eChapters

Abstract

Pulse combustors provide an advantageous superposition of unsteady gas flow and high intensity sound waves. Such a combination does not only accelerate drying rates because of increased heat and mass transfer but also allows processing of liquids, pastes and agglomerated solids in a dispersed state due to aerodynamic impact from the high intensity sound wave. Over last decades, applications of pulse combustion in drying have been exploited continuously and different pulse combustion dryers have been designed and fabricated. In pilot tests and technical reports on these dryers, short drying time, high energy efficiency and product quality are generally reported, which cause that pulse combustion drying is regarded as a technology of the future in convective drying.

This chapter attempt to introduce basic knowledge and state-of the art about this emerging technology and summarizes some recent studies in pulse combustion drying and equipment design. Following a concise description of pulse combustion and pulse combustor, the basic types of pulse-combustion dryers are presented, including spray dryers, fluidized bed dryers, impinging dryers, and dryers of special design. The existing commercial applications and pilot test projects are described and potential applications are identified.

Photosynthesis- the word photo refers to light and synthesis means preparation. Thus, photosynthesis is the process by which the green plants use light energy of the sun to synthesize carbohydrates. Carbohydrates like simple sugars (glucose) can be stored as starch.

The green plants are eaten by the herbivores, which in turn are consumed by carnivores. Ultimately, the decomposers derive their nutrition from the dead plants and animals. Thus, all organisms are dependent directly or indirectly on green plants, which synthesize food by photosynthesis. Thus, photosynthesis is the most important life sustaining process of nature (Calvin, 1976; Emerson and Arnold, 1932). Photosynthesis is a series of biochemical reactions, which can be essentially summarized as follows:

Food security is one of the most important issues during this century under the projected climate change scenario. The world is facing severe food crisis due to weather vagaries as a part of global warming and climate change. Many countries are under severe food crisis during the crisis of weather abnormalities since 75 per cent of world’s population is dependent on agricultural activities for their livelihood. Therefore, there is an urgent need to produce more and more foodgrains at the global as well as national levels to meet the food requirement of growing population under the projected climate change scenario. There has been a major decline in world rice production since late 2007 due to various reasons including global warming and climate change in top rice producing countries. Deficit monsoon in India results to less foodgrains production including rice as the area under cultivation was less. Floods are also not uncommon in many States of India. Andhra Pradesh, one of the major rice producing states of India, was affected first by drought and then by floods. Thus rice production decline in India was a real set back in 2009. Similar was the case in 2010 due to excess rain during monsoon and floods during NE monsoon across the rice growing regions. At the same time, Philippines got hit by two major typhoons in September-October, 2009 causing damage to rice crop on ground. Approximately one million tonnes of rice in storage also got damaged. These events resulted to low world rice production including India in 2009. The immediate impacts of global warming and climate change on rice production systems and food security will be felt in the form of adverse effects of extreme weather events such as floods, droughts, heat and cold waves, hailstorms and cyclones on rice production. Less immediate but significant impacts are anticipated due to changes in mean temperatures, increasing weather extremes and sea level rising. West Bengal, Uttar Pradesh, Andhra Pradesh, Punjab, Tamil Nadu, Bihar, Orissa, Assam, Karnataka and Haryana are the major rice producing states in the Country. More than 50 per cent of the total rice production comes from West Bengal, Uttar Pradesh, Andhra Pradesh and Punjab. Although the country exports several varieties of rice, many scientists have expressed concern that current Indian rice production techniques cannot sustain the growing domestic population. In the event of projected climate change scenario, foodgrains production is likely to be under threat. Rapid urbanization, desertification, environmental issues, decline of agricultural lands and shifting of cropping patterns led to less foodgrains production. Apart from this, monsoon behaviour, its timely onset, further advancement, distribution of rainfall and occurrences of droughts and floods determine the foodgrains production in India. Long breaks in monsoon during July-August results to drought like situation in the Country as experienced in 2002, 2009, 2012, 2014 and 2015. The saying “Indian agriculture is a gamble of monsoon” is true as it is solely dependent on monsoon. A shift is noticed in India that the area under horticultural crops is increasing at the cost of area under foodgrains. This is one way beneficial to farmers since they can withstand against droughts during monsoon season and sustain horticultural production while not so in the case of foodgrian crops.

Horticulture and allied sector are integral elements for food and nutritional security in the country. Horticulture is the main segment, while its various sub- segments are fruits, vegetables, aromatic and herbal plants, flowers, spices, tubers, plantation crops and ornamental plants. All these are regarded as essential ingredients of economic security. The wide range of agro-climatic conditions of India is conducive for growing a large variety of horticultural crops, including, root and tuber crops, mushroom and ornamental crops.

The Government of India recognized horticulture crops as a means of diversification in agriculture in an eco-friendly manner through efficient use of land and optimum utilization of natural resources. Horticulture seeks to create ample opportunities for employment, particularly for unemployed youths and women folk. India has maintained leadership in the production of many commodities like fruits, vegetables, flowers and ornamental plants and particularly in landscape business.

India is coming up in landscaping and ornamental horticulture. There is wide scope since large number of MNC and business houses have come up in India. The purchasing power of people has increased to a greater extent.

Thus, over the years, much progress are made for advancement of horticulture and allied sector. Rising investments resulted in increased production and availability of horticultural produces in the rural and urban areas. Many schemes and policies were introduced from time to time for upliftment and commercialization of the sector. Large number of investors are taking advantage of the existing potentials in the sector, as well as trying to explore the untapped potentials in the field of horticulture.

Insect and non-insect pests cause extensive damage to standing crops, stored grains and stored products resulting in huge economic loss. Besides these, several pests cause annoyance, as well as attack livestock such as, cattle, poultry and pet animals. Some others damage household articles such as, clothing, upholstery, carpets, paper, books, leather articles, wooden and bamboo furniture and all sorts of wooden structures. These obnoxious creatures besides consuming any kind of food materials, spoil them by contaminating and polluting them with their faecal matter and urine and impart a repulsive, bad odor and make them unfit for consumption by humans and livestock. The damages caused by them pave the way for easy access and infection by some of the saprophytic microorganisms, which hasten the deterioration process. A few of these microorganisms produce mycotoxins, which are poisonous and may even be fatal to the consumers.

Among the household pests, cockroaches, crickets, silver fish, ants, white ants, carpet and powder post beetles and clothes moths are quite important. These insects not only cause annoyance but different types of flies, mosquitoes, bugs, fleas and lice either suck and feed on the blood from humans, cattle, poultry etc. but are also responsible for disseminating several disease causing microorganisms.

1. Introduction

Bryophytes are atracheate, archegoniate non-flowering group of highly diversified plants. Among plants they form the second largest group comprising of 15000 – 25,000 species (Gradstein et al. 2001, Crum 2001). They occur in every continent on globe, in every location habitable by photosynthetic plants and grow luxuriantly between altitude of 1000-3500m. In India, nearly 850 species of liverworts, 41 species of hornworts and 2000 species of mosses, such as are known so far (Singh 1997, Vohra and Aziz 1997). These plants exhibit a variable range of size as some of them are only 0.5-2 mm in size, while on the other end mosses Polytrichum commune and Dawsonia superba can attain a height of 50 and 70 cm, respectively. These plants play a vital role in soil conservation and formation of fertile substrata for other plants in forest ecosystem. On account of unique moisture retaining capacity, Sphagnum and other pleurocarpous mosses are being used as mulching substances, moss grass, moss sticks and bags in horticulture industry. These plants are very sensitive to environmental pollution due to simple structure and devoid of cuticle, and accumulate heavy metals too, hence serve as good bio-monitor of pollution. Some novel compounds viz., marchantin, riccardin, lunularic acid, terpenes and other phenolic compounds have been detected in several thalloid as well as leafy liverworts.

Bryophytes exhibit heteromorphic alternation of generations in which the gametophytic phase (haploid phase) is a prominent and nutritionally self- sufficient independent phase in the life cycle while the sporophyte (diploid phase) is attached and dependent on the gametophyte. The main plant body (Gametophyte) is either thalloid or leafy (differentiated into axis and leaves). They are attached to substratum by simple hair like structures called as rhizoids. The rhizoids are usually unicellular, simple (smooth walled) in hornworts; simple, tuberculate or sinuate in liverworts or multicellular, oblique septate in mosses. Sex organs, antheridia and archegonia produce antherozoids and eggs respectively. After fertilization the zygote is formed which develops into the sporophyte. The sporophyte consists of foot, seta and capsule. The foot is embedded in the gametophytic tissue and draws nourishment for the development of sporophyte. Seta is generally stalk like may be of variable length which holds the capsule. The capsule is the main fertile portion of the sporophytic generation. The spore mother cells, after meiotic division, form spore tetrads having haploid spores. The elater mother cells form elaters, which are sterile and help in the dispersal of spores. Bryophytes are homosporous. Spores germinate to form young gametophyte in liverworts and hornworts, while in mosses, spores first give rise to protonema then buds develop on the protonema to form new gametophytes.

1. Introduction

The study of systematics and genetic diversity between or within different species, populations, and individuals is a central task for many disciplines of biological sciences. Systematic studies can indicate which genomes in the plant kingdom to search, sample, and study for the answers to questions relating to the evolution of chemical and physical structures and their synthesis or ontogeny as well as questions about the kinship of the individuals. Such studies would help find new and useful genes and provide information about the phylogenetic relationships among crop species and their wild relatives. The application of molecular markers has been the most active area of research in both animal and plant systematics. The analysis of the genetic variability within and among populations of the species is crucial for understanding their future maintenance and developing improvement as well as conservation programs.

Classical phenotypic characters, such as morphological traits, are still extremely useful but they can sometimes be influenced by environmental conditions. Therefore, during the past decade, classical strategies of evaluating genetic variability such as comparative anatomy, morphology, embryology and physiology have been increasingly complemented by molecular techniques. These include the analysis of chemical constituents (e.g., plant secondary metabolites) and, most importantly, the characterization of macromolecules. The development of molecular markers, which are based on polymorphisms found in proteins or DNA, has greatly facilitated research in a variety of disciplines such as taxonomy, phylogeny, ecology, genetics, and plant breeding (Weising et al. 1995). The greater utility of molecular markers derives from following five inherent properties that distinguish them from morphological markers.

Plant oleoresins, often referred to as resins, are sticky plant secretions synthesized in large quantities by about 10 % of plant families. Resin is secreted when a plant is disturbed and the sticky substances produced contain many toxic compounds used to defend the plant from herbivores and pathogens. A major component of resin is the terpenoid compounds. Although terpenoid compounds can be quite complex, they are all composed of five-carbon units, with an isoprene unit as the base. The simplest of these terpenes are the monoterpenes that possess 10- carbon atoms derived from two fused isoprene units. Monoterpenes are an important component of the volatile portion of terpenes and often emit very strong odors.

Abstract: Anthurium, popularly known as aristocrat of the plant world, is admired for its unique ornamental value. The Netherlands remains the world’s largest grower and primary source of new colours and cultivars to the international market; while Hawaii remains the epicenter for published research on various aspects of anthurium genetics, propagation and improvement. Flower breeders have created numerous genotypes during the millennia of breeding this crop, which has enabled its establishment as pot plant and cut flower industry. Continued breeding and improvement of anthurium focus on floral fragrance, disease resistance, new flower shapes/ colours and improved floral longevity. Wonderful results achieved through interspecific hybridization, multiway crosses, polyploidy breeding and molecular genetic techniques have been discussed. Cultivars are almost exclusively asexually propagated. Anthuriums are cross pollinating perennial shrubs and progeny can segregate widely for traits due to heterozygosity. Long life cycle of plants, slow seed formation and maturation, slow suckering often pose significant challenges to breeders. Biotechnology has created a new horizon in anthurium breeding. Increasing knowledge of the inheritance of traits and molecular genetics techniques are valuable tools aiding modern anthurium breeders. Future crop idiotype is proposed to continue transformation of this monocot aroid crop during the next millennium.

9.1. Balance and Weighing

9.1.1. Principle of Functioning of a Balance

It is one of the important tools used in the laboratory and one should have thorough knowledge about its assembly, use and care, otherwise it may be the initial step for introducing error in any physical or chemical analysis. Every balance has its maximum load limit and sensitivity depending upon its construction.

Essentially balance may be regarded as a rigid beam, BC having a central fulcrum, O and two arms of equal length, d₁, d₂ (Fig.9.1). The both ends of beam have prism edges upon which the balance pans are suspended by means of suitable suspension.

11.0. Introduction

Agricultural marketing is one of the important branches of agricultural economics. Farmers have one commodity or the other in surplus and need to be disposed off or sold to earn some money to satisfy other needs, which otherwise cannot be satisfied on the farm or in the village. Thus, agricultural marketing has two-fold objective i.e. Sale of surplus commodities and buy other commodities to satisfy family needs. In modern commercial agriculture, the surpluses with farmers are steadily rising, so also their family needs are changing with the change in lifestyle. Therefore, agricultural marketing has assumed important place. Traditionally, market is place or building where buying or selling of goods takes place. But, in modern times with fast and long distance communication facilities like telephone, market is no more restricted to a particular place only, but it has become wider and has assumed regional, national or even international status. Buying and selling is finalized on telephones only from distant places. Thus, the concept of market has radically changed.

So, marketing of food/ processed food is an important and vital constituent of modern business management. Knowledge about market is critical for the success of the product in such a highly competitive global market place. Now a day, in such modern time, marketing is itself a highly specialized and distinctive discipline. Based on marketing rules and laws, marketing is sometimes regarded as marketing science. Modern marketing strategies, tools and techniques have attained such complexity that marketing is linked with those of the modern warfare. The results of the marketing wars are witness by Cola wars and other brand bars being fiercely fought in the global market. So, the markets have become virtual battlefield for the brand wars. Markets and technologies are the two powerful forces driving the food processing industry. Further packaging has become a powerful tool in the promotion and marketing of the processed food products.

Abstract

The anaerobic fungi are one of the early organisms in evolution which are commonly found in the digestive tract of ruminating and non-ruminating animals, (including herbivores) deep sea and earth, dumping sites, etc. In animals, these are considered the primary colonizers of the plant biomass ingested by them. Still their taxonomy was unclear for a long period of time. However, with the help molecular techniques, they are now classified under a separate phylum Neocallimastigomycota. There are 38 species known so far belonging to 11 genera. These have been identified based on both morphological data (like thallus, rhizoids, flagella per zoospore, etc.) and phylogenetic analysis. There is a need to explore the undiscovered anaerobic fungi and look for their potential in industrial applications and solutions to the present environmental problems. It can be achieved by improving techniques of sampling, isolation, maintenance and long term preservation. Animals like herbivores do not have the ability to produce enzymes for degrading the plant biomass and anaerobic fungi help them by producing a range of extracellular enzymes. This ability of anaerobic fungi are of use to humans in bioenergy (biogas production) and biomass degradation (by producing cellulases). Recent advances in metagenomics coupled with new methods of cultivation are helping immensely to know the uncultivated anaerobic fungal populations from the animal gut. The present book chapter discusses the past and present of anaerobic fungi, lacunaes and need for more work on this group of fungi, It focuses on the progress in sampling, isolation and preservation techniques, simultaneously discussing the advances in the application these fungi in biotechnology.

3.1 Tomato

Tomato (Lycopersicon esculentum) is an important vegetable crop. Its 2n= 24.

Floral biology

Flowers are borne in small forked racemose cyme. Anthesis starts at 6.30 a.m. and continues up to 11.00 a.m. Anther dehiscence is longitudinal. It occurs 1-2 days after opening of corolla. The stamen sheds its pollen when the style grows up through anther tube, thus self-pollination occurs. When the stigma protrudes above the anther tube, chances of cross pollination through bees increases. The optimum temperature for pollination is around 21°C.

Introduction

Potato (Solanum tuberosum) is the most important food crop of the world. Potato is a temperate crop grown under subtropical conditions in India. The potato is a crop which has always been the ‘poor man’s friend’. Potato is being cultivated in the country for the last more than 300 years. For vegetable purposes it has become one of the most popular crops in this country. Potatoes are an economical food; they provide a source of low cost energy to the human diet. Potatoes are a rich source of starch, vitamins especially C and B1 and minerals. They contain 20.6 per cent carbohydrates, 2.1 per cent protein, 0.3 per cent fat, 1.1 per cent crude fibre and 0.9 per cent ash. They also contain a good amount of essential amino acids like leucine, tryptophane and isoleucine etc.

Potatoes are used for several industrial purposes such as for the production of starch and alcohol. Potato starch (farina) is used in laundries and for sizing yarn in textile mills. Potatoes are also used for the production of dextrin and glucose. As a food product itself, potatoes are converted into dried products such as ‘potato chips’, ‘sliced’ or ‘shredded potatoes’.

Potato is grown almost in all states of India. However, the major potato rowing states are Himachal Pradesh, Punjab, Uttar Pradesh, Madhya Pradesh, Gujarat, Maharashtra, Karnataka, West Bengal, Bihar and Assam.

The main constraint to potato farming in India are: It is vulnerable to control the pests hence implying a high risk of failure, growing potatoes requires substantial capital and the crop needs intensive care and attention. However, a proper Biointensive insect pest management programme will minimize losses to potato crop.

The measurement of greenhouse gases (GHGs) has been started during middle of the last century. Initially, CO₂ and water vapour were measured with other common meteorological variables like temperature, sunshine hours, rainfall, humidity etc., for monitoring the weather condition and pollution. The absolute or relative concentrations of gasses in atmosphere are used to measure basically for monitoring purpose. However, limited studies were dealt with actual gaseous exchanges of fluxes. The concern about gaseous flux measurement and GHGs-exchanges started after 1900s when people got concerned about anthropogenic pollution, environmental sustainability and climate change issues. The GHGs-exchanges in earth-atmosphere systems primarily occur due to change in meteorological variables, soil responses and physiological activities of crops. If we are interested for environmental data inventories, then absolute GHGs concentrations of atmosphere at a specific time is required. However, presently researchers, students, environmentalists, climate scientists are primarily interested for quantitative data on GHGs fluxes and or GHGs-exchanges. They want to know what and how much quantity of a particular GHG is emitting from unit area at unit time.

Flux refers to the amount of any gas emitted per unit area per unit time. The dimension of that is M A^-11 T^-1. (Where, M= Mass/ Quantity; A= Area; T= Time). The SI unit of flux is g m²s^-1. Therefore, flux is a vector. It has magnitude as well as direction. As for example positive flux of CO₂ from earth surface means, CO₂ is moving out from earth surface to atmosphere. If it moves in opposite direction then the flux would be negative. In that case CO₂ gas may be absorbed by the soil surface from adjacent atmosphere. Similarly, GHGs fluxes of earth surface are either positive or negative. Generally, positive GHGs flux refers to emission of GHGs from earth to atmosphere and vice versa.

This guidance explains when a botanical drug may be marketed under an over-the-counter (OTC) drug monograph and when FDA approval of a new drug application (NDA) is needed. In addition, this document provides guidance to sponsors on submitting investigational new drug applications (INDs) for botanical drug products, including those botanical products (or botanicals) currently lawfully marketed as foods and dietary supplements in the United States. This guidance also discusses several areas in which, because of the unique nature of botanicals, FDA finds it appropriate to apply regulatory policies that differ from those applied to synthetic, semisynthetic, or otherwise highly purified or chemically modified drugs (including antibiotics). In particular, the guidance states that applicants may submit reduced documentation of preclinical safety and of chemistry, manufacturing, and controls (CMC) to support an IND for initial clinical studies of botanicals that have been legally marketed in the United States as dietary supplements or cosmetics without any known safety concerns.

Introduction

Tropical tuber crops viz., cassava (Manihot esculenta Crantz), sweet potato (Ipomoea batatas), taro (Colocasia esculenta), yams (Dioscorea sp.), Elephant foot yam (Amorphophallus paeoniifolius), arrowroot (Maranta arundinacea) etc., are the important sources of starch after cereals and are used as staple or supplementary food in many of the tropical and sub tropical countries. Being the crops with adaptability to wide range of soil, climate and environment of the tropics and sub tropics and requiring minimum agronomic input and care for growth, they can be very well fitted into the prevailing cropping systems. They are the most efficient converters of solar energy and have the ability to reserve energy in the form of carbohydrate in the bulky roots and hence tuber crops are also called as calorie density crops. Tuber crops, though branded as poor man’s crops in rural areas have considerable unrealized potential for processing into high end products for food, feed and industrial uses. They are generally consumed as vegetable after boiling it in water and eaten along with some spicy curry or by extracting starch or flour. Besides serving as an insurance crop during times of food scarcity, it can also function as an industrial raw material for a wide spectrum of products

Introduction

Milk, an integral component of our staple diet is nature's most ideal and complete food. There is a long history and tradition of high consumption of dairy products in India. Consumption pattern of dairy products in India is quite unique and is centred on traditional products; however, novel products are gradually gaining momentum in urban areas. Despite being the largest milk producing country in the world, India accounts for a negligible share in the worldwide dairy trade. Domestic demand for dairy products is showing an increasing trend and it is expected that demand-supply gap will further widen which might transform India being a net importer of dairy products. The domestic demand for dairy products is showing an increasing trend and it is expected that demand-supply gap will get further widened. India, world’s largest milk producer has enough scope for diversified value addition as this can definitely assure a better margin of profit. However, for this, one has to maintain reputation and competitiveness in the market. To emerge as a leader in this competitive global market, continuous improvement of quality is highly essential. Safety, just as the other side of the coin is also of utmost importance to reinforce consumer confidence. Nowadays, quality is not a matter of choice but a necessity and even a responsibility of all stake holders. In the case of food, the term, 'Quality' refers to physical, chemical, microbiological, technological, economic and aesthetic characteristics. From consumer point of view, the word, 'Quality' embraces mostly the organoleptic characteristics like body, texture and flavour than the objective properties like fat, protein, lactose and acidity as determined by science based tests.

Introduction

Humans have primarily consumed "meat/meat products based on where they lived and how they evolved. According to Food Safety and Standards Act 2006, “meat means fresh meat, poultry and game meat which could be in the form of whole pieces, cuts or comminuted (minced etc.), whereas, meat products are those that have been processed by various methods so that they no longer resemble fresh meat”. These products include meat, poultry, and game products in whole pieces or cuts that are cured salted and dried, processed by non-heat treatment, fermented non-heat treated products, heat treated or frozen products. Edible casings used for sausages etc. also come in the category of meat and meat products. Through a notification dated 12^th September, 2017, the FSSAI has included domestic rabbits (Oryctolagus cuniculus) in the Food Safety and Standards (Food Products Standards and Food Additives) Regulation 2011 in the regulation under meat and meat products.

With the advent of globalisation, there has been an increase in food trade which has led to the introduction of exotic meat and meat products. Moreover, rapidly growing economies like India, now demonstrate a growing appetite for meat. As the consumer demand for high quality meat is increasing in most countries, the meat industry should consistently produce and supply quality meat that is safe and healthy for the consumer to ensure continued consumption of meat products.

Introduction

Wheat is pre-eminent both in regard to its antiquity and its importance as a food of mankind in the world. In prehistoric times, it was cultivated throughout Europe and was one of the most valuable cereals of ancient Persia, Greece and Egypt. Wheat has been cultivated for several thousand years in India with the evidence of presence of wheat grains in the Mohen-Jo-Daro excavations. Till 1947, the total wheat production was only about 6 million tonnes and was not sufficient to meet the demand, leading to large scale importation of wheat. Subsequently production increased due to an increase in both total cropped and irrigated area. Wheat crop has exhibited a robust growth trend since the onset of the ‘green revolution’ in 1968. India, one of the greatest success stories of ‘green revolution’, is the second largest producer of wheat in the world after China. During 2018-19 (Fig. 1) India produced a record breaking 101.20 million tonnes of wheat from 29.62 million ha area indicating 3.42 tonnes/ha wheat yield (ICAR-IIWBR, 2019). On the other hand, India is also the second largest wheat consumer after China. Thus, wheat and its various products play an increasingly important role in managing India’s food security and India became the wheat surplus nation as against the wheat deficient nation during 1960’s. The tremendous progress in area, production and productivity of wheat to the tune of 2.9, 12.2 and 4.2 times, respectively as compared to 1950 has made India (Table 1) the member of elite group of wheat exporting countries (Workman, 2018).

Introduction

Maize (Zea mays L.) is one of the most versatile promising crops having wider adaptability under diverse agro-climatic conditions. Worldwide, maize is known as “Queen of cereals” because it has the maximum genetic yield potential amongst the cereals. It is cultivated on nearly 197 million ha in about 170 countries having wider diversity of climate, soil, biodiversity and management practices that contributes 36% (1135 million tonnes) of the global grain production. The United States of America (U.S.A.) is the largest producer of maize contributes nearly 33% of the total production in the world and other important growing countries are China, Brazil, India, Argentina, Indonesia, Ukraine and Mexico (Table 1).

Introduction

The Indian hot arid zone occupies an area of 0.32 million km to forming a continuous stretch in the north western states of Rajasthan, Gujarat, Punjab, Haryana and scattered land masses in the states of Maharashtra, Karnataka and Andhra Pradesh, 70 per cent of it falls in western Rajasthan. Low and erratic rainfall, extreme temperatures, long sunshine duration (6.6-10 hours), low relative humidity (30-80 per cent), high wind velocity (9-13 km/h) and high evapo transpiration (1600-1800 mm) and characteristic features of the region. Moreover the soils are poor in nutrients and scarcity of water and recurring droughts are perennial constraints. Despite hostile conditions, the western arid Rajasthan supports a large human and livestock population and a variety of flora and fauna. However, the ever increasing human and livestock population and development activities exert enormous pressure on the natural resource in the region. These areas experience an annual rainfall between 100 and 500 mm with a coefficient of variation varying from 40 to 70%. The region is characterized by low and erratic rainfall with extremes of temperature (1–48 °C), high wind velocity and sandy soils. In dry and arid region, wind erosion affects 13.5% in India (Sehgal et al., 1994, Kar et al.,1959). Wind erosion is very active in the Indian Thar Desert and poses severe multifaceted problems (Dey et al., 2016). Loss of nutrient-rich particles from agricultural fields has been occurring due to suspension of fine particles in air and deposition of eroded soil. Among terrain properties, soil aggregate distribution, surface roughness, soil moisture and vegetation cover are important factors influencing wind erosion. Indiscriminate grazing in the region also further destroys vegetation and exposes the land surface, thus making it more vulnerable to wind erosion.

In 1920, a 30-year-old Czech writer Karel Èapek, wrote a play called “R.U.R.” (Rossumovi Univerzální Roboti or Rossum’s Universal Robots). For this dystopian work about a bad day at a factory populated with sentient androids, Èapek called the androids “roboti”, as suggested byhis brother Josef, a painter and writer. It was premiered in Prague on 25^th January, 1921.

Èapek was admired for his opinions:

My dear Miss Glory, Robots are not people. They are mechanically more perfect than we are, they have an astounding intellectual capacity, but they have no soul.

But surprisingly he was keen on gardening!

Energy is vital for the whole universe. Since the formation of the universe, energy acts a specific role. Steven Hawkins, George Ellis and Roger explained “The Theory of Relativity “Time and space had a finite beginning than corresponded to the origin of matter and energy from the time of BIG BANG.”. Before invention of fire, energy hovers everywhere but people did not have any knowledge about that. Living being requires energy for every day work which cells of the body provide them. Energy is also a basic requirement for the existence and development of human life. Energy plays an important role in the entire process of evolution, growth and survival of all living being and also in the social –economic development and human welfare of country. Energy is defined as the ability to work. Then we run or walk or do any type of work, we burn the energy in our body produced in cells by transforming food. Cars,planes,trolleys,ships, aeroplanes etc and all kind of machineries require energy to run. There are many sources to get energy as coal, natural oil, natural gas, wind, water, wave, sun and nuclear etc. The commercial sources of energy as fossil fuels (coal, oil, and natural gas) hydro-power and then nuclear power provide the need of energy now of the world. The demand of energy is growing an alarming rate. As for example, according to International Energy Agency the Global consumption of energy has increased from 4606 Mtoe (Million Ton Oil equivalent) in 1973 to 7287 Mtoe in 2003.

Soil survey is essentially a study and mapping of soils in their natural environment. It is the systematic examination, description, classification and mapping of soils of an area.

2.1. History of Soil Survey in India

The original investigations on Indian soils were carried out by Voelcker dates back to 1893 and by Leather to 1898.They classified the soils of the country into four major groups, namely the Indo-Gangetic alluvium, the black cotton soil or regur, red soil and laterite soil. Schokalskaya (1932) has published a soil map of India based on the Russian concept which describes 16 soil groups such as climate,vegetation, soil-forming materials, salinity, alkalinity, swamps and peats (Bhattacharyya et al. 2013). In 1935,Wadia and his co-workers collected a soil map of India with significance on geological formations and classified the soils as red, black (regur), laterite and lateritic soils of Peninsular India and also Indo-Gangetic Plains (IGP) which includes delta, desert, bhabar, terai and alkali soils. Vishwanath and Ukil (1943) published a soil map of India by placing the soils in different climatic zones for the first time. This was prepared by Imperial Agricultural Research Institute, New Delhi, and published in the year 1943. There were 17 kinds of soils identified, viz., deep black soils, black clay soils, black loamy soils, black sandy soils, red sandy soils, brown sandy soils, red and yellow soils, dark reddish brown soils, mixed soils (white and yellow), alluvium (Indus, Gangetic, Brahmaputra), coarse alluvium, soils of swamp lands, calcareous soils, usar soils, kallar soils, coastal alluvium soils and soils of Great Himalayan Ranges.

Soil survey works were started in 1954, in most of the states as a part of their agricultural development programme, and Bihar (Soil Survey and Land use Planning Scheme, Sabour) was pioneer. In 1954, the soil survey work was started under the leadership of Dr. P. P. Jha following the conventional procedures in Bihar (including Jharkhand) to delineate the soil associations based on geology, relief, physical and chemical characteristics of soils for the first time in India by the then Soil Survey Scheme at Sabour (Mishra et al. 2001; Mishra 2015, 2016). Meanwhile, the National Atlas Organization, Kolkata, prepared a soil map of India in 1957 classifying Indian soils into six major groups and 11 broad types. Murthy and Pandey (1983) applied the working principles of the USDA 7^th Approximation in classifying the Indian soils with available data on soil classes and thus used the US system for the first time at great soil group level, which was transformed into a soil map of India on 1:6.3 million scale. Mishra et al. (1994) attempted to propose “Fluvisols” as the 13th Order in USDA Soil Taxonomy for active floodplain soils frequently occurring in different parts of India and elsewhere. Mishra (2015, 2016) proposed a framework of Indian system of soil classification mainly based on land use options.

Improved Varieties of Bulb Crops

A. ONION

Eventhough nematodes occupy nearly every habitat on earth, they are remarkably similar in morphology and life stages. Despite their structural complexity, certain basic principles are common to all nematodes. Nematodes are triploblastic, bilaterally symmetrical, unsegmented, pseudocoelomate, vermiform and colourless animals. The plant parasitic nematodes are slender, elongate, spindle shaped or fusiform, tapering towards both ends and circular in cross section. The length of the nematodes may very from 0.2 mm (Paratylenchus) to about 11.0 mm (Paralongidorus maximus). Their body width vary from 0.01 to 0.05 mm. In few genera, the females on maturity assume pear shape (Meloidogyne), globular shape (Globodera), reniform (Rotylenchulus reniformis) or saccate (Tylenchulus semipenetrans). The swelling increases the reproductive potential of the organism. Radially symmetric traits (triradiate, tetraradiate and hexaradiate) exist in the anterior region. The regions of intestine, excretory and reproductive systems show tendencies towards asymmetry. The nematodes have one or two tubular gonads which open separately in the female and into the rectum in the male which also have the copulatory spicules.

The free living saprophytic nematodes are generally larger in size. The animal and human parasitic helminths may have length of few centimetres to even a meter or more. The helminth parasitising whale fish is about 27 feet long. The study on these animals and human parasites are known as Helminthology.

Although some forms of electromagnetic energy, such as light and heat, can be detected by the human senses. One of the greatest draw backs to high energy radiation is the inability to detect it. We cannot see, feel, taste, smell, or hear the various forms of ionizing radiation. Fortunately, ionizing radiation interacts with matter which makes detection and measurement possible by utilizing specialized equipment. In this section we want to introduce you to the various ways and means of detecting and measuring ionizing radiation.

As mentioned previously, Becquerel discovered radioactivity because it left marks on photographic film as a means of detecting radiation. However, there are more definitive means commonly used by scientists and technicians who study and work with radiation. The equipment utilized for the detection and measurement of radiation commonly employs some type of a substance or material that responds to radiation. Many common methods use either an ionization process or molecular excitation process as a basis. Remember that we stated earlier that radiation interacts with matter. For detection and measurement purposes the process of ionization is the most commonly employed technique, based on the principle of charged particles producing ion pairs by direct interaction. These charged particles may collide with electrons, which remove them from their parent atoms, or transfer energy to an electron by interaction of electric fields.

1 Introduction

The purpose of these Guidelines on Audit Quality is to assist Supreme Audit Institutions assure the high quality of their work and the resulting products. This Section describes the background of the document, provides key definitions applicable to these guidelines, discusses the types of SAIs and audits to which the guidelines apply, lays out the form in which the guidelines are presented and identifies some other sources of useful guidance for assuring quality. Section 2 then deals with quality control as the “hot review” ofthe audit process. Subsections 2.1 — 2.6 set forth some basic premises for establishing effective quality controls, discuss the nature of the controls required to assure quality in the areas of selection and timing of audits, planning specific audits, executing audits, reporting the results of audits, and following up on audits, respectively. Section 3 describes the procedures necessary to assure that needed quality controls are in place and operating effectively, that is it presents the characteristics of post-audit quality assurance. Finally, Section 4 focuses on institutional measures to enhance quality, especially management of human resources (recruitment, training, staff development and ethical standards), institutional risks and external relations. The Annexes provide other information that was considered potentially useful, including reference material, checklists and excerpts regarding quality controls from other guidance documents. The list of reference documents is contained in Annex A.

Audit quality is obtained by a process of identifying and administering the activities needed to achieve the quality objectives of an SAI. All types of SAI need to understand the benefits that can be realised once audit quality is made a priority. Improving audit quality requires a systematic SAI- wide approach. Piecemeal efforts by individuals and individual audit teams are not enough and will not work. There are no quick fixes to be obtained where audit quality is concerned. SAIs needs to proceed methodically in an organised way to fix each quality issue and problem in turn. As new problems will always emerge, this should be a continuous process for the SAI. It is also evident that most audit quality related problems are mainly the result ofpoor management of the audit process or the SAI itself.

Introduction

In many of the experimental designs considered previously like CRD and RCBD ,the main feature was to compare varieties,methods of cultivation,different kinds of fertilizers, etc. In general, in such experiments, only one factor is allowed to vary at a time, while all other factors known to affect the response are generally controlled. Such experiments are called ‘Simple’, or ‘Classical’ experiments.

Biological organisms are simultaneously exposed to many growth factors during their lifetime. Because an organism’s response to any simple factor may vary with the level of the other factors, simple factor experiments are often criticized for their narrowness. Indeed, the result of a single-factor experiment is, strictly speaking, applicable only to the particular level in which the other factors were maintained in the trial. But there are numerous occasions, especially in agriculture and animal experiments, where the main interest of an investigator does not lie with the effect of a single factor at a time but lies with simultaneous influence of many factors. For example, the interest of an investigator may not be in merely knowing the effect of spacing on the yield of a certain crop, but his interest would lie in finding out the simultaneous effect of both spacing and method of fertilizer application, that is, whether along with spacing, split dose of fertilizer at periodical intervals would be more beneficial than applying full recommended dose at one time. In order to answer this and many other questions, there are some special experiments called factorial experiments.

Soil fertility is the resultant of several factors, not the least important of which is the soil itself. Theoretically, the soil only plays the part of a support and could be very easily dispensed with and replaced by sand and even that can be replaced by a wire framework to support the plant mechanically and it will grow quite well if the right amount of nutrient materials have been added to water. ‘Where does the soil come in?” you will ask. The importance of the soil is two-fold: (1) It provides vast reserves of plant food which is slowly made available. (2) It provides limiting factors which restrict plant growth; these limiting factors must be neutralized. We have already discussed these reserve food materials and limiting factors in Chapter II.

It has been shown that if we treat a soil with dilute acid exhaustively we can remove everything from it except the mineral framework. If we try to grow anything in this mineral framework nothing will grow. Yet it is not like sand, for whereas in sand by adding appropriate amounts of nutrient materials in water solution you could grow a crop, nothing will grow if you added the same solution of nutrient materials to the soil. This mineral framework, therefore, is not inert like sand, but it is active and can react with the nutrient salts in such a way that either they are rendered unavailable or something else which is toxic is produced by the interaction between the soil and the nutrient salts. This mineral framework is not acted upon by dilute acids, but it reacts with alkalies in such a way that the alkalies are neutralized. In this respect, therefore, the mineral frame work behaves like an acid. With alkalies it forms salts and different alkalies are required in equivalent amounts for the formation of these salts. Thus we can have salts of a number of bases and if we use sodium hydroxide for neutralizing we shall have sodium soil, similarly we can have a calcium, magnesium or potassium soil. Now in nature, all the various bases principally, calcium, magnesium, sodium, and potassium, are associated with it in different proportions. The nature and amount of these bases determines the physico-chemical properties of the soil affecting crop yield and leading to soil infertility. We have already indicated the method of bringing the soiil to the normal state when it suffers from any of the defects associated with the soil framework.

Tomato (Lycopersicum esculentum Miller, 2n = 2x = 24, also known as Solanum lycopersicum, Family Solanaceae) has been the leading vegetable crop globally. Tomato genome is composed of approximately 950 Mb of DNA, more than 75% of which is heterochromatin and largely devoid of genes. The global production of tomato in 2017 has been 182 million tons from 5 million ha area giving a productivity of 36.4 tons/ha. Top 10 countries in tomato production in descending order are China, India, Turkey, USA, Egypt, Iran, Italy, Spain, Mexico and Brazil. Tomato is planted almost throughout the year in different parts of India in an area of 8 lakh ha (0. 8 million ha) with production of 20.8 million tons giving a productivity of 26 ton/ha. Tomato area in India is almost 10% of total vegetable area. The states accounting for major tomato production in India are Andhra Pradesh, Orissa, Telangana, Madhya Pradesh, Karnataka, Maharashtra, West Bengal, Chhattisgarh, Bihar, Gujarat, and Himachal Pradesh.

Out of total area, about 78% is planted with F₁ hybrid seed while remaining 22% of the area still goes to open-pollinated varieties. The average productivity of tomato close to 26 tons/ha is still very low compared with the global productivity of 36.4 tons/ha. However, with the introduction of high performing and disease resistant hybrids, the productivity and production are continuously improving. Most of hybrid tomato seed (95 tons) is sold by the private seed companies. There are more than 375 tomato hybrids in the commercial chain in India produced and marketed by different companies. About 50 hybrids out of these 375 hybrids are being grown on more than 80% of the area under tomato in India. Leading companies in tomato hybrid seed segment are Seminis (Bayer), Syngenta, Rasi HyVeg, and Namdhari (NHB, 2015; Kapur, 2016).

Chilli is reported to be an inhabitant of South America and widely scattered in all tropical and sub-tropical countries including India. Amongst all the important consumed crops, chilli occupies a dominant position and its economic losses worldwide due to few serious diseases like chilli anthracnose, Phytophthora leaf blight and fruit rot, bacterial leaf spot, bacterial wilt, Cercospora leaf spot, chilli leaf curl virus and so on. Capsicum annuum L., C. frutescens L. are the biological names of chilli. Bird’s eye chilli is grown in Mizoram and some areas of Manipur and Assam. Chilli has got its own regional names. In Hindi, it is popularly known as Lal Mirch, in Gujrat as March, in Marathi as Mirchi and so on. Kanthari White is grown in Kerala and some parts of Tamil Nadu. Kashmir chilli is grown in temperate region such as Himachal Pradesh, Jammu and Kashmir and also in sub-tropical regions of North India. Red chilli held high amount of vitamin C and provitamin A, whereas green chilli too contain a considerable amount of both substances. In addition, peppers are a good quality source of most B vitamins, vitamin B6 in particular. They are very high in Potassium, Magnesium and Iron supplement.

Marine shrimp farming is a century-old practice. Until a decade ago, this commodity was generally considered a secondary crop in traditional fish farming practices. Shrimp fry trapped in salt beds, coastal paddy fields, or brackish water fishponds are allowed to grow to marketable size and harvested as a secondary crop. However, in recent years when higher income are derived from the harvest of shrimp than the principal crop, many farmers have converted their rice fields, salt beds and fishponds into shrimp farms.

In the traditional farming system, the ponds are stocked with fry either collected from the wild or concentrated through tidal water entering the ponds. Shrimp production is inconsistent and varies from year to year due to the dependence on seasonal supply of fry from the wild. Pond yield is also low (100–300 kg/ha/ year) because of inefficient control of predators and competitors, full dependence on natural food and inadequate pond depth.

Some improvements of the traditional farming methods have been made in the past years. The stocking density of shrimp ponds can be increased through the concentration of fry by pumping more tidal water into the pond. Pond depth is increased to minimize fluctuations of environmental parameters. As a result, pond yield has correspondingly increased. However, the expansion of the shrimp farming industry is still restricted due to the inconsistency in fry supply.

Earthworms have been on the earth for over 20 million years. In this time they have faithfully done their part to keep the cycle of life continuously moving. Their purpose is simple but very important. They are nature’s way of recycling organic nutrients from dead tissues back to living organisms. Many have recognized the value of these worms. Ancient civilizations, including Greece and Egypt valued the role of earthworms played in soil. The Egyptian Pharaoh, Cleopatra said, “Earthworms are sacred”

4.1 Earthworms

Earthworms belong to Phylum Annelida of animal Kingdom. They are long and cylindrical shape, length of earthworms vary from a few mm to nearly 3mtr as noted in case of Megas colex species found in Australia. The body of earthworms has a large number of grooves. Due to these grooves the body of the earthworm is divided into number of compartments called segments. In mature earthworms, few anterior segments appear swollen due to glandular thickening. This part is called as clitellum. The segments are not clearly seen in this part. There are 2500 to 3,000 species of earthworms in the world which are adapted to range of environment. More than 350 species have been identified in India. The species of earthworms are differentiated mostly on the basis of external features such as length of earthworms, number of segments, position of clitellum and external aperture present on the body. Earthworms were referred by Aristotle as “the intestines of earth and the restoring agents of soil fertility”

6.1 Introduction

India experienced an impressive growth and productivity gains in agriculture since Independence reflecting our farmers’ resilience against multiple odds and challenges. Despite a structural transformation post-Green Revolution, characterized by a consumer centric and food security policy objective, the regular distress and crises in the recent past pose a severe threat to income and livelihood security of farmers. The income realised from agriculture compared to nonagriculture, has been too low with a wide variation across regions. The average income of an agricultural household during 2012-13 has been estimated as low as at `6426 per month, marginally higher than the average consumption expenditure (`6223). Further, around 23 per cent of the farmers still live below the poverty line (DFI Committee, 2017a). Estimates from the Central Statistics Office’s (CSO) indicated that the annual growth in gross value added from agriculture has reduced drastically from as high as 6.9% (October-December, 2016) to a mere 2.3% (April-June, 2017) at 2011-12 prices in the recent past ten quarters. Shockingly, the growth was lower in nominal terms in comparison to real prices during the April-June, 2017 quarter indicating the creeping deflation in farm sector.

The area of circle, rectangular, square, triangle, trapezium, rhombus,parallelogram etc are to be calculated by simple formulae but some times the combined area of more than two either circles or trapezium is difficult to calculate. It needs to understand the concept of area and how it is related to different planes. Some of the tips are given below to understand how to calculate the are

a. Area

A part of the plane enclosed by a simple closed figure is called a plane region and the measurement of plane region enclosed is called its area. Area is measured in square units.

The different geometrical shapes formula of area and perimeter with examples are discussed below:

A ratio is the comparison or simplified form of two quantities of the same kind. This relation indicates how many times one quantity is equal to the other; or in other words, ratio is a number, which expresses one quantity as a fraction of the other. For example, the ratio of 1 to 2 is 1 : 2. The numbers forming the ratio are called terms. The numerator, “1”, in this case, is known as the antecedent and the denominator, “2”, in this case, is known as the consequent.

In this article we will learn the approach applicable to solve various problems on ratios and proportions. In the next few lines you will go through some important concepts related to ratio problems and the methods you should apply to solve those problems. It is always better to solve as many problems as you can to boost your confidence. Some important points are given below to remember;

Suppose you go to a Big Bazar to buy a shirt. You finalize the shirt and are shocked to see its price tag. The price mentioned on the sweatshirt is Rs. 2500. You ask the owner to give some discount. He offers a discount of 20%. Now just figure out, how much you will pay to the shopkeeper. Did you say 2000 rupees? You are bang on1 You will pay a sum after subtracting 20% of amount written on price tag i.e. Rs. 500 from Rs. 2500. You finally pay the shopkeeper 2500 – 500 = Rs. 2000. This example introduces you to the concept of marked price and discount. What you indirectly learned from this case is that the discount is calculated on the marked price only. Now let us assume here that the shopkeeper has purchased that sweatshirt for Rs.1600. How much money that shopkeeper has earned by selling this sweatshirt ? Now the shopkeeper has invested Rs. 1600 to buy this sweatshirt and finally sells for Rs. 2000. He makes a profit of Rs. 2000 – 1600 = Rs. 400

He earns this profit by putting in Rs. 1600. Thus his percentage profit is 100 x 400/1600 = 25%. This makes another concept of cost price and profit clear to you i.e. the price you put in from your pocket to buy a product is called cost price and the extra amount you get after selling the product is called the profit. The profit and loss percentage is calculated on cost price. Profit and loss problems are an integral part of all the competitive exams. You must understand the meaning of the basic terms used in profit and loss questions.

In most of the examinations, the questions related to boat and stream are asked. These questions are seemed to be very difficult but are very ticklish and easy to solve. The students need to concentrate on flow of stream upward and down ward. If the boat is moving towards the flow (downstream), the speed of boat and stream will be added and if the boat is moving towards opposite of stream flow (upstream), the distance covered by the baot will be equal to boat speed minus strean speed. Few important tips are given below to solve such type of questions.

Downstream and Upstream Motion

Downstream motion of a boat is its motion in the same direction as the flow of the river. Upstream motion is exactly the opposite. There are two parameters in these problems.

In mathematics, we use different type of digits called numbers. These numbers may be real, natural, rational, irrational, composite and complex, imaginary, perfect, positive and negative integers, whole number, prime and co prime numbers and even-odd numbers and make students confused. Therefore the concept of numbers should be very clear to the students so that they may answer the questions easily.

The number system mainly into classified into 8 types.

Introduction

Almost every test of reasoning contains questions on coding. In such questions, generally one word and its code are given, and the students are required to find the code for the other word. The student is required to apply the same logic, as was applied in the given words.

Let’s discuss some of the commonly asked questions based on coding : Some of the major types of coding logics are

5.1. What is soil organic matter?

Plant and animal residues which are not yet added to the soil are considered as organic materials. However, once they are added to soil, they become soil organic matter. Therefore, organic materials contributing to the soil matrix are referred as Soil Organic Matter (SOM). Sometimes SOM is also used to highlight only the non-living organic materials produced by living organisms. But SOM should be regarded as a broad term that includes biomass, partially decayed residue, and highly decomposed and transformed organic substances, humus. Agricultural soil contains nearly 1-5% of SOM, which is regarded as least amount in soil as compared to other three soil components, minerals (45%), air (25%) and water (25%). However, it contributes enormously to soil productivity. Soil productivity and fertility exhibit direct positive relationship with SOM content in soil. Plants and animals are considered as primary and secondary sources of soil organic matter, respectively. Plant residues and application of organic manures e.g., farmyard manure, compost or green manuring help to build up organic matter in soil and thus, enrich the soil with organic carbon and other plant nutrients. Under natural conditions, roots of grasses in grasslands, the leaves including shoot portion of the large trees in forest lands and after harvesting the crop remnants in agricultural field provide enough incorporation of organic materials in soil. SOM plays a vital role to maintain sustainability in agricultural production through producing healthy soils and thus, healthy crops.

4.1 INTRODUCTION

It has been suggested that the relationship of surface chemistry to soil science is similar to that of biochemistry to biology. Certainly the fact that surfaces of soil particles are extensive and reactive leads to a dominance of surface chemistry in soil behaviour, but it is not an exclusive relationship, because many precipitation reactions, oxidation and reduction processes, and biological reactions take place more or less independently of the surface processes. Nevertheless it is difficult to understand soil properties fully without an appreciation of the nature and extent of the surfaces of the soil constituents, and this chapter is devoted to a discussion of this topic.

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

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

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

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

Occurrence of various diseases affecting agricultural and horticultural crop is known for several centuries. However, critical examination of crop diseases to understand the nature of the causative agents and extent of losses induced by diseases and development of effective disease management systems were possible much later. Any deviation from normal form and function of plants is considered as ‘disease’. Both pathogenic (biotic) and physiogenic (abiotic) causes are involved in diseases of plants. Adverse environmental conditions such as extremes of temperature, light and oxygen, soil moisture, pH and polluted air may alter the physiological conditions of the plants. Nutritional deficiencies also affect various crops leading to considerable losses. Microbial plant pathogens–fungus-like oomycetes, fungi, bacteria, phytoplasmas, viruses and viroids–form the major group of biotic agents that induce different diseases of crop plants in the field as well as during transport and storage (Narayanasamy 2002,2006). Presentation of information in this book is confined to various aspects of the microbial plant pathogens and the diseases caused by them.

Microbial pathogens may induce symptoms that may be visible externally and also in the deep-seated internal tissues which have to be examined using light or electron microscope. In the case of some diseases, the symptoms may be localized in different plant parts such as roots, leaves, stems, floral parts or seeds / fruits / vegetables. Such infections are known as local infection. On the other hand, the pathogen may spread from the point of entry into the host to other plant parts which exhibit characteristic symptoms. These diseases are termed as systemic diseases. In some cases, no recognizable visible symptom is produced although the pathogen is able to develop without inconveniencing the host plant species which are called as carriers and the infection is designated latent infection. Plant viruses are carried symptomlessly by many weed plant species which may serve as sources of infection for crop plants.

Detection and identification of the causes and diagnosis of the diseases rapidly and precisely are the basic requirements for developing effective crop disease management systems suitable for different ecosystems. Incorrect diagnosis leads to failure to contain the disease spread and consequent additional expenditure to the growers. Hence, it is essential that proper diagnostic procedures are followed to achieve the goal of reducing both quantitative and qualitative losses of agricultural and horticultural produce. Morphological, biological, biochemical, physiological, immunological and genomic characteristics of microbial plant pathogens have been carefully considered to develop rapid, sensitive and reliable methods of detection and identification of cause(s) of newly observed disease (s) in the locations concerned. Various methods of establishing the nature of microbial plant pathogens are discussed in detail in earlier publications

Acid soils occupy about 30 percent of the land area of the world out of which 67% acid soils support forests and wood lands and 18 percent are covered by grassland vegetation. Only 4.2 per cent (179 million hectare) of the acid soils across the globe is used for arable crops.

Soil acidity is a major constraint in crop production. The removal of basic cations especially Ca and Mg by leaching and their replacement by acidic cations, H, Al and Fe on exchange complex leads to soil acidity. Soil developed from granite parent material are more acidic than those developed from basalt, shale or lime stone. In acid soils, low pH leading to toxic concentration of H⁺, Al³⁺, Mn²⁺ influences nutrient availability, organic matter decomposition and microbial activity.

Efficient soil amelioration and nutrient management practices are necessary for crops susceptible to soil acidity.

A. General Morphology

2.1 The Root

It is the organ of a plant that typically lies below the surface of the soil.The root is best defined as the non-leaf, non-nodes bearing parts of the plant’s body. However, important internal structural differences between stems and roots exist. Root spices are, rather surprisingly, rare. Some popular examples of spices having roots are: Apium graveolens (Celery), Armoracia rusticana (Horse radish), Coriandrum sativum (Coriander), Ferula asafoetida (Asafetida), Glycyrrhiza glabra (Licorice), Levisticum officinale (Lovage), (Petroselinum crispum (Parsley), etc. All of the mentioned plants have aromatic roots.Roots of gingiberaceae are adventitious and storage roots arise from among the nodes of these scales.