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For the intelligent appreciation and understanding of various reactions and processes associated with soils a little basic knowledge of chemistry is helpful. If the reader follows this chapter carefully, the working knowledge of chemistry thus acquired will enable him to follow all the complicated chemical reactions taking place in the soil.

What is Chemistry? Chemistry is the science that deals with the chemical changes. What is a chemical change? When two or more substances combine to give a substance entirely different in properties to the individual components, the change is called a chemical action to distinguish it from the purely physical action in which the properties of the product are intermediate between the components. The latter naturally can be separated easily by mechanical means. For instance a mixture of sand and water can be separated by passing through a filter, and a mixture of salt and water can be separated by evaporating the water when the salt is left as residue. But water itself is a compound of two gases: oxygen and hydrogen. Its properties are totally different from its components. We can freeze it, evaporate it and perform a host of other operations on it without changing it in the least.

Atoms and molecules: The whole science of chemistry rests on atoms and molecules If these are understood clearly, basic chemistry is reduced to simplicity. Take a familiar object like gold or silver and go on subdividing it into smaller and smaller bits. You will reach a stage that further subdivision will become impossible. You will have reached the primary units, the elementary bricks of which the substance is made up, namely the “Atoms”. An atom in chemistry is the smallest brick from which all material substances in the world are made up. Not that you can see an atom. It is so small that even the most powerful microscope will nut reveal its presence. You could perhaps just see a collection of a million atoms as a tiny spot of light if it is illuminated with a powerful beam of light. Even then you could not say if it was round, square, or oblong. However, you need not look for any such tangible proof to believe in the existence of atoms. Even pure logic would compel you to stop somewhere if you started with an imaginary division and sub-division of a substance. You could not go on ad infinitum. Even the ancients, who knew no modern chemistry, believed in their existence purely from philosophical reasoning.

For electromagnetic radiation, there are four “laws” that describe the type and amount of energy being emitted by an object. In the following sections, these four laws of radiation e.g. Planck’s law, Wien’s displacement law, Steffan-Boltzman law and Kirchhoff’s law are described briefly.

Planck’s Law

Planck’s law describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T. The spectral radiance of a body, B_í, describes the amount of energy it gives off as radiation of different frequencies. It is measured in terms of the power emitted per unit area of the body, per unit solid angle that the radiation is measured over, per unit frequency. Planck showed that the spectral radiance of a body at absolute temperature T is given by

Abstract
 
Food products can have moisture content as high as 90% which needs to be lowered to acceptable limits to prevent microbial growth and deteriorative reactions. Drying is one of the most common and cost effective techniques for removal of excess moisture from the food by application of heat. In addition to its role of extending the product shelf life and providing stability, drying also helps to produce variety of products from agricultural, horticultural and industrial products. But to obtain the desired quality product, adequate drying is essential which depends on type of dryer and drying technique employed which further requires proper understanding of drying process. Despite being important unit operation in food processing industry, appropriate scientific knowledge of the drying process is still limited. So, the fundamental principles and associated terminologies with drying has been discussed in detail in this chapter to have thorough understanding of the drying process. In addition, different models and calculation procedures for drying of different types of commodities has also been reviewed.

Introduction

The insulating material (may be fluid or air) used in circuit breaker should serve two important functions. They are written as follows:

1. It should provide sufficient insulation between the contacts when circuit breaker opens.

2. It should extinguish the arc occurring between the contacts when circuit breaker opens.

The second point needs more explanation. To understand this point let us consider a situation if there is some fault or short circuit in the system, the relay provides desired signals to the circuit breaker so as to prevent system from ongoing fault. Now when circuit breaker opens its contacts, due to this an arc is drawn. The arc is interrupted by suitable insulator and technique.

Methods of Arc Interruption

Introduction

In normal working condition of electrical network, the current flows through the network is within the rated limit. If a fault occurs in the network mainly phase to phase short circuit fault or phase to ground fault, the network current crosses the rated limits. This high current may have a very high thermal effect which will cause permanent damage to the valuable pieces of equipment connected to the electrical network. So this high fault current should be interrupted as fast as possible. This is what an electrical fuse does. A fuse is a part of the circuit which consists of a conductor which melts easily and breaks the connection when current exceeds the predetermined value. An electrical fuse is the weakest part of an electrical circuit which breaks when more than predetermined current flows through it.

Introduction

Geostatistics is a branch of statistics that deals with the analysis and modelling of geo-referenced data. Its main aims are to quantify spatial variability and to create maps from point observations. Of course there is much more to geostatistics than just that and indeed some of the other uses of geostatistics are addressed in this chapter too, but the emphasis is on the assessment of spatial variability and geostatistical interpolation.

The first step of geostatistical interpolation is to quantify the spatial correlation structure of the variable of interest. This can be done by examining the observations and how these vary in space. Next spatial interpolation makes use of the quantified spatial correlation to derive optimal predictions at unobserved locations and create a map. The interpolation error is quantified as well, which helps to design optimal spatial sampling schemes that balance data collection costs and map accuracy. All this will be explained in this chapter, but in order to do so we first need to explain the statistical theory that underlies geostatistical interpolation followed by representation of the spatial correlation structure, the basics of geostatistical interpolation (‘kriging’), kriging extensions and spatial stochastic simulation.

1. Pomology word is derived from a—————————

   a) Greek word

   b) Latin word

   c) English word

   d) None of these

2. Deficiency of ————————vitamin causes scurvy.

   a) A

   b) B

   c) C

   d) D

‘Hydroponics’ technique was first developed on commercial scale as early as in 1930 by

A. De. Condole             B. J.D. Hooker

C. W.F. Greicke            D. Hugo De Vries

Present day hydrogeomorphological research is the explanation of landscape and landforms: what they are, how they function and have developed with reference to the hydrological conditions. Research is a much more complex undertaking than giving names to landforms or even the study of processes, both in terms of what we mean by process and how explanations are approached. It is worthwhile examining some reasons for this, as it shows the increasing complexity of the subject and lead to ideas of how hydrogeomorphology can be studied. Here are some of the fundamentals required for hydrogeomorphological studies:

Mechanism and Processes

‘Mechanism’ provides explanations in detail by describing physical or chemical effects. ‘Process’ signifies the integration of mechanisms in time. Thus, for example when we talk about ‘fluvial process’ or, more specifically, about the ‘mechanism of saltation’, then we have to discuss about the energy source and processes of carrying the material. A process can thus be viewed as the simultaneous operation of a set of specific mechanisms over a specific time period.

Inroduction

The process of connecting neutral point of 3-phase system to earth (i.e. soil) either directly or through some circuit element is called neutral grounding. Neutral grounding provides protection to personal and equipment. It is because during earth fault, the current path is completed through the earthed neutral and the protective devices (e.g. a fuse etc.) operate to isolate the faulty conductor from the rest of the system. This point is illustrated in Figure 10.1.

Figure 10.1 shows a 3-phase, star-connected system with neutral earthed. Suppose a single line to ground fault occurs in line R at point F. This will cause the current to flow through ground path as shown in Figure1. Note that current f lows from R phase to earth, then to neutral point N and back to R-phase. Since the impedance of the current path is low, a large current flow through this path. This large current will blow the fuse in R-phase and isolate the faulty line R. This will protect the system from the harmful effects of the fault. One important feature of grounded neutral is that the potential difference between the live conductor and ground will not exceed the phase voltage of the system i.e., it will remain nearly constant.

Definition of Plant Pathology

‘Plant pathology’ may be defined as ‘the study of microorganisms and of the environmental factors that cause disease in plants; of the mechanisms by which these factors induce disease in plants; and of the methods of preventing or controlling disease and reducing the damage it causes’. Plant Pathology or ‘Phytopathology’ is a branch of Biological Science, which exclusively deals with plant diseases and various aspects connected with plant diseases. The term Phytopathology had been derived from the Latin language. The Latin word ‘PHYTON‘ means plants; ‘PATHOS‘ means suffering and ‘LOGOS‘ means Science. So, Phytopathology means the Science dealing with suffering plants. Trees, shrubs, grasses etc., whether cultivated or wild are termed as plants and they form the majority of the earth’s living environment. These plants, which are so vital for humans, animals and insects are vulnerable to attack by numerous microorganisms, called ‘plant pathogens’. Some environmental factors are also detrimental to the normal growth of plants, resulting in diseases. Diseased plants exhibit some type of abnormalities and these abnormalities are termed as ‘disease symptoms’. Depending upon the pathogens attacking the plants or adverse environmental factors the disease symptoms vary markedly.

The Science of Plant Pathology has four main objectives:

1. To acquire knowledge about biotic plant pathogens and abiotic environmental factors, which are responsible for causing diseases.
2. To know more about the occurrence and mode of spread of the pathogens on a large scale.
3. To study the interaction between the host and the pathogen with respect to environmental factors.
4. To adopt suitable methods of preventing or controlling the diseases, thereby reducing the damage caused by the pathogens.

Systematic knowledge about Plant Pathology will be of much help in protecting the plants from attack by the pathogens, thereby allowing the plants to grow and attain maturity according to their genetic potential.

2.1. LABORATORY SETUP

The setting up of a tissue culture laboratory needs proper planning. It depends on the nature of research works to be under taken and/or commercialization of tissue culture technology and the availability of space. The ideal tissue culture laboratory should have the following components:

1. Store facility for chemicals
2. Media preparation room
3. Autoclave room
4. Storage facilities for autoclaved laboratory-ware and media
5. Washing facilit
6. Culture room
7. Inoculation room
8. Instrumentation room
9. Hardening facility

The term probiotic means “for life” and it is currently used to refer bacteria that are associated with beneficial effects for humans and animals. The credit for first observation made on the positive role of some selected bacteria was attributed to Eli Metchnikoff, the Russian born Nobel Prize recipient, worked at the Pasteur Institute in the beginning of the last century. Metchnikoff suggested that - “the dependence of the intestinal microbes on the food makes it possible to adopt measures to modify the microflora in our bodies and to replace the harmful microbes by useful microbes”. Interim Henry Tissier, a French paediatrician, observed that children with diarrhea in their stools had a low number of bacteria which are characterized by a peculiar Y shaped morphology. On the contrary, these “bifid” bacteria were abundant in healthy children. Based on these observations, Tissier suggested that “bifid” bacteria could be administered to patients with diarrhoea to help restore a healthy gut microflora. These two scientists were the first to give scientific intimation for the use of probiotics when even the term probiotics was not coined. Later in 1965, the term probiotics is coined by Lilly and Stillwell to describe substances produced by one microorganism, that stimulate the growth of another. Subsequently, Parker defined probiotics as organisms and substances that contribute to intestinal balance. Further, Fuller (1989) improved the Parker’s definition of probiotics as “live microbial feed supplements which beneficially affect the host animal by improving its intestinal microbial balance”. Havenaar and Huis in’t Veld (1992) extended the probiotic definition with the description: “A viable mono or mixed culture of microorganisms which, applied to animal or man, beneficially affects the host by improving the properties of the indigenous microflora”. At the end of the millennium, Salminen and his coworkers (1999) proposed the following definition: “probiotics are microbial cell preparations or components of microbial cells that have a beneficial effect on the health & well- being of host”. Whereas FAO/WHO (2001) defined probiotics as “living bacteria that, when administered in adequate amounts, confer a health benefit on the host”. This definition for probiotics is widely accepted.

1.1.1 Definition and Scope of Soil Science

Definition: Soil science encapsulates the scientific exploration of one of Earth’s most vital components—soil. It goes beyond the everyday understanding of soil as mere dirt, positioning it as a dynamic and complex system that supports life. At its core, soil science is an amalgamation of various scientific disciplines, each contributing to the comprehensive study of soil. This multidisciplinary approach ensures a holistic understanding that extends far beyond the surface.

Soil science is not confined to the physical substance beneath our feet; rather, it embraces a nuanced perspective that involves decoding the intricate language of the soil. It is the science of uncovering the secrets embedded in the Earth’s outer layer—examining its history, composition, and the myriad interactions that shape its character

Introduction

Colocasia esculenta (L.) Schott, also known as taro, belongs to the family Arecaceae. Taro is believed to have originated in Southern or South-East Asia, and to have been dispersed to Oceania through the Island of New Guinea to many centuries ago but cultivated in Asia for more than 10,000 years. Taro is considered as an important vegetable grown throughout India. Taro is herbaceous perennial plants with a large corm on or just below the ground surface and can be grown in the ground or in large containers. They can be grown in almost any temperate zone as long as the summer is warm.

Taro root contains very significant amount of dietary fibre and carbohydrates, as well as high levels of vitamin A, C, E, B6 and folate, as well as magnesium, iron, zinc, phosphorus, potassium, manganese and copper. Thogh negligible, the plant is also known to provide some protein in our diet. As Taro is a great source of fibre and other nutrients, it offers a variety of potential health benefits, including improved blood sugar management, gut and heart health.

Globally, taro is grown in an area of 1.6 m ha producing 11.66 mt with an average productivity of 7.25 t ha^-1 (FAO, 2009). The plant can be grown in wide range of climatic condition but during growth period taro is prone to attack by at least twenty- three (23) pathogens, of which, only a few causes serious reduction in the potential yield of the crop. Some of the mentionable diseases that commonly occurs and causes yield loss of the plants are as follows:

Introduction

Plant parasitic nematodes are important pests, causing major damage to the world’s food and fibre crops. The management of nematodes is more difficult than that of other pests because nematodes mostly inhabit the soil and usually attack the underground parts of the plants. Nematodes in soil are subject to infections by bacteria and fungi. This creates the possibility of using soil microorganisms to control plant-parasitic nematodes. Biocontrol of nematodes was first studied by Duddington (1951). The development of biological control agents is also considered an effective alternative for nematode control on vegetables (Van Gundy, 1985; Kerry, 1987). There are more than 200 species of nematophagous fungi described. Based on the infection mechanism, they are commonly subdivided into three main groups: the nematode-trapping fungi that captures free living nematodes using specialized morphological structures (i.e., traps), the endoparasitic fungi that infects nematodes using adhesive spores, and the egg- and cyst-parasitic fungi that infect these stages with their hyphal tips (Barron, 1977). The nematophagous fungi that have received most attention for biological control of plant-parasitic nematodes include various species of the nematode-trapping fungi Arthrobotrys spp. (Stirling and Smith, 1998), and the egg-parasitic fungi Pochonia chlamydosporium (Kerry, 2001) and Paecilomyces lilacinus (Gaspard et al., 1990).

ABSTRACT

Biotransformation is an essential step in the elimination of drugs and reduction of their toxicity. The use of fungi in biotransformation reactions can provide information about the metabolism of new drugs and facilitate the attainment of necessary amount of metabolites for toxicological and pharmacological evaluation. Biotransformation studies require the right choice of the microorganisms and also of the culture conditions (pH, substrate, oxygen, salts, temperature, etc). The optimization of these procedures is essential to achieve good results. The fundamental aspects of drug biotransformation by fungi are discussed here as well as some applications showing that many fungi are used in biotransformation studies, mainly Cunninghamella species. Several species mimic the mammalian metabolism producing the same metabolites observed in humans.

Plant pathogens are known to cause yield reduction of almost 20 per cent in the principal food and cash crops worldwide (Oorke et al., 1994). These losses may be more severe when highly susceptible cultivars are widely grown in a particular region of the globe. The increased world’s population is posing a major global challenge to provide sufficient quatity of food with high quality fruits and vegetables. Nearly, 570 million US $ is now spent annually on research and development by the leading 15 agricultural Companies to combat with the important diseases of major food, fruits and vegetable crops. There are more than 150 active ingredients registered as fungicides worldwide (Mc Dougal, 1996). In the present era of intensive agriculture, fungicides play an important role in our fight against plant diseases and reduce the losses in yield and quality of farm produce. The global fungicide sale has been estimated to be $ 6.0 billion US. The cereal and vine industries of the Western European have become largest fungicide market followed by North America. However, the fungicide use is not intensive in Asia and the new world.

This article presents the historical development of fungicides, mode of their action, development of resistance to fungicides, fungicidal residue and chemical control of various diseases of horticultural and plantation crops.

Fungus is member of group of eukaryotic organisms that includes yeasts and molds. The fungi are heterotrophs and they acquire their food by absorbing dissolved molecules by secreting digestive enzyme in the environment. It is present in common place in the environment and some are normal inhabitants of the skin, gastrointestinal tract and other mucous membrane surfaces. Generally if birds immunity is intact and fully operational then it will overcome the fungal infection in most situations, In case of compromised immune system it will cause development of serious infections. Paramount to properly managing fungal infections in avian species is the ability to recognize infection early in the course of disease, to administer appropriate antifungal medications for the location and severity of infection, and to continually assess a patient’s response to therapy.

Clinical Symptoms

• White/brown cotton-like foci on the surface of the skin and/or gills

• Peritonitis

• Extensive haemorrhage • Necrosis

• Adhesions

1. What is a characteristic feature of fungal cell walls?

a) Peptidoglycans

b) Ergosterol and polysaccharides

c) Antiphagocytic capsules

d) Fruiting bodies

2. How do fungi reproduce in tissues?

a) Binary fission

b) Budding

c) Simple division of round, yeast-like forms or slender, tubular hyphae

d) Spore formation

Summary

Nanotechnology is an interdisciplinary areas of science and technology which refers broadly to a field of applied science and technology whose unifying theme of control of matter is on the molecular scale that integrates material science and biology. Due to their advantages over non-biological systems, several research groups have explored the use of biological systems for the synthesis of nanoparticles. Among the different microbes used for the synthesis of nanoparticles, fungi are efficient candidates for fabrication of metal nanoparticles both intra-and extracellulary. The nanoparticles synthesized using fungi present good polydispersity, dimensions and stability. The potential applications of nanotechnology and nanoparticles in different fields have revolutionized the health care, textile and agricultural industries and  they are described in present chapter.

For growing fungi, a wide range of media are used. Media affect colony morphology and color. For utilizing different carbon sources some fungi lack the necessary enzymes. For growth and reproduction all fungi require several specific elements. The requirements for growth are generally less specific than for sporulation, so it is often necessary to try several types of media when attempting to identify a fungus in culture. Sporulating cultures should be used because repeated transfers of a pathogen on artificial media usually result in loss of sporulation or pathogenicity or both. Transfer should be made using spores and cultured alternately on nutrient rich and poor culture media. Most fungi thrive on potato dextrose agar (PDA), but in some fungi excessive mycelial growth is obtained at the expense of sporulation. Similarly, wood-inhabiting fungi and dematiaceous (dark pigmented) fungi often sporulate better on Corn meal agar (CMA) or Oat Agar, both of which have less easily digestible carbohydrate than PDA. Cellulose-destroying fungi grow on a weak medium such as Water Agar (WA) or Potato Carrot Agar (PCA). By adding pieces of tissue, such as filter paper, wheat straw, rice, grains, leaves or dung, often produces good sporulation dependent on the organism grown. Some special methods of inducing sporulation in fungi.

Fungi are achlorophyllus so they have to depend on other organisms hence heterotrophic nutrition. Depending on the nutrition, fungi are classified as Saprophytes, Parasites and Symbionts.

3.1 Saprophyte (sapros = rotten; phyton = plant)

Fungi which get their nutrition only from dead organic are called saprophytes ex: Saprolegnia, Rhizopus, Mucor, Alternaria etc.

3.1.1 Facultative saprophyte (Facultas = ability)

Ability of a fungus to become saprophyte. It is a parasite ex. Ustilago

3.1.2 Obligate saprophyte (obligate = to bind itself)

When they strictly get their food only from dead organic matter and can never become parasites are called obligate saprophyte ex. Mucor.

Introduction

Seed, the basic input of crop production technology, is exposed to various stress factors right from its formation to the completion of its germination. Even after germination, the stressed seeds may fail to emerge into a healthy plant and thus, the subsequent seed formation is also affected both quantitatively and qualitatively.

The stress factors may be abiotic, biotic or mesobiotic. Environmental factors such as climatic parameters, nutritional deficiencies, soil factors and conditions of storage are the examples of abiotic stress factors. Insects, fungi, bacteria, nematodes and other plant parasites constitute biotic stress factors whereas viruses, viroids and virusoids and similar agencies are the examples of mesobiotics factors that bring about stress over the seed. Apart from these conspicuous causes of stress, there are certain other factors also, which may affect the influence of stress over the total performance of the seed. For example, the crop improvement efforts bring about changes in seeds quality that can have considerable effects on the vulnerability of the seed to invasion by various biotic factors.

Introduction

Fermented foods and beverages comprise an indispensable part of the human diet. They can be generally defined as those foods and beverages produced via controlled microbial growth and conversion of various substrates using either enzymes or as whole cell itself, as shown in Figure 1.

9.1. Fungi useful against plant disease pathogen

9.1.1. Trichoderma viride

Trichoderma viride (Fig. 231) fungus is used as a bio-fungicide. It is used for seed and soil treatment for suppression of various diseases caused by fungal pathogens. It is also a pathogen in its own right,causing green mould rot of onion.

The fungicidal activity makes T. viride useful as a biological control agent against plant pathogenic fungi. It has been shown to provide protection against pathogens like Rhizoctonia, Pythium and Armillaria.

It is found naturally in soil and is effective as a seed dressing bioinoculant in the control of seed and soil-borne diseases including Rhizoctonia solani, Macrophomina phaseolina and Fusarium species. When it is applied to the seed, it colonizes the seed surface and kills not only the pathogens present on the cuticle, but also provides protection against soil-borne pathogens.

3.1. Plant diseases caused by soil borne fungi

3.1.1. Clubroot Disease causing fungi

Plasmodiophora brassicae (Fig. 125)

It infects Crucifers host species.

Infected plants in the begening shows pale green to yellowish leaves, which later on show wilting in the middle of hot, sunny days, and recovering during the night. Young plants may be killed by the disease soon after infection, whereas older plants may remain alive but become stunted and fail to produce marketable heads.

The most characteristic symptoms of the disease appear on the roots as spindle-like, spherical, knobby, or club-shaped swellings. The swellings may be few and isolated or they may coalesce and cover the entire root system. The older and usually the larger clubbed roots disintegrate before the end of the season because of invasion by bacteria and other fungi.

5.1 Ringworm (in Cattle) causing fungi

Trichophyton verrucosum

Ringworm is one of the commonest skin diseases in cattle. Ringworm is a transmissible skin infectious disease caused most often by Trichophyton verrucosum, a spore forming fungi. The spores can remain alive for years in a dry environment. Although unsightly, fungal infections cause little permanent damage or economic loss. Direct contact with infected animals is the most common method of spreading the infection.

The symptoms of Ringworm include Lesions with greywhite areas with an ash like surface usually circular in outline and slightly raised that appears on skin. Size of lesions vary and can become very extensive. In calves the infection is most commonly found around eyes, on ears and on back. In adult cattle infection on chest and legs are more common (Fig. 183)

7.1. Black Gill Disease (in Shrimps) causing fungi

Fusarium spp

The affected prawns show brown to black spots on the gills. In acute cases gills may completely become brown or black with atrophy and necrosis (Fig. 192).

7.2. Saprolegniasis disease causing fungi

Saprolegnia

Saprolegniasis is a fungal disease of fish and fish eggs, most commonly caused by the Saprolegnia species called “water molds.” They are common in fresh or brackish water. Saprolegnia can grow at temperatures ranging from 0° to 35°C but seem to prefer temperatures of 15° to 30°C. The disease fungus attack an existing injury on the fish and spread to healthy tissue. Poor water quality (for example, water with low circulation, low dissolved oxygen, or high ammonia) and high organic loads, including the presence of dead eggs, are often associated with Saprolegnia infections.

6.1. Aspergillosis disease causing fungi

Aspergillus fumigatus

Aspergillosis is a fungal infection that commonly causes respiratory disease in pet birds. It can infect both upper (nose, sinuses, eye, and trachea) and lower (lung and air sacs-a specialized part of the respiratory tract that birds have) respiratory organs or more broadly distributed systemic infections (Fig. 187).

The Symptoms includes Weight loss, Open-mouth breathing or gasping for breath, Tracheal movement or in-out-in movements in the region of the neck, Tail-bobbing or movement of the bird’s tail up and down while breathing in and out, heavy breathing after flight or exercise, Change in voice and persistent itching or rubbing of cerenares.

4.1. Aspergillosis disease causing fungi Aspergillus

Aspergillosis is usually caused by the fungus Aspergillus (Fig. 161) and usually occurs in people with lung diseases or weakened immune system

The different types of aspergillosis can cause different symptoms. The symptoms are similar to asthma symptoms, and include:

4.1.1. Allergic bronchopulmonary aspergillosis (ABPA)

The symptoms of ABPA includes Wheezing, Shortness of breath, Cough and Fever (in rare cases).

4.1.2. Allergic Aspergillus sinusitis

The symptoms of Alleric Aspergillus Sinusitis include stuffiness, Runny nose, Headache and Reduced ability to smell.

Abstract

Many airborne fungal spores are important as allergens, human and plant pathogens, in the bio-deterioration of stored materials like paper, leather, textile, paintings, historical monuments and spoilage of food stuffs. Surveys have been conducted to elucidate the magnitude of the problem. Indoor environment also plays an important role in the precipitation of allergic symptoms caused by fungal spores. The present review briefly highlights some of the qualitative investigations carried out on indoor environments like bakery, building, cold storage, cow shed, dormitory, educational institutions, garbage disposal plant, ware house, hospital, library, food grain godown, leather godown, house dust, poultry house, chick hatcheries, plastic industries and textile industries.

10.1. Phosphate Solubilisers

10.1.1. Aspergillus spp.

Several species of Aspergillus (Fig. 249) have been reported to be involved in the solubilization of inorganic phosphates such as A. flavus, A. fumigates, A. awamori. A. niger and A. terreus.

These fungi are able to solubilize inorganic phosphate through the production of acids viz. citric, gluconic, glycolic, oxalic acids and succinic acid.

Aspergillus fumigates isolated from compost has been reported to be potassium releasing fungus.

11.1. Pleurotus ostreatus

Researchers in Mexico have shown that oyster mushrooms can break down/ decompose disposable diapers

11.2. Chaetomium globsum

It is a saprophytic fungus that primarily resides on plants, soil, straw, and dung. They are found in habitats ranging from forest plants to mountain soils across various biomes. C. globosum colonies can also be found indoors and on wooden products

C. globosum assists in cellulose decomposition of plant cells.

12.1. Penicillium chrysogenum

Penicillium chrysogenum (Fig. 255) (previously known as Penicillium notatum), produces the antibiotic penicillin, known as WONDER DRUG.

The antibiotics produced from fungus Penicillium is listed in table.

8.1. Fungi useful in food processing

8.1.1. Aspergillus sojae and Aspergillus oryzae

Aspergillus sojae and Aspergillus oryzae (Fig. 198) is a mold species in the genus Aspergillus. Its use was originated in China in the 2nd century AD and spread throughout East Asia where it is used in cooking and as a condiment.

Uses

• It is used to prepare Soy sauce (also called soya sauce) a condiment made from a fermented paste of boiled soybeans, roasted grain and brine,
• In Japan it is used to make the ferment (K?ji) of soy sauce, the mirin and other lacto-fermented condiments like tsukemono. Soy sauce is a condiment produced by fermenting soybeans with Aspergillus sojae, along with water and salt.

a) Definition

Fungus is Latin word meaning ‘mushroom’

Alexopoulus and Mims 1979 defined fungus as eukaryotic, achlorophyllous organism generally produced by sexual or asexual method and whose filamentous branched somatic structure is typically covered by cell wall.

Eukaryotic, spore – producing, achlorophyllous organisms with absorptive nutrition that generally reproduce both sexually and asexually and whose thallus is usually filamentous, branched somatic structures known as hyphae, typically surrounded with cell wall.

Mycology – Study of fungi

The fungi can be divided into two groups namely

True fungi: Chytridiomycota, Zygomycota, Ascomycota, Basidiomycota

Additional phyla: Myxomycota, Dictyosteliomycota, Acrasiomycota, Plasmodiophoromycota, Oomycota, Labyrinthulomycota, Hypochitridomycoya.

1.1 Introduction

Fungi are chlorophyll-less thallophytic plant. Due to absence of chlorophyll, they are heterophytes which depend on other form of life for food. They grow in various habitats and show much diversity in their structure, physiology and reproduction. They evoloved long back from the ancient time.

Their existence was recorded from Pre-cambrian period. Information from ancient literature indicates that the fungi were used as food by men. At present, the fungi are used in medicine as well as food in addition to other aspects. The fungi cause diseases in crop plants (spots, rusts, smuts etc.) and on human beings (Aspergillosis, Blastomycosis etc.).

At present biologists use the term fungus (fungus mushroom, from Greek, sponagos = sponge) to include eukaryotic, spore bearing, achlorophyllous organism that generally reproduce sexually and asexually and whose usually filamentous, branched somatic structure are typically surrounded by cell wall containing chitin or cellulose or both of these substances, togather with many other complex molecules

More than 1.5 million species (Hawksworth 2001; Kirk et al., 2001) of fungi have been recorded, but their number may be much more than the actual record. The subject which deals with fungi is known as Mycology (mykes — mushroom; logos—study) and the concerned scientist is called mycologist. The various definitions of fungi as proposed by mycologists are:

Alexopoulos (1962) defined fungi as “nucleated, spore-bearing, achlorophyllous organisms which generally reproduce sexually and asexually and whose usually filamentous, branched somatic structures are typically surrounded by cell walls containing cellulose or chitin or both”.

Alexopoulos and Mims (1979) defined fungi as eukaryotic spore bearing, achlorophyllous organisms that generally reproduce sexually and asexually, and whose usually filamentous, branched somatic structures are typically surrounded by cell walls containing chitin or cellulose, or both of these substances, together with many other complex organic molecules.

Fungi are a diverse group of multicellular eukaryotic organisms with wide variation in vegetative and reproductive morphologies and diverse life cycles. They are more abundant, on a mass basis, in soils than any other group of microorganisms; their biomass ranges from 500 to 5000 wet kg ha^-1 (Metting, 1993). Fungi inhabit almost any niche containing organic substrates, so that they are active participants in ecosystems as -

• degraders of organic matter
• agents of disease as well as beneficial symbionts - lichen (algae and fungi), mycorrhizal association

Introduction

Plant pathogens can cause significant crop loss both pre- and post-harvest. Fungicides continue to plays an important role in controlling plant diseases caused by fungal pathogens. In the last 100 years, fungicides have evolved from a few simple inorganic compounds to multiple groups of organic compounds, from contact and multisite fungicides to systemic and site specific fungicides with curative properties have evolved. The introduction of new fungicides is an integral part of sustainable disease control in staple crops. The need for new and innovative fungicides is driven by resistance management, regulatory hurdles and changing farmer needs.

A same active ingredient are available in the market with different trade name and are the product of different companies. These may also differ in their formulation and hazard class (table 7), the knowledge of which is necessary in the plant disease management in view of their effect on the pathogen, ecosystem and environment.

Fungicides are chemical compounds or biological organisms used to kill or inhibit the growth of fungi and their spores. They are essential tools in agriculture and horticulture for protecting crops and plants from fungal diseases, which can cause significant yield losses and economic damage.

Fungistat: Some chemicals do not kill the fungal pathogens. But they simply arrest the growth of the fungus temporarily. These chemicals are called fungistat and the phenomenon of temporarily inhibiting the fungal growth is termed as fungistatis. Antisporulant Some other chemicals may inhibit the spore production without affecting the growth of vegetative hyphas and are called as ‘Antisporulant’. Eventhough, the antisporulant and fungistatic compounds do not kill the fungi, they are included under the broad term fungicide because by common usage, the fungicide has been defined as a chemical agent which has the ability to reduce or prevent the damage caused to plants and their products

1. Introduction

As dealt in earlier chapters, fruits and vegetables represent the most essential of horticultural component for acreage of production, yield, nutritional and nutraceutical values, of definite taste, texture, flavor and colour, involving defined health and medicinal benefits. Every year and over the course of every ten years, significant quantum of research data accumulates on the various facets of fruit and vegetable technologies, and also trends in production, processing and marketing, may also tend to change. At every stage, more thinking has gone to improve the technology, product quality and cost economics to suit wider markets, both domestic and foreign. It is a continuous endeavor to record newer and newer problems emerging and to set the strategies to solve them. Several relevant references, fitting to the various aspects representing the cross section of the fruit and vegetable technologies are dealt here, to conclude the subject and spell out the future.
Consumer demand for healthy convenience meals with ‘near fresh’ properties challenges researchers and industry to develop new or improved conservation procedures for processed products. Development of a dehydration process based on electromagnetic energy (EME) may bring about a major breakthrough with respect to retention of product quality and improved rehydration characteristics (Nijhuis et. al., 1996). Economic potential and current limitations of fruit and vegetable processing in India included improvements in preliminary treatment (harvesting, washing/cooling) precooling (including refrigerated transport/storage) and processing of juices and pulps. Establishment of a National Horticulture Board has aided to provide market information and so aid growers to get remunerative prices (Anon, 1993). The use of food irradiation as a quarantine method for treatment of food and agriculture commodities was organized by the joint Food and Agriculture Organization/International Atomic Energy Agency Division of Nuclear Techniques in Food and Agriculture, held in Kuala Lumpur, Malaysia, on 27-31 Aug., 1990. (FAO,1992). This has been experimented with various commodities, particularly for export trade of fruits like mango, as stipulated by the importing country like U.S.A.

Introduction
 
The future of functional foods is bright and there are several reasons for the growing interest in “functional” foods, such as awareness of personal health deterioration, led by busy lifestyles with poor choices of convenience foods and insufficient exercise; increased incidence of self-medication; increased level of information from health authorities and media on nutrition and the link between diet and health; scientific developments in nutrition research; and a crowded and competitive food market, characterized by pressurized margins. Now, the consumer is well aware of the relationship between diet and health. Consumers understand that the risk for chronic diseases such as heart disease, stroke, colon cancer, and type II diabetes is possibly preventable by modification in their diet pattern. This scientific progress in understanding the relationship of diet to disease, along with increasing health care costs and the consumer’s desire to initiate healthy eating and lifestyle habits, makes this a potentially fertile ground for the development of food products that meet these demands.

INTRODUCTION

Functional genomics is the science where genes are employed to determine their function. The gene expression is an approach to analyze the functional changes in the genes. The expression level for a gene across different experimental conditions are cumulatively called the gene expression profile and the expression levels for all the genes under an experimental condition are cumulatively called the sample expression profile. Different techniques for gene expression analysis have been used so far. cDNA-AFLP (Bachem et al., 1996), SAGE (Serial Analysis of Gene Expression) (Neto, Neto & Costa, 2012) and MPSS (Massive Parallel Signature Sequencing) (Brenner et al., 2000) are the techniques for expression analysis where the genomic or transcriptome sequence of the organism is not needed. Some advanced and largely used techniques are Microarrays (Schena et al., 1995) and Real-time PCR (Higuchi et al., 1993) where the previous knowledge of the sequence is required. These two techniques are most frequently used for gene expression analysis (Perez-Torres et al., 2009). DNA microarray technology has made it possible to simultaneously monitor the expression levels of thousands of genes during important biological processes and across collections of related samples (Jiang, Tang & Zhang, 2004).

In spite of the problems with dosage and viability of probiotic strains, a lot more work is required for industry standardization and safety issues. However, it is noted that probiotics have considerable potential against many pathogenic and other diseases. A wide range of clinical trials are still needed to standardize and optimize the conditions. Ongoing basic research will continue to identify and characterize existing strains of probiotics, identifying strain-specific outcomes, determine optimal doses needed for certain results and assess their stability through processing and digestion.

India is the second largest producer of vegetables in the world. Indian Council of Medical Research, New Delhi recommends intake of 125g leaf vegetables, 100g roots and 75g other vegetables/ day / adult for a balanced diet. Green leaf vegetables occupy an important place among the food crops as these provide adequate amounts of many vitamins and minerals for humans. Besides this, leaf vegetables are easy to grow and readily fit in any cropping system owing to its short duration. They are rich sources of carotene, ascorbic acid, riboflavin, folic acid and minerals like calcium, iron and phosphorus (Ramdasmurthy and Mohanram, 1984).
 
In nature, there are many greens of promising nutritive value, which can nourish the ever increasing human population. In spite of their nutritional importance, in India, leaf vegetable production is limited to kitchen gardens and market gardens due to various reasons. Although they can be raised comparatively at lower management costs even on poor marginal lands, they have remained underutilized due to lack of awareness and popularization of technologies for utilization.

7.1 Introduction

Artificial intelligence (AI) is the imitation of human intellect in machines designed to emulate human activities and cognitive functions. These machines are designed to accomplish tasks that normally require human intellect, such as learning, problem solving, perception, and decision-making (Zhang et al., 2022). Horticultural crops, including fruits, vegetables, nuts, and ornamental plants, are of paramount importance in global agriculture, as they contribute significantly to food security, economic prosperity, and environmental sustainability. Nevertheless, the cultivation of these crops poses numerous challenges for growers, such as fluctuating market demand, insufficient resources, unpredictable climate conditions, and the constant threat of pests and diseases (Nowak & Grant, 2018). In recent years, the agricultural sector has experienced a significant shift owing to advancements in Artificial Intelligence (AI) technologies (Liakos et al., 2018). AI has emerged as a powerful tool for the cultivation of horticultural crops, providing solutions for boosting productivity, sustainability, and efficiency (Shrivastava & Kumar, 2021). By utilizing AI, horticulturists can overcome the traditional challenges associated with crop management, resource allocation, and environmental sustainability, paving the way for a more resilient and productive agricultural sector (Garg et al., 2019). The integration of AI into horticultural crop production encompasses a diverse range of applications, including precision agriculture, crop monitoring and management, predictive analytics, automated harvesting, and genetic improvement (Golhani et al., 2018). These applications leverage machine learning algorithms, remote sensing technologies, and data analytics to analyze vast amounts of agricultural data ranging from soil composition and weather patterns to crop health and market trends (Araus& Cairns, 2014). Through intelligent data-driven insights, AI enables farmers to make informed decisions in real-time, optimize resource utilization, minimize waste, and maximize yields (Kamilaris et al., 2017). This technological convergence offers promising prospects for food production, enabling stakeholders to explore new avenues for growth, resilience, and sustainability in horticultural crop cultivation (Mohanty et al., 2016).