3. INTRODUCTION
( A ) WATER :
Properties of water
Types of water
Mechanism of absorption
Water stress effects
Heavy water effects
Physiological influences of water in plant
4. ( B ) MINARAL NUTRITION :
Criteria of essentiality
Classification
Role
Deficiency symptoms
Mechanism of absorption of ions
5. water
Def : Water is an unusually good solvent for a large variety of substances & is
an essential component of all organisms , being necessary for most biological
processes unlike most substances , water is less dence as than liquid form ,thus
ice floats on liquid water .
In the words of Leonardo da Vinci – Water is the driver of the life .
Usable water restricted to barely 0.60%
Oceans – 97.39%
Polar ice bergs & glaciers – 2.01%
Ground water & soil moist – 0.58 %
Lacks & rivers – 0.02%
Atm Water – 0.001%
Total - 100 %
6. Water is indispensable input for the life of animal as well as plants .it said to be the liquid of life or
elixir of life .
Leaves : 35 – 95 %
Roots : 60 - 90 %
Fleshy fruits : 70 – 90 %
WATER PLAYS MULTIFOLD ROLES IN PLANT SYSTEM :
1.Water is a way of transportation of nutrients from roots to shoots & vice – versa .
2. Water is a means of thermal regulation of temperature inside the plants .
3. Many organic constituents of plants such as carbohydrates proteins , nucleic acids & enzymes etc.
are denaturated in the absence of water .
4. Water forms the source of hydrogen for the reaction of carbon di oxide in the process of
photosynthesis .
5. Water is essential for maintain the turgidity & is essential for survival of plants .
7. Types of water
Soil is reservoir of water for plants .
Soil gets water due to percolation of rain water .
Soil water is 4 types
Run away water : is drains away along the slopes due to heavy rain fall is run away water .
Gravitational water : due to the influence of earth gravity some amount of percolates towards earth crust
forming water table .
Hygroscopic water : this film of water found around soil particles is hygroscopic .
This type of water is adhered to soil particles due to strong surface forces .
Capillary water : the water present in small pore spaces of soil thin column called capillary water .
Having horticultural importance because this is available to plants for absorption .
8. Properties of water
1. water is a polar molecule
2. water is highly cohesive
3. water has high specific heat
4. water in pure state having the neutral pH
5. universal solvents
6. high surface tension .
9. ASCENT OF SAP
DEFINITION : the upward movement of water along with low con of mineral ions
through the treachery elements (xylem) against earth‘s gravitational pull from the under
ground absorbing root system to the aerial transpiring shoot system is called ascent of
sap .
MECVHANISM OF ASCENT OF SAP : COHESION TENSION THEORY BY
Henry Dixon.
Theory : 3 basic elements :
1. Transpiration pull
2. Cohesion of water molecules
3. Adhesion of water molecules with the lignified walls of xylem.
11. STEP WISE DESCRIPTION
1. Due to transpiration , mesophyll cells of the leaves loose a huge quantity of water ,
which result in the decrease of water potential in those plants .
2. due to the decrease in the water potential ,water from adjacent cells move into
mesophyll cells .
3. A water potential gradient extends up to the xylem elements of the leaf , resulting in
building up tension in the xylem , which is ultimately transmitted to the root ,
through the stem .
4. since the xylem of leaf is in continuity with the xylem of stem and root , the water
ascends in the form of an unbroken water column.
5. The water column dose not break up due to strong cohesive forces of attraction
between two water molecules ,which is around -300 bars(-30 Mpa).
12. 6. Water continuously moves through the xylem due to high adhesive forces of
attraction between water molecules & the lignified walls of xylem elements .
OBJECTIONS: Embolism
Tracheid eliminating by xylem in course of evolution .
TRANSPIRATION
DEF : Plants absorb more water than what they required .only about 5% of the
absorbed water is used for their growth & development , the remaining 95% is lost
in vapour or liquid form .this loss of water in the form of vapour from the living
tissues of areal parts of the plant is called transpiration.
Transpiration can be demonstrated by bell jar & cobalt chloride .
13.
14. Transpiration
It is a physiological process .
It is regulated by activity of guard
cells .
Several types of biological factors
are involved .
The surface area of transpiration is
regulated by guard cells.
It prevents dryness of cell –
surface.
Evaporation
It is a physical process.
It is not a biologically regulated
process.
No involvement of biological factors.
The surface area of evaporation is
fully exposed .
Evaporation leads to drying up of
surface .
15. Types of transpiration
Based on structure involved in loss of water following 3 types of transpiration
are recognised.
STOMATAL TRANSPPIRATION :80- 90 %
CUTICULAR TRANSPIRATION : 5-10%
LENTICULAR TRANSPIRATION : 1-2%
16. FACTORES EFFECTING ON TRANSPIRATION
EXTERNAL FACTORS : light
1.Temperature
2. Wind
3. Atmospheric humidity
4. Availability of soil water .
INTERNAL FACTORS :
1. Structure of the leaf
2. Area of transpiring surface
3. Number of stomata
4. Root / shoot ratio
17.
18. HEAVY WATER EFFECTS
1. Due to water logging oxygen deprivation or anoxia as excess water it self dose not react
chemically with the plant .
2. Plants need oxygen for cell division , growth & the uptake & transport of nutrients .
3. Since oxygen diffuses through undisturbed water much more slowly than a well drained soil
,oxygen requirements rapidly exeed that which is available when soils are saturated .
4. At higher temperatures oxygen depletion is more .
5. water logging conditions also reduce root growth & can predispose plant to root rots , so the
ultimate effect of excess moisture may not be known until late in the season.
6. Stem rotting
7. Increases the spreading of diseases.
8. Reduces the nitrogen availability by leaching nitrate form of nitrogen.
9. phosphorus deficiencies later in the season due to restricted root development.
10. Reduces the yield
19. Effects of Water stress
1. photosynthesis
2. protein synthesis
3. morphological, anatomical & cytological changes
4. ABA accumulation
5. Mineral nutrition
20. ( B ) MINARAL NUTRITION :
Criteria of essentiality
Classification
Role
Deficiency symptoms
Mechanism of absorption of ions
21. MINARAL NUTITION : The study of how plants obtain mineral elements &
utilise them for their growth & development is called as mineral nutrition .
JULUS SACHS & W. KNOPS : Taking the advantage of technique of
growing plants in water culture called hydro phonics .
It revealed by plant analysis that 30 – 40 elements occur in a plant .
Scientists proved around 70 elements exist in one plant .
How ever questions are arise all these elements essential for plants .
As an answer to this question 2 American physiologists Daniel Arnon & Perry
Stout in 1939 proposed criteria of essentiality .
22. CRITERIA OF ESSENTIALITY
1 . The elements is essential to complete the vegetative or reproductive or both
the stages of life cycle of plants .
2 . The requirement of element must be specific & not replaced by another
elements .
3. The element must be directly involved in the metabolism of the plants .
4. The elements which satisfy the criteria of essentiality are considered
essential elements .
5 . Total essential elements - 16
7 . Ni was added - 17
23. Based on quantitative requirement
1. Macro nutrients :
H , C , O
N , P , K
Ca , Mg , P, S
2 . MICRO NUTRIENTS :
Cl , B , Fe
Mn, Zn , Cu
Mo , Ni
24.
25. ROLE OF MINARALS
C H O 1. CO2 – Synthesis of carbohydrates & fats which
build protoplast & cell wall .
2. H2O – Very essential for enzymatic activities .
3. All components of living organisms contain CHO .
Without which the plant life shall not exist
N 1. Important constituent in porphyrin structure of
chlorophylls & cytochromes .
2. N is one of the major constituent in porphyrin structure
of chlorophyll & cytochromes .
26. MINARAL ROLE
P 1. P is a important structural component of cell membranes ,
certain proteins & nucleic acids .
2. It is important component of ATP , the energy currency of cell .
K 1. Helps in maintain the anion & cation balance in the cell.
2. It plays an important role in stomatal movement .
Ca 1. Important component of cell wall , particularly as calcium
pectate in middle lamella .
2. It plays an important role in cell division .
Mg 1. It inactivate the enzymes of respiration & photosynthesis .
2. Mg is a central atom of porphyrin ring of chlorophyll .
27. Element ROLE
S 1. It is important constituent of some amino acids .
(cysteine , cystin , Methionine ) .&
Vitamins – biotin , thiamine , co – enzyme A .
2. Disulphide linkages helps to stabilise the protein
structure .
Fe 1. Is essential for synthesis of chlorophyll .
It is important constituents of cytochromes .
Mn 1. Helps in spitting the water to liberate O2 during
photosynthesis .
2. It is activator of IAA oxidase enzyme .
Zn 1. Activator of carbonic anhydrase enzyme .
2. Zn is needed for synthesis of IAA .
28. ELEMENT ROLE
Co 1. Part of plantacyanin & thus play a role in ETC of
photosynthesis .
2. It is also important component of cytochrome C – Oxidase the
most important respiratory enzyme in aerobic organisms .
B 1. It facilitate the translocation of sugars in plants.
2. B require for pollen germination .
Mo 1. A component of nitrate reductase involved in N uptake .
2. A very significant role in N fixation since it is apart of co –
enzyme dinitrogenase .
Cl 1. Involved in photosynthesis of water & oxygen evolution during
photosynthesis .
2. It is important osmotically active solute as it determines the
solute concentration & anion cation balance in cell .
29. 1. Basic nutrients – C H O
2. Macro nutrients –
Primary – N P K
Secondary – Ca , Mg .
3. Micro nutrients – Fe ,Zn, Cu, Mo, Cl.
4. Beneficial nutrients – Na, Co, Va , Ni, Si .
30. Mobility in plant
Highly mobile : N P K
Moderately mobile : Zn
Immobile : Ca , B .
31. FUNCTIONS IN THE
PLANTS
Energy storage &
bonding
N S P
Regulators &
carriers
K Ca Mg
Acts as regulators &
carriers
Fe Mn Zn Cu B Mo Cl
32. Deficiency symptoms appeared on :
Old leaves : N P K , Mg , Mo
New Leaves : S , Fe ,Mn , Cu
OLD & NEW LEAVES : Zn
Terminal bud : Cu , B .
ION ABSORPTION studies Hoagland ,knops , Epstein & others .
Except C , H , O remaining essential elements absorbed from soil in
ionic form by roots .
MODE OF ABSORPTION :1. Active absorption
2. Passive absorption
33. Mode of absorption
Passive Absorption
1. transport propelled by
physical driving forces .
2. metabolic energy is not
utilized .
3 .It is also called as non –
metabolic ion absorption .
Active Absorption
1. transport propelled by
metabolic energy.
2. ATP is utilised for ion
absorption.
3. it is also called as metabolic
type ion absorption .
34.
35. WHAT IS ACTIVE ABBSORPTON ?
Active means more ion concentration in plants than in exist soil solution .
For ex : Nitrella ( algae ) absorbs potassium ions to a concentration several
times more than the surrounding water .
It is proved by : When metabolic inhibitors like azides , cyanides are used
they inhibit the property of respiration hence ATP is not generated .
As result the ion accumulation is also inhibition .
It is clear evident that transport of ions dependent upon metabolic energy .
36. IRREGULAR DOSES - DISSORDERS
NITROGEN : Higher Dose : Soft Nose – Mango (Kent) ,Improper Ca
Degrain – Banana
Granulation – Citrus
Fruit Cracking – Citrus
Fruit Cracking – Pomegranate
Fruit Cracking – Cherry
Fruit Cracking - Litchi
Malformation – Strawberry
Water Berry – Grape
Deficiency : Fruit Pitting – Mango
BORON : Deficiency : Fruit Pitting – Mango
Short Berry – Grape
Fruit Necrosis – Amla
Crown Chocking – Coconut
Higher Dose : Water Core – Apple
Janathan spot - apple
37. POTASSIUM : Higher dose : banana - yellow pulp
apple – brown core
ZINC deficiency – citrus Frenching /mottle leaves /little leaves
MANGANESE deficiency – mouse ear – pecan nut
CALCIUM deficiency – bitter pit – apple
Complexive irregularities
N +K - Heavy Dose – Calyx Cavity – Persimmon
N + P +K – Heavy Dose – Albinism – Strawberry
B + Ca – Deficiency – Fruit Cracking – Citrus
B+ K – Deficiency - Barren Nuts – Coconut
B+ Zn – deficiency - Hen & Chicken Disorder – Guava
Heavy Soil Fertility - Pine Apple – Fasciation
P + K + Zn - Bronzing in guava
Unfavourable Water Relations B/W Fruit & Other Parts – Hard End – Pear
38. REFERENCE :
1. Text book of biochemistry
2. Basic horticulture – Jethendra Singh
3. Instant horticulture – S. N . Guptha
4. google .com
