Cultivation, Methods of Propagation, Factors Affecting Cultivation and Plant
Hormones
Contents
• Cultivation
• Methods of propagation
• Factors affecting cultivation
• Plant hormones
Objectives
At the end of this
lecture, student will be able to
• Explain the various methods of propagation, advantages and
disadvantages of cultivation
• Discuss the effect of following parameters on cultivation
– Altitude
– Temperature
– Rainfall
– Day length and radiation characteristics
– Soil and soil fertility
– Fertilizers and manures
• Describe pests and pesticides
• Enumerate various plant hormones
• Discuss the role of plant hormones in growth Cultivation
Cultivation
• Cultivation is a process of preparing and use of land for growing crops
• Preparing and Use of land
• Factors from agricultural to pharmaceutical sphere
Advantages
• Purity and Quality
• Good quality
• Better yield and Therapeutic quality
• Regular supply
• Industrialization (Coffee and cocoa cultivation in Kerala)
• Modern technologies
Disadvantages
• High cost
• Prone to loss
Methods of
Propagation
• Sexual method (Seed propagation)
• Asexual method (Vegetative propagation)
Sexual
Method (Seed Propagation)
• Should be collected from the perfectly ripe fruits
• Should be stored in a dry and cool place
• Must not be over dried
• Long storage of seeds reduces its germinating power
Examples: Cinnamon, Cocoa, Nutmeg etc
• Sometimes immediate sowing of seeds are advised
Cultivation- Seed
propagation method
• Slow germinating seeds – soaked in water or 0.2% solution
of gibberelic acid for 48 hours before sowing
• More drastic methods are used such as
– Soaking in sulphuric acid eg. henbane seeds
– Partial removal of testa by grind stone. eg. Henbane seeds
– Scarification of seeds. eg. Ipomea, gave 95% germination
in 8 days
• Chemical treatments – gibberelic acid, cytokinins,
ethylene, thiourea, potassium nitrate or sodium hypochlorite
• Gibberelic acid – dormant seeds & stimulates the
seedling growth
• Thiourea – those do not germinate in dark or high
temperatures
Methods of
Propagating Seeds / Sowing Seeds
Seed Propagation
Method – Advantages
• Bear heavily
• Long lived
• Sturdy
• Easy to raise
• Chance seedlings of superior merits
• Where other methods cannot be utilized, this is only
method of choice
Seed Propagation
Method – Disadvantages
• Cost of harvesting, spraying of pesticides
• Not uniform in growth, yielding capacity
• More time to bear
• Not possible to avail the modern technologies
Asexual
Method (Vegetative Propagation)
Vegetative parts of the
• Bulbs (Squill)
• Corms (Colchicum)
• Tubers (Aconite)
• Rhizomes (ginger)
• Division (Rhubarb, Gentian)
• Runners and offsets (Chamomile & Mint)
• Suckers and Stolons (Liquorice & Valerian)
• Cuttings or Portions (Mint, Vanilla)
• Layering (Cascara)
• Grafting and Budding: STOCK
and SCION or GRAFT
• Budding – Piece of bark bearing a bud into a suitable
cavity or a T shaped slit made in the bark of the stock
• Fermentation
• Inoculation
• Cell culture
Advantages of asexual
method (Vegetative propagation)
• No variation
• Seedless varieties
• Bear earlier
• Disease resistant plants
• Modifying influence of root stocks on scion
• Inferior and unsuitable varieties
Disadvantages of
asexual method (Vegetative propagation)
• Not vigorous in growth
• Not long lived
• No new varieties can be evolved by this method
Factors
affecting cultivation of crude drugs
• Growth and development
• Nature and quantity of secondary metabolites
– Altitude
– Temperature
– Rainfall
– Day length and radiation characteristics
– Soil and soil fertility
– Manures and fertilizers
– Pests
– Important factor
Altitude
• Some plants grow in higher altitude, some in medium
altitude and some in sea level
• Cinchona succirubra – low altitude with NO alkaloids
• Bitter principle of Gentiana lutea increases with increase
in altitude
• Alkaloids of Aconitum napellus, Lobelia inflata, oil content
of thyme decreases with increase in altitude
• Pyrethrum – lower altitude – increased vegetative growth,
High altitude – increased flower heads
Cinhona
1000 – 2000 M
Tea 1000 – 1500 M
Camphor 1500 – 2000 M
Cinnamon
250 – 1000 M
Temperature
• Controls the development and metabolism in plants
• Exist in variable range of temperatures
• Plants in tropical and subtropical places – withstand heat
in summer, lack frost resistance in winter
• Optimum temperature for nicotine in Nicotiana rustica is
20OC, less incase at 11-12OC and at 30OC
• Fixed oil produced at lower temperature – more double
bonds
Cinchona 60 – 75oF
Coffee 55 –
70oF
Tea 70 –
90oF
Rainfall
• Effect of rain fall should be considered with relation to
– Annual rainfall
– Distribution throughout the year
– Effect on humidity
– Effect coupled with the water holding capacity of the soil
• Continuous rain – Leaching out of water soluble components
• Senna – Leaf bio mass
• Xerophytic plants
Day Length
and Radiation Characteristics
• Vary much in their light and radiation requirements
• Wild condition – Shade requirements are met
• Cultivation – Shade should be provided
• Light an important factor – alkaloids and glycosides
– Belladona, Stramonium, C. ledgeriana, full sun shine ↑ses alkaloids
– D. stramonium var. tatula – intense light for long time ↑ses
the hyoscine content at the time of flowering
• Catharanthus roseus – irradiated with near UV light –
stimulates the synthesis of dimeric alkaloids
• Day and night changes – Nicotiana sylvestris, benzyl
alcohol increases in night, no increase in volatiles like linalool,
caryophyllene etc
• Flowering plants – day length pattern
• Peppermint leaves –
– Long day, more of menthone, menthal, traces of menthofuran
– Short day, menthofuran is major
• Types of radiation
– Ocimum basillicum – UV-b radiation increases the phenyl
propanoids, terpenoids, falvonoids and anthocyanins
Atmospheric
conditions
• Digitalis – exposed to 1000 ppm of CO2, digoxin content
increased by 3.5 times
Pest and
Pest Control
Pest
• Undesired plant or animal or microorganisms
Pesticides
• Synthetic and natural sources effective in small
concentration against pests
Examples
Virus, fungi, insects, weeds, non-insect pests etc
Virus
• Mosaic virus- necrosis of leaves, stems etc
• Tobacco mosaic virus – tobacco, digitalis etc
• Cucumber mosaic virus – digitalis and Hyocyamus
• Yellow vein mosaic virus, graft transmissible virus etc
Fungi
Fungus affects the plant and decreases the yield
• Eg. Ascophyta atropae – leaf necrosis
• Cercospora atropae – leaf spot
• Pythium spinosa
• Cercospora dioscorea
• Other diseases are damping off (death of seeds), downy
mildew (white and grey patch in leaf), powdery mildew (white powdery patch),
rust and smuts (in cereals)
Insects
• Causes drastic damage – Agrotis, caterpillar, grass
hopper, spiders, ticks, mites etc
• Either by Biting and Chewing or by Piercing and Sucking
Weeds
• Undesired Plants
• Compete for nutrient, sunlight, space and water
• Enhance the effects of other pests
• Even causes allergies to humans
– Parthenium causes hay fever
– Poison ivy causes dermatitis
Non Insect Pests
• Vertebrates – rats, monkeys, birds, rabbits etc
• Non – Vertebrates- snails, mites, crabs etc
• Contaminate the crops with faecal matter
Pest
Control Methods
• Mechanical
• Agricultural
• Biological
• Chemical
Mechanical
Method of Pest Control Methods
• Collection – Eggs,
larvae, pupae, small insects
• Trapping
– Used to capture rats, mice, flying insects etc
– Flavoured attractants were used
– Rose oil / anise oil mixed with saw dust
• Pruning / Cutting
• Burning
– Helps to eradicate both plant pest & animal pest
– Preferred when pruning or cutting is not possible
• Hand picking,
Shaking and Beating
Agricultural
method of Pest Control Methods
• Advanced plant breeding techniques – genetically
manipulated / pest resistant crops
• Systemic insecticides
• Crop rotation
• Deep ploughing – eradicate the weeds / early stages of
insects
• Change in environment
Eg. Checking supply of foods, spreading of oil layer in
water with mosquito larvae
Biological
method of Pest Control Methods
• Combating the pests, mostly the insects, with other living
organisms and the latter will be the parasite form
Examples
• Sex phremones
• 7, 8, epoxy 2 methyloctadecane – gypsy moth
• Rabbit destroys certain types of weeds
• Birds eat insects
• Certain flies and wasps lay their eggs on larger insects,
which further hatch into smaller larvae and consume the body of the insect
EFFECTIVE – SAFE –
ECONOMIC
Chemical
method of Pest Control Methods
• Rodenticides –
against rodents like rats, mice etc
• Insecticides –
against various insects and arthropods
• Ovicides –
against egg stage
• Larvicides –
against the larva stage of insects
• Acaricides –
against ticks and mites (Chlorbenzolate)
• Herbicides /
Weedicides
– Used to kill or inhibit the growth of the undesired plant
– Protective or eradicant activity in the form of spray,
aerosol, suspension etc
– Stomach poisons – protective in action, Contact poisons –
eradicants
– Fumigants and insect repellent
Examples
• Chlorinated hydro
carbons: DDT, DDE, BHC, Gammaxine, Aldrin, Eldrin etc
• Organo phosphorous
compounds: Dichlorvos, Malathion, Methyl parathion, Carbophenothion,
Trichlorophon, Tetra ethyl pyro phosphate etc
• Carbamates:
Carbaryl
• Inorganic
compounds: Calcium arsenate, Lead arsenate, Zinc phosphite etc
• Fumigants:
Aluminium phosphide, Hydrogen cyanide, Ethylene dichloride, Methyl bromide,
Phosphine
• Natural Pesticides:
Tobacco, Pyrethrum, Derris, Neem, Sabadilla
Ideal
Properties of Pesticides
• Nontoxic, non-injurious to medicinal plant and humans
• Selective in action and effective in small concentration
• Stable under normal storage conditions
• Non inflammable
• Non corrosive
• Free from obnoxious odour
• Non-cumulative in soil
Soil and
soil fertility
• Fertilizers and manures
• Most important natural resource
• Provides anchorage, water and essential minerals
• Soil Fertility
• Growth depends on the
– Physical arrangement
– Nature of soil particles
– Organic matter
– Living organisms of soil
• Upper shallow layer – friable, plants find foot hold and
nourishment
• Clay – finest particle holds the nutrient
• Depending upon the size of the mineral matter it is
classified as,
Less than 0.002 mm Fine clay
0.002 – 0.02 mm Coarse clay or silt
0.02 – 0.2 mm
Fine sand
0.2 – 2 mm Coarse sand
• If the soil contains less than
0.5 % organic matter – Poor soil
1.5 – 5 % – Rich soil
0.5 – 1.5 % –
Intermediate soil
• Based on the percentage of clay covered,
More than 50 % clay Clay
30 – 50 % clay Loamy
20 – 30 % clay Silt loam
10 – 20 % clay Sandy loam
More than 70 % sand Sandy soil
More than 20 % lime Calcarious soil
• Good Soil – 50 % pore space, water and rest 50 % pore
space air
• PH: 6.5 – 7.5 – Optimum range
• Acidic Soil,
Alkaline Soil
• CO2, Water, Sunlight and Minerals
• C, H, O, N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B, M0, Cl;
Na, Co, Va , Si
Chemical Fertilizers
• Basic nutrients – C, H, O 96% in plants – present in
atmosphere, no need to apply
• Primary nutrients – Large amounts – N, P, K
• Secondary nutrients – Smaller quantity – Mg, Ca, S
• Micro elements – Trace elements – Cu, Mn, Fe, B, Z
• C, O2, N2, H2, Chlorine – air and water
Based on functions
performed in plants:
• Basic structure: C, H, O
• Energy storage, bond transfer: N, S, P
• Charge Balance: K, Ca, Mg
• Enzyme activation & electron transport: Fe, MN, Zn,
Cu, B, Mo, Cl
Mobility in soil:
• Mobile: Highly soluble, not adsorbed on clay complex; NO3–,
SO4=, Cl–
• Less Mobile: Soluble, adsorbed on clay complex; K+,
NH4+, Ca+, Cu++
• Immobile: Highly reactive, gets fixed in soil; H2PO4–,
HPO4=, Zn++
Mobility in Plants
• Helps in finding the deficient nutrient
• Mobile nutrient moves to the growing point in case of
deficiency
• N, P, K – Highly mobile
• Zn – Moderatley mobile
• S, Fe, Mn, Cu, Mo, Cl – less mobile
• Ca, B – Immobile
Nutrients based on
chemical nature
• Metals: K, Ca, Mg, FE, Mn, Zn, Cu
• Non-metals: N, P, S, B, Mo, Cl
• Cations: K, Ca, Mg, FE, Mn, Zn, Cu
• Anions: NO3, H2PO4, SO4
Fertilizers
• Materials having definite chemical with high analytical
value that supply plant nutrients in available form
• Mostly organic, except CaCN2 – Inorganic
– Complete fertilizer
– all three major nutrients: N P K
– Incomplete
fertilizers – Lacking any one major nutrients
– Straight
fertilizers – only one nutrient; murate of potash
– Complex fertilizer
– more than one primary/major nutrient produced by chemical reactions
– Mixed fertilizers –
2/ more mixed as dry powders, granules, pellets, bulk blends or liquids
Methods of
applications of Fertilizers
Broadcast
• Broadcasting at planting
• Topdressing
Placement
• Plough sole placement
• Deep placement
• Subsoil placement
Localised placement
• Drill placement
• Hill placement
• Pellet placement
In liquid form
• Starter solutions
• Sprays – foliar
• Direct application to soil
• Through irrigation water
Nitrogen
fertilizers
Ammonium / nitrate
ion
• Ammonical
fertilizers – Ammonium sulphate, chloride, phosphate
• Nitrate fertilizers
– Sodium nitrate, calcium nitrate, Nitro phosphate
• Ammonium/nitrate
ions – Ammonium nitrate, Calcium ammonium nitrate
• Amides – Urea,
Urea phosphate, Urea sulphate
• Nitrogen solutions
– Aqueous ammonia, anhydrous ammonia, Solution of urea, ammonium nitrate,
ammonia
• Slowly available N
fertilizers – Urea- formaldehyde compounds, Oxamide
Phosphatic
fertilizers
• Phosphorus when burnt gives P2O5; with water its gives
meta phosphoric acid, HPO4
• Meta phosphoric acid with water gives ortho phsphoric acid
– H3PO4
• H atoms are replaced, 3 salts are formed
– Ca(H2PO4)2
– water soluble – superphospahte, enriched superphosphate, triple superphosphate,
ammonium phosphate
– Ca2(HPO4)2 dicalcium phosphate – citric acid soluble
– raw and steamed bone meal
– Ca3(PO4)2
(tricalcium phosphate) – mineral acid soluble – rock phosphate, raw bone
meal, steamed bone meal
• Plants take P2O5 in the form of H2PO4 – supplies available
P2O5 – Superphsphates
Potassic
fertilizers
Raw materials for manufacturing K nutrient,
• Carnallite (KCl, MgCl2, 6H2O)
• Kainite (KCl MgSO4, 3H20)
• Langbeinite (K2SO4, 2MgSO4)
• Sylvite (KCl)
Sources of potassium
• Potassium chloride or murate of potash (60-62 % K2O)
• Potassium sulphate or sulphate of potash (48-52 % K2O)
• Potassium magnesium sulphate (20-30 % K2O)
• Potassium nitrate (44 % K2O)
• Bittern potash (7 % K2O)
Manures
• Farm yard manure, compost castor seed cake, poultry waste,
neem seed cake, Blood meal, fish meal, bone meal
• 3-6 % nitrogen, 2 % phosphates, and 1-1.5% potash
Biofertilizers
• Micro-organisms or lower organisms
• Examples: Rhizobium, Azotobacter, Azosperillum, Blue green
algae Etc
Plant Hormones
• Naturally occurring growth regulators – low concentration
controls the physiological processes
• Plant growth regulators – Endogenous & Exogenous
(synthetic)
• Growth and development
• Five groups of plant hormones
– Auxins,
– Gibberelins,
– Cytokinins,
– Abscisic acid,
– Ethylene
Use of Plant Hormones
• Regulating cell enlargement
• Cell division & differentiation
• Organogenesis
• Senescence
• Dormancy
Auxins
• In 1931, Dutch workers
– Auxin-a (human urine) and auxin-b (cereals)
• General term – Promote the elongation of coleoptile
tissues
• Involved in
– Internode elongation
– Leaf growth
– Initiation of vascular tissues
– Cambial activity
– Fruit setting in the absence of pollination
– Fruit growth
– Apical dominance
– Inhibition of root growth
– Influencing physical, chemical properties in leaf
abscission
– Inhibition of lateral buds
• Major auxin –
Indole Acetic acid (IAA)
• Other natural
auxins
– Indole 3 Acetonitrile,
– 4 chloroindole 3 AA
– Phenyl acetic acid
Synthetic auxins
• Indole 3 butyric acid
• 2 Naphtyloxy acetic acid
• α naphthyl acetic acid
• 1 naphthyl acetamide
• 2, 4 dichloro phenoxy acetic acid
• 2, 4, 5 tri chloro phenoxy acetic acid
• 5 carboxy methyl NN dimethyl carbamate
Practical uses of
auxins
• Low concentration –
rooting of woody, herbaceous cuttings
• Higher concentration
– selective herbicides or weed killers
– 1:500 000 solution of NAA for 24 hrs subsequently develop
roots
– 2, 4 Dichloro phenoxy acetic acid – toxic to dicots,
little effect against monocots
– Carbamates and urea derivatives – toxic to grass but no effect
on dicots
Gibberelins
• In Japan, rice plants affected by a disease – plant grow
taller and not support themselves – Gibberella fugikuroi
• Crystalline active material – Gibberelin
• GA1, GA2, GA3
• GA1 is isolated from Phaseolus multiflorus
• GA3 – Gibberelic acid
• By 1980, 58 gibberelins were known; 50% from fungus, 50%
from higher plants
• Gibberelins – leaves, accumulate in relatively large
quantities in the immature seeds and fruits of some plants
• Cell elongation – sub-apical meristem region where young internodes
are developing
Important Actions of
Gibberelins
• Initiation of synthesis of various hydrolytic and
proteolytic enzymes upon which seed germination and seedling establishment
depends
• Used to treat secondary metabolites like volatile oils,
terpenoids, alkaloids, glycosides etc
Cytokinins
• Specific effect on cell division (cytokinesis)
• Not confined only to cell division; also regulate the
pattern and frequency of organ production; position and shape
• Inhibitory effect on senescence
• Kinetin –
autoclaved DNA of herring sperm
• Zeatin – liquid
endosperm of coconut and in extracts of maize embryos
• Complex – Cambial region of various woody tissues
• Tissue culture work – promote the formation of
adventitious buds and shoots from undifferentiated cells
Growth
Inhibitors
• Natural growth inhibitors – affect bud opening, seed
germination and development of dormancy
• Abscisic acid (ABA), natural, fungus Cenospoara rosicola
• Carotenoids – Similar to abscisic acid
• Xanthophylls – Violaxanthin produce a germination inhibitor
on exposure to light
• Related substances – Vomifoliol (have same activity as
abscisic acid in stomatal closure tests)
• Synthetic growth inhibitors – maleic hydrazide, N dimethyl
amino succinamic acid
Ethlyene
• Evolved by stored apples; inhibited the growth of potato
shoots enclosed with them
• Role in fruit ripening
• Synthesized from S adenosyl methionine
• Stimulation of de novo synthesis
• Secretion of cell wall dissolving enzymes like cellulase
during leaf abscission and ripening of fruit
• Ethephon (2 chloroethyl) phosphonic acid is a compound
which gives similar response to that of ethylene
Other
Growth Regulators
• Aliphatic and aromatic carboxylic acids
• Phenolic and neutral compounds
• Salicylates
• Polyamines
• S and N heterocyclic compounds, including alkaloids and
terpenes
• Brassinosteroids – seeds, pollens, galls, leaves, flower
buds and shoots
• Other substances stimulate cell enlargement and cell
division and influence gene expression and nucleic acid metabolism at the
molecular level
Summary
• Cultivation is a process of preparing and use of land for
growing crops
• Methods of propagation includes both sexual and asexual
method
• Sexual method is by using seeds and the germinating
capacity is improved by using physical or chemical treatments
• Asexual method is by using any vegetative part of the
plants
• Both sexual and asexual methods has its own advantages and
disadvantages
• The factors that affects cultivation includes altitude,
temperature, rainfall, day length and radiation characters, atmospheric
conditions, fertilizers and manures, pest and pest control etc
• The growth, development and the production of active
constituents varies according to the above said factors
• Active constituents varies according to the altitude where
the plant grows
• Temperature controls the development and metabolism in
plants
• Except xerophytic plants, all other plants require water
either in the form of irrigation or rainfall
• Day length and radiation characteristics affects the
composition of the constituents
• Pests are undesired plants or animals or microorganisms
which causes damage to crops & includes virus, fungi, insects, weeds and non-insect
pests
• Pests can be controlled by mechanical method, agricultural
method, biological method and chemical method
• Soil fertility is the ability of the soil to provide the
nutrients in correct proportion and quantity to the plants
• Soil can be classified based on particle size, %
composition of clay, mineral content etc
• Chemical fertilizers includes primary nutrients, secondary
nutrients and micro elements
• Manures and bio fertilizers are also used for the proper
growth of plants
• Plant hormones are naturally occurring growth regulators
and in low concentration controls the physiological processes
• Plant hormones includes auxins, gibberelins, cytokinins,
abscisic acid and ethylene
• Generally auxins, gibberelins and cytokinins promotes
growth, whereas abscisic acid and ethylene are growth inhibitors