eChapters

5.1 Introduction

Evanescent field absorption spectroscopy is a powerful well-established laboratory technique for chemical analysis. The technique utilizes the evanescent wave penetration at the boundary between two dielectric media in conditions of attenuated total reflection (ATR). One of the media, a thin slab-shaped non-absorbing crystal, is called a waveguide, while the other medium of lower refractive index is the absorbing sample being studied. At each reflection at the boundary of the crystal and the sample, the penetration of the evanescent wave of the guided ray into the absorbing sample gives rise to a reduction of the power propagating in the crystal. The degree of absorption depends on the amplitude of the evanescent field in the sample medium and the number of reflections within the waveguide. The former increases dramatically for incident angles approaching the crystal-sample critical angle while the latter increases with the decrease in the thickness of the waveguide. The number of reflections can also be increased by increasing the length of the waveguide. Thus, to achieve maximum absorption, an unclad optical fiber is well suited for evanescent wave absorption spectroscopy. This is because, unlike the crystal waveguide, the narrow core diameter of the fiber provides a large number of reflections per unit length. Further, the use of an optical fiber to transmit light to a section of its core in contact with an absorbing sample offers the possibility of remote sensing or in-line analysis. These advantages, together with the benefits of simplicity, reliability, flexibility and relatively low cost have motivated a number of research groups all over the world to investigate evanescent wave spectroscopy at the surface of an unclad optical fiber. This chapter will be devoted to the fiber optic sensors utilizing evanescent field absorption spectroscopy.

6.1 Introduction

There are a variety of intrinsic and extrinsic fiber-optic sensors which use absorption spectroscopy indirectly for the detection of various chemical species. These include pH, metal ions, oxygen in water etc. In such sensors a suitable reagent is immobilized on a solid support. The support can be the core of the fiber or some optical material attached at the end of the fiber. Further it is optically transparent to allow transmission of the light signal from the interface and should remain inert to the chemical reaction being analyzed. The analyte (or the chemical species) when comes in contact of the reagent affects the absorption properties of the reagent. In other words, in these sensors, the reagent acts as a chemical transducer for analytes that are not directly measurable by optical techniques. Following conditions for the use of reagents in sensors must be met:

7.1 Introduction

There are numerous wavelength dependent phenomena that may be used to modulate the wavelength of incident light source. These are wavelength dependent absorption, luminescence, dispersion, interference and scattering. Wavelength modulated sensors use a broadband source, a wavelength modulator or measurand (i.e. analyte), a form of spectrometer (using prisms, gratings or interference filters), a detector (single photodiode or array) and signal processing unit. Silicon photodiode is cheap and can be used for detection but it limits the detection wavelengths to the region 400 to 1050 nm. The sensitivity or the resolution of the wavelength modulated sensor depends on the characteristics of the detector, the inherent resolution of the spectrometer, mechanical stability of the modulation unit and the spectrometer, and the capability of the signal processing unit. However, wavelength modulated sensors do not require any form of referencing like intensity modulated sensors. In intensity modulated sensors, loss in intensity occurs due to connectors and splices, microbending, mechanical creep and misalignment of light sources and detectors due to environmental effect. Further the fluctuations in light source can affect the performance of the sensor. Thus, for intensity modulated sensors one needs referencing to cancel out these losses. In some intensity modulated sensors two wavelengths are used. One wavelength is used to cancel out all of the losses while the second is used to sense the measurand.

Wavelength detection is relatively easy if the spectral changes result from changes in chemical indicator dyes, fluorescence, phosphorescence, or black-body radiation. In these cases the incident and emitted wavelengths are far apart and therefore detection is easy. If the spectral change occurs due to mechanical movement, then the wavelength filtering mechanisms must have sufficient resolvable spectral points. The reasons for using fluorescence in the fiber optic sensors are well known. Fluorescence is intrinsically more sensitive than absorbance and is more flexible in that a great variety of analytes and physical parameters are known to change the emission of particular fluorophores. The fluorescence based sensors utilize the change in the intensity, lifetime or colour of fluorescence as the affected parameter by the measurand. That means, any interpretable observation of fluorescence can be made the basis of a sensor. In this chapter we shall first describe luminescence phenomenon and then various physical and chemical fiber optic sensors based on wavelength modulation and fluorescence phenomenon.

8.1 Introduction

Interferometric or phase modulated sensors have received special attention because these are much more sensitive than intensity modulated sensors and can be used over a much larger dynamic range. The sensors rely on the interferometric technique. Generally, the sensor employs a coherent light source such as a laser and two single mode optical fibers. Light is split and coupled into both the fibers. If the measurand perturbs the optical properties of one of the fibers relative to the other, a phase shift occurs. The change in phase can be measured very precisely. For the measurement a sophisticated electronic processing equipment is needed. Thus the interferometric sensors are expensive compare to intensity modulated sensors. There are four kinds of interferometer configurations: Mach-Zehnder, Michelson, Fabry-Perot and Sagnac interferometers. The Mach-Zehnder, Michelson and Sagnac interferometers are the two beam interferometers while in the case of Fabry-Perot interferometer multiple beam interference occurs. In this chapter we shall first describe interference phenomenon and then different kinds of fiber optic interferometers. In the end we shall describe a number of sensors based on interference phenomenon or phase modulation.

9.1 Introduction

Many physical parameters such as pressure, temperature, electric current etc. can be measured using polarization-modulated sensors. In these sensors modulation of state of polarization of light in the sensing region by an external stimuli takes place. A variety of physical effects influence the state of polarization of light. These phenomena are Faraday effect, electro-optic effect and photo-elastic effect. Polarization modulated sensors, in some cases, offer significant advantages not only over conventional sensors but also over widely used fiber optic interferometric sensors. These sensors require control over the state of polarization of light entering the sensing region of the fiber. Thus, for these sensors, highly birefringent fibers or single mode fibers are used. In this chapter we shall first discuss magneto/electro-optic effects and then shall describe sensors for the measurement of electric current/ magnetic field, voltage, pressure, temperature etc. utilizing polarization modulation.

10.1 Introduction

There are very few frequency modulated fiber optic sensors. This is because frequency modulation of light occurs under a limited range of physical conditions. The principal one is based on Doppler effect. There are few other circumstances under which the frequency of light is modulated. These include luminescence and Raman scattering. Luminescence has been included in chapter 7under fluorescence based sensors. In this chapter we shall focus on the sensors based on Doppler effect and Raman scattering. In particular, we shall discuss the measurement of blood flow velocity, colloidal particle motion and Raman spectrum using optical fibers.

11.1 Introduction

In previous chapters we have described fiber optic sensors based on intensity and phase modulations. These sensors have some problems in practical applications that need to be solved. Some of these are fluctuation of light source power, loss in couplers, scattering and absorption effects that affect measurement performance, temperature drifts and vibrations. In comparison to intensity and phase modulated sensors fiber Bragg grating (FBG) sensors have following advantages:

High resolution

Insensitive to intensity fluctuation because the signal obtained from an FBG sensor is encoded directly in wavelength domain.

Provision of well localized sensing region

Linear output as a function of the measurand

The capability of multiplex many sensors along one fiber

12.1 Introduction

Among a variety of optical evanescent wave techniques, spectroscopies based on the resonant excitation of surface plasmons have matured into a widely accepted surface analytical method used in different fields. Liedberg et al¹ were the first who demonstrated the exploitation of surface plasmon resonance (SPR) for chemical sensing. Since then the SPR sensing principle has received much attention. In this chapter we shall first describe the principle of this technique and then few sensors that have utilized this phenomenon.

13.1 Introduction

Distributed optical fiber sensors are those sensors which monitor a single measurand at a large number of locations or continuously over the path of the optical fiber. The measurand can be a physical or a chemical quantity. The distributed optical fiber sensor generally consists of a common light source, optical fiber to carry light to the sensing probes and a return fiber to carry modulated light to a photodetector. These sensors can utilize any kind of light modulations described earlier. The advantages associated with distributed sensing are reduced number of components and hence the cost, reduced weight and cabling, and electrical passivity. The applications include the measurements of temperature, pressure, strain, current and chemical concentration. If the measurand is monitored continuously along the fiber length then the sensor is called intrinsic distributed sensor. If it is measured at a finite number of locations then the sensor is called quasi-distributed sensor. The quasi-distributed sensor has a number of advantages over intrinsic distributed sensor. In quasi-distributed sensor, spatial resolution is not as important as in intrinsic distributed sensor provided that individual sensors can be clearly resolved. Further, in quasi-distributed sensing, the sensor elements can be tailored in terms of responsivity and range to meet the specific needs of the application. In this chapter we shall describe various kinds of distributed sensing approaches and few optical fiber distributed sensors.

14.1 Introduction

In this chapter we shall describe various simple and easy to fabricate fiber optic sensors. Most of these sensors are based on intensity modulation. Intensity modulated optical fiber sensors have been extensively studied in comparison to sensors based on other modulation techniques. This is because of their several advantages such as simplicity, reliability, flexibility and relatively low cost. Intensity modulated sensors make use of multimode fibers. Multimode fibers have large core and high numerical aperture that make the coupling of light into the fiber easier. The large core is also better suited to propagate high power laser beams. Further, the plastic-clad fused silica multimode fibers are available. Plastic-clad silica multimode fibers have an additional advantage. Their plastic cladding can be removed easily permitting access to the core. The evanescent field in the unclad part has been used for various kinds of chemical and biochemical sensors (see chapter 5). Above all, these fibers are cheap. This chapter is devoted to simple and easy to make both intrinsic and extrinsic type sensors. Sensors utilizing bare-ended fibers have also been described.

INTRODUCTION

Alstroemeria is still a relatively new cut flower in the world market and the interest in it is continuously growing. This increase is due to the fact that this flower crop is fairly easy to cultivate and does not require special demands. Its flowers are beautiful and have a very long vase life. It is commonly known as Brazilian Parrot lily or Peruvian lily or Incan lily or Red Parrot Beak or New Zealand Christmas Bell. In the Dutch market, it is an important cut flower and gaining popularity in the international market. Recently some efforts have been made to popularize this flower in India as cut flower and pot plants by some multinational companies. Its cultivation has been started around Bangalore, Pune and Hyderabad. Recently it has been introduced in Palampur, Solan, Srinagar and Ooty, to popularize this crop among growers for domestic and export markets. This crop can be grown successfully on the hill areas of Uttaranchal. Mid and high hill areas are very suitable for growing it. Alstroemeria is a typical greenhouse crop, but can be grown in open under mild environments with partial modifications. It is a potential, low volume and high value crop for hill horticulture.

INTRODUCTION

Anthuriums are a perennial herbaceous plant of great beauty and grown either for their showy cut flowers or for their attractive foliage. They are valued for their colourful long lasting spathe and spadix. The cultivars contribute elegance and attractiveness, which are pre-requisites for quality and floral design. It is also known as Flamingo flower or Flamingo lily. What is usually considered the flower is comprised of a colourful, modified leaf (spathe) and hundreds of small, botanical flowers on the pencil like protrusion (spadix) rising from the base of spathe. Anthurium have been cultivated from many decades for cut flower production. Since the mid 1980’s its popularity has increased dramatically and has now become a popular addition to many foliage growers. The economic life span of anthurium is around 6-8 years.

In India the cut flowers of Anthurium andreanum are cultivated for considerable length of time although still in small scale. Commercial viable production should be estimated of approximately 5 ha, which is far below the market demand. The anthurium is getting increasing popularity in the Indian market and therefore, most of the locally produced anthurium is sold in the domestic market against reasonable prices. Its export possibility appears very promising as the flowers are already exported to the Middle East. The development of main flower distribution centre in Dubai offers important possibilities for Indian floriculture.

INTRODUCTION

Strelitzia is known as Bird of Paradise. The uniquely shaped flower of this exotic tropical resembles a head of bird and due to its brilliant orange and blue colour and unusual form, it resembles not any bird but a bird of paradise. Its another common name, Erane flower is another bow to its exotic avian shape. Fantastically handsome flowers aside, this is also a very attractive foliage plant resembling the related heliconia in vegetative appearance. Due to the brilliant colour and unique appearance of the flower, it is exceptionally popular as a cut flower which appears periodically throughout the year. Therefore, it is cultivated in different countries for cut flower production to supply it in local and export markets. Commercial production of cut bloom is done in California, Hawaii, Israel, France, South Africa and Japan.

Bird of paradise occupies a place of pride in the garden and is an important choice for landscaping. It is grown in backyard and also for mass effect. Plants of strelitzia can be used in the landscape in a low growing ground cover to enhance the beauty of garden. They serve well anchoring island beds when surrounded by lower growing annuals or ground cover. It can also be used in shrub borders and adaptable beauty is perfect for home and commercial interiors.

INTRODUCTION

Carnation is one of the most beautiful and commercially important flower crop. It occupies prime position in the international cut flower trade and is a good commercial cut flower for internal market as well. Carnation flower can easily withstand long distance transportation as it has an excellent kee in ualit Its cut flowers with a 70 to 90 cm stem length, healthy and bright flower commands a better price. Carnations have a sweet fragrance and also commercially utilized for extraction of oil in France and the Netherlands. The volatile oil of carnation contain 40% benzyl benzoate, 30% eugenol, 7% phenylethyl alcohol, 5% benzyl salicylate and 1% methyl salicylate. It is used only in sophisticated perfumes. Carnation flowers round the year and have wider colour range like red, salmon, pink, purple, yellow, orange, bicolour, stripped, white and fancy combinations. The major break through in carnation flower industry was evolvement of cultivar William Sim. This cultivar was produced in 1938 to 1939 by William Sim of the USA. From this red variety there have been mutations to white, pink, orange and different variegated forms. The first genetically modified carnation variety Moon Dust is released in Australia by a plant biotechnology company Florigene. There are several distinct types of carnations and each of these can be grown in cooler parts of the plains and at medium to higher elevation. Carnations are cultivated under glasshouses in temperate countries and in the open or in semi-protected conditions under polythene cover, in both tropical and sub-tropical regions. Because of strong emphasis on quality in both export and domestic market, commercial production of spray and standard carnations is considered as a crop of protected conditions. Before being planted in the greenhouse, the crop must be carefully planted so that it will meet the demands of the international markets.

INTRODUCTION

China aster is one of the most popular annual flowering plant grown throughout the world. Among annuals it ranks next to chrysanthemum and marigold and is grown mainly by marginal and small farmers. It can easily be grown in the open fields and lath houses for the roduction of cut flowers Cut asters last long and are used in vases and floral decoration. When asters are grown in large mass, they make very showy bedding plants and are valuable for filling up the gap in mixed herbaceous border. The dwarf types are put in front and the taller behind.

Some strains are used as pot plants, while dwarf cultivars are suitable for edging and window boxes. The prominent colours of flowers are blue, violet, lavender, rose, white, etc. In tropical and subtropical countries aster is extensively grown for bedding and cut blooms during winter month and spring. China aster is one of the most important traditional flowers in India and has maximum use for traditional purposes. The commercial importance of China aster is increasing in India especially in Karnataka, Tamil Nadu, West Bengal and Maharashtra.

INTRODUCTION

The chrysanthemum is one of the most beautiful and perhaps the oldest flowering plant, commercially grown in different parts of the world. It is commonly known as Queen of East, Autumn Queen and Guldaudi. It is im ortant both as cut flower and as potted plant in the international market. In Dutch cut flower auction, chrysanthemum ranks second after rose. It is preferred practically due to vast range of shapes and sizes of flowers, brilliance of colour tones, long lasting floret life, diversity of height and growth habit of the plant, exceptionally hardy nature, relative ease to grow all the year round and versatility of use.

It is one of the most important traditional flowers of India mainly used as a potted plant, loose flower, cut flower and as border plant in the garden. Chrysanthemum cinerariifolium inflorescences are of considerable importance in the manufacture of pyrethrin insecticides. The leaves of Chrysanthemum balsamita become leathery on drying and can be used as bookmarks. Fresh young customary leaves can be used in salads and to add a balsam flavour in beer, soups and bread. Now programmed blooming of chrysanthemum all the year around is possible by environmental manipulations.

INTRODUCTION

Crossandra is an important traditional flower crop of south India. It is small evergreen shrub that is quite hardy and has the ability to produce beautiful flowers with a remarkable range of colours almost all the year. This has made it extremely popular in southern states of India where the flowers are widely used in temple offering and for making gajras and venis to use as hair adornments.

Owing to their attractive colours, light weight and good keeping quality, crossandra flowers are ideal for garland making. Even though the flowers lack fragrance, they are widely used in garlands either alone or along with jasmine to produce charming colour contrasts. Steady market demand and assured and regular income have made crossandra a profitable venture for south Indian farmers.

INTRODUCTION

In the world of flower, together with lilies, gladioli, begonias; the dahlias are one of the most important and popular flowering bulbs. With the blast of different colours, shape and sizes, dahlias bring life and beauty back to the landscape in late summer and autumn. The diversity of dahlias allows their usage in many different aspects due to huge range of flower types available and fairly easy cultivation.

In modern garden, dahlias are extensively used for exhibition, garden display and decoration. It can be grown in any form in the garden; in beds, in borders or even in mixed borders alongwith other plants. It grows well in pots also. For border purpose dwarf growing type are preferred while in pots usually large flowering dahlias are grown. The long stemmed flowers of various forms and colours are used in flower arrangement. Dahlias make excellent cut flowers, which typically last about a week in the house and are also used in making garlands.

The tubers of dahlias contain appreciable amount of insulin and fructose and small quantities of phytin and benzoic acid which are of medicinal and nutritional value. Flavanone 3-hydroxylase, which catalyses the conversion of flavanones to dihydro flavonols, was detected in flower extracts of cyanic strains of dahlia.

INTRODUCTION

Freesias are extremely popular bulbous plants that are best known as florist flowers. They bear bell-shaped tubular flower and are grown commercially on a vast scale. They are grown both for flower trade as well as in house gardens. Freesias are suitable for pots, shallow pans, beds, indoor decoration and window boxes. Freesia flowers are prized for their curious elegant form, peculiar arrangement of the blossoms on their stalks and a vast range of delicate colours ranging from creamy white to yellow, orange, red, purple, brown, lavender and vermillion. They are highly valued cut flowers.

Freesia flowers are so strongly scented that only a few potted or cut blossoms can bring fragrance to an entire room. Its unusual appealing shapes make them suitable line flowers for any arrangement. They also make fragrant additions to bouquets and their wide range of colours increases their versatility for design uses.

INTRODUCTION

Gerbera is a herbaceous flower crop with leafless stalk and daisy like flowers. It is popularly known as Barberton daisy, Transvaal daisy, Veldt daisy, African daisy and Hilton daisy. Gerbera is a popular cut flower grown throughout the world. It is ideally suited for flower beds, borders, pots, window boxes and gardens. The gerbera plant is also used in the preparation of traditional Chinese medicine i.e. Tu-er-feng, derived from whole plant of gerbera, is used for curing cold with cough and for rheumatism. Gerberas have wide range of bright, vivid and clear colours. Some of the flower colours available today are pink, yellow, red, scarlet, orange, salmon, lavender, violet, rose, cream and white. They are great plants for adding colour to any room or garden to create festive and elegant display. These spectacular, eye catching flowers are a complement to any kind of flower arrangement or bouquet and have a longer vase life. Their daisy shaped flowers have a velvet texture with green or dark centers and are cherished by florists and the cut flower industry.

It grows well in open tropical and sub tropical regions but in a temperate climate should be protected from frost and cultivated in greenhouses. Production of quality flowers of gerberas can be done under protected conditions, since they require partial shade. In California and Florida, it is grown in outdoors and is becoming increasingly popular as potted plant and bedding plant, whereas in other parts of United States it is cultivated in greenhouses. Gerbera cultivation has emerged as a very important option to progressive farmers in many parts of India, especially in Maharashtra, Karnataka, north-eastern states, U.P. and Uttaranchal.

INTRODUCTION

Gladiolus is very popular bulbous flowering plant. It is an important commercial flower crop and having pivotal place as cut flower both in domestic and international market. Gladiolus was introduced into cultivation towards the end of the sixteenth century. It is relatively easy to grow and is ideal for bedding and exhibition. The fascinating spikes bear a large number of florets, which exhibit varying sizes and forms with smooth, ruffled or deeply crinkled tepals. Except true blue and green, practically all colours are available in gladiolus. The flowers are used in flower arrangement, in bouquets and for indoor decorations. Now it ranks next to tulip in the Netherlands and other European countries in trade for use as cut flowers of bulbous crops and fourth in international trade of ornamental for cut flowers. Its keeping quality makes it a very popular commercial cut flower after rose. Gladiolus occupies first place in terms of returns as compared to other cut flowers. Gladiolus, a potential floral crop forms part of Rs. 200 crores floriculture industry in the country. It is estimated that throughout India gladiolus is grown in about 1270 ha, producing about 127 million cut spikes. In India, gladiolus is commercially grown in West Bengal, Maharashtra, Uttar Pradesh, Uttaranchal, Punjab, Haryana, Sikkim, Jammu and Kashmir, Karnataka, Gujarat, Himachal Pradesh, Tamil Nadu, Madhya Pradesh, Delhi and Rajasthan. The area of the states of U.P., Uttaranchal, Haryana, Punjab, Rajasthan and H.P. and surrounding Delhi grow gladiolus mostly for Delhi flower market. Important pockets of commercial gladiolus cultivation are Lucknow, Meerut, Bulandsahar, Ghaziabad and Uttaranchal. In Delhi market, gladiolus is available virtually throughout the year as growers stagger the corm planting from July to December to harvest the flowers from September to May. During the period between June to December, the supply of gladiolus spikes to Delhi market comes from Jammu and Kashmir, Uttaranchal and Himachal Pradesh. The high remuneration in this market is obtained from winter grown gladiolus.

INTRODUCTION

Gloriosa is commonly known as glory or gloriosa lily. Gloriosa lilies have assumed an important place in flower trade and are widely grown for cut flower and tuber production both in USA and Europe. Gloriosa lily is the national flower emblem of Zambia. Their cut flower stems last well in summer heat and their buds take lon time to open after picking. The bright vibrant and intense, red, gold, lemon and pink flower colours and the lush green leaves of gloriosa lilies bring a sense of the tropics or festivity to room. They combine well with many other flowers from roses to heliconias. Gloriosa blooms make perfect posies for the office desk, bedside cabinets or small tables and shelves. The stiff stems of gloriosa and their ability to hold their form out of water for a longer time make them ideal for out of water floral installation work. They are light climbers and are suitable for training on low walls or trellis. With proper trailing they can also be grown in pots. Its flowers are fascinating and its tubers and seeds have great medicinal value. The tubers are rich in alkaloids. Colchicine has been obtained from various plant parts viz., young leaves, flowers, old leaves, tubers, seeds and stems.

INTRODUCTION

Irises are among the easiest of perennials to grow, providing an abundance of beauty with minimum care. Iris means ‘rainbow’ because they come in various colours. These are herbs with sword like leaves and roots are generally rhizomatous, although in a few species they are bulbous. The majority of garden irises are hybrid, often complex ones, whose parentage is obscene. Bulbous irises are more important in commercial horticulture, with over 50 cultivars, but dominated almost equally by two i.e. Ideal and Professor Blaauw which together account for over 70% of the area grown in the Netherlands. Regular irises make great cut flowers with their tall, sturdy stalks. Dwarf varieties are suited for flower beds and rock gardens.

Certain irises were at one time widely used in the manufacture of perfume, also has been widely used in folk medicine, mostly because of the fragrance of its dried roots which are used in the preparation of face powder and dentifrices. Commercially, the powder is known as Orris-root or Orris. The rhizomes of certain irises also have edible value.

INTRODUCTION

Jasmine is one of the first plants that come to mind when one thinks of sweet fragrance. A single jasmine vine can perfume an entire room or garden. Jasmines have adorned the gardens of central Asia, Afghanistan, Iran, Nepal and many other tropical and sub tropical countries. India exports jasmine flowers to the neighbouring countries like Srilanka, Singapore, Malaysia and also the Gulf. Jasmine contributes substantially to the national economy and annually about Rs. 20 crores worth of flowers are produced in India.

Plants are grown both as shrub and climber. Flowers and flower buds are used for making garlands, bouquets and veni and for religious offerings. Jasmine oil extracted from the flower is highly valued as it is used in manufacturing perfumes, cosmetics, creams, hair oils, soaps and shampoos. Flowers are used in jasmine tea or herbal or black tea. As a medicinal plant, jasmine has traditionally been considered an aphrodisiac and calmative. In India, it is grown in different states especially Tamil Nadu, Karnataka, Kerala, Uttar Pradesh, Bihar and West Bengal because their flower and floral buds are in great demand.

INTRODUCTION

Liatris is a group of versatile and popular wild flowers of North America. It is commonly called as Blazing Star or Gay Feather and can be found growing in dry or damp places, uncultivated fields, thin woods or sunny locations. It is suitable for herbaceous border, wild gardens, cut flower and dry flower. Liatris spp. take up minimal space and are suitable for even very small gardens. Long floral spikes of liatris create a mesmerizing effect when arranged in bouquets as well as when grown in gardens.

One of the reasons for such popularity of liatris as cut flower is its ease of culture, durability, long season of bloom and the most important thing being its unusual mode of blooming. Unlike most other flowers produced in spikes, liatris open from the top to downward, i.e. basipetally. Liatris grow about 60-180 cm in height, stiff, erect and hardy perennials having linear (long and narrow) grass like leaves. The flowers are purple or white, lavender to mauve, composed of multiple florets which are arranged in a wandlike spike covering top one third of the stem. With increasing popularity, their demand as a cut flower crop for both greenhouse and outdoor production has increased. Purple varieties are in greater demand. Liatris spicata, L. aspera and L. pycnostachya are the major commercial species.

INTRODUCTION

Lily is one of the most important ornamental bulbous plants. It comprises one of the distinctive flowers in form, appearance and colour. The flower stems of lily are long and sturdy with luxuriant foliage and it has longer vase life. Lilies are very useful flowering plants which can be planted in any location as they do well in the bed or border with other perennial. Almost all varieties of lily are suitable for planting in combination with other plants and in front of tall shrubs. They look very charming in large clusters for mass effect. Shorter varieties are planted in containers. Lilies may be planted in the perennial border, preferably with the plants having ample foliage. They seem to have fascination for some companion and thus can be grown with other flowers in the garden. The bulbs of some varieties of lily are edible and somewhat bitter in taste but fairly pleasant when properly cooked. In China, bulbs of tiger lily are prefered as food due to its specific taste. Lilaline, an alkaloid is also found in the flower of some lilies. Lily has several medicinal properties. The bulb is diuretic, emmenagogue, emollient and expectorant. The flowers are carminative. They are used to strengthen the eye lid muscles and are commended in the treatment of myoptic astigmia.

Among the lilies, two groups have been evolved through extensive improvement and referred as coloured lilies and extensively grown for cut flowers and other popular type is generally grown for garden display in India. Asiatic and Oriental lilies are leading cut flower group and in the international market. It is dominated by the Netherlands. An oriental hybrid cultivar Tiara is developed. It is true pollen free lily, excellent for bouquets. Oriental and Asiatic hybrid lilies are compact, with plant height of 60 to 150 cm that bears many flowers. Spikes of 10 to 15 cm flower diameter that may point up, out or down. Blooms may be red, pink, orange, yellow, lavender or white in colour. They grow well in full sun or light shade, although flowers sometimes fade if exposed to hot sun. They can be grown with companion plants providing less competition. Popularity of Oriental lily is increasing over Asiatic lily.

INTRODUCTION

Lotus is the foremost symbol of beauty, prosperity and fertility. According to Hinduism, within each human inhabiting the earth is spirit of sacred lotus. It represents eternity, purity and divinity and is widely used as a symbol of life, fertility, ever-renewing youth and to describe feminine beauty especially the eyes. Egyptians considered it a symbol of rebirth, since it closes in the evening and falls to the water, then reopening again in the morning, thus emulating the behavior of the sun. All lotuses are day-bloomers that open early in morning and close by mid afternoon for three successive days, with first flower closing earlier. It possesses an amazing ability to flourish in a variety of environment ranging from clear ponds to muddy marshes. The exquisite flowers with long herbaceous stalk arise from the rhizomatous stems and a flat and peculiar seedcase at its center.

Lotus, the national flower of India, has been a part of Indian culture, religion and history from ancient times. It is considered sacred not only by the Hindus of India but also by the Buddhists of China and Japan. To early Egyptians, a lotus bud or Sesen was a symbol of rebirth. Lotus is offered to Goddess Lakshmi and is considered as her symbol. Besides, lotus has found place in one of the postage stamps in India. Every year some prestigious awards are given to the distinguished personalities of the country like Padmashree, Padmabhushan, Padmavibhushan and Swarna Kamal (Golden Lotus).

INTRODUCTION

Marigold is an important flower crop and constitute as one of the five most commonly cultivated and used flower in urban and rural India. They are extensively used for making garlands, beautification and other purposes i.e. pigment and oil extraction and thera eutic uses A art from these uses marigold is a widely grown plant in gardens and pots. It is highly suitable as a bedding plant, in a herbaceous border and is also ideal for newly planted shrubberies to provide colour and fill the space. French marigold is most ideal for rockery, edging, hanging baskets and window boxes. Flowers remain fresh for 4-5 days at room temperature and are used for religious offerings and social functions. Recently marigolds are grown commercially for extraction of carotene pigments mainly xanthophylls. The carotenoid extracted from petals are added to poultry feed for intensification of yellow colour of egg yolk. Lutein which is the major constituent of xanthophylls is used for colouring food stuffs. Purified extract of marigold petals containing lutein dipalmitate is marketed as an ophthalmologic agent under the name adaptinol. Dietary carotenoids can be used to treat cancer and photosensitivity diseases.

Marigold leaves contain a distinct odoriferous oil. Wild marigold (Tagetes minuta) oil has valuable and precious essential oil which is used in high grade perfumes and cosmetics. Ketones present in the oil are base material for synthesizing aroma chemicals. Marigold essential oil has bronchodilatory, tranquilizing, anit-inflammatory as well as insect repellent activities. The floral extract of marigold is used for treating eye diseases and ulcers.

INTRODUCTION

Narcissus is a hardy or tender herbaceous perennial, growing from bulbs and seeds. In India it is commonly called Nargis. The splendid yellow and white flowers of the narcissus alone could make April and May month of delightful sweetness in the garden. Shakespeare mentioned Narcissus again and again as common symbol of the English spring. Narcissus are highly suitable for rowin in beds ots under the deciduous trees, window garden, etc. They are very good cut flower and are sold in the market. The bulbs of the European species are used in folk medicine as these are believed to possess the purgative, dermal and depurative properties. Few species are used for extraction of essential oil in France. There is often confusion as to whether the name narcissus or daffodil should be used. Popular thought attached the former name to the sweet scented tazetta or poet narcissus and the latter to the small wild Lent Lily which is still to be found massed in the wood and open pastures. Today daffodil usually refers to long trumpet and large flowered garden forms while, all the rest are narcissus. In the simplest words, the species of this are called narcissi, although the trumpets, which have trumpet (corona or cup) as long as or longer than the surrounding petals are usually called daffodils.

INTRODUCTION

Orchids are the most beautiful flowers in God’s creation and have conquered the cut flower industry all over the world during the last few decades. They are most pampered of the plants, occupy top position among all flowering plants and are valued for cut flower production and as potted plant. They are known for their beautiful flowers, which exhibit an incredible range of size, shape and colour, long life of flowers on the plants and an amazingly long keeping quality which no other plant can claim.

Orchids are excellent for garden and can be grown in beds, pots, baskets, split hollows of bamboo pieces, etc. They are also suitable for interior decoration and remain fresh for many days. Before their aesthetic qualities were exploited, orchids were grown for their tubers which were considered as aphrodisiac. The leaves of Vanda roxburghii have been used against rheumatism in older days in India. Habenaria, a terrestrial genus of orchid also possess medicinal properties. Vanillin produced from Vanilla planifolia is used in flavouring industries. Orchids are used in indigenous system of medicine, particularly Ayurveda. Many of the orchid species contain alkaloids, which are important secondary metabolites. From Dendrobium nobile dendrobine and nobilonine are extracted. Similarly, laburnine from Liparis bicallosa, malaxine from Malaxis congesta and phalaenopsine from Phalaenopsis mannii are extracted. Pseudobulbs of Cymbidium madidum and Dendrobium speciosum are used as food.

Orchid industry in India is not as old as the cultivation and trade of other flowers. Our position in export market is very low as compared to south-east Asian countries like Thailand, Malaysia and Singapore, where orchid growing has become a multi-million dollar industry.

INTRODUCTION

The rose is one of the oldest flowers in cultivation and most popular of all garden flowers throughout the world. It is one of the nature’s beautiful creations and is universally known as the Queen of Flowers.

Th e cultivation of th is f lower h as developed with the distillation of rose as mentioned in Ayurveda by Charaka around 100 A.D. At present, it has become the most important commercial flower. A large quantity of rose flowers is used for decoration purpose. Beside, it has been growing for centuries for the extraction of its essence. The rose water is frequently used for flavouring sweets and other food articles as well as for sprinkling over guests on festive occasions. Hips of some rose species are rich in vitamin C while its petals are used for preparing Gulkand and Pankhuri.

Domestic demand for roses has two components; the demand for stemless roses supplied by field grown roses and demand for stemmed roses, mainly grown under protected conditions. In most parts of India, rose flowers throughout the year, in a succession of flushes of blooms, without having any true dormant period. Good quality blooms are produced in winter when local market demand is good. There is a growing demand of value added floral extracts in world market, hence there is great scope for commercial cultivation of rose for production of floral extracts.

The fragrance of rose is said to be the only fragrance that never tires the human olfactory system. Export of rose water started in 8^th century from Iran and later in 9^th century from India and China, mostly to Arabian countries. Rose cultivation was introduced as an industry in Turkey in 17^th century and later spread to other countries like Egypt, Morocco, France, China, India, etc. About 80% of rose flower are utilized for rose water, 10% for attar, 1 to 2% for pankhuri and remaining for manufacture of gul-rohan and gulkand. Rose oil is used primarily as a fragrance component in pharmaceutical preparations e.g. ointments and lotions and is extensively used as a fragrance ingredient in perfumes, creams and soaps. Food products in which they are used include beverages, frozen dairy desserts, sweets, baked foods, gelatins and puddings.

INTRODUCTION

In many cultures, fresh cut flowers are deeply symbolic, conveying the message of nature to man. In recent times revolutionary changes have been seen in Indian floriculture sector which is due to the introduction of various annuals from abroad. Snapdragon too is the one of the relatively recent introduction in the field of cut flowers. Now-a-days, snapdragons are usually grown as annuals, though traditionally they are cultivated as perennials. Due to its curious shape of flowers, which resemble a dog, rabbit or dragon, it is popularly called as snapdragon, dog flower, bunny rabbit or bunny mouth. Snapdragons are one of the most popular and widely grown garden annuals. It is ideally suited for beds, pot, edging, window boxes, herbaceous border and rock gardens. Tall cultivars can be used among the shrubs, at the background of the annuals like hollyhock, larkspur, etc. in mixed borders or with herbaceous plants. The intermediate cultivars are very useful for bedding and potting purposes. Both these types are excellent for cut flower production. The dwarf cultivars are good for edging and bordering formal beds. The dwarf hybrids are suitable for covering the patches in rock garden. They are used in floral arrangements and in bouquets too. Their production for cut flower purpose began with the introduction of a winter flowering cultivar Chevoit Maid, followed by several F₁ hybrids with desirable cut flower qualities. The F₁ hybrids are grown all the year round. Flowers have good keeping quality, as they remain fresh for 6-7 days. Snapdragon has also been reported to have medicinal importance. It has diuretic and astringent properties and have been employed for the treatment of scurvy, liver tumor and ulcers.

INTRODUCTION

Stock or Gilly flower is an annual or biennial plant flowering in terminal clusters. It exists as both single and double forms and is valued for fragrant flowers that can be used as fresh or dried cut flower. Stocks are a most valuable race of garden plants for they are easy to grow and can be in bloom during the greater part of the year. They are excellent pot plants for the greenhouse in winter and spring and provide good cut flowers. Flowers are well arranged on a long column and the colours are variable from white to rose, crimson, purple, yellow, mauve, pink, etc. Seeds of stock are aphrodisiac, bitter, diuretic, expectorant, stimulant and are used as tonic. An infusion has been used in the treatment of cancer and when mixed with wine, it has been used as an antidote to poisonous bites. The highly fragrant flowers are used as a garnish, especially with sweet deserts.

INTRODUCTION

Among the important ornamental bulbous plants, tuberose occupies a very prominent position. In the orient, where ‘white’ goes for virtue and purity, tuberose flower is much adored for its prettiness, elegance and fragrance. It is commercially grown as cut flower, loose flower as well as for its potential in perfume industry.

The flowers of tuberose are used for artistic garlands, floral ornamentals, bouquets and buttonholes. The long flower spikes are excellent as cut flowers for table decoration when arranged in bowls and vases. They remain fresh pretty long time and stand long distance transportation and fill a useful place in the flower market.

Plants of tuberose can be used in landscapes; in all-white gardens or with other plants. Variegated varieties with golden or yellow striped leaves are very attractive and these varieties are suitable for garden beautification. Potted plants can be put in decorative containers and used for entranceways and interiors.

INTRODUCTION

Tulips are one of the most popular and widely grown flowering plant. Tulip is a main stay of spring gardens providing abundant flowers in vivid and vibrant spectrum and colours. It is first among bulbous ornamentals due to its attractive colours and exquisite flowers. Tulip is the national flower of Turkey and tulip motifs feature prominently in Turkish folk arts. The first European cultivation of the tulips as a garden flower occurred in the Netherlands in sixteenth century. In the following century, the early enthusiasm for the new flowers triggered a speculative frenzy now known as tulipomania. The Netherlands and tulips are still associated with one other. Tulip festivals are held in the Netherlands and in North America every May. A number of bewitching cultivars grown to perfection in a large variety of delicate and brilliant shades have developed tulip cultivation into a great bulb growing industry. Tulips are not only widely cultivated for cut flower production world wide but also grown for pot culture, in beds, borders, formal and informal location. They are also suitable for growing in orchards, lawns, rockeries and wild gardens.

The word tulip industry is dominated by the Dutch tulip growers. There is 10,000 hectare of tulip bulbs grown in the Netherlands. About 70 per cent of tulip bulbs cultivated are for forcing for flowers with 30 per cent for pre packs for gardens. The world market for bulbs has been buoyant for the past ten years. Production has been increasing at the rate of 6-8 per cent per annum and the market has expanded in line with this growth. In the Netherlands, three quarters of the total bulbs produced are exported, with the highest percentage going to the United State followed by Germany. In India, tulips are gaining popularity among the flower growers owing to congenial climate in hilly areas. Particularly in Kashmir valley, production of cut flower is increasing. Some area has been increased in Himachal Pradesh. It can also be grown successfully in other hilly parts of the country like Uttaranchal between 1300 to 3000 metre above mean sea level.

INTRODUCTION

Zantedeschia is commonly known as Calla lily. The other names are Arum lily, Aroid lily, Lily of the Nile and Pig lily. They are mainly grown for their attractive, large flower spathes, which are usually produced in the spring and summer and also for their variegated and spotted foliage. They are grown in large quantities by commercial growers because they are commonly used for decoration in Easter and throughout the spring and early summer months. It grows very well in open conditions in warm climate. Regular gardeners may have their bloom in winter, spring or early summer depending upon the temperature conditions maintained in the greenhouse.

Zantedeschia is an excellent cut flower and last a long time in water. There are various species, which produces different coloured flowers. The flower spathes of calla or arum lily (Zantedeschia aethiopica) are white, the spathes of the yellow or golden callas (Z. elliottiana) are yellow, whereas the pink calla (Z. rehmannii) produces lavender red, rose red, violet red or pink spathes. The white arum (common calla) forms large colonies in marshy areas ranging from the coast to an altitude of 2250 m above mean sea level. Thus, they may exist in humid, salt laden air at the coast and freezing, misty mountain grassland at high altitudes and as a result, are very versatile in the garden. The leaves of the calla are very interesting in that they contain water stomata, which can discharge excess water by a process known as guttation. This prevents logging and enables calla lily to grow in wet conditions.

INTRODUCTION

Zinnias are popular in flower gardens because of their variable coloured blooms and their ability to withstand hot summer temperatures. They are easy to grow from seeds. Plants come in many colours, shape and size adapted well to most growing conditions. Out of about twenty species, these are some eight to ten species of zinnia known to the gardens, but only few of them have become favourite and that abundantly deserves the pre-eminence. They have attained position as one of the most splendid of annual flowers. Most varieties are prolific bloomer, making them excellent for landscape. They are also available as compact varieties suitable for hanging baskets, window boxes and containers. Recently, new hybrid zinnia cultivars have attracted attention as a cut flower crop. There are at least hundred varieties in the diversity of flower colour and types. Some with flower heads upto 15 cm across. The colour of zinnias are white, cream, green, yellow, apricot, orange, red, bronze, crimson, purple and lilac with stripped, speckled and bicoloured flowers. An important variety of zinnia is Coccinea or Scarlet-rayed. This variety became popular after its existence in 1829 and was thought much of for its brilliant colour and stately habit. During the fifty years that have elapsed since it appeared, the flower has been in all characters and now posses a race of perfectly double zinnias, the flowers of which show no central disc, but are perfect rosettes of exquisite form and of every shade of colour except blue. There is not a more striking instance of floral advancement, accomplished by systematic selection, than is afforded by zinnia, which is at once one of the largest and long standing of many good and cheap annual flowers.

Flower growing, once used to be a gardener’s activity has today transformed into an astounding business proportion. Globally, more than 140 countries are involved in cultivation of floriculture crops. The global floriculture trade stands at US $ 60 billion with an annual growth rate of 10-15%. But the picture is not all that rosy. The extensive use of pesticides especially in greenhouse grown crops is threatening workers health and safety, besides disturbing environment and may also affect consumers health.

Gaston Dorren and Niala Maharaj, authors of “The Game of the Rose” noted that floriculture consumes more pesticides than any other agricultural sector. Floral workers suffer the brunt of the trade’s pesticide use. About 60% of Colombian flower workers (the sprayers and handlers) suffer from headaches, nausea, impaired vision, rashes and asthma, reports Pesticide Action Network, North America. A study published by the Netherlands ‘Ministry of Social Affairs and Employment’, reports that Dutch floral workers are exposed to pesticide concentrations of up to 60 times the amount considered safe.

Dr. Marion Moses of the San Francisco-based Pesticide Education Center says that many of the pesticides in use are highly toxic. “One of the chemicals widely used in greenhouses for flowers is temik (aldicarb), and that has caused serious problems”. Methyl bromide, an ozone destroyer and a category I acute toxin, among the most dangerous toxic substances known, is also heavily used in Latin America and the U.S. on flower crops. According to a 1997 EWG (Environmental Working Group) study, California-grown roses have 1000 times the level of cancer causing pesticides as comparable food products. Consumers are buying roses that, toxicity levels suggest, should be handled by workers wearing protective gear. Testing the leaves and petals of roses from California, New Hampshire, Colorado, Canada and Colombia, EWG found two probable human carcinogens, three Category I pesticides (the most hazardous) and three neurotoxins at up to 50 times the amount allowed in food.

Biotechnology can be defined as utilization of materials and methods for benefit of mankind by the utilization of microorganisms and biological agents. It is an area with a tremendous potential in solving basic problems of food, fibre, fuel and medicines in developing countries. According to the office of the Technology Assessment of the US Congress, biotechnology can be defined as any technique that uses living organisms to make or modify a product, to improve plants or animals or to develop micro organisms for specific uses. Flower industry has always increasing demand for new forms, colours and types of flowers. Biotechnology has made significant advances in the improvement of ornamental crops and development of new varieties has great potential to be utilized in future. Utilization of this technology can be done in floriculture under two broad subheads viz., tissue culture and genetic engineering.

TISSUE CULTURE

The major commercial utilization of tissue culture has been micropropagation, which is an alternative to vegetative propagation. Micropropagation permits true to type multiplication of a desired genotype using in vitro culture techniques. Micropropagation process can produce a large number of propagules in a relatively short time and space under controlled conditions. It has already revolutionized production process of several nurseries. The dream of multiplying disease free plants in required quantity on the specified time schedule in an industrial way has become true due to micropropagation. Some of the important floricultural crops that are successfully propagated in vitro in Indian laboratories are given below with their explant source:

Carnation: Leaf segments, internodes, petals

Gerbera: Leaf, petiole, flower stalk segments

Gladiolus: Inflorescence stalk, leaf sections

Orchids: Epidermal peelings, leaf segments, root tips

Rose: Internodal segments, petals, leaf segments, immature embryos, root segments

Information is a basic resource essential for individual and organization in order to survive and succeed in society. Floriculture is a technology driven industry needing technological advancement. The new technologies that are being developed at various places the world over, needs to be disseminated through proper and quick linkage between the researchers and the beneficiaries i.e. the farmers. This demand can be met out by information technology. Information is data put into a meaningful and useful text. Today, information technology (IT) is a metaresource and computers are being used as a metatool and a metamedia.

COMPONENTS OF INFORMATION TECHNOLOGY

An information technology architecture is an integrated framework for acquiring and evolving IT to achieve strategic goals. It has both logical and technical components. Logical components include mission, functional and information requirements, system configurations and information flows. Technical components include IT standards and rules that will be used to implement the logical architecture.

Input devices: The advent of touch screen monitors has made it possible to develop user-friendly interface for farmers. It is now possible to capture and store good quality graphics and video clips with digital cameras.

Output devices: Output devices like monitor screen, printers and plotters, data projectors support high resolution and good quality output.

Processors: The processing speeds of computers have improved a lot these days. At present, Intel P-IV based processors @ 3.3 Ghz are available in the PC range.

Storage devices: To store substantial information at local level. Capacity of 40 GB and higher are common in hard disk devices, besides floppy disk drives and CDs; all making it possible to transfer large amount of data to locations which cannot be connected to networks quickly.

World Trade Organization (WTO) is an international body which deals with the “Rules of Trade” between nations on the basis of the agreements negotiated and signed by most of the world’s trading nations. These agreements are essentially contracts that bind governments to keep their trade policies within predefined limits. The goal is to help producers of goods and services, exporters and importers.

The purpose of WTO agreement is to help free flow of trade, serve as a forum for trade negotiations and to serve as a dispute settlement body. There are 5 broad principles of the trading system followed under WTO:

Trade without discrimination

Freer trade, gradually through negotiations

Predictability, through binding

Promotion of fair competition

Encouragement to development and economic reforms.

Flowers symbolize beauty, purity, peace and love. These are intricately associated with social beliefs and no social function is complete without the use of flowers; especially in a country like India, where it is a popular saying that flowers are associated with man from birth till death. Floriculture can be defined as a specialized branch of horticulture which deals not only with the cultivation of flowers, foliage, climbers, trees, shrubs, cacti, succulents, etc., but also with their marketing and production of value-added products from them.

Floriculture is increasingly regarded as a viable diversification from the traditional field crops due to higher returns per unit area and increasing habit of “saying it with flowers”. Flowers play a cardinal role in human behaviour and culture, bringing tranquility and peace of mind. From a symbol of love, flowers have transformed into an industry, generating both income as well as employment. India is blessed with a diversity of agroclimatic conditions prevailing in different regions of the country ensuring production of almost all the ornamental crops through out the year. Floriculture in India is a dynamic and expanding industry recording impressive annual growth rate.

The floriculture industry comprises of:

1. The florist trade traditional and contemporary cut flowers and cut foliage, both fresh and dried and value-added products like bouquets, floral baskets, flower arrangements and garlands.
2. The plant nursery for propagation and supply of plant material including tissue culture plants, seeds, bulbs, corms and other propagated material.
3. Plant rental service for supply of house plants on annual rent for a specific period.
4. Flower perfume and gulkand.

As a result of political changes in India, many entrepreneurs are changing to floricultural activities, which have become a high priority for the Indian government. Due to availability of sufficient winter and summer sunshine, high temperature, good soil fertility, good water quality, different climatic zones for different type of products and low labour and investment costs, India has great potential for floriculture. In the flower industry, significant changes are occurring in the competitive relationships worldwide. European integration, democratization in eastern Europe and the liberalization of world trade in the context of the GATT negotiations will have consequences on international trade. A number of traditional markets are displaying signs of saturation while, on the other hand, new countries are trying to get their place on the market. At the same time, we see new developing markets and in some parts of the world (USA, Japan) it is expected that per capita consumption will go up. Enormous genetic diversity, versatile human resources and varied agro-climate offers India unique scope for diversification not explored yet fully.

Abstract

The genetic improvement of crop plants is possible only through employing an appropriate breeding technique. The use of plant breeding technique depends on mode of pollination and reproduction of plant species e.g. selection and hybridization are used in sexually reproduced species, while clonal selection in asexually propagated plant species. The plant species/ varieties are usually derived through conventional techniques (vi z. introduction, selection, hybridization etc.), which are commonly used in various breeding programmes, while some modern techniques viz. transgenic breeding and marker assisted selection etc. are also available which are equally effective for improvement of all crop species. Various techniques applied for development of new varieties and hybrids are briefly described in this section.

Plant breeding is an art, science and technology of improving genetic make-up of crop plants in relation to their economic usefulness for mankind. Various techniques/methods of breeding used for genetic improvement of crop plants are: introduction, selection, hybridization, mutation, transgenic breeding etc.

Classification of Breeding Techniques: Plant breeding techniques are classified as conventional and modern breeding techniques.

Abstract

Plantbreeding is an ancientart practiced throughselection ofplants fordesirable traits. Over a period of time it has evolved into scientific discipline with various methodologiesbasedon theories and principles ofgenetics. Since the rediscovery of Mendel’s law, there has been accelerated increase in yield of various crop plants due to development of high yielding varieties. Conventional approaches of following phenotypic selection from a variable population in early generation followed by yield testing in later generations have been highly successful in most of the crop species. This coupled with hybrid varieties led to significant increase in food-grain production during later half of the 20^th century. At present manycrops are facing yield plateau asthey have reached their maximum genetic potential. The growing condition is also deteriorating due to changing climate. There is an urgent need among breeders to utilize full arsenal of techniques available to them to sustain crop productivity. Molecular markers and marker assisted selection has come as a boon to the breeders to increase the efficiency ofselection in early generation breeding especially for traits whose phenotypic evaluation is difficult. Further, transgenic technology has the potential to incorporate genes from diverse sources, thus enriching the gene pool from which breeders can search for specific traits. Although at present there is skepticism about transgenic crops among public but this may become a viable strategy in future.

Abstract

Seed technology deals with the various aspects of seed- right from production to make it readily and timely available to the end users. The advancement in seedtechnology was realizedlong back and itwas considered equally important to the development of new technology (varieties). Considering the importance of seed as well as variability among seed of different crop species or even in same crop species, the researchers initiated work and focused their direction of research accordingly which resultedinto worthy achievements. Brief overviews of the advancements made in seed technology are being discussed in this chapter. However, efforts are still on to get rid of problems of seed technology in order to strengthen the seed industry, which makes the highest contribution to rural development, probably among all industries.

Abstract

Water scarce state Rajasthan is without efficient and effective management. Water, when at surface is cheaper and like free commodity to use. Most of it gets evaporated rapidly due to aridity. There is no water during summers and drought years. This is now critical time to rethink and review our planning and policies and make it ground water oriented instead of completely surface water based. Ground water management should be the thrust area and key issue. There is need to conserve andharvest each drop ofwater especially for recharge to ground water. Utilize the augmented ground water resources as crisis management during long dry spells. Also, enforcement of regulatory measures, creating awareness among masses and participatory approach ofmanagement are the key factors for ensuring sustainable availability of water resources.

Abstract

Modern agriculture largely depends on use of high cost inputs and energy intensive farm machinery. Worlds increasing population and continuously deteriorating soil fertility has alarmed agriculture system to look for some safe alternatives. Organic manures are rich source ofnutrients and humans, therefore crop residue recycling by composting is a best alternate of modern high cost input based agriculture. Compost is an aerobically decomposed organic matter .Bacteria, fungi, actinomycetes algae and protozoa are involved in the process of composting and are found throughout the natural environment. The composting material warms up due to microbial activity and it’s temperature becomes up to 160 ⁰F active stage of microbial activity . There are four types of compositing i.e. Windrow composting, Aerated static pile composting, In-Vessel composting and Vermi-composting. The C: N ratio, aeration, temperature and moisture are major factors affecting composting process. Major advantages of composting are: Aggregate formation, Reduction in bulk density, Increase in hydraulic conductivity, Reduction in loss of soil moisture, Increase in organic carbon content and pH of soil.

Abstract

Sustainable agriculture or farming is one that contributes to the overall objective ofsustainable developmenti.e. to meetthe present needs withoutcompromising the ability of the future generations to fulfill their own food needs and related demands from the land. A farming system is a complex, interrelated matrix of soils, plants, animals, power, implements, labour, capital and other inputs controlled by farming families and influenced to varying degrees by political, economical, institutional and social forces that operate at any levels. Research witha farmingsystems perspective has variousobjectivesranging fromincreasing the body of knowledge about farming system. The whole farming rather than the individual crops/enterprises need to be considered in the decision making under the farming systems approach. This is a multidisciplinary whole-farm approach and very effective in solving the problems of small and marginal farmers. Farming systems approach in analyzing the problems of agriculture is gaining lot of importance in recent years. Such a study would throw light on the problems associatedwith different farmingsystems and enable theacademicians and policy makers to formulate and implement appropriate policies for a balanced and integrated agricultural development.

Abstract

Though India is second largest producer of fruits and vegetables but is far behind in per capita availability of this protective food as compared to many developed countries. Floriculture and allied horticulture crop production (spices, medicinal & aromatic crops, mushroom etc.) have great potential to generate high income, jobs and new careers. Hi-tech horticulture is the need of all the developing countries and it refers to “the precise production techniques for efficient use of inputs at appropriate time and quantity for maximization of yield and quality of crops”. Various ways to make horticulture hi-tech include modern nursery management including micro propagation, protected crop production, high density planting including canopy management, use of agrochemicals, rejuvenation technique, interated nutrient management, integrated water management, integrated pest and disease management. Inspite of this, in present context, major emphasis has been given on clean horticulture production with bio-derived, renewable energy sources for developing a profitable CEA (controlled environment agriculture) that would help in sustaining the system, improving socio-economic status of growers and of-course environment-friendly.

Abstract

Indian is rich biodiversity and availability of a variety plants of enhances the interest of scientist for the possible use of plant products as natural herbicides. The emphasis should be to collect the information about such plants from the concerned people who have traditional knowledge about the use of these herbs and then to study scientifically to arrive at conclusions. The study of compounds produced by a plant which inhibit or stimulate the germination and the development of other plants is important for understanding the mechanisms of the ecologicalinteraction. Therefore, there is continuing need to develop and release new phytotoxic chemicals that preserve the environment and enable a more efficient control of weeds, improving crop yield and quality. Ageratum conyzoides a herb traditionally used for treatment of many diseases, releases some potential allelochemicals and other chemicals to the environment which inhibit the germination and growth of neighboring plants. A complete study of its potential allelochemicals may be useful in biological control for sustainable agriculture.