eChapters

The term “plant health” has two overlapping meanings. In the more specific meaning, plant health refers to plant quarantine, while in the less specific use, it covers all areas of plant protection, such as plant pest management, plant quarantine, and pesticide regulation and application.

Thiamann (1948) designated the plant hormones by the term ‘phytohormones’ in order to distinguish them from animal hormones. He defined a phytohormone as “an organic compound produced naturally in higher plants, controlling growth or other phy-siological functions at a site remote from its place of production and active in minute amounts.”

According to Johannes van Over-beek (1950), the plant hormones are defined as “organic compounds which regulate plant physiological process – regardless of whether these compounds are naturally occurring and/or synthetic; simulating and/or inhibitory; local activators or substances which act at a distance from the place where they are formed.”

When crops are grown in either intercropping or sequential cropping interaction between different component crops occurs which is essentially a response of one species to the environment as modified by the presence of another species is commonly referred to as interference or interaction.

The interaction are classified into three groups

1. Competitive interaction: One species may have greater ability to use the limiting factor and will gain at the expense of the other and this is called competitive interaction or when one or more growth factors are limiting, the species that is better equipped to use the limiting factor(s) will gain at the expense of the other and this is called competitive interaction.
2. Non competitive: If the crops are grown in association and the growth of either of the concerned species is not affected, such type of interaction is called non competitive interaction or if resources (growth factors) are present in adequate quantities, as a result of which, the growth of either of the concerned species is not affected, then it is non-competitive interaction or interference.
3. Complementary: If one species is able to help the other, it is known as complementary interaction or if the component species are able to exploit growth factors in different ways (temporal or spatial) or if one species is able to help the other in supply of factor (like legumes supplying part of N fixed by symbiosis to non-legumes), it is complementary interaction or interference and also referred to as Annidation.

16.1 Introduction

Plant introduction is the process of introducing plants from their growing locality to a new locality. Introduction of plants from a foreign country is called foreign introduction or exotic collection. Introduction from one state to another within a country is called indigenous collection or indigenous introduction. With introduction, the process of acclimatization is associated. Acclimatization is the adaptation or adjustment of an individual plant or population of plants under the changed climate for a number of generations. Plant introduction is an oldest method of plant breeding. It is used in self-pollinated, cross-pollinated and asexually propagated crops. The material of seed-propagated crops is introduced in the form of seed and that of vegetatively propagated crops in the form of cuttings or propagules. The introduced material may be a new crop, a wild relative or a new cultivar of a crop already grown in the area. There are five important sources of plant collection, namely, (1) centres of diversity, (2) gene banks, (3) gene sanctuaries, (4) seed companies, and (5) farmers’ fields.

Plant mineral nutrition is a sub branch of plant physiology which addresses issues on uptake of elements that plant needs to absorb from air or water or soil to grow and to live. Besides function of nutrient elements in plants, it also includes deficiency symptoms and how to address deficiency symptoms in a plant. Plant mineral nutrition and mechanism of uptake has two major aspects:

Plants are responsible for highly useful molecular reactions. All the enzymatic  reactions  that  occur in the cell are  termed  as metabolic reactions.  They  take place within organisms in an orderly and regulated way.  They  are  the  metabolic pathways and the compounds  resulting from the process, namely,  metabolism are called  the metabolites. Metabolism in Greek means change. It is the set of life sustaining chemical transformations within the cells of living organisms. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to the environments around them.
 
Metabolism is a highly organized,   coordinated and purposeful enzymatic activity inside a cell. Metabolism has four functions: 1. To obtain energy from the environment, 2. To convert molecules into building blocks, 3. To convert the building blocks into proteins, lipids, sugars, nucleic acids and other cell components and 4. To synthesize and degrade organic molecules for specific needs of the cell.

Introduction

Plants are considered as immobile organisms with poor sensitivity and limited ability to respond. Within the plant kingdom, Mimosa pudica (also called the sensitive plant), Drosera (sundews), Dionea muscipula (flytraps) and tendrils of climbing plants which showed rapid and purposeful movements were considered as exceptions. These sensitive plants attracted attention of outstanding pioneer researchers like Pfeffer (1845-1920), Burdon-Sanderson (1828-1905), Darwin (1809-1882), Haberlandt (1854-1945) and Bose (1858-1937). Stahlberg, 2006 reported the presence of various mechanoreceptors in such species which could trigger action potentials (APs) which activated these sudden movements.

The first extracellular recording of a plant action potential (AP) development was initiated by Charles Darwin; later, the animal physiologist Burdon-Sanderson in 1873 performed similar studies on leaves of the Venus flytrap (Dionea muscipula Ellis). Haberlandt (1884) demonstrated that phloem strands were the actual paths for excitation by destroying the external, non-woody part of vascular bundles. This notion was confirmed in Mimosa and other plant species by a number of recent studies. Houwink (1935) carried out experiments with two species of Vitis (grape) and obtained electrical fluctuations which was similar and comparable with the action potentials he obtained with Mimosa. In 1907, Bose, used a D’arsonval galvanometer to demonstrate propagating electrical effects in different genera of plants such as Ficus, Artocarpus, Cucurbita, Corchorus, “fern” etc. APs have their largest amplitude in phloem sieve cells and cells adjacent to this area (Sibaoka, 1969). Other studies found that AP-like signals are propagated with equal rate and amplitude throughout the cells of vascular bundles.

The essential plant nutrients, or essential elements, are listed in the Table 41. It enumerates 16 chemical elements of which the essentiality for plant growth and reproduction has been established according to the criteria formulated by D.I. Arnon and P.R. Stout, 1939. This listing has existed since 1954 with chlorine as the latest addition (cited by Hopkins 1999).

These plant nutrients are classified into various groups:

1.    Major elements and trace elements : Of the 16 listed, 9 are major elements or macronutrients and 7 are trace elements or micronutrients. Major elements are those which are needed by plants for their growth and reproduction in relatively large amounts while trace elements are needed in smaller amounts compared to the former. The major elements are further sub classified into structural elements (carbon, oxygen and hydrogen), primary macronutrients (nitrogen, phosphorus and potassium), and secondary macronutrients (calcium, sulfur, and magnesium). Micronutrients are Zn, Cu, Mn, Fe, Mo4 and boron (Table 41).

Plant nutrient disorders result from nutrient imbalances in soils. Nutrients are considered essential for plants, when it satisfies the following criteria (Arnon and Stout,1939):
    1.    The deficiency of the nutrient element makes it impossible for the plant to complete its life cycle
    2.    The deficiency of the element is specific and can be corrected only by supply of that element
    3.    The element is directly involved in the nutrition of the plant

Plant nutrition is the study of the chemical elements and compounds necessary for plant growth, plant metabolism and their external supply. In 1972, Emanuel Epstein defined two criteria for an element to be essential for plant growth:

In its absence the plant is unable to complete a normal life cycle.

The element is part of some essential plant constituent or metabolite.

This is in accordance with Justus von Liebig’s law of the minimum. The essential plant nutrients include carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil.

7.1. Introduction

Like all other living organisms such as humans, animals, and microorganisms, plants also need elemental nutrients for their growth and development. They assemble the nutrients from soil, water and air. However, to obtain economical crop yield, nutrients are also supplied to the crops from external sources such as chemical fertilizers and manures and using biofertilizers. It is the present-day need to handle the soil fertility status in a more realistic and careful way to obtain maximum crop harvest. Under poor management practices, soil may become infertile and loose its importance in agricultural use. In modern days, huge food demand for the burgeoning human population does not permit to show luxury to use only fertile soil. Moderately fertile soil or even degraded soil should also be managed properly so that they may be used to grow crops. For this, plant nutrients status of the soil plays a significant role along with other soil properties. For sustainable soil fertility management, parameters such as crop to be raised, its nutrient demand at various growth stages, current nutrient status of the soil, amount of nutrient application based on the soil testing results etc are important to be considered. Balanced nutrition to the plants is the prerequisite to obtain maximum benefit. If nutrients supplied to the plants are low in quantity than their requirement, crop production is lowered down. Similarly, if the nutrients are provided in more amount in the soil or unbalanced way through fertilizer or manure applications, total crop yield is suffered. It is a very common example that excess of phosphorus leads to zinc deficiency in most crop plants and it has been observed that excess N is responsible for potassium starvation in potato. Again, excess of iron, manganese, zinc, copper shows plant toxicity. Addition of nutrients to soils in excess also causes environmental pollution when the excess nutrients are lost from soil by leaching, surface run-off and volatilization. Unscientific way of soil fertilization leads to increasing cost of cultivation and imparts adverse effect to the environment instead of doing any good. Therefore, one should have a clear knowledge on soil fertility to obtain a sustainable productivity.

Sixteen chemical elements are known to be important to a plant’s growth and survival. The sixteen chemical elements are divided into two main groups: non-mineral and mineral.  The Non-Mineral Nutrients are hydrogen (H), oxygen (O), and carbon (C). These nutrients are found in the air and water.
  
In a process called photosynthesis, plants use energy from the sun to change carbon dioxide (CO₂ - carbon and oxygen) and water (H₂O- hydrogen and oxygen) into starches and sugars. These starches and sugars are the plant’s food. Since plants get carbon, hydrogen, and oxygen from the air and water, there is little the farmers and gardeners can do to control  how much of these nutrients a plant can use.

Involved in plant metabolic functions and the plant cannot complete its life cycle without the element.

7.1. Plant nutrient concentration and plant growth

1. Deficient

Lowest concentration of an essential element that limit yield severely and cause distinct deficiency symptoms.

In the realm of natural elements, there exist approximately one hundred and three distinct elements. Among them, nearly ninety elements are absorbed by plants. To differentiate essential elements from those that plants can assimilate but are not vital, Arnon (1954) established the following criteria:

1. The plant must be incapable of normal growth or completing its life cycle in the absence of the element

2. The element is specific and irreplaceable by another

3. The element directly participates in plant metabolism

By applying these criteria, molybdenum and chlorine are not deemed essential, even though they serve a functional role in plant metabolism. This is because they can be substituted by vanadium and halides, respectively. Subsequently, D. J. Nicholas refined the definition of essential elements, replacing the term “functional or metabolic nutrient” to encompass any mineral element that contributes to plant metabolism, regardless of whether its action is specific.

Plant nutrition is the study of the chemical elements and compounds that are necessary for plant growth, and also of their external supply and internal metabolism. The criteria for an element to be essential for plant growth:

In its absence the plant is unable to complete a normal life cycle; or

That the element is part of some essential plant constituent or metabolite.

Definition

Neamtode may be defined as triploblastic, bilaterally symmetrical, unsegmented, pseudocoelomate individual invertebrate, with 4 main hypodermal chords, a triradiate oesophagus, circum oesophageal nerve ring, and lacking specialized organs for respiration and circulation.They have tubular gonads which open separately in females but join alimentary canal in males to open through a cloacal aperture.

DEFINITION

The term Plant Pathology is derived from Greek words- pathos (suffering) + Logos (study) i.e. the study of the suffering plant. Plant Pathology has two phases broadly-

• Science- understanding of the disease i.e. the theoretical consideration of the suffering plants and how do pathogens invade, how do plants defend themselves, what causes symptoms etc.
• Art- the application of the science to the field problems i.e. Diagnosis and Control.

Plant pathology or phytopathology is the branch of agricultural, botanical or biological science which deals with the cause, etiology, resulting in losses and management methods of plant diseases.

Plant pathology can also be defined as the study of the nature, cause and prevention of plant diseases. Plant pathology is related to most of the old and new sciences like biology, physics, chemistry, physiology, mathematics, genetics, soil science, biochemistry, biotechnology etc.

Study of plant pathology includes the study of sciences viz, microbiology, bacteriology, virology, mycology, nematology, protozology, phycology, unfavorable environmental factors, nutritional deficiencies and flowering plant parasites.

Prologue: The Issues

Farmers lose a significant portion of their income when their crops and products become infested with various insects, diseases and weeds, resulting in much lower crop productivity and lower actual yields than the attainable yield of crops. Yield losses due to pests, pathogens and weeds are responsible for 20-40% losses in global agricultural productivity. India reports crop losses of 20-25% annually due to pest infestations. Without the use of crop protection solutions, there could be a 78% loss in fruit production, 54% loss in vegetable production and 32% loss in cereal production. According to the Ministry of Agriculture, India loses INR 1.48 billion worth of agricultural production annually due to pests, weeds and plant diseases.

1. ………… is the father of plant pathology.

   a) T J Burril

   c) Anton De Barry

   b) Needham

   d) E J Butler

2. ……… first time reported that plant diseases are caused by bacterium.

   a) Robert Koch

   c) Kuhn

   b) E F Smith

   d) T J Burril

Important Points to be Remember

• Father of Indian plant pathology – E.J.Butler
• Father of Plant virology – Beijerinck
• Wheat rust is associated with Indian scientist – K.C.Mehta
• Kresek phase of rice is due to – Bacterial leaf blight
• Bakanae disease of rice is also known as – Foot rot and Foolish seedling disease

Plant physiology is a sub-discipline of botany concerned with the functioning, or physiology of plants. Closely related fields include plant morphology (structure of plants), plant ecology (interactions with the environment), phytochemistry (biochemistry of plants), cell biology, genetic, biophysics and molecular biology. Fundamental processes such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropism, nastic movements, photoperiodism, photo-morphogenesis, circadian rhythms, environmental stress physiology, seed germination, dormancy, stomata function and transpiration, both parts of plant water relations, are studied by plant physiologists. The field of plant physiology includes the study of all the internal activities of plants those chemical and physical processes associated with life as they occur in plants. This includes study at many levels of scale of size and time. At the smallest scale are molecular interactions of photosynthesis and internal diffusion of water, minerals, and nutrients. Major sub disciplines of plant physiology include phytochemistry (the study of the biochemistry of plants) and phytopathology (the study of disease in plants). The scope of plant physiology as a discipline may be divided into several major areas of research.

Basic LabTechniques - This laboratory is intended to:

(1) Provide an introduction to basic techniques used in biology labs

(2) provide some experience with the equipment employed in future labs

2.1 Microscopy

The compound light microscope is a veryimportant tool in the study of biology. Typical compound light microscopes allow specimens to be viewed at 400 to 1000 times their actual size (total magnification is determined by multiplying the objective lens magnification by the ocularlens magnification). Thelight microscopeis made up of a system of lenses aligned in such a way thatallows magnification, as well as improved resolution. The resolution obtainable is also dependent on contrastin the specimen. Contrast can be adjusted with the iris diaphragm, located below the condenser lens,and can also be enhanced by the addition of stains to the specimen.

Scientific drawings of specimens observed under the light microscope are often used to provide a record of what was viewed. Proper scientific drawings should be neatly drawn,with smooth lines, in pencil (they should never be in colour). More than one cellshould be drawn to illustrate the cellularassociation to the observer(e.g.found singly or as part of a tissue). Labels should be added using straight horizontal lines to the right side of the drawing, and care should be taken with singular and plural forms of structural terminology. To demonstrate differences in density of specific structures, use stippling rather than shading. A figure caption thatindicates the specimen viewed, how viewed, and the to right side of the drawing, and care should be taken with singular and plural forms of structural terminology. To demonstratedifferences in densityof specific structures, use stippling rather than shading. Afigure caption thatindicatesthe specimen viewed, how viewed, and the magnification of the drawing is always necessary.

Significance in Agriculture

The Green Revolution resulted in many fold increase in the food grain production. Crop yields have increased steadily over time, but continuing these increases above the current high levels would be difficult. But in order to meet the demands of the increasing population, the crop production must increase in a sustainable manner. Sustainable increase in the total production without increasing cultivated area represents a huge challenge that can only be met by integrative investigations at the whole plant-plant community level. Improvement of crop production systems will require a thorough understanding of basic principles of yield production. This involves the study of the plant processes responsible for the growth, development and production of economic yield by crop plants, focusing on whole plants and plant communities and not individual plant parts, organs, or cells because most of the processes that control yield operate at the whole plant-plant community level.

The processes responsible for the primary productivity of crop communities are photosynthesis, respiration, transpiration, nutrient utilization and how the products of these processes are converted to economic yield and morphogenetic processes.

Crop physiology is the study of plants at the whole-plant and plant-community level of organization and Agronomy is the study of crops and cropping systems at the farm level over a period of time. At this level of organization, the complexity of the system is so large that comprehensive attempts are to be made to examine the mechanisms underlying the crop responses to management or climate.

The scientific approach to agriculture has been to isolate (i.e., the experiments in which everything else is equal except the studied phenomenon) and to reduce (i.e., the process by which, a phenomenon is quantified in terms of one or more essential molecular processes), because the production system is too complex. Whereas the unraveling of crop production systems to simple chemical and physical phenomena has improved our general understanding of the system, it is necessary to understand how these chemical and physically processes interact within a whole plant grown from seed to maturity under natural conditions for this information to be useful in agronomy.

1. A man supplied excess fertilizer and water the grass well. After sometime the leaves turn brown because

   a) Due to water logging

   b) It decreases photosynthesis

   c) Fertilizer is drained in lower layer of soil

   d) Osmosis occurs in root and root dies

2. If roots of plant are removed and plant is placed in water, then what will be happen?

   a) Passive absorption will continue

   b) Imbibition will continue

   c) Active absorption will continue

   d) None of these

Plant pigments impart colour to the different components like leaves, flowers, fruits etc. They in turn are responsible for the colour of raw food, we eat. Pigments like chlorophyll, anthocyanins, flavonoids, tannins, xanthones etc. are the different pigments that are present in plants. The primary function of pigments in plants is photosynthesis, which uses the green pigment chlorophyll along with several red and yellow pigments that help to capture as much light energy as possible. Chlorophyll is green in colour. Carotenoids like a, b, and g, carotenoids are yellow in colour. Lycopene is red in colour. Flavones and falvonols are also yellow in colour. Anthocyanins are purple and magenta in colour. Other functions of pigments in plants include attracting insects to flowers to encourage pollination. The assay of pigments is mostly based on their native colour.

Plant pigments impart colour to the different components like leaves, flowers, fruits etc. They in turn are responsible for the colour of raw food, we eat. Pigments like chlorophyll, anthocyanins, flavonoids, tannins, xanthones etc. are the different pigments that are present in plants. The primary function of pigments in plants is photosynthesis, which uses the green pigment chlorophyll along with several red and yellow pigments that help to capture as much light energy as possible. Other functions of pigments in plants include attracting insects to flowers to encourage pollination.

Biological pigments, also known simply as pigments or biochromes are substances produced by living organisms that have a colour resulting from selective colour absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, fur and hair contain pigments such as melanin in specialized cells called chromatophores.

Pigment colour differs from structural colour in that it is the same for all viewing angles, whereas structural colour is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural colour, although many butterflies have cells that contain pigment as well.

1. Chlorophylls

Chlorophyll can be regarded as a true representation of health of green plants. This presumption is based on the fact that chlorophyll is most commonly and immensely influenced by biotic and abiotic stress conditions in addition to events like pathogenic invasion, pollution, mineral deficiencies as well as mineral toxicity. This is the reason that estimation of chlorophyll is considered to be one of the most important parameters in plant physiological studies.

Eukaryotic plant cells possess many types of ‘reserves’, one of them is plastid. A plastid, that contains green colour is known as chloroplast and the green colouration of a chloroplast is mainly due to the presence of a pigment to which we call as chlorophyll. Normally, chlorophyll constitutes about 4% of chloroplast dry weight.

Chlorophyll ‘a’ and ‘b’ are the most abundantly found in all autotrophic higher plants. However, there are other chlorophylls also such as ‘c’, ‘d’, ‘e’, bacteriochlorophyll and bacterioviridin which have restricted presence in blue-green, brown and red algae.

A chlorophyll molecule contains ‘Tetrapyrrole’ skeleton formed into a ring with an atom of magnesium (Mg⁺⁺) in the centre. A so-called ‘Pyrrole’ molecule contains four carbon and one nitrogen atoms arranged in a ring. Four such pyrrols arranged in a ring form the ‘Head’ of chlorophyll molecule. Attached to this is ‘porphyrin ring’, at one point, is a ‘phytol’ tail- a long chain of linked carbon.

Crop Stand Establishment

Good crop establishment is one of the most important features in better crop production. The better crop establishment is in turn expressed as optimum plant population in fields.

Plant population is the number of plants per unit area in a cropped field. It indicates the size of the area available for individual plant.

Optimum Plant Population

It is the number of plants required to produce maximum output or biomass per unit area. Any increase beyond this stage results in either no increase or reduction in biomass.

Crop geometry is the pattern of distribution of plant over the ground or the shape of the area available to the individual plant, in a crop field.

Introduction

In agriculture and public health sectors, a variety of pesticides are still in uses that are toxic chemicals and having broad-spectrum actions. They kill target species but also harm the ecosystem seriously by affecting desirable organisms, thus, badly impairing prey-predator relationship. Most of these pesticides are persistent or non-biodegradable and hence exhibit biological magnification by accumulating at higher concentration in the organism, which are on the top of the food chain. The other drawbacks of repeated use of pesticides are eradication of natural enemies of pests, increased level of pesticide residues in soil, water, food and fodder crops, resistance of pests to pesticides and resurgence of minor pests in addition to the environmental pollution. It is clear that once used pesticide may persist, somewhere causing serious harm to the mankind and his ecosystem.

The increasing incidence of pesticide harms is fueling the need for new pesticides, which are toxicologically safe, more selective and efficacious and environment-friendly. Now the natural compounds, thus, have increasingly become the focus of those interested in discovery of pesticides. Tens of thousands of secondary products of plants have been identified and there are estimates that hundreds of thousands of these compounds exist. There is growing evidence that most of these compounds are involved in the interaction of plants with other species-primarily the defense of the plants from plant pests. Thus, these secondary compounds represent a large reservoir of chemical structures with biological activity. This resource is largely untapped for use as pest management agents^3, 4. The extraction of such chemicals from plants and derivatives of potent compounds are being encouraged all over the world under the Integrated Pest Management (IPM) approaches. The natural compounds and their synthetic derivatives are more selective in action, completely biodegradable and environment-friendly. In short, natural ways of pests control have already been established and are receiving much attention these days.

Plant Propagation

Plant propagation involves the formation and development of new individuals, which are used in establishment of new plantings. It is simply the reproduction or multiplication of a plant from a source that is often referred to as a mother plant. In general, two methods are employed: 1) sexual and 2) asexual. Sexual propagation is multiplication of plants from seed and asexual or vegetative propagation involves starting a new plant from some vegetative part of a plant. Propagation by seed results in seedling variability. It is an extreme disadvantage for a nursery operator trying to produce a uniform crop containing chosen desirable characteristics. Seed propagation is not practiced in fruit nursery as plants raised by this method fail to bear true to type fruits.

Germination of seed

The activation of the metabolic machinery of the embryo leading to the emergence of a new seeding plant is known as germination. Germination is essentially a quickening of the growth of the embryo. As germination proceeds, the growing points of the radical and plumule divide rather rapidly Usually the radical emerges from the seed coat first, proceeds downward, and develops into the root system, the plumule proceeds upward and develops into the shoot system. Germination is entirely a food utilization process. Processes going on in seed during germination are: 1) Absorption of water; 2) Secretion of enzymes and hormones; 3) Hydrolysis of stored food into soluble form; and 4) Translocation of soluble foods and hormones to the growing points. These processes are either wholly or in part influenced by the food reserves, hormone supply, water supply, oxygen supply and temperature level.

Pomegranate is emerging as one of the important fruit crops for semiarid and arid areas of India with the identification of superior varieties like Ganesh, Mrudila, Arka Ruby, and Bhagwa the area under pomegranate is increasing fast. Therefore the demand for elite planting material is also increasing fast. Pomegranate is propagated vegetatively either by cutting or air layering since ages. However now a day’s orchards raised from tissue culture are also very common. Nursery as a business preposition can also be as profitable as raising a crop. 

Types of Nurseries According to Marketing
    1.    Wholesale nurseries
    2.    Garden centers
    3.    Nurseries for large-scale gardening (municipals etc.)
    4.    Regular nurseries

Plant structure

• Peach – In leaf axils is called – as (blind bud).
• Pecans and walnut, 2-4 buds development at one bud.
• Plants which grow from adventitious buds on the roots are called suckers.
• Some are broad-leaved evergreen: Citrus, mango, litchi, avocado.
• Narrow-leaved evergreen – (coniferous trees)
• Deciduous plants: apple, pears, grape, apricots, pecans.
• Monoecious: Walnut, pecan nut, hazelnut, Tung coconut, cucurbits.
• Dioecious: Papaya, date palm, pistachio nut muscadine grape pointed and snake gourds asparagus.
• Spike inflorescence: Banana
• Catkin: is a spike pecan nut, oak, mulberry, dates and walnut.
• Raceme: Pear
• Corymb: Cherry, pear, candytuft.
• Fascicle Inf.: Phlox and apple.
• Panicle: Mango, grape, litchi.
• Self-pollination (autogamy)
• Cross-pollination (autogamy) (gait gamy)
• Dischongamy: Walnut, pecan nut, macadamia nut.
• Self sterility: Almond, some fruit, onion, marigold.
• Incompatibility: Mango, ber, loquat, apple.
• Wind pollination: Walnut, pecan, nuts, coconut, dates.
• Insect pollination: Apple, mango, peach, fig, coconut.
• Birds: Pineapple and banana.
• Water: Water lily, water chestnut.
• Seedless fruits: Banana, pineapple.
• When plants set and mature fruits without pollination, it is called as vegetative parthenocarpy. Banana, Japanese person, fig, orange, grapefruit.
• Monocarpic: One crop of seed and then dies.
• Polycarpic: One crop of seed and then does not die.
• Media for propagation: 5.5-6.5 pH.

Introduction

After the green revolution, India achieved significant strides in agricultural output, but productivity is still poor owing to climate change and the interference of old agriculture techniques. In order to fulfill the world’s food demand in 2050, global output will have to grow by 70 % (FAO, 2020). Man has devised technical techniques for growing crops round the year.

Crop propagation is a natural process that is enhanced via the use of modified and regulated settings. These conditions are altered to guarantee that the crop in question grows to its full potential. The purpose of propagation structures is to build environments that can be changed and controlled.

1.1 WHAT IS PLANT PROPAGATION?

Propagation of plant is defined as multiplication and perpetuation of new individuals from a selected plant having all the characters of the original one. It is the process of increasing the number of plants of a particular species or cultivar. It refers to the multiplication of an individual plant or group of plants, which have specific value to mankind. New plants or new individuals are required for establishing new plantings/new gardens/new orchards.

History of plant propagation

The propagation of plants is one of the absolutely necessary occupations of human beings since time immemorial. Civilization might have started when ancient man learned to plant and grow different kinds of plants, which fulfilled the nutritional and other allied needs of human beings and their animals. Cultivated plants commenced mainly by direct selection from wild species (e,g., lima bean, barley, tomato, and rice), hybridization between species, accompanied by changes in chromosome number (e,g., strawberry, pear, and prunes), and a group of plants occurs naturally as rare monstrosities (e,g., cabbage, broccoli, and brussel’s sprouts).

Plant propagation: Plant propagation means multiplication of plant by sexual or asexual method.

There are two type of plant propagation

1.    Sexual propagation

2.    Asexual propagation 

A. Sexual propagation: Sexual propagation means multiplication of the plant by seed. It is also known as seed propagation.

Advantages of sexual propagation

1.    This is the easier and cheaper method.

2.    Some of the plant does not response well by asexual method (Papaya) this type of plant only propagated by sexual propagation.

3.    Sexually raised plant are long lived have extensive root system and bear heavily as compare to asexually propagated plants.

4.    Hybrid can develop only by seed propagation.

5.    Seed can be store for longer duration.

Propagation

Plant propagation means multiplication of plant by sexual or asexual method. The success in plant propagation depends on a thorough knowledge of the growth of plants, choice of suitable method and technical skill. The propagation of plants may be done either by the gametes or from the somatic cell, tissues or organs. In other words, propagation may be done by sexual methods or by asexual methods. The details of the methods are presented below.

Plant Propagation is a technique through which multiplication or production of new individuals take place from selected propagules.

Plant Propagation is a technique through which multiplication or production of new individuals take place from selected propagules. The methods of propagation are broadly divided in two categories:

1. Sexual method
2. Asexual method

1. Sexual method of Propagation

In this method, plants are produced from seeds and such plants are called seedlings. Seed is considered as a dormant plant which develops into a complete plant if subjected to congenial environment.

Advantages

1. This is very simple, cheap and easy method of propagation.
2. Some species of fruits, ornamental annuals and vegetables which cannot be propagated by asexual means should be propagated by this method. e.g. papaya, marigold, tomato etc.
3. Hybrid seeds can be developed by this method.

Plant propagation refers to the process of increasing number of plants of a cultivar. Plant propagation is of two types viz. sexual and asexual. Sexual propagation is done by seeds, whereas asexual plant propagation is done by vegetative means such as stem/root cuttings, slips, corm, bulbs, rhizomes, grafting, budding, layering, etc. Good quality seed or planting material of established crop varieties should be procured from authentic source to get desired result. The seed should be uniform in size, free from disease infestation, possess good vigour and having good viability. The quality of the seed is decided based on germination percentage. Seeds can be directly sown to raise a crop or seedlings are raised in nursery beds, which are transplanted later to main plot.

Seedlings can be raised in nursery beds, poly bags or pro-trays. The nursery beds are usually kept one meter wide, convenient length and of 15 cm height. The soil of the bed is prepared by addition of well decomposed bulky organic manure, sand and garden soil in equal proportion. The beds have to be disinfected by exposing the soil to sun (solarisation) and addition of neem or karanj oil cake. After sowing the seeds in the bed, those are covered with straw, leaves or compost to protect the seeds from birds and to conserve moisture in the soil. It also helps to maintain the temperature for quick germination. The seeds are sown in lines on the bed.

Plant propagation is one of the important fundamental aspects since the time of Rigveda (1400 B.C.) in the horticulture industry. It refers to the multiplication or perpetuation of individual or group of plants having specific value. Agriculture began, when ancient people started domestication of certain plants by growing around them and now these are cultivated in much improved form due to continuous selection and maintenance of better plant types. During the process of civilization; many plant types were selected for food and other purposes and are classified as food crops, fodder crops, fruit crops, vegetable crops, spices and condiments, aromatic and medicinal plants, etc. Now due modern plant sciences; newer and better plant types came into commercialization for cultivation. However, to maintain their qualities; it needs their propagation to keep their original form. Thus, it indicates that plant propagation has paramount importance in the horticulture industry to supply true-to-type sapling to farmers.

For effective and economic control of pests, besides selection of appropriate plant protection chemicals, application of the chemicals at the most vulnerable growth stage of the pests and use of chemicals at the correct dosages, selection of proper plant protection appliances to carry out the operation is also of vital importance so as to ensure uniform application of the chemicals.
 
Plant protection chemicals are mostly used as sprays and dusts using sprayers and dusters respectively. However, in most of the cases spraying is preferred to dusting. Different types of sprayers and dusters are being used for these operations and in both, there are manually operated as well as power operated equipments and in sprayers there are both hydraulic and pneumatic types of sprayers.

The nature of the pesticide formulations to be used and the purpose for which they are used also determine the type of equipment to be used. Dusters are used for dusting insecticidal dust formulations; sprayers are used for spraying insecticidal liquid formulations; granular applicators are used to apply granular formulations; fumigators are used to apply fumigants to fumigate godowns, warehouses, rat holes etc.; soil injectors are used to inject pesticides at a particular depth of soil under pressure; flame throwers are used to throw flames at specified targets.

For effective and economic control of pests, besides selection of appropriate plant protection chemicals, application of the chemicals at the most vulnerable growth stage of the pests and use of chemicals at the correct dosage, selection of proper plant protection appliances to carry out the operation is also of vital importance, so as to ensure uniform application of the chemicals.

Plant protection chemicals are mostly used as sprays and dusts using sprayers and dusters respectively. However, in most of the cases spraying is preferred to dusting. Different types of sprayers and dusters are being used for these operations and in both, there are manually operated as well as power operated equipments and in sprayers there are both hydraulic and pneumatic types of sprayers.

The nature of the pesticide formulations to be used and the purpose for which they are used also determine the type of equipment to be used. Dusters are used for dusting insecticidal dust formulations. Sprayers are used for spraying insecticidal liquid formulations. Granular applicators are used to apply granular formulations. Fumigators are used to apply fumigants to fumigate godowns, warehouses, rat holes etc. Soil injectors are used to inject pesticides at a particular depth of soil under pressure. Flame throwers are used to throw f lames at specified targets.

Chemicals are commonly employed to manage plant diseases, pests, and weeds, but they are only effective if administered promptly once an infestation has been discovered. These chemicals must be sprayed, dusted, or misted over the ground and plants. Since the chemicals are expensive, it is important to have tools for applying them evenly and effectively. Crop Protection Products (CPP) like herbicides, pesticides, and fungicides work best when they are used at the right time during the crop’s most productive times. This problem is getting worse because there aren’t enough people to do the work. In this situation, the only choice that makes sense is to automate the application process. Most of the time, poisons are put on with dusters or sprayers. Dusting is the easier way to apply chemicals. It works best with movable equipment and usually only needs simple tools, but it is less effective than spraying because the dust doesn’t stick around as long. High volume spraying is usually efficient and reliable, but it is more expensive than low volume spraying, which fixes some of the problems with the first two methods while keeping the things that work well about them.

3.1. What is the International Plant Protection Convention (IPPC)

The International Plant Protection Convention (IPPC) is a 1951 multilateral treaty deposited with the Food and Agriculture Organization of the United Nations (FAO) that aims to secure coordinated, effective action to prevent and to control the introduction and spread of pests of plants and plant products. The Convention extends beyond the protection of cultivated plants to the protection of natural flora and plant products. It also takes into consideration both direct and indirect damage by pests including weeds.

The IPPC as an intergovernmental treaty signed by over 180 countries, aiming to protecting the world’s plant resources from the spread and introduction of pests, and promoting safe trade. The Convention introduced International Standards for Phytosanitary Measures (ISPMs) as its main tool to achieve its goals, making it the sole global standard setting organization for plant health.

The IPPC is one of the “Three Sisters” recognized by the World Trade Organization’s (WTO) Sanitary and Phytosanitary Measures (SPS) Agreement, along with the Codex Alimentarius Commission for food safety standards and the World Organization for Animal Health (OIE) for animal health standards.

Ever since man started domesticating plants and animals for food, feed and fiber, he is facing competition from insects, disease and other pests. The struggle is going to continue as long as man wants plants and animal. The need to save plants/crops from the ravages and depredations of pests and to reduce the losses caused by them became more urgent (Patel, 2004).

India is a predominantly agricultural country and will continue to be so. Neither individuals nor nations can live without agriculture. India is witnessing growth of its agriculture, industry and economy in general, at the same time the population is growing at an alarming pace.

The crop losses by pests in our country are enormous. Chemical control continues to play a major role in crop protection; at the same time it enhances the environmental pollution problem. One has to use chemical control in a precise way by adopting Integrated Pest Management (IPM). In applications of pesticide (which are poisonous), the technique used should be such that minimum quantity of pesticides is applied to cover the Target-Leaf-Foliage with less environment pollution. Water is usually used as a carrier to apply pesticides to the Target-Leaf-Foliage. Beside water, air stream is also used, to carry fine droplet-particles to reach the Target-Leaf-Foliage.

The application of agricultural chemicals for control of insects, pests, fungi, weeds and plant diseases plays an important role in crop production. Before 1980 few chemicals were known for control of plant pests.  The chemical pesticides have played an important role in the rapid advancement of agricultural production. Chemical pesticides are getting popular due to non availability of labours especially for weeding operation during kharif season. The chemical pesticides and herbicides are applied with the help of different types of sprayers and dusters.