eChapters

The word indigenous, originates from the Latin work, indigena, implies that the individual and its ancestors originated from a specified country or continent. Presently, certain synonymous words used for indigenous chicken are: ‘native’, ‘local’ or ‘village chicken’. The indigenous fowls are well adapted to the local climate, need less input and produce tasty egg and meat at the least possible cost through scavenging. The birds require no scientific feeding, health care, housing and management and thus make the indigenous birds suitable for backyard poultry farming. Indigenous birds are normally handled by women, can significantly contribute to farmers’ livelihoods through increased food security and cash income. These breeds are self-propagating; contribute to poultry diversity and cultural heritage. Because of their local origin they are less prone to disease or predator attacks, and their cultural and sporting values secure additional income. The prices of egg and meat of local birds are 100- 150 percent higher than that of commercial counterpart. Some of these fowls are described in brief, as below.

The modern breeds of chicken have known to be descended from the wild jungle fowl. India, Nepal, Bangladesh, Myanmar, Thailand, Sri Lanka and Malaysia are the homeland to these jungle fowls. There are four known species of jungle fowl viz. Gallus gallus (Red jungle fowl), Gallus lafayetti (Ceylon jungle fowl), Gallus sonnerati (Grey jungle fowl) and Gallus varius (Java jungle fowl). The domestic breeds of chicken/fowl have originated from Gallus gallus.

The modern commercial poultry production in India is barely 50 years old, although backyard poultry keeping dates back to pre-historic period. In between 1955 to 1965, some Christian Missionaries had imported White Leghorn, Rhode Island Red and White Rock breeds, to upgrade the local chicken, having very high disease resistance power; but highly broody. Later, hybrid broiler (Arbor Acres) and layer (Babcock) strains were brought to India in early seventies, to start modern poultry industry. Among the two, the layer industry took wings early and registered a spectacular growth rate between 1970 and 1985. The broiler industry came to existence five years later and showed 25 -100% annual growth rate initially and 10-20% growth rate subsequently; between 1975 – 2005. The growth indicators of poultry development in India are presented

Introduction

Drought is one of the primary factors responsible for depressing rice yield in chronic areas and in destabilising rice production in drought-prone areas. It is a production constraint common to all rainfed rice cultures: wetland, upland, and deepwater (O’Toole and Chang 1979). Breeding for drought resistance, a major component of the International Rice Research Institute’s (IRRI) Genetic Evaluation and Utilization (GEU) Program since the early 1970s, aims at countering the adverse effects of drought in unfavoured rice production areas.

Rice germplasm has such remarkably rich diversity that a continuous spectrum of genotypes differing in the various physiological mechanisms can be found and is available for genetic manipulation (Chang et al. 1982a). However, effective evaluation methods are essential for unravelling the specific mechanism(s) involved and for devising eficient selection criteria in a breeding program. Moreover, the broad spread in growth duration among rice cultivars makes it impractical to obtain uniform evaluation of a large number of cultivars when they differ in physiological responses that are specific to certain growth stages. Methods that can accommodate large numbers are essential to breeding program.

Introduction

Man’s intervention in the evolution of plants, to adapt them to suit his needs, constitutes the practice of plant breeding. Historically regarded as an art and still too empirical to be accepted universally as a science, it has recently been described as a technology (Riley 1978). Whether art, science or technology, it certainly draws on a wide range of disciplines and embodies all those principles of organisation and management that determine success in any production-oriented programme.

Perhaps the biggest contribution that the plant breeder has made to increased production during the past 50 years has been in helping to alleviate the effects of natural hazards such as lodging, pests and diseases on crop production. While most of this progress has been through the manipulation of biotic stresses, much is still to be achieved under non-biotic stresses such as drought, salinity, temperature, etc. This argument is strengthened by the fact that in spite of the spectacular achievements made possible by the ‘Green Revolution’, the productivity level of most crop plants, including wheat and rice, has remained both low and static under stress conditions. Concerted efforts are needed through an approach of interdisciplinary research, since not much has been done to define criteria for stress assessment and evolving breeding approaches for incorporating stress tolerance in crop plants.

Introduction

Drought is the most common adverse environmental factor which limits crop production in different parts of the world. Often drought is accompanied by relatively high temperatures, which promote evapotranspiration, and hence could accentuate the effects of drought and thereby further reduce crop yields. Since these events occur more frequently in tropical and semitropical regions where most of the developing countries are situated, droughts are often associated with food shortages and an overall setback to developmental activities. Therefore, raising of drought-resistant crops is common sense to achieve stability in production and to enhance the possibility of self-suficiency in food. Consequently, breeding for drought resistance is a major objective of many research programmes in the international and national institutions. This has been so for the past several decades. But, it is disappointing that, there has not been any measurable success in these programmes compared with the success achieved in breeding for yield; or breeding for disease resistance or breeding for quality attributes. In fact, this was amply expressed by Arnon (1980) when he stated “Breeding for drought resistance has been a consistent theme for as long as I remember and probably the greatest source of wasted breeding efforts in the whole field of plant breeding.” However, the fact remains that we do hear of drought resistant varieties in many crops. For example, C-306 in wheat, Lalnakanda in rice and M 35-1 in Sorghum are some of the better known examples in India. It is also claimed that a large number of cultures among the Assam Rice Collection exhibit a considerably high degree of drought tolerance. Many land races and wild relatives of several crop species are said to contain drought resistant traits, which could be profitably utilised in breeding programmes. This situation is not unique to India alone but is a common experience in different parts of the world. However, to afirm a conviction a short questionnaire to assess the current state-of-art on breeding for drought resistance was distributed to 75 distinguished plant breeders and plant physiologists all over the world. The questionnaire and a summary based on the responses is as follows:

Expression of genetic potential for growth and yield of a crop variety is directly dependent upon the environment comprising both climate (weather) and soil components. As discussed in the preceding chapter, the term ‘salt-affected soils’ encompasses a broad group of adverse but distinct soil conditions, namely, saline, alkali (sodic) and acid soils with further variations such as coastal and inland locations as well as arid and water-logged situations (Swaminathan 1977; Bresler et al. 1982). Factors limiting growth and yield of crop plants in various categories of problem soils are different and specific. Likewise, adaptive strategies evolved by plants to cope with the prevailing edaphic stresses, such as salt stress, also vary a great deal as indicated in Table 1. It is not unexpected therefore, that even varieties within a crop often show notable differences regarding tolerance to adverse soil conditions (Epstein et al. 1980; Devine 1982; Shannon 1984; Sayed 1985). Hence, it is essential that the breeder must understand the inherent charaderistics of the problem soil with which he is concerned and should also simultaneously appreciate that basically it is the sensitivity of crop variety, rather than the soil parameters per se, that essentially determines the occurrence as well as the magnitude of actual soil problem (Rana 1977). Since the degree of tolerance (adaptation) of crop varieties to different kinds of salt affected soils is genetically controlled, it is axiomatic that it can be improved through genetic manipulations by adopting suitable breeding procedures.

Introduction

Accumulation of excess soluble salts in the root zone of soils resulting in partial or complete loss of soil productivity is a worldwide phenomenon. The problems of soil salinity are widespread in the arid and semi-arid areas but salt-affected soils also occur extensively in the sub-humid and humid climates particularly in the coastal regions where the ingress of sea water through estuaries and rivers and through ground water movement causes large scale soil and water salinisation. Soil salinity is also a serious problem in areas where ground waters of high salt content are the only source of water available for irrigation. By far the most serious problems of salinity are being faced in the irrigated, arid and semi-arid regions of the world. Our ability to manage salt-affected soils and waters both in the irrigated and in the unirrigated regions will constitute a major effort in meeting potential food requirements. The magnitude of the problem can be appreciated from the following.

Nanotechnology, which deals with understanding and control of matter at dimension of roughly 100 nm and below, has a cross sectoral application and an interdisciplinary orientation. At this scale, the physical, chemical and biological properties of materials differ from the properties of individual atoms and molecules or bulk matter, which enable novel applications. Nanotechnology research and development is directed towards understanding and creating improved materials, devices and systems that exploit these properties as they are discovered and characterized

There are many applications of nanotechnology such as in the area of medicine, chemistry and environment, energy, agriculture, information and communication, heavy industry and consumer goods. The alleged potential of this technology has garnered the attention of both developed and developing countries across the globe. The US National Science Foundation (NSF) has listed it as one of six priority areas; it is one of the themesin the EU Framework Program for Research and Technological Development in Europe; and it has been the focus of research in countries worldwide.

Nanotoxicology is the study of the toxicity of nanomaterials. Because of quantum size effects and large surface area, nanomaterials have unique properties compared with their larger counterparts

Nanotoxicology is that branch of bionanoscience, which deals with the study and application of toxicity of nanomaterials. The nanomaterials, even when they are made of inert elements like gold, become very active at a nanometer range. Nanotoxicological studies are intended to determine whether and to what extent these may pose a threat to the environment and to human beings. For instance, Diesel nanoparticles have been found to damage the cardiovascular system in a mouse model.

Human health and safety

Calls for tighter regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks associated with nanotechnology. The Royal Society identifies the potential for nanoparticles to penetrate the skin, and recommend that the use of nanoparticles in cosmetics be conditional upon a favorable assessment by the relevant European Commission safety advisory committee. Andrew Maynard also reports that ‘certain nanoparticles may move easily into sensitive lung tissues after inhalation, and cause damage that can lead to chronic breathing problems’.

The societal implications of nanotechnology are the potential benefits and challenges that the introduction of novelnanotechnological devices and materials may hold for society and human interaction. The term is sometimes expanded to also include nanotechnology’s health and environmental implications, but this article will only consider the social and political implications of nanotechnology.

As nanotechnology is an emerging field andmostof its applications are still speculative, there is much debate about what positive and negative effects that nanotechnology might have.

Beyond the toxicity risks to human health and the environment which are associated with first-generation nanomaterials, nanotechnology has broader societal implications and poses broader social challenges. Social scientistshave suggestedthatnanotechnology’s social issues should be understood and assessed not simply as “downstream” risks or impacts. Rather, the challenges should be factored into “upstream” research and decision making in order to ensure technology development that meets social objectives.

Over the past few decades, the fields of science and engineering have been seeking to develop new and improved types of energy technologies that havethe capability of improvinglifeall over the world. In order to make the next leap forward from the current generation of technology, scientists and engineers have been developing Energy Applications of Nanotechnology. Nanotechnology, a new field in science, is any technology that contains components smaller than 100 nanometers. For scale, a single virus particle is about 100 nanometers in width.

An important subfield of nanotechnology related to energy is nanofabrication. Nanofabrication is the process of designing and creating devices on the nanoscale. Creating devices smaller than 100 nanometers opens many doors for the development of new ways to capture, store, and transfer energy. The inherent level of control that nanofabrication could give scientists and engineers would be critical in providing the capability of solving many of the problems that the world is facing today related to the current generation of energy technologies.

People in the fields of science and engineering have already begun developing ways of utilizing nanotechnology for the development of consumer products. Benefits already observed from the design of these products are an increased efficiency of lighting and heating, increased electrical storage capacity, and a decrease in the amount of pollution from the use of energy. Benefits such as these make the investment of capital in the research and development of nanotechnology a top priority.

Nanosensors are any biological, chemical, or sugery sensory points used to convey information about nanoparticles to the macroscopic world. Their use mainly include various medicinal purposes and as gateways to building other nanoproducts, such as computer chips that work at the nanoscaleand nanorobots. Presently, there are several ways proposed to make nanosensors, including Top-down and bottom-up design, top-downlithography, bottom-upassembly, and molecular self-assembly.

Predicted applications

Medicinal uses of nanosensors mainly revolve aroundthe potential of nanosensors to accurately identify particular cells or places in the body in need. By measuring changes in volume, concentration, displacement and velocity, gravitational,electrical, and magneticforces, pressure, or temperature of cells in a body, nanosensors may be able to distinguish between and recognize certain cells, most notably those of cancer, at the molecular level in order to deliver medicine or monitor development to specific places in the body. In addition, they may be able to detect macroscopic variations from outside the body and communicate these changes to other nanoproducts working within the body.

The impact of nanotechnology in the food industry has become more apparent over the last few years with the organization of various conferences dedicated to the topic, initiation of consortia for better and safefood, along with increased coveragein themedia. Several companies which were hesitant about revealing their research programmes in nanofood, have now gone public announcing plans to improve existing products and develop new ones to maintain market dominance. The typesof application include:smartpackaging, on demand preservatives, and interactive foods. Building on the concept of “on-demand” food, the idea of interactive food is to allow consumers to modify food depending on their own nutritional needs or tastes. The concept is that thousands of nanocapsules containing flavour or colour enhancers, or added nutritional elements (such as vitamins), would remain dormant in the food and only be released when triggered by the consumer.24 Most of the food giants including Nestle, Kraft, Heinz, and Unilever supportspecific research programmes tocapturea share of the nanofood market in the next decade.

The definition of nanofood is that nanotechnology techniques or tools are used during cultivation, production, processing, or packaging of the food. It does not mean atomically modified foodor foodproduced by nanomachines. Although there are ambitious thoughts of creating molecularfood using nanomachines, this is unrealistic in the foreseeable future. Instead nanotechnologists are moreoptimisticabout thepotential to changethe existing systemof food processingand to ensure the safety of food products, creating a healthy food culture. They are also hopeful of enhancing the nutritional quality of food through selected additives and improvements to the way the body digests and absorbs food. Although some of these goals are further away, the food packaging industry already incorporates nanotechnology in products.

Nanomedicine is the medical application of nanotechnology. The approaches to nanomedicine range from the medical use of nanomaterials, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials.

Nanomedicine research is receiving funding from the US National Institute of Health. Of note is the funding in 2005 of a five-year plan to set up four nanomedicine centers. In April 2006, the journal Nature Materials estimated that130 nanotech-based drugsanddeliverysystems were being developed worldwide.

Nanotechnology has the potential to revolutionizethe agricultural andfood industry with newtools forthemoleculartreatmentof diseases, rapid disease detection, enhancing the ability of plants to absorb nutrients etc. Smart sensors and smart delivery systems will help the agricultural industry combat viruses and other crop pathogens. In the near futurenanostructured catalysts will beavailable which will increase the efficiency of pesticides and herbicides, allowing lower doses to be used. Nanotechnology will also protect the environment indirectly through the use of alternative (renewable) energy supplies, and filters or catalysts to reduce pollution and clean-up existing pollutants.

Infrared spectroscopy (IRspectroscopy) is the spectros copy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light. It covers a range of techniques, mostly based on absorption spectroscopy. As with all spectroscopic techniques, it can be used to identifyand study chemicals. A common laboratory instrument that uses this technique is a Fourier transform infrared (FTIR) spectrometer.

The infrared portion of the electromagnetic spectrum is usually divided into three regions; the near-, mid- and far- infrared, named for their relation to the visible spectrum. The higher energy near-IR, approximately 14000–4000 cm^–1 (0.8–2.5 μm wavelength) can excite overtone orharmonic vibrations. Themid-infrared, approximately 4000– 400 cm^–1 (2.5–25 μm) may be used to study the fundamental vibrations and associated rotational-vibrational structure. The far-infrared, approximately 400–10 cm^–1 (25–1000 μm), lying adjacent to the microwave region, has low energy and may be used for rotational spectroscopy. The names and classifications of these sub regions are conventions, and are only loosely based on the relative molecular or electromagnetic properties.

Infrared spectroscopy exploits the fact that molecules absorb specific frequencies that are characteristic of their structure. These absorptions are resonant frequencies, i.e. the frequency of the absorbed radiation matches the frequency of the bond or group that vibrates. The energies are determined by the shape of the molecular potential energy surfaces, the masses of the atoms, and the associated vibronic coupling.

A Scanning electron microscope (SEM) is a type of electron microscope that images a sample by scanning it with a high-energy beam of electrons in a raster scan pattern. The electrons interact with the atoms that make up the sample producing signals that contain information about the sample’s surface topography, composition, and other properties such as electrical conductivity.

The types of signals produced by an SEM include secondary electrons, back-scattered electrons (BSE), characteristic X-rays, light (cathodoluminescence), specimen current and transmitted electrons. Secondary electron detectors are common in all SEMs, but it is rare that a singlemachine would havedetectors for allpossiblesignals. The signals result from interactions of the electron beam with atoms at or near the surface of the sample. In the most common or standard detection mode, secondary electron imaging or SEI, the SEM can produce very high-resolution images of a sample surface, revealing details less than 1 nm in size. Due to the very narrow electron beam, SEM micrographs have a large depth of field yielding a characteristic three dimensional appearance useful for understanding the surface structure of a sample.

Electron Microscope

An electron microscope is a type of microscope that uses a particle beamof electronstoilluminate a specimen and createa highly-magnified image. Electron microscopes have much greater resolving power than light microscopes that use electromagnetic radiation and can obtain much higher magnifications of up to 1 million times, while the best light microscopes are limited to magnifications of 1000 times. Both electron and light microscopes have resolution limitations, imposed by the wavelength of the radiation they use. The greater resolution and magnification of the electron microscope is because the de Broglie wavelength of an electron is much smallerthan that of a photon of visible light.

The electron microscope uses electrostatic and electromagnetic lenses in forming the image by controlling the electron beam to focus it at a specific plane relative to the specimen. This manner is similar to how a light microscope uses glass lenses to focus light on or through a specimen to form an image.

X-ray scattering techniquesarea family of non-destructive analytical techniques which reveal information about the crystallographic structure, chemical composition, and physical properties of materials and thin films. These techniques are based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy.

Nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and applications. Characterization is done by using a variety of different techniques, mainly drawn from materials science. Common techniques are electron microscopy (TEM, SEM), atomic force microscopy (AFM), dynamic light scattering (DLS), x-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF),ultraviolet-visible spectroscopy and dual polarisation interferometry.

Whilst the theory has been known for over a century (see Robert Brown), the technologyfor Nanoparticle trackinganalysis (NTA) allows direct tracking of the Brownian motion and thismethodtherefore allows the sizing of individual nanoparticles in solution.

Strength

Carbon nanotubes are the strongest and stiffest materials yet discovered in terms of tensile strength and elastic modulus respectively. This strength results from the covalent sp² bonds formed between the individual carbon atoms. In 2000, a multi-walled carbon nanotube was tested to have a tensile strength of 63 gigapascals (GPa). (This, for illustration, translates into the ability to endure tension of 6300 kg on a cable with cross-section of 1 mm².) Since carbon nanotubes have a low density for a solid of 1.3 to 1.4 g·cm”³, its specific strength of up to 48,000 kN·m·kg”¹ is the best of known materials, compared to high-carbon steel’s 154 kN·m·kg”¹. Under excessive tensile strain, the tubes will undergo plastic deformation, which means the deformation is permanent. This deformation begins at strains of approximately 5% and can increase the maximum strain the tubes undergo before fracture by releasing strain energy.

1. Mechanical Properties of Nanomaterials

Scientific challenges in nanoscience and nanotechnology include the development of nanomaterials with novel mechanical properties. The need for scratch, mar and/or abrasion resistance is well established in various markets, including fingernail polishes, flooring, plastic glazing, headlamp covers and other automotive parts, transportation windows and optical lenses, where clear scratch-resistant coatings are used. Because the nanosize, many of their mechanical properties of the materials is modified, among others, hardness and elastic modulus, fracture toughness, scratch resistance, fatigue strength, and hardness. Energy dissipation, mechanical coupling within arrays of components, and mechanical nonlinearities are influenced by structuring components at the nanometer scale. This includes also the interpretation of unusual mechanical behavior (e.g., strengths approaching the theoretical limit) and the exploration of new ways to integrate diverse classes of mechanically functional materials on the nano-size.

Techniques have been developed to produce nanotubes in sizeable quantities, including arc discharge, laser ablation, high pressure carbon monoxide (HiPCO),andchemicalvapor deposition (CVD).Mostof these processes take place in vacuum or with process gases. CVD growth of CNTs can occur in vacuum or at atmospheric pressure. Large quantities of nanotubes can be synthesized by these methods; advances incatalysis and continuous growthprocessesare making CNTs more commercially viable.

The most commonly used technique has been discussed and we have tried to generalize the type of particle that can be synthesized by each of these methods. Though it is not a rule that is applicable to all cases but it can be applied to most cases.

Polymerization Radical Polymerization

The polymerization could be a free radical polymerization or an atom transfer radical polymerization. The process of atom transfer radical polymerization (ATRP) is better than the free radical polymerization as control of molecular weight and size of the particle can be achieved. The coating of polymer on silica nanoparticles is generally done by ATRP. The surface of the silica particle is modified with a suitable initiator.

Nanoparticles synthesis is done by two major routes, which include classical synthesis and green synthesis. The green synthesis techniques generally utilize relatively non-toxic chemicals non-toxic solvents, biological extracts and systems. Biological methods are considered safe and ecologically sound forthe nanomaterial fabrication asan alternative to conventional physical and chemical methods

Nanoparticles

Gold, silver, and copper have been used mostly for the synthesis of stable dispersions of nanoparticles, which are useful in areas of photography, catalysis, biological labeling, photonics, optoelectronics and surface-enhanced Raman scattering (SERS) detection

The need for biosynthesis of nanoparticles rose as the physical and chemical processes were costly. So in the search of cheaper pathways for nanoparticle synthesis, scientists used microorganisms and then plant extracts for synthesis. Nature has devised various processes for the synthesis of nano- and micro- length scaled inorganic materials which have contributed tothedevelopment of relatively newandlargely unexplored area of research based on the biosynthesis of nanomaterials.

Chemical synthesis is spontaneous organization of molecules into stable, structurally well-defined aggregates at the nanometer length scale. Chemical synthesis is largely an art form (i.e., theory often does not quantitatively predict how to make new materials from molecules).Yet, chemical synthesis can be quite powerful (e.g., proteins and complex organic molecules can be made from simple reagents) Semiconductor nanocrystals have been synthesized via “natural self-assembly” in two steps:

1.Capped cluster molecule forms spontaneously from molecular reagents in solution

2.Cluster molecules crystallize out of solution

It is classified asbottom-up manufacturing which involves building up of the atomor molecular constituents asagainstthetop methodwhich involves making smaller and smaller structures through etching from the bulk material as exemplified by the semiconductor industry.

Atoms and molecules are the essential building blocks of every object. The manner in which things are constructed with these basic units is vitally important to understand their properties and their reciprocal interactions. An efficient control of the synthetic pathways is essential during the preparation of nanobuilding blocks with different sizes and shapes that can lead to the creation of new devices and technologies with improved performances. Traditionally nanoparticles were produced only by physical and chemical methods. Some of the commonly used physical and chemical methods are ion sputtering, solvothermal synthesis, reduction and sol gel technique

Basically there are two approaches for nanoparticle synthesis namely the Bottom up approach and the Top down approach. In the Top down approach, scientists try to formulate nanoparticles using larger ones to direct their assembly. The Bottom up approach is a process that builds towards larger and more complex systems by starting at the molecular level and maintaining precise control of molecular structure.

These two different methods highlight the organization level of nanosystems as the crossing point hanging between the worlds of molecular objects and bulk materials.

The top-down approach has been advanced by Richard Feynman in his often-cited 1959 lecture stating that “there is plenty of room at the bottom” and it is ideal for obtaining structures with long-range order and for making connections with macroscopic world. Conversely, the bottom-up approach was pioneered by Jean-Marie Lehn (revealing that “there is plenty of room at the top”) and it is best suited for assembly and establishing short-range order at the nanoscale. The integration of the two techniques is expected to provide, atleast in principle, thewidest combination of tools for nanofabrication.

There aremany different points of view aboutthe nanotechnology. These differences start with the definition of nanotechnology. Some define it as any activity that involves manipulating materials between one nanometer and 100 nanometers. However the original definition of nanotechnology involved building machines at the molecular scale and involves the manipulation of materials on an atomic (about two-tenths of a nanometer) scale.

The debate continues with varying opinions about exactly what nanotechnology can achieve. Some researchers believe nanotechnology can be used to significantly extend the human lifespan or produce replicator-like devices that can create almost anything from simple raw materials. Others see nanotechnology only as a tool to help us do what we do now, but faster or better.

The third major area of debate concerns the timeframe of nanotechnology-related advances. Will nanotechnology have a significant impact on our day-to-day lives in a decade or two, or will many of these promised advances take considerably longer to become realities?

Finally, all the opinions about what nanotechnology can help us achieve echo with ethical challenges. If nanotechnology helps us to increase ourlifespans orproduce manufactured goodsfrom inexpensive raw materials, what is the moral imperative about making such technology available to all? Is there sufficient understanding or regulation of nanotech based materials to minimize possible harm to us or ourenvironment? Only timewill tell how nanotechnology will affect our lives.

A fullerene is any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Spherical fullerenes are also called buckyballs, and cylindrical ones are called carbon nanotubes or buckytubes. Fullerenes are similar in structure to graphite, which is composed of stacked graphene sheets of linked hexagonal rings; but they may also contain pentagonal (or sometimes heptagonal) rings.

The first fullerene to be discovered, and the family’s namesake, was buckminsterfullerene C₆₀, made in 1985 by Robert Curl, Harold Kroto and Richard Smalley. The name was homage to Richard Buckminster Fuller, whose geodesic domesit resembles. Fullereneshave since been found to occur (if rarely) in nature.

The discovery of fullerenes greatly expandedthe numberof known carbon allotropes, which until recently were limited to graphite, diamond, and amorphous carbon such as soot and charcoal. Buckyballs and buckytubes have been the subject of intense research, both for their unique chemistry and for their technological applications, especially in materials science, electronics, and nanotechnology.

“Small is beautiful”, today we know that small is not only beautiful but also powerful. With the range of applications that nanoparticles find in varied fields of engineering and science, nanoparticles seem a promising option when compared to the conventional materials used. Nanoparticles are particles that have at least one dimension in less than 100nm range. They have a high surface to volume ratio and thus mass transfer and heat transfer properties are better than bulk materials. Recently; core/shell nanoparticles are finding widespread application. There is a class of core/shell nanoparticle that has its entire constituent in the nanometer range. Core/shell nanoparticles are nanostructures that have core made of a material coated with another material. They are in the size range of 20nm-200nm. Also, composite structures with these core/shell particles embedded in a matrix material are in use. The necessity to shift to core/shell nanoparticles is the improvement in the properties. Taking into consideration the size of the nanoparticles, the shell material can be chosen such that the agglomeration of particle can be prevented. This implies that the monodispersity of the particles can be improved. The core/shell structure enhances the thermal and chemical stability of the nanoparticles, improves solubility, makes them less cytotoxic and allows conjugation of other molecules to these particles. The shell can also prevent the oxidation of the core material. “When a core nanoparticle is coated with a polymeric layer or an inorganic layer like silicabecausethe polymeric orinorganiclayerwould endow the hybrid structure with an additional function/property on top of the function/property of the core hence synergistically emerged functions can be envisioned”.

Polymeric nanoparticles are nanoparticles which are prepared from polymers. The drug is dissolved, entrapped, encapsulated or attached to nanoparticles and depending upon the method of preparation, nanoparticles, nanospheres or nanocapsules can be obtained. Nanocapsules are vesicular systems in which the drug is confined to a cavity surrounded by a polymer membrane, while nanospheres are matrix systems in which the drug is physically and uniformly dispersed.

In recent years, biodegradable polymeric nanoparticles have attracted considerable attention as potential drug delivery devices in view of their applications in drug targeting to particular organs/tissues, as carriers of DNA in gene therapy, and in their ability to deliver proteins, peptides and genes through oral route of administration.

In spite of development of various synthetic and semi synthetic polymers, natural polymers still enjoy their popularity in drug delivery, some of them are: gums (Eg. Acacia, Guar, etc.,) chitosan, gelatin, sodium alginate, and albumin. A range of materials have been employed to delivery of bioactive agents. A polymer used in controlled drug delivery formulation, must be chemically inert, non-toxic and free of leachable impurities. It must also have an appropriate physical structure, with minimal undesired aging, and be readily processable. Some of the polymeric materials are: cellulosics., poly(2-hydroxyethyl methacrylate), poly(N-vinyl pyrrolidone), poly(methyl methacrylate), poly(vinyl alcohol), poly(acrylic acid), polyacrylamide, poly(ethylene-co-vinyl acetate), poly(ethylene glycol), poly(methacrylic acid).

A semiconductor is a material that has an electrical resistivity between that of a conductor and an insulator.

A semiconductor is a substance, usually a solid chemical element or compound that can conduct electricity under some conditions but not others, making it a good medium for the control of electrical current. Its conductance varies depending on the current or voltage applied to a control electrode, or on the intensity of irradiation by infrared (IR), visible light, ultraviolet (UV), or X rays.

An external electrical field changes a semiconductor’s resistivity. Devices made from semiconductor materials are the foundation of modern electronics, including radio, computers, telephones, and many other devices. Semiconductor devices include the transistor, solar cells, many kinds of diodes including the light–emitting diode, the silicon controlled rectifier, and digital and analog integrated circuits. Solar photovoltaic panels are large semiconductor devices that directly convert light energy into electrical energy. In a metallic conductor, current is carried by the flow of electrons. In semiconductors, current can be carried either by the flow of electrons or by the flow of positively–charged “holes” in the electron structure of the material.

Nanomaterials are a field which takes a materials science-based approach to nanotechnology. It studies materials with morphological features on the nanoscale, and especially those which have special properties stemming from their nanoscale dimensions. Nanoscale is usually defined as smaller than a one tenth of a micrometer in at least one dimension, though this term is sometimes also used for materials smaller than one micrometer.

An aspect of nanotechnology is the vastly increased ratio of surface area to volume present in many nanoscale materials which makes possible new quantum mechanical effects, for example the “quantum size effect” where the electronic properties of solids are altered with great reductions in particle size. This effect does not come into play by going from macro to micro dimensions. However, it becomes pronounced when the nanometer size range is reached. A certain number of physical properties also alter with the change from macroscopic systems. Novel mechanical properties of nanomaterials are a subject of nanomechanics research. Catalytic activities also reveal new behaviour in the interaction with biomaterials.

What is Nanotechnology? Answers differ depending on who you ask, and their background. Broadly speaking however, nanotechnology is the act of purposefully manipulating matter at the atomic scale, otherwise known as the “nanoscale.” Coined as “nano-technology” in a 1974 paper by Norio Taniguchi at the University of Tokyo, and encompassing a multitude of rapidly emerging technologies, based upon the scaling down of existing technologies to the next level of precision and miniaturization. Taniguchi approached nanotechnology from the ‘top-down’ standpoint, from the viewpoint of a precision engineer.

Foresight Nanotech Institute Founder K. Eric Drexler introduced the term “nanotechnology” to the world in 1986, using it to describe a ‘bottom-up’ approach. Drexler approaches nanotechnology from the point-of-view of a physicist, and defines the term as “large-scale mechano synthesis based on positional control of chemically reactive molecules.” In the future,“ nanotechnology” will likely include building machines and mechanisms with nanoscale dimensions, referred to these days as Molecular Nanotechnology (MNT).

ABSTRACT

Contour hedgerow technology has different names in different regions. Sloping Agriculture Land Technology (SALT) has alley farming with hedgerow barrier technology. It is basically an agroforestry system in which nitrogen - fixing trees or shrubs are planted very closely in rows and cash crops grown in between the alleys. The SALT has been considered as an alernative to shifting cultivation. Forest dwellers are mostly tribals and shifting cultivation have been their practice for food production. The slash and burn has caused enormous damage to the forest composition. The forests on the hills and on the mountains have suffered a lot due to “Podhu” cultivation. The similar situations have been observed also in most of the Asian country. The hilly area has been considered under the hedgerow system for soil and water conservation. The introduction of the agroforestry systems in the farmers fields and in the wastelands have brought potential forest farming. The young leaves of some hedge row plants provide good fodder for livestock. Hedgerows can also be managed to provide fuelwood, if necessary. The hedgerows and their trimming provide mechanical and biological barriers and help minimise soil erosion by reducing surface runoff velocities, leading to higher deposition of soil sediments and living source of nutrient cycling. The food and cash production has been observed to be the most essential components in four types of SALT models.

ABSTRACT

In agroforestry and forestry sectors, little efforts have been made for tree improvement research in India. Planting of genetically poor quality of seedlings/propagules is one of the major reasons of low level impact of agroforestry systems in Indian Agriculture. Most of the agroforestry tree species have not been even gone through simple selection for superior types (plus trees). Exploration, collection and conservation of germplasm of woody agroforestry species, selection for fast growing trees, clonal propagation, seed orchards and other advances in tree breeding are still in fancy stage. At present, all the woody agroforestry species are propagated through collected seeds and/or propagules by unskilled labourers. It is well known that through tree breeding and establishment of seed orchards of improved genotypes, significant achievements towards the improvement of productivity of economic tree products is possible as happened in agricultural crops in India and industrial trees in USA and Europe. Even by small efforts of tree improvement, productivity of economic tree products can be raised by 20-30 per cent. In this paper breeding methodology, limitations, status and strategy of various agroforestry species has been discussed in special reference to Leucaena leucocephala (Subabul), Prosopis cinereria (Khejri), Azadirachta indica (Neem), Populus spp., Dalbergia sissoo (Shisham), Acacia nilotica (Desi babul), Eucalyptus spp. Casuarina equisetifolia (Casuarina), Albizia lebbek (Desi siris) and Jatropha curcus (Ratanjot).

ABSTRACT

Minerals are important raw materials for the economic development of any nation. However, unscientific mining for minerals poses a serious threat to the environment. Mine spoils from outer Uttaranchal Himalaya are highly variable from loose to hard and compact at places. Rehabilitation technology for degraded mine sites consist of several steps, each of them playing an important role. Rehabilitation of these spoils is imperative to meet our demand of fuel, fodder, timber, reduce soil erosion and improve environmental pollution. The paper presents the efforts of rehabilitation of mine spoils in Uttaranchal Himalayas both mechanical as well as vegetative measures. Agroforestry techniques used in rehabilitation of mine spoils has been given in this paper.

INTRODUCTION

Himalayan region which constitute about 54 million ha (16.5%) area of the country is characterized by marginality, inaccessibility and fragility, compounded by high intensity erratic rainfall, steep slopes, large scale deforestation and faulty management practices. Natural resources in the region are under great stress due to mounting human and livestock populations. The increasing frequency of natural disasters, e.g. landslides, floods, droughts and deterioration of water bodies due to accelerated deforestation, conversion of marginal/forest land into agriculture and unscientific developmental activities e.g. mining, roads etc. further aggravate the problem. Soil erosion is the major constraint in crop production. High intensity rains in the monsoon season cause excessive runoff and soil loss. On erosion-prone steep slopes, about 50 per cent of the rainfall is lost as runoff, carrying with it 20 t ha-l soil.

ABSTRACT

The paper discusses distribution of bamboo, their uses and bamboo based agroforestry systems in India and their future potential. Bamboo, one of the fastest growing plant species is extremely versatile and has been traditionally put to a large number of uses. Application of modern technology and industrial processing has catapulted bamboo into a new global limelight. At present there is huge demand of bamboo based raw material viz., timber, plywood, bamboo flooring, edible bamboo shoots, etc. in the international market and most of the international market of bamboo is captured by China. In India, most of the bamboo raw material comes from natural forest. To capture the emerging bamboo market we have to increase the bamboo cultivation outside the forest under different bamboo based agroforestry systems. Experiments have shown that bamboo based agrisilviculture systems is technically and economically feasible in our country under different agro-ecological conditions. The agriculture crops which can be profitably grown with bamboo are soybean, pigeon pea, ginger, turmeric, etc. Keeping in view the international scenario, ecological conditions and taking clues from China’s success stories, some of the bamboo based agroforestry system components are also proposed.

ABSTRACT

Women nearly constitute half of the population of the mountainous region of northwestern Himalayas. Rural hill women with their multiple roles and functions in the society, form an integral part of sustainable development of hills. Irrespective of age and health, they have to perform domestic household and agriculture work. Collection of fodder, firewood and fuel wood from the forest areas for energy requirements and household cooking are also done by women. The present paper provides the background information about the women in hilly areas and their dependence on agroforestry for meeting daily requirements of household.

INTRODUCTION

More than ninety per cent of mountain population inhibit in rural areas. Women nearly constitute half of the population of the region having composite social profile. Mountain specificities which consists of habitats, societies and their interactions and adaptations can prove to be constraints as well as opportunities. Comparative economic growth or development and dynamism in social-economic structure are due to interlinking of various land use systems including agriculture, horticulture, forestry, animal husbandry and tourism. Rural women play a pivotal role in sustainable development of their areas and form an integral part of subsistence rural economy (Thakur, 2003). They are considered nucleus of hill farming because of their multiple functions/ role in the society. Hence this section of the society in the region is the main and basic asset. They depend on their surrounding environment for many of the basic needs, therefore they are inextricably linked with natural resources and environment, and thus have to cope with the harsh environment by developing mountain specific adaptations.

ABSTRACT

The integration of woody perennials on the farm lands for obvious reasons has been the common practice with the farming community for ages. It is true that the integration of trees on the farmland, albeit paves the way for the improvement of existing system, but nevertheless creates complex biological interactions, which may not necessarily result in yield advantage. Management of multipurpose tree species, especially agroforestry tree species, integrated on the farmland with crops, is essential for two reasons, i) because canopy size decides the transmission of photosynthetically active radiation to the understorey crops and ii) that the impact of canopy management practices some times have drastic implications. Canopy management practices like coppicing; pollarding and partial crown removal not only affects foliage and branch wood biomass production but also modifies physiological parameters and resource utilization pattern. This paper deals with the need and techniques of managing canopy as well as the research activities carried out in this regards.

ABSTRACT

The popularity and belief in natural and herbal healthcare systems is inseparable from traditional ethos and practices in India. India has been known to be a rich repository of medicinal plants since time immemorial. Now many countries like China, Cuba, India, Sri Lanka, Thailand etc. have endorsed the official use of traditional system of Medicines in their healthcare programmes. The western system of medicine (allopathy) too has a large component of plant based drugs and most potent medicines use specific chemical constituents which in turn has generated bulk demand. A dramatic increase in exports of MAP’s (medicinal and aromatic plants) attests to global interest in their products as well as in the traditional health system. Past efforts of 27 years in agroforestry research and extension is now yielding results; Agroforestry is coming up in private as well as community lands in a big way for both subsistence as well as commercial purposes. Incorporation of medicinal plants in agroforestry will not only diversify the cropping system but will also lead to conserve and reduce pressure on medicinal plants in forest besides improving economic status of the farmers.

ABSTRACT

Modelling has been used in natural sciences since centuries in one-way or the other. However, system modelling as a discipline in itself is established in the recent years. Agroforestry modelling is a complex process that essentially involves at least two elements viz. tree and crop, where tree is the long term and crop is the short-term component. Agroforestry models, usually, predict tree growth and yield and the reduction/enhancement in crop yield as influenced by the tree component in temporal and spatial sequence. In this paper the need of modeling, stages of model development, its validation and classification of models are given. The models, which are relevant to agroforestry, have also been given.

INTRODUCTION

Agroforestry combines agriculture and forestry technologies to create more integrated, diverse, productive, profitable, healthy and sustainable land use systems. According to the Association for Temperate Agroforestry - “Agroforestry practices are intentional combinations of trees with crops and/ or livestock that involve intensive management of the interactions between the components as an integrated agroecosystem”. These key characteristics are the essence of agroforestry and are what distinguish it from other farming or forestry practices. To be called agroforestry, a land use practice must satisfy all of these criteria:

ABSTRACT

Tamil Nadu, the southern most state of India has 8 per cent of the country’s population and its net sown area is only 4-5 per cent of the country’s area. The state is endowed with varied physiography from hills to coastal lands and hence varied agroclimatic and edaphic conditions. This paper details the characteristics of different agroclimate and provides varied perennial and annual components being practiced in different combinations in these agroforestry systems.

INTRODUCTION

Land is a major non renewable natural resource. With the increase in population, the demand of land for all activities increases. The requirement of food, fibre, fodder and fuel of the ever increasing population has to be met with the finite land resources. In India, the pattern of land use in agriculture and forestry took a drastic turn during the period from fifties to eighties. Conservation, development and management of the available land is basic for ensuring food, ecological, environmental and economic security of our country. Tamil Nadu’s population is around 8 per cent of the total country and the net sown area is only a meager 4-5 per cent of that of the country. With the ever increasing population and expanding industrialization, steps need to be taken to utilize the land to the optimum extent possible and to identify and utilize lands effectively and efficiently in order to make full use of their maximum capability.

ABSTRACT

Agroecologically the state is divided into 13 zones based on altitudinal variations, precipitation pattern, soil type and topographic features. Land use systems that integrate woody perennials with other life forms abound in all these zones, along with a great diversity of trees and field crops. Although these practices are apparently specific to the topographic and edaphic factors, a complex pattern of overlapping which transgresses over a wide range of agroecological zones is obvious. An attempt is made to describe the important agroforestry systems of Kerala, both traditional as well as those potentially suitable.

INTRODUCTION

The state of Kerala with many woody perennial-based land use practices is often regarded as the “Mecca” of agroforestry. Most of these are, however, traditional systems evolved over centuries of cultural and biological transformations and may represent the accrued wisdom and insights of farmers who have interacted with environment, without access to exogenous inputs, capital or scientific skills. Over long periods in the history of land use in these highly populated humid tropical lands, such diverse land use systems have apparently remained as engines of food security, besides sourcing multiple products and services including certain intangible benefits (e.g., microclimatic modification, soil and water conservation); thus providing the rationale for the co-existence of an array of pluralistic land use orders often in close juxtaposition with one another. Yet another plausible explanation for the occurrence of many diverse woody perennial-based systems and practices over a relatively small geographical range is perhaps the brute heterogeneity of the Kerala landscape.

ABSTRACT

Agroforestry a sustainable land use system being practiced since long back through out the country. A diverse climatic, edaphic, and environmental conditions prevailing in the country has made it possible to practice different kinds of agroforestry systems. The local research organizations and individuals have undertook various studies for the betterment of the local agroforestry systems for getting higher yields to meet the need of food, fodder, fuel wood etc. It was found that Jowar+Teak+Papaya followed by Chilli+Teak+Papaya combination gave more economic returns compared to pure agricultural crop. Casuarina equisetifolia, Grevillea robusta, Dalbergia sissoo and Melia dubia have been found to be suitable for agroforestry systems in dryland. Coffee based agroforestry system and other tree-crop combination tried have been elaborated in this paper.

INTRODUCTION

Agroforestry is a new word for the old practice of growing woody plants with agricultural crops and/or livestock together on the same land. Various experts and scientists working on agroforestry or involved in land use related sciences have defined agroforestry according to their individual understanding of what they call agroforestry.

“Agroforestry is sustainable management system for land that increases total production, combines agricultural crops, tree crops and forest plants and or animals simultaneously or sequentially and applies management practices that are compatible with the cultural patterns of the local population” (Chundawat and Gautham, 1993).

ABSTRACT

Andhra Pradesh is predominently an agrarian state, where 70 per cent of the people live in rural areas. Andhra Pradesh has 7 Agroecological zones spread over in coastal Andhra, Telangana and Rayalaseema regions with varied climatic situations. The existing agroforestry systems in costal Andhra are Mango-based Agrihorticulture system, Betelvine-sesbania system, Borrasus flabellefer, Glyrecidia boundary plantations, Eucalyptus, Causarina and Subabul block plantations. Besides Neem, Tamarind and jamuns are also found in isolated manner. In Telangana region, Custard apple based Agrihorticulture system, Mango based Agrihorticulture system, Boundary plantations of Neem, teak, Jamun etc., are present. Eucalyptus based Agrisilviculture system is propagated by ITC, Bhadrachalam in Khammam and elsewhere in the state. In Rayalaseema region in all the districts tamarind, mango and sweet orange based agroforestry systems are prominently seen. The betelvine - sesbania system alone is fetching an income of 100 crores/year to the states’ exchequer. The common trees and tree systems available in the state are : Azadirachta indica, Tamarindus indica, Acacia nilotica, Pithecellobium dulce, Parkinsonia aculeata, Pterocarpus santalinus, Dalbergia latifolia and many others.

ABSTRACT

Homegarden is a least studied agroecosystem of the world. Present study, conducted in 430 homegardens before Tsunami in five island groups namely North Andaman, Middle Andaman, South Andaman, Car Nicobar and Noncowry (former three, Andaman group and later two, Nicobar group of islands), India, reports composition, species structure and its distribution and functioning of the system. The homegarden is comprised of 6 components i.e., garden, livestock, poultry, fishpond, homesteads, and rice fields. Coconut and arecanut trees predominate in the garden. Fruits, spices and agroforestry trees are other ligneous species, which together with the former trees form multistorey canopy structure. But, composition and dominance of the tree species vary across the islands. Arecanut to coconut ratio is greatest invariably in all the homegardens in the Andaman. Family members do maximum 70 per cent labour in the homegarden and consume 35-65 per cent fruits, poultry, livestock and fishpond products, however, surplus is sold. Free range grazing in nearby protected forests is an age old practice of animal feeding whereas poultry birds are fed among the garden trees and household refuge. Livestock includes cattle, buffaloes and goats in Andaman and pig and goat in Nicobar. Cattle are used for milk, he buffaloes as a draft animal and pig and goat for meat. Cattle, mostly local breed, yield a little amount of milk, an average, 1 liter cow-1. Plantation crops production is low: coconut 18-30 nuts palm^-1 and arecanut 0.75 kg palm^-1. The homegardens serve the subsistence as well as earn income, but low (US$ 2357) to the house. In Nicobar, Nicobarese huts interspersed in a big natural coconut plantation form the homegarden. Tribe Nicobarese do not know crop husbandry, rather they pursue round the year sea fishing and pig rearing. They relish most pork, unripe boiled wild banana, Nicobari tuber, fruits and seeds of Pendanus and fried fish.

ABSTRACT

Homegardens are traditional agroforestry systems present throughout the northeast India especially in foothill region. The high diversity and the intensive care that is given to the homegarden in and around Arunachal Pradesh results in a unique combination of high levels of productivity, stability and sustainability of the system. The homegardens studied here were vertically distributed in four different layers viz, floor, middle, sub-canopy and canopy. Such stratification has given rise to the distribution of a variety of species based on light requirement in the system. Density and diversity index of tree species in the homegardens were highest in Harmutty in the foothills (468.5 plants ha^-1 and 1.17 respectively), whereas lower values were recorded in Ziro in the upper elevation (16 plants ha^-1, 0.651 respectively). Soil nutrients were greater in Harmutty, followed by Doimukh, Nirjuli and then Ziro. Maximum plant detrital (litter and fine roots) biomass and their subsequent decomposition in the homegardens of Harmutty (10185.67 kg ha^-1) might be the probable reason for the efficient nutrient cycling and generation of more available nutrients.