
growth (10%), the leaf chlorophyll content (11%), the stomatal density
(6.5%), photosynthetic rate and the fruit production (27%) of the plant.
It can also be used in hydroponic solution, besides their usual
application in soil and on plant foliage.
Polysaccharide contents of the sea weed extract results gel formation,
when applied to soil and thus results better water retention and soil
aeration.
Hormone content of the sea weed extract results enhancement in seed
germination. This is because the following hormones / hormone like
compounds have been found in sea weed extract : Auxin, Cytokinins, GA,
Abscisic acid, sterols and polyamines.
Seaweed extracts also helps the plants to withstand transplanting
shock.
Seaweed extract

Beneficial effects of Seaweed extracts.

Beneficial effects of
Seaweed extracts.

Ascophyllum nodosum
Some commercial
formulation of
seaweed extract
Doses : 1 – 2 mL / L of water.

Some commercial
formulation of
seaweed extract

Mixed formulations of Bio - stimulantsMixed formulations of Bio - stimulants

Mixture of Seaweed extracts and Humic Acid
Seaweed extracted from algae act as bio-stimulants due to
presence of plant hormones and Humic acid help in uptake of
nutrients from soil by plants. The combination use of both result
in better growth and yield of the plant.
The use of This combination has the
following benefits on plants :
 Increase plant elongation.
 Improves uptake of nutrients
 Increases cell multiplication
 Increases the growth of the plants
 Improves seed germination
 Improves flowering and fruit formation
 Improves Stress tolerance (like drought).
It is suitable for fruit plants like
Mango, Litchi, Guava, Lemon,
Orange, Grape, Banana, and other
flowering plants.

Mixture of Amino Acid 12%, Nitro Benzene 12%, & Humic Acid 6%
It accelerates white root development
and helps to enhance uptake of
nutrients which increases yield
parameters such as Tiller numbers,
Branches, Panicle numbers and Test
weight.
Doses
2 to 3 ml per liter of water (for Liquid)
10 kg per acre (for Granule)

Mixture of Amino Acid 6% w/w Fulvic Acid 5% w/w
Cytokinin 7% w/w
Gives strength to plants
against drought and diseases,
reduces immature flower and
fruit dropping and increases
flower and fruit setting and
yield.

 Amino acids function as biostimulants for plants. Amino acids can play
important roles in enhancing plant productivity, especially under abiotic and
biotic stress conditions.
 Amino acid fertilizers are readily absorbed, transported, and utilized as a
source of nitrogen and carbon for plants.
 Amino acids helps in enhancing plant productivity, especially under abiotic
and biotic stress conditions.
 Foliar Nutrition of amino acids in the form of Protein Hydrolysate (Known as
Amino Acids Liquid) and foliar spray provide readymade building blocks for
Protein synthesis.
Amino Acid containing products & protein hydrolysate as Bio-stimulant
Amino acid based Plant bio stimulants affects the nitrogen balance in
plants and also increase enzyme activity. It improves hormonal activity
and organize chemical balance.
Amino acids also increase mineral absorption, due to these activity
plants become healthy and yields higher.

Liquid Amino Acid formulations can be used by:
1) Foliar Spray, which provides readymade building blocks for Protein
synthesis.
2) Soil Drenching, which improves soil structure & texture.
Dosage: 5 ml / Liter of water once in every 15 - 20 days after 15 days of
sowing / transplantation, Apply the liquid spray on the plants before
sunrise or sunset to avoid leaf burn.
Benefits of using Amino acids as bio - stimulator
a) Provides an organic source of plant nutrients, vitamins and trace
elements.
b) Increases soil microbial life and organic matter breakdown. Aids in
disease and insect suppression by producing healthier plants.
c) Helps to improve soil structure and texture.
d) Improves nutrient availability by enhancing soil microbial activity.
e) Increases plant stress tolerance by increasing carbohydrate
reverses in the plant.
f) Reduced the requirements of synthetic fertilizers.
g) Act as chelating agent, which helps better nutrient uptake and
removal of heavy metals / toxicants from the soil.

Some formulations of Amino acids, available in India.

Female Flowering Booster
 Increases flower forming substances by
optimizing Auxin, Cytokinin, Gibbrellic acid
and Ethylene ratio.
 It induces higher level of flower forming
secondary metabolites, increasing flowers
by more than 60 to 75% and yield.
 Enhances color, sugar content, fruit
firmness and flower sturdiness.
 Increases nitrogen uptake and gives growth
stimulation.
 Increases yield due to more protein and
carbohydrate synthesis.
 Increases effectiveness against biotic and
abiotic stress like high temperature,
salinity, alkalinity and herbicide treatment.

Other type of plant bio – stimulants
Mixture of succinic acid, ascorbic acid and fulvic acid.
It promotes the vital process of plants through better utilization of bio chemical
reserves and help the plant to overcome constraints during critical stages of
growth, it provides tolerance to plant against environmental stress and pest
attack leading to normal functioning of plant system and improved quality and
yield of crops.
It induces flowering and fruit setting.

Nitrobenzene 35%
Nitrobenzene keeps quality of post harvest products for longer period.
Mostly used as foliar, but also used as seed treatment agent. It also has soil
application. Nitrobenzene induces profuse flowering in plants. Nitrobenzene
also provides strength to the plant and thus protects it from insects pests and
fungi.
Nitrobenzene stimulates
secretion of plant enzymes
and root growth. It increase
vitamin contents of plants and
buffering properties of soil. As
a result, it chelates with
nutrient ions under alkaline
conditions and thus makes
soil more workable.
It increases water holding
capacity of soil and reduces
soil erosion. It retains water
soluble fertilizers in the root
zone & releases them slowly
to plant when needed.
Nitrobenzene increase C.N.
ratio of the soil, significantly.
Dose : 2 mL formulation per litre of water

Sodium Para - Nitrophenolate 0.3% +
Sodium ortho -nitrophenolate, 0.2 % +
Sodium 5-nitroguaiacolate 0.3 %
This mixture is a Plant Growth Regulator it effects
various stages of development of plants. These are
as follows :
Enhances enzymatic activity, seed germination and
rooting.
Stimulates Vegetative growth and Flower bud
development.
Accelerates Pollen germination and tube growth
thus improving flower fertilization and fruit set.
Alleviates detrimental effect of stress and favours
speedy recovery. It Improves overall health of crops.
Improves quality, increases yields and profits.
Effective for cotton and tomato plant.
Doses : 1.5 mL / L of water
Applied at flower initiation
stage through foliar
application

Homo-Brassinolides are considered as plant growth regulators,
which can modulate plant growth and development activities and
have been known to improve the crop tolerance to biotic
stresses like draught and cold temperature.
Homo-Brassinolides
It yields best results when applied 5-10 days before
harvest period to fruits, vegetables and flowers @ 1 –
1.5 mL / L of water.
 It Promotes Cell
Division and cell
elongation.
 Plays a vital role in
Polen tube formation.
 Provides protection
during draught and
chilling temperature.

Action of Brassionsteroids towards plants stress tolerance

n-Triacontanol is a long chain aliphatic alcohol, having the general
formula C30H62O. The n-triacontanol is a prominent plant growth
promoter
n - Triacontanol
n-Triacontanol is isolated from active fraction of tea waste. It can
also be extracted from sugarcane press mud & rice bran waste.
Tricontanol is a plant growth regulator that shows its effects by
influencing mineral uptake, increased permeability of water, enhancing
the activity of naturally available enzymes and plant hormones,
increasing the rate of photosynthesis and enhancing the synthesis of
proteins.
It has the following advantages :
1. increases the grain yield and dry matter content of plant.
2. increases plant height.
3. Ensure earlier and stronger tillering,
4. Better spread of roots,
5. Uniform and early maturity in crops.
6. It enlarges stomatal opening & thereby increases the rate of
photosynthesis.

Three types of Formulations of Triacontanol is available in India.
For 0.05 % Granular formulation, it should be broadcasted to the field 2 – 3 days
before sowing / transplanting @ 500 gm / bigha.

Some LiquidSome Liquid
formulations of
Triacontanol
( 0.05 % EC)

Some granular formulation of Triacontanol ( 0.05 % GR)

Some Liquid formulations of TriacontanolSome Liquid formulations of Triacontanol
( 0.1 % EW)

Florigen (or flowering hormone) is the Hormone like molecule responsible for
controlling and/or triggering flowering in plants.
Flowering hormoneFlowering hormone
It is generated in leaves and transported to the shoot apical meristem to
promote floral transition
Florigen is Absorbed by the plant tissues where it is broken down in to naturally
occurring compounds: Which acts by balancing endogenous plant growth hormones to
induce flowering and decreased senescence of flower.
For best result dissolve 0.5 ml formulation in 1 L of water, applied as foliar spray
between 6.00 am to 9.00 am at an interval of 15-20 days.

Plant based metabolites and plant based growth regulators,
Known as FLOWER BOOSTER.
 It increases flower forming substances by altering the ration of
auxin and cytokinin inside plant as well as C: N ratio.
 It improves flowering and prevents dropping of immature flowers.
 This should be applied to the plant during flowering @ 3- 4 mL / L of
water. It improves flower setting and encourage full flower
expression.

FLOWER BOOSTER
It contains 20% nitrobenzene along with naturally available proteins which are
essential for plants. It acts as growth regulator and thus induces profuse
flowering. It is also used as plant energizer, flowering stimulant & yield booster.
It affects the numerous physiological processes like cell division, elongation,
autumnal loss of leaves & formation of buds, roots, flowers & fruits.

Chitosan as Bio - Stimulator
Chitosan is a sugar that is
obtained from the hard outer
skeleton of shellfish, including
crab, lobster, and shrimp.
It is used in Agriculture as a
seed treatment agent, helping
plants to fight off fungal
infections.
Chitosan is a naturally occurring
cationic biopolymer derived from
chitin with unique bioactive
properties in antimicrobial, plant
growth induction and plant
defense modulation.

Combination of Biologically Fermented
Chitin
Improves root mass, its length, and
thick cell wall formation in crops.
Facilitates growth of beneficial
microbes & fungi to multiply in the root
zones.
It creates Protective shield around the
root zone of the crop and protect the
crops from Nematodes attack.
It provides strengths to crop root and
its cell structure.
It stimulates plant defense mechanism.
It induces crop to resist against soil
borne pathogens and pest.
It increases plant growth.
It enhance tuber size in Potato.
Doses : 3.0 mL / L of
water

Some Chitosan based formulations available in India

Plant Growth Promoting Micro organisms as Bio-Stimulants.
Among the beneficial fungi for
cultivation of plants, the following
species are noted:
1. Glomus intraradices,
2. Trichoderma atroviride,
3. Trichoderma reesei, and
4. Heteroconium chaetospira
Among the Plant growth promoting
bacteria following are important from
agricultural point of view :
1. Arthrobacter spp.
2. Enterobacter spp.
3. Acinetobacter spp.
4. Pseudomonas spp.
5. Ochrobactrum spp.
6. Bacillus spp.
7. Rhodococcus spp.

Interaction of Soil living micro-organisms with plant root.
Interactions between
plants and bacteria
occur through
SYMBIOTIC,
ENDOPHYTIC or
ASSOCIATIVE
processes with
distinct degrees of
proximity with the
roots and
surrounding soil.

Different beneficial activities
of Plant Growth Promoting
Bacteria

Mechanism of action of Phosphate Solubilizing Bacteria.

Different beneficial activities of Plant Growth Promoting
Bacteria

Enhancing draught tolerance capacity of plants by Plant Growth
Promoting Bacteria

Advantages of PGPR
 PGPR to control wide range of phytopathogenic fungi, bacteria, viruses,
nematodes etc. Bio control mechanism which may be due to antibiotics,
siderophores, enzymes or by systematic resistance against phytopathogen
throughout the entire plant system.
 Effective against root rot and stem rot caused by Scelerotiana, Rhizoctonia,
Damping off, Cercospora, Macrophomine, Downy mildew and powdery
mildew.
 Helps in nitrogen fixation in soil. By both symbiotic and non – symbiotic
means.
 PGPR turns Insoluble phosphates into soluble form so that the plants can
absorb them.
 Improves stress tolerance of plants like tolerance to drought, salinity, etc.
 Increase uptake of micronutrients like Zinc and Fe through more root surface
area
 Production of phytohormones like IAA and GA.

Formulation of different types of PGPR Biological Nitrogen Fixer

Formulation of different types of PGPR Phosphate Solubilizer

Potassium solubilizing bacteria (KSB)
can solubilize K -bearing minerals and
convert the insoluble K to soluble
forms of K available to plant uptake.
Many bacteria such as
Acidothiobacillus ferrooxidans,
Paenibacillus spp., Bacillus
mucilaginosus, Bacillus edaphicus, and
Bacillus circulans have capacity to
solubilize K minerals
Formulation of different types of PGPR Potassium Mobilizer

Nutrients applied or present in the soil are not always available to
plants due to various reasons. One of the main reasons is due to
nutrients getting fixed in the soil. Nutrient Mobilizers are soil living
micro-organism, helps to release these non available nutrients by
mobilizing the nutrients and increasing the buffering capacity of the
soil, which in turn improves and optimizes availability and uptake of
nutrients by plants.
It also helps in retaining water soluble inorganic fertilizers in the
root zones and thereby reducing the leaching.
Nutrient Mobilizers

Nutrient Mobilizers : Combination of different beneficial micro-organisms.
Formulations

Plant Growth Promoters are substances which improve the overall
health, growth and development of plants. These substances may be
either synthetically produced or obtained from Biological derivatives.
Plant Growth Promoters (PGP) are effective in improving the crop,
quality and productivity significantly. PGPs, especially biological
derivatives are more affective and safe. They can be recommended for
all crops.
Plant Growth PromotersPlant Growth Promoters
Presently among different classes of PGPs, Amino acids are enjoying a major
chunk of market share because of their properties which help in plant growth
and development like flowering, fruiting and overall increase in yield. These
amino acids are obtained biological sources like fish waste, animal waste
(slaughter house waste), Plant protein like Soyabean, maize, groundnut etc
Growth promoter is a natural /herbal fertilizer, especially designed for the
overall growth of the plants. These growth promoters are intended to
accelerate the rate of growth and maturation of crops or plants, without
disturbing their natural physiological actions.

Some Commercial Plant Growth PromotersSome Commercial Plant Growth Promoters

Commercial Plant growht regulators used in india

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