eChapters

Pathogens are different from parasites, Parasites penetrate into the host and obtain nutrients from the host. They live inside the host without causing any other damage. They may be at times symbionts also i.e. they may be beneficial to the host. The examples for parasites are Rhizobium spp. which form nodules in leguminous plants and mycorrhizal fungi. Pathogens not only take nutrients from the host but also damage the host severely. They induce numerous symptoms of the disease and even kill the plants.

Pathogens in their life cycle enter into two distinct phases. One is biotrophic and the other is necrotrophic phage. In the biotrophic phase they invade the host cells inter and intracellularly and establish themselves in the living cells. In the second phase, they kill the cells and obtain nutrition from the dying cells. This phase is called necrotrophic phase. In case of obligate pathogens the biotrophic phase may be much longer while in case of facultative saprophytes, long biotrophic phase may be followed by necrotrophic phase. In case of facultative parasites necrotrophic phase will be much longer with short biotrophic phase. However in case of all pathogens, both the phases may exist either as a short or long spell.

In the biotrophic phase the pathogens establish themselves in the host cells. The first barrier between host plant and the attacking pathogen is the cuticle. Host cells have cell wall, structure surrounding the protoplast. Cell wall is divided into three regions: middle lamella, primary wall and secondary wall. Below the cell wall membranes are found. The membrane provides a semi permeable barrier between the cell and its external environment. The membrane consists of lipids and proteins. During the biotrophic phase, the pathogen invade the cells by degrading cuticle, middle lamella,cell walls and cell membranes, by producing a series of enzymes.After the biotrophic phase, the pathogens produce toxins which kill the cell and enter into the necrotrophic phase. Thus, enzymes, toxins, growth regulators are important tools of the pathogens for their pathogenesis.

INTRODUCTION

Variability in different organisms is common feature and is an important process for the continuity of life under stress conditions. Plant pathogens especially fungi, bacteria, virus and nematode show variations in their pathogenic potential (virulence) and physiological functions that support their survival and perpetuation in different environmental conditions. These variations may be largely due to genetic factors that may be conditioned by environmental factors. Various studies on genetic variability of microbial plant pathogens have shown that variations may occur in characters which affect their ability to infect host plants and also other characters that do not alter the pathogenic potential, but they may be concerned with their survival. Knowledge of variation in pathogenic characteristics is valuable in planning effective measures for disease management. In addition, development of resistant to fungicides has been a serious concern to growers, researchers as well as the administrators, since the decision to continue application or withdrawal of a fungicide can affect both the growers and industry.

DEFINITION

Fore casting involves all the activities in ascertaining and notifying the grower of community that conditions are sufficiently favourable for certain diseases, that application of control measures will result in economic gain or on the other hand, and just as important that the amount expected is unlikely to be enough to justify the expenditure of time , energy and money for control. The above statement made explicit distinction between positive forecast and negative forecast and both have value for growers as well as society in general.

Positive forecast: Employs need based chemical sprays, provides adequate protection to crop and reduces damage to environment.

Negative forecast: Avoids unnecessary chemical sprays, no risk to the crop health and no disruption of environment.

PRINCIPLES

The principles involved in thermotherapy is that the pathogens present in seed material are inactivated or eliminated at temperatures nonlethal for the host tissues.The exact mechanism by which heat inactivates the pathogen is not fully understood. However, it is universally accepted that heat causes inactivation and not immobilization of the pathogen by heat. Thrate at which the pathogen is inactivated is determined by temperature, the higher the temperature, the faster is the inactivation.

1. Deoxyribo Nucleic Acid (DNA)

DNA is a genetic material, originally confined to nucleus of a cell. In plants, some DNAs are also present in mitochondria and chloroplasts. DNAs are vital macro molecules having high molecular weight.

Isolation of plant DNA is cumbersome or difficult primarily because of the presence of a number of secondary plant products. Secondly, a protocol, which is found suitable for isolation of DNA in one plant, may not work in other. The efficiency of DNA extraction depends on many factors, such as sample material, ionic conditions of the extraction medium and type of lysing agent used etc.

There are two methods, one developed by Dellaporta et al. (1983) and the other by Murray and Thompson (1980) which are most commonly used for extraction of DNA in a number of plant genera.

Murray and Thompson’s (1980) method is described here below with minor modifications.

Introduction

Whey is the serum or watery part of the milk that remains after separation of curd that result from the acid or proteolytic enzyme mediated co-agulation of milk. It is major by product of dairy industries manufacturing products like channa, paneer, cheese and chakka (Sharma and Bhatia, 1999).The current world production of whey is estimated at about 165 million tones, in that cheese whey accounts for nearly 95 % of total whey. In India near about one million tonne of whey is annually derived, in that major source of whey is from the production of channa, paneer and shrikhand production. This is mostly thrown away as a waste which creates environmental pollution, also in that way about 70, 000 tonnes of Nutritious solids are lost (Puranik, 1999).

Abstract

The production of natural food colours through bio-processing is preferred now-a-days due to health related issues associated with their synthetic counterparts. Microorganisms are generally preferred sources as these have high production rate, high growth rate, ease of handling under controlled conditions and absence of seasonal variations. Biopigments can be produced from different genera of bacteria, yeast and mold. Different types and colours of pigments have been produced from microorganisms depending upon their origin, media components and process conditions. The biopigments have variety of applications in food industry such as food additives, food preservatives, biological control agents and nutritional supplements. These have also been associated with therapeutic, and antioxidant properties. Lycopene from B. trispora is used as a food ingredient in dietary supplement. Astaxanthin from X. dendrortious has also been reported to have beneficial effect on human health as it possesses strong antioxidant properties. Arpink red P. oxalicum is used as red colorant in meat products, non-alcoholic drinks, milk products and confectionary. 0- carotene is considered as leading food colorant in world and is applied to range of baked, dairy and canned foods to improve their appearance. The antioxidant andprecursory properties of0-carotene increase its applications in pet foods. Zeaxanthin is used as additives in poultry fed to intensify the colour of the egg yolk. Monascus pigments are utilized for coloration of sausages, ham, marine products and tomato ketchup. Monascus extract is also marketed as dietetic supplement in Japan. Thus, the biopigments can serve as a chromophore for colorant production with broad spectrum of colours and wide applications.

Abstract

Health benefits of aloe vera include its application in wound healing, treating burns, protection against skin damage, lung cancer, intestinal problems, increasing high density lipoprotein (HDL), reducing low density lipoprotein (LDL), reducing blood sugar in diabetics, fighting acquired immune deficiency syndrome (AIDS), allergies and improving immune system. Phytochemistry of aloe vera gel has revealed the presence of more than 200 bioactive compounds. Aloe vera gel is extracted from its leaves and appropriate processing techniques are needed for stabilization and preparation of the food products. Aloe vera gel products have become available in our country for internal consumption as a tonic and diversification in its products is on progress. The use of aloe vera has gained popularity because of herbal movement initiated by naturopaths, yog gurus, alternative medicine promoters and holistic healers. A recent market analysis report indicates that Americans have spent almost 40 billion dollars on functional foods, drinks and supplements for the improvement of their appearance as well as to provide energy and added nutrition to handle health issues such as hypercholesterolemia and diabetes.

Abstract

The concept of functional foods has received significant media attention and, as a result, interest has focused on the need for research into the non- nutrient constituents of food plants. This has enabled market penetration of functional foods containing increased amounts of bioactive food compounds or physiologically active nutrients and non-nutrients within food that impart proven health benefits. Functional foods can take many forms. Some may be conventional foods with bioactive components that can now be identified and linked to positive health outcomes. Some may be fortified or enhanced foods, specifically created to reduce disease risk for a certain group of people. Numerous observational studies have shown that omega-3 fatty acids enriched diets are associated with a reduction of cardiovascular mortality, heart attack and sudden death. In several studies, a higher fish intake has been associated with decreased incidence of coronary artery disease (CAD) and cardiovascular mortality. A trial revealed that fish oil supplementation of 130 mg/kg of body weight each day decreased the number of stiff joints, duration of morning stiffness, pain and global arthritis activity. Many supplements contain active ingredients that have strong biological effects in the body. The bioavailability of nutrients within a given food is governed by the composition and microstructure of the food, commonly referred to as the food matrix. More specifically, numerous studies investigating the development of functional foods have shown that the interactions between nutrients and non-nutrients within the food matrix can be synergistic, additive, or neutralizing in nature. The preventive and curative effects of the functional foods on health concludes it to be integral components of established public health programs to reduce the risk of specific diseases.

Abstract

The amaranth as a pseudocereal has shown its role in the development and diversification of agricultural products and food which is a priority trend for world agriculture. The amaranth has excellent nutrient profile and technological advantage in various food formulations in comparison to other conventional cereals. Recently, current interest in amaranth also resides in the fact that it has a great amount of genetic diversity, phenotypic plasticity and is extremely adaptable to adverse growing conditions, resists heat and drought, has no major disease problem. This crop is among the easiest of plants to grow in agriculturally marginal lands in hilly area. Moreover, these contain significant amount of bioactive components such as phytosterols, squalene and polyphenols along with good amount of micronutrients such as minerals and vitamins. Amaranth consumption has been shown to improve plasma lipid profile in animals. Methanolic extracts of amaranth have demonstrated anti-hyperlipidemic,anti-diarrheic, anti-fungal and anti-malarial properties. Specific polyphenols such as rutin, isoquercetin and nicotiflorin and phenolic acids and amides with antioxidant activity have been found in amaranth seeds. In addition to above, amaranth, seeds are gluten free and thus they are currently emerging as healthy alternatives to gluten containing grains in gluten free diet for celiac people.

Abstract

Demand for starch is increasing day by day and is met by restricted range of crops. In recent years, substantial progress has been made in obtaining starch from non-conventional sources such as sweet potato, buckwheat, sago, water chestnut, which can be used as a substitute for conventional sources. So it is necessary to search for other underutilized and nonconventional sources of starch to meet the increased demand. Typha angustifolia, an aquatic weed containing appreciable amount of starch in its rhizome and roots, can be used for starch isolation to make its use in food and non-food derivatives. In many parts of the world, starch-rich roots of Typha angustifolia are eaten raw or boiled or dried roots are pulverized into a powder, and then, used as a thickener in soups or added to cereal flours to make biscuits and bread.

Abstract

Quinoa is a pseudo-cereal which belongs to family Chenopodiaceae. Quinoa can act as highly potential crop for areas where ecological conditions do not support other food crops because of its rusticity, tolerance to frost, salinity, drought and ability to grow in marginal soils. Recently, much attention is focused on quinoa for people with celiac disease and allergic to gluten. Quinoa contains high-quality protein, complete with all essential amino acids and is a good source of carbohydrates, lipids, vitamin C, vitamin E (natural antioxidants) and adequate amount of important micronutrients such as minerals. Carbohydrates of quinoa possess excellentfreeze-thaw stability and can be used as thickener in frozen foods.

Quinoa also consists of bioactive components such as phytosterols, squalene, fagopyritols and polyphenols which act as powerful anti-oxidants in-vitro and thus couldprevent degenerative diseases such as coronary heart disease, atherosclerosis and Alzheimer's disease. Fibre accounts for 6% of the grains total weight, and quinoa intake therefore promotes intestinal transit, regulates cholesterol, stimulates the development of beneficial bacterial flora and helps prevent colon cancer. The quinoa grain can be used to combat liver disease, angina and cystitis. The radical scavenging ability and Angiotensin I converting enzyme (ACE) inhibition activity of quinoa is higher than that of amaranth, rice and wheat. Recent studies have identified significant amounts of ecdysteroids, kaempferol, quercetin, two phytoestrogen - daidzein and cenistema in quinoa. Ethanolic extract of quinoa was observed to have Antioxidant and antihypertensive activity.

Abstract

This review presents an idea on the botanical description, medicinal properties and traditional usage of wild, edible and aromatic plant (Nymphaea alba) in the human nutrition. Nymphaea alba Lin, also known as the White Water lily, White Lotus, or Nenuphar is an aquatic flowering plant of the family Nymphaeaceae. Nymphaea is a weed in India and its production pretty much as good as water chest nut and Nelumbo nucifera. Its rhizome is rich in tannic acid, gallic acid, alkaloids, sterols, flavonoids, glycosides, hydrolysable tannins and high-molecular-weight polyphenolic compounds. It is used as associate aphrodisiac, anodyne, antiscrophulatic, astringent, cardiotonic, demulcent, sedative and antiinflammatory. Further, it conjointly produces calming and sedative effects upon the nervous system, and is beneficial within the treatment of sleep disorder, anxiety and similar disorders. Moreover, the content of starch in the rhizome is said to be 40%. Extensive work has been carried out on agronomic and phenotypic properties for most plants, but relatively little study has been carried out on the properties which are of direct technical and economic interest to competitive food and nonfood industry. Non-conventional food resources and their value addition have attracted attention in the recent yearsfor their potential use as functional ingredients in food formulations, besides food they have also been used for non-food applications. Moreover, Plants provide the predominant ingredients of medicines in most medical traditions. So, there is tremendous potential for the profitable industrial use of these medicinal plants and exploring them for further use. Keywords: Non-conventional food resources, Nymphaea alba, Rhizome.

Abstract

Pomegranates are usually consumed as fresh fruit, with only a limited quantity being processed into products like juice, syrup, beverages, wine, confectionary and anardana. The special structure of fruit is one of main factors which limit its industrial processing. Knowing the importance of health benefits of pomegranate and all related aspects, the present study was carried out in order to utilize pomegranate fruit for preparation of pomegranate mouth freshener. Arils of two cultivars like Ganesh and Araktaweredried by two drying methods viz., sun drying (SD) and cabinet drying (CD).Nutritive and palatable mouth freshener was prepared from anardana of two different cultivars as Ganesh (G) and Arakta (A). Production cost of 100g pomegranate mouth freshener is about Rs.55/. It was noticed that moisture content, acidity and ascorbic acid content decreased at the end of storage.

Abstract

India has got a pool of medicinal herbs which are proved to be beneficial in curing various diseases. Their regular consumption not only will improve the health status but also reduce risk of lifestyle diseases. Though simple solutions, associated colloids, suspensions and emulsions are some of the traditional techniques for encapsulating functional agents, micro-encapsulation techniques is the most successfully employed technique for the controlled release of sensitive bioactive compounds. Owing to the targeted delivery of functional components directly to the human gut system, emulsion based delivery system are getting more attention now-a-days. With advancement in science, more complex and novel structures can be created which can successfully deliver these nutraceutical and bioactive ingredients into existing food systems. The technological interventions in emulsion science have opened great opportunities to improve the delivery of bioactive herbal components into milk and milk products. Various milk and milk products functionality can be improved in this way which will improve the gut- microflora within short period of time after consumption.

ABSTRACT

This paper reviews the various application of hyperspectral remote sensing data carried out by the scientists of India emphasizing its advantages.

1. INTRODUCTION

The most significant recent breakthrough in remote sensing has been the development of hyperspectral sensors. The ‘Hyper’ in hyperspectral means ‘too many’ and refers to the large number of measured wavelength bands. Hyperspectral images are spectrally over determined, which means that they provide ample spectral information to identify and distinguish spectrally unique materials. Hyperspectral imagery provides the potential for more accurate and detailed information, extraction than is possible with any other type of conventional remotely sensed data.

Imaging spectroscopy (Goetz et al., 1985) in hyperspectral imaging is concerned with the measurement, analysis, and interpretation of spectra acquired from a given scene (or specific object) at a short, medium or long distance by an airborne or satellite sensor. The concept of imaging spectroscopy originated in the 1980's, when A. F. H. Goetz and his colleagues at NASA's Jet Propulsion Laboratory began a revolution in remote sensing by developing new instruments such as the Airborne Imaging Spectrometer (AIS), then called AVIRIS, for Airborne Visible Infra-Red Imaging Spectrometer (Green et al., 1998). This system is now able to cover the wavelength region from 0.4 to 2.5 μm using more than two hundred spectral channels, at nominal spectral resolution of 10 nm. The special characteristics of hyperspectral datasets pose different processing problems, which must be necessarily tackled under specific mathematical formalisms, such as classification and segmentation (Jia et al., 1999, Green, R 1998) and spectral mixture analysis (Adams et al., 1986; Smith et al., 1990a, b).

ABSTRACT

Pests and diseases cause serious economic losses in yield and quality of many cultivated crops. Detection and assessment of their damage symptoms is very crucial to initiate timely control interventions. The conventional scouting technique adopted for assessment of pest and disease in field crops is very laborious and time consuming. Remote sensing may provide a better means to objectively quantify disease stress than visual methods and it can be used to repeatedly collect sample measurements non-destructively and non-invasively. In this paper we report the changes in the reflectance spectra due to pest and disease incidence in three crops viz., groundnut, castor and rice. Canopy reflectance measurements were made with a hand held multispectral radiometer (MSR 16-R, CropScan Inc) which records incoming radiation and light reflectance with up looking and down looking sensors, respectively in 16 pass bands. Data of percent reflectance at each pass band were processed subsequently using the calibration and correlation constants through a mini computer connected to the sensor. A total of 10 samples were selected for each level of pest/disease. At each sampling, six measurements were recorded and the resulting data were averaged. The reflectance spectra varied for different biotic stresses in the three test crops. Higher absorption in the NIR region between 760-1240 nm was observed for healthy plants compared to the diseased plants in all the three crops tested. The spectral signatures from severely defoliated (by semilooper pest) castor crop showed that the percent reflectance in the visible region between 560-710 nm was higher in the defoliated crop compared to healthy and reverse is true in the NIR region between 810-1100 nm. In case of rice, spectral reflectance in the region between 760-1100 nm could differentiate the healthy and brown plant hopper affected plants. Decrease in reflectance in this region was proportion to the number of hoppers per plant. This could be due to collapse of leaf tissues by hopper damage. The higher reflectance in the visible region (560-710 nm) was observed only when the damage is very severe (hopper burn). Different spectral indices viz., SR (simple ratio), NDVI (normalized difference vegetation index), NPCI (normalized total pigment to chlorophyll index), DWSI (disease water stress index) and WBI (water band index) were compared to distinguish healthy and diseased plants. NDVI was found useful in distinguishing semilooper damaged (defoliated) castor crop from healthy castor. All the indices tested were useful to differentiate the rice plants damaged by sap-sucking pest, BPH at different levels of infestation. Incase of groundnut, the differences in the spectral indices between different disease incidence levels were not significant. Results of the present study demonstrated that by comparing the reflectance spectra generated using ground based high-resolution radiometer, it is possible to distinguish healthy and pest/disease affected crops.

ABSTRACT

Petroleum exploration is the art of searching hydrocarbon reserves in unknown regions by geological, geophysical and geochemical methods. The selection of effective exploration targets is an important step to achieve success in oil exploration and its selection also dependents on study of basic petroleum geological conditions. Petroleum geologists generally consider basins to be a basic geological unit for petroleum exploration and their main task is to find and determine various sedimentary basins. The remote sensing images have characteristics of really and macroscopic to provide accurate and visualization data for directly determining geometric shapes of sedimentary basins. Remote sensing techniques are more effective in understanding the study of basins in an out-of-the-way about mountains and remote deserts.

Key words: Petroleum Exploration, Sedimentary basin, geology, basin, geometry.

The history of gardening dates back to the history of human civilization. In order to meet various utility purposes, primitive people used to grow plants initially. Some of them had beautiful flowers and drew attention. Gradually, the importance of growing flowers / ornamental plants for worshiping Gods and Goddesses came into existence. The need for growing plants for aesthetic purpose came much later. Development of formal gardens also initially confined to temples and, thereafter, attached to the residential places. Concept of developing parks and gardens for beautification purpose exclusively for public use came much later during 17^th century. With the influence of different regimes as prevailed in India time to time, the gardening styles and plants also changed a lot for fulfilling new taste and need of the people.

Gardens have played a very important role in development of nations of the world. In fact, humanity started its cultural development from a garden rememberd as ‘Garden of the Paradise’. Gardens always occupied a prime place in our social and cultural life. Every race has its own idea of gardening and the characters of the nation is expressed in its gardens and parks.

Garden designing has also got certain principles like other subjects. These help proper designing by selecting right garden features, plant species besides their placement, allocation of space, colour scheme etc. Moreover, style, elevation, harmonization, type of the garden etc. are also to be taken into account while designing gardens. The main purpose is to achieve an aesthetic effect in totality.

Keeping these in mind, the main principles are categorized into following two groups.

Lawn is the basic feature of garden without which a garden is seldom complete. All other features are selected and placed considering lawn as a first primary feature. A well spread out land planted with uniform lush green grass of particular type serves as a heart of all gardens. Lawn with systematic planting of shrubs and seasonal flower beds along with well placed specimen plants is the most striking feature of the garden.

Developing a good lawn is not an easy task. One has to consider many things like selection of site, preparation of the land and type of grass to be planted besides its maintenance. Following points need to be considered while developing a lawn.

Site and Soil

Selection of site is an important primary factor. Under full or partial shade, a good lawn can not be developed. The part of proposed garden which receives full sunlight at least four hours a day preferably in the morning should be selected as a site for lawn. Planting of tall trees is to be avoided at the south and south-eastern side of the lawn which obstructs sunlight and provides shade.

Dahlia (Dahlia variabilis) belongs to the family Compositae and is a native of Mexico. Modern garden Dahlias with large blooms in wide array of colours are important flowering plant for Indian gardens. The range of forms, size and colours of the flowers is simply amazing. In the plains of India, Dahlias produce flower during winter season and usually grown as potted plants for display purpose. At suitable sunny locations, they are planted in beds also.

Classification

There is enormous variation in shape, size and flower colour of Dahlia. In addition, hundreds of cultivars are available for use in the garden. For having information on various groups having different flower structure, size etc., it is important to know classification. Garden Dahlias have been classified in the following major categories (based on the National Dahlia Society, United Kingdom).

Anemone - Flowers double having one or more rows of petals; disc florets tubular; ideal as cut flower for floral arrangement.

Ball - Flower head in ball-shape, fully double; petal tips ovate or round and rolled half length. There are large variation in the size of flower head and categorization.

Factories are the backbone of industrial growth for economic prosperity of any nation especially for developing countries like India. There is usually huge area available in the factories but the whole area is not covered under construction or used. The vacant spaces of the factory premises are ideal for development of gardens. Moreover, plantation of trees and development of greeneries are now compulsory in industrial areas as per laws for the purpose of environmental amelioration.

Purpose

Gardens at the factories and other industrial places are different from the normal ornamental gardens. These gardens are generally less intensive in nature. The main function isto fulfill dual purpose i.e., beautification and minimizing environmental pollution. Selection of plants should be evergreen trees, free flowering perennials tolerant to air pollution.

Scope

There are large open spaces available within the campus of factories. These are generally located along the boundary wall, inner open areas and other unutilized spaces. As a whole, there is ample scope for development of gardens and other kind of plantation.

Institutes like schools, colleges, universities, R&D laboratories besides hospitals, offices, hotels, banks, courts etc. come under this group. It is recommended that these institutions should develop ornamental gardens and greeneries in order to create ambience and producing aesthetic effects. Lawn, flower beds, creepers, shrubbery borders, trees should be planted as a part of beautification programme.

Purpose

Garden attached to these institutions serves various purposes. The main purpose is aesthetic improvement of these campuses by way of planting various ornamental plants in a planned manner which provides scope for relaxation. Educational institutions may develop small gardens for botanical collection which are related with the course curriculum so that these collections complement educational courses. In that case, representative collections of different families are to be planted as per requirement of the course.

Any kind of garden established on roof top of the building is known as ‘Roof Garden’. The concept of roof gardening is not new. There are references that in ancient Mesopotamia (600 BC) plants were grown on terraces. During Roman period also ‘Villa of the Mysteries’ in Pompeii had plants on elevated terraces. However, in 21^st century, scarcity of land has driven us again towards development roof gardens.

With the advancement of time, necessity and utility, the concept of roof gardening has also completely changed. In urban environment, development of ornamental roof garden or green roof top is a necessity as it helps in temperature reduction, minimizing environmental pollution and, above all, a source of unlimited enjoyment with greens and flowers. Therefore, building architects are now include roof gardens while planning new building. The environmental issues and aesthetic benefits of the cities by way of developing roof gardens are the prime consideration.

This is a very special type of garden for the visually impaired and disabled persons. The pleasure of seeing beauty of the nature like meadows, sky, sea, mountain and plants has always fascinated mankind who has vision. Unfortunately, people who are not able to see are entirely deprived of the pleasure associated with seeing such visual objects. Their world is entirely different from the others. However, they have got better sense of touch, smell and hearing ability to compensate loss of vision.

Disabled persons are also not in a position to enjoy fully the beauty of nature and plants due to restricted mobility. In addition, most of the ornamental gardens are not fully accessable by disabled persons particularly on wheel chairs.

The ‘Touch-‘N‘-Smell Garden’ is very rare and unique kind of garden meant for the visually impaired and disabled persons enabling them to learn about the diversity of plant species by touch and smell. In India, there are three such gardens. One in the Botanic Garden, CSIR- National Botanical Research Institute, Lucknow and the others are at M.S. Swaminathan Foundation, Chennai and Rashtrapati Bhavan, New Delhi. Similar such sensory gardens of the world are in Berlin (Germany), Kyoto (Japan), New York (U.S.A.), Nanjing (China) and Warsaw (Poland).

20.1 Exchange Capacity

Soil colloidal particles carry both negative and positive charges on their surface which attract and hold equivalent amount of oppositely charged ions to their surface. The total number of negative charges present on a given mass of soil or capacity of a given mass of soil to exchange cations or total number of cation held by a given mass of soil is termed as cation exchange capacity (CEC). Similarly, the capacity of a soil to retain anions is known as anion exchange capacity (AEC). The ion exchange capacity of a soil depends upon the type and amount of colloidal particle (clay and organic matter) present in the soil. Ion exchange capacity (CEC/AEC) is expressed as milliequivalent ion (cation/ anion, respectively) per 100 g of soil (meq/100g). It is also expressed as centimoles of charge (positive/negative) per kg of soil [cmol (±) / kg]. Meq/ 100g = cmol (±) / kg of soil.

20.1.1 Determination of Cation Exchange Capacity of Soil Principle

Soil is first saturated with normal ammonium acetate (pH 7.0). Excess ammonium (NH₄⁺) ions and displaced cations are then removed by washing with alcohol. The amount of NH₄⁺ ions retained by the soil is measured by steam distillation of NH₄-saturated soil with MgO. During distillation evolved ammonia is absorbed in a boric acid solution as ammonium borate and the amount ammonium borate formed is determined by titration with standard sulphuric acid in presence of mixed indicator.

Industrial Microbiology is the discipline that uses micro organisms, usually grown on large scale, to produce commercial products or carry out important chemical transformations.

The products derived from such processes are

1 Alcohols and alcoholic beverages.
2 Production of pharmaceutical agents like antibiotics, vaccines etc.
3 Food additives
4 Enzymes
5 Chemicals
6 Single cell proteins

Development of sophisticated procedures for the isolation, manipulation and expression of genetic materials is a field called genetic engineering. Genetic engineering has applications in both basic and applied research. In basic research, genetic engineering techniques are used to study the mechanisms of gene replication and expression in prokaryotes, eukaryotes and viruses. For applied research, genetic engineering used for development of microbial cultures capable of producing valuable products such as human insulins, growth hormones, interferons, vaccines, enzymes etc. The commercial application of genetic engineering is sometimes referred as Biotechnology. In broad sense, Biotechnology refers the use of living organisms to carry out defined chemical processes for industrial application.

The process of isolation, purification and replication of specific DNA fragment is called molecular cloning or gene cloning. Molecular cloning is the base of most of the genetic engineering procedures. The purpose of molecular cloning is to isolate large quantity of specific genes in pure form. Thus molecular cloning is very important in genetic engineering and can be divided into several steps depends on the purpose. The steps are as follows:

Introduction

Lentil is one of the important Rabi pulses. It is one of the oldest pulses crops and the most nutritious of the pulses. It has the potential to cover the risk of dryland agriculture. It is also used as a cover crop to check the soil erosion in problem areas. It is mostly eaten as ‘dal’. Lentil can also be used as green fodder. Its straw is also used as cattle. Being a leguminous crop, it restores the soil fertility.

Area of cultivation

Lentil is mostly cultivated in the northern and central parts of India. The important lentil growing states are Madhya Pradesh, Uttar Pradesh, Bihar, West Bengal, Orissa, Haryana, Rajasthan, Punjab and Assam. Uttar Pradesh and Madhya Pradesh together contribute 78% towards total national area as well as production.

Climatic requirements: Lentil requires cold climate during growth and warm temperature at the time of maturity. It can tolerate cold and frost winter up to great extent. The optimum temperature for growth is 18-30 degree centigrade. Excessive drought and/or high temperatures during the flowering and pod-fill period also reduce yields.

Soil: Lentil can be grown on a variety of soils such as light loams; alluvial soils and black cotton soils. This crop is also suited to the poorer types of soils, low lying areas such as paddy fields. Lentil does not tolerate flooded or waterlogged soils. Good drainage is required, because even short periods of exposure to waterlogged or flooded field conditions kill plants. A soil pH near 7.0 is best for lentil production. Acidic soils are not fit for growing lentil.

India has made a considerable progress during the last three decades in horticulture production in India producing 300.6 million tonnes of horticultural produce from 24.85 million hectares in 2016-17. The average productivity of different horticultural crops is quite low as compared to the best yields at national and world level, indicating the scope to enhance the yield in different horticultural crops by many fold along with its quality specially in vegetables. Unlike vegetables, flower cultivation is growing at a very fast speed and registered a marked growth along with employment generation through protected cultivation. According to NHB (National Horticulture Board), during the year 2014-15 the area under floriculture production in India was 248.51 thousand hectares with a production of 1,658 thousand tonnes loose flowers and 484 thousand tonnes cut flowers. However, India’s total export of floriculture was Rs. 548.74 crores/ 82.05 USD Millions in 2016-17. This is because of an appealing gap between potential yield and the actual yield of various vegetable crops. In many vegetable crops, the yields realized are even less than 50 % of their potential yield. Due to fluctuating market prices and poor storage infrastructure available for horticultural crops, farmers are not able to get their production cost. Though, there are some crops, fetches high prices during off-season. Several biotic and abiotic stresses are major factors, responsible for low productivity and poor quality in several horticultural crops under their open field cultivation during rainy and post rainy season more specifically, in vegetables. The increasing demand of off-season and high quality vegetables in various markets of the big cities has drawn the attention of the vegetable growers for diversification from traditional system.

The floriculture has become an important sector all over world. In India, floriculture has been associated with culture and heritage since very ancient time. In recent decades there has been increasing in demand of floriculture products with increasing income. It is souring industry in Asian countries including India. Floriculture is an emerging area with great potential both in the domestic as well as export market.In India, commercial floriculture is ongoing development but have a long tradition of various types of flowers.Floriculture was being cultivated in 3.5 lakh hectares in the country and 250 varieties of flowers exist in the country.Besides potted plants, roses, carnation, orchids and chrysanthemum are important cut flowers, which are popular in our country. In the increasingly competitive international cut flower and pot plant market, new and novelty ornamental plants plays an important role in stabilization and expanding market share. Always novelty has been considered as an important attribute in ornamental industry. The consumer choice is also changing for product quality level depending upon purpose of purchase, as well as for higher levels of services and a wider and deeper assessment suggesting product diversification. The increasing pace of agricultural transformation in India has been characterized by widening share of commercial crops in the overall basket. Among others, horticulture has shown great promise because of the availability of high-value domestic and international market against the low production base so far. Understandably, it has received special attention of policy-makers and being termed as the sunrise industry within agriculture. India, with its varied agro-climate is ideally suited for growing several types of flowers in different seasons. Although traditional ornamental crops will continue to play key role in the floriculture trade, a distinct trend towards increasing the share of new crops is clearly evident in recent years often referred to as ‘specialty flowers’, these are cut flowers, which are not widely known and also grown in small pockets but have high prospects in the international market. There are over 60 types of new ornamentals, which have been reported to hold potential for commercial utility. Some progressive growers in India have already initiated the process of introducing new ornamental crops in their fields.These new products normally fetch high prices than the traditional crops for a certain period, but quite often the prices drop when market is saturated. By that time new products should be ready to enter the market. In this context introduction of new ornamental crops is therefore continuous effort.

Plant parasitic nematodes are microscopic, thread like, soil-born organism, found in every conceivable environment. Severity of nematodes as plant pathogen is more a problem in tropical than temperate climate. These organisms are basically root feeders causing injury to the plants, which adversely affect the function of the root to absorb and translocate nutrients and water efficiently. This result into nutrient deficiency like symptoms, and as such nematode problems go unnoticed. Such symptoms are not corrected even after a dose of fertilizers.

Based on feeding habits, they are classified as migratory ectoparasitic, sedentary semi-endoparasitic or endoparasitic nematodes. They feed silently but constantly without killing the host producing debilitating symptoms and in the process reproducing to great numbers at the end of the crop season. Normally, nematodes complete their life cycles in a span of 20-25 days at temperature of 25-30 °C. They have a great egg laying capacity, which varies from 40-1000 eggs.

The most important nematode is root-knot nematode, Meloidogyne sp. distributed worldwide and can infest more than 2000 species of plants. Cereal cyst nematode, Heterodera avenae - an important nematode pest of wheat, barley and oat, citrus nematode, Tylenchulus semipenetrans associated with citrus dieback and slow decline, burrowing nematode, Radopholus similis causing spreading decline in plantation crops, the reniform nematode, Rotylenchulus reniformis in vegetables and cotton and the rice root nematode, Hirschmanniella spp in lowland rice are few other damaging nematodes.

Scientific agriculture is the only solution for increasing productivity of various crops and the input resources most effectively. Fertilizer, the most efficient and often the most expensive input can be applied to crops on the basis of generalized state level fertilizer recommendations. However, state level fertilizer recommendations do not take into consideration fertility status of the field which is neither uniform nor constant and which varies from field to field. Sometimes more fertilizers are added leading to unnecessarily higher investment, while under another situation, inadequate quantities of fertilizers may be added, resulting in lower returns. Inefficient and imbalanced uses of fertilizers affect both soil health and agricultural productivity.

Therefore, the best and most effective method for fertilizer recommendation is soil testing. It is a mode of assessing the nutrient supplying capacity of a soil.

What is biofertilizer?

Biofertilizers are ready to use live formulates of such beneficial microorganisms which on application to seed, root or soil mobilize the availability of nutrients by their biological activity in particular, and help build up the microflora and in turn the soil health in general.

Why should we use biofertilizers?

With the introduction of green revolution technologies the modern agriculture is getting more and more dependent upon the steady supply of synthetic inputs (mainly fertilizers), which are products of fossil fuel (coal+ petroleum). Adverse effects are being noticed due to the excessive and imbalanced use of these synthetic inputs. This situation has lead to identifying harmless inputs like biofertilizers. Use of such natural products like biofertilizers in crop cultivation will help in safeguarding the soil health and also the quality of crop products.