eChapters

Introduction

Banana (Musa sp; family: Musaceae) is the second most important fruit crop in India next to mango. Its year round availability, affordability, varietal range, taste, nutritive and medicinal value makes it the favorite fruit among all classes of people. It has also good export potential. Banana evolved in the humid tropical regions of South East Asia with India as one of its center of origin. Modern edible varieties have evolved from the two species – Musa acuminata and Musa balbisiana and their natural hybrids, originally found in the rain forests of S.E. Asia. During the seventh century AD its cultivation spread to Egypt and Africa. Banana and plantains are grown in about 120 countries. Total annual world production is estimated at 86 million tonnes of fruits. India leads the world in banana production with an annual output of about 14.2 million tonnes. Other leading producers are Brazil, Eucador, China, Phillipines, Indonesia, Costarica, Mexico, Thailand and Colombia. In India banana ranks first in production and third in area among fruit crops. It accounts for 13% of the total area and 33% of the production of fruits. Production is highest in Maharashtra (3924.1 thousand tones) followed by Tamil Nadu (3543.8 thousand tonnes). Within India, Maharashtra has the highest productivity of 65.70 metric tones /ha. against national average of 30.5 tonnes/ha. The other major banana producing states are Karnataka, Gujarat, Andhra Pradesh and Assam.

Introduction

A symposium organized by the Food and Agricultural Organization (FAO) in 1966 and International Organization of Biological Control (IOBC) in 1967, felt the need for the development of a new concept called “Integrated control” which was later replaced by “Integrated Pest Management”. The origin of IPM was necessary after the serious failure of the chemical age which started in the 1940’s. The pesticides were used as the only tactic to completely annihilate the pests from the crop ecosystem, which did miraculously decreased the pests and increased the production of the crop extensively, but they failed to realize the balance of life, by nature and by virtue of the selection pressure pests started developing resistance against all kind of pesticides being dumped on them.While the pests were getting resistant, the dumped pesticides were accumulating in the environment and biomagnifying inside the bodies of animal (WHO, 1990; Alewu & Nosiri, 2011; Eskenazi et al., 1999). The indiscriminate use of pesticides led to the significant health hazard to the humans (WHO, 1990; Alewu & Nosiri, 2011; Sanborn et al., 2007; Mnifet al; 2011; Semchuk et al., 1992; Goad et al., 2004; McKinlay et al., 2008; Gasnier et al., 2009; Lin et al., 2015; Waddell et al., 2001), reproductive malfunction in male (Jamal et al., 2015), nervous system (Jaga and Dharmani, 2003; Rosenstock et al., 1991; Wesseling et al., 2002; Eskenazi et al., 2006), cardiovascular system (Hung et al., 2015) and ultimately death (WHO, 1990; Gunnell et al., 2007). From the lessons acquired of the hazards, the concept of IPM proposed the concept of “pest eradication” was replaced with “pest management”. There are more than 64 definitions of IPM but the most accepted one came from FAO (1967) which defined IPM as “a system in context with associated environment and the population dynamics of pest species, utilizes all suitable techniques and methods in as compatible manner as possible and maintains the pest populations at level below those causing economic injury”. IPM decreased the pest pressure of the crop and increased the productivity of the crop and income of the farmers. IPM is a complex approach that advocates the integration of several components such as physical, mechanical, biological, legal, ecological and chemical tactics, in a compatible manner in a complete ecological set up, so that natural mortality has a role in checking the pest population building up above economic injury level (EIL).

Introduction

Litchi (Litchi chinensis Sonn), like most fruit tree crops, is usually attacked by two or three key pests, several secondary pests and a large number of occasional pests in localized areas where it is grown. Litchi is an important subtropical evergreen fruit crop belongs to family Sapindaceae. It is known as queen of the fruit due to its attractive deep pink/red colours and flavoured juicy aril (Singh et al., 2012).

Insect pest attacks on litchi, in China there are 193 species of litchi pests in two classes, 11 orders, and 57 families. In India, nearly 42 insects and mite species reported to attacking on trees and fruits of litchi at different stages of growth (Singh et al., 2012). The majority belong to the Lepidoptera and Coleoptera, followed by the Homoptera and Hemiptera. However, only about three or four key pests including fruit and flower borers, sucking bugs, stem borers and erinose mites which require regular control, and the species involved vary between orchards. Secondary pests viz., fruit-piercing moths, defoliators etc generally occur at sub-economic levels, but can become serious pests as a result of changes in cultural practices and litchi cultivars or because of indiscriminate use of insecticides against a key pest. Recently, litchi fruit borer and litchi leaf roller have acquired the status of major pests and now, litchi looper, litchi bug and bag worm are emerging pests of litchi (Choudhary et al., 2013; Singh et al., 2014). Occasional or incidental pests also can cause economic damage only in localized areas at certain times; the great majority of pests reported here fall within this last category.

Biointensive IPM incorporates ecological and economic factors into agricultural system design and decision making while addressing public concerns about environmental quality and food safety. It provides suitable guidelines and options for the effective management of pests and beneficial organisms in an ecological context in a holistic self-sustaining manner. The flexibility and environmental compatibility of the Biointensive IPM strategy make it useful in all types of cropping systems particularly in an agro-biodiversity rich ecosystem.

Introduction

Horticulture is the science and art of propagation, production, utilization, improvement, harvesting and marketing of crops such as fruits, vegetables, ornamental plants, spices & condiments, medicinal & aromatic plants, plantation crops, postharvest technology etc. The term is derived from the Latin word hortus mean garden and cultura means to cultivate. These crops are diverse which includes annuals to perennials, edible to ornamentals, temperate to tropical, humid to desert, etc. Horticultural plants help to sustain and enrich people by providing nutritious food, medicines, enhances the beauty of surroundings, besides reducing carbon footprint. They also serves as raw material for various industries, such as processing, pharmaceutical, perfumery and cosmetics, chemical, confectionery, oils and paints, etc.

Importance of Horticultural Crops

The horticulture crops are a source of variability in farm produce as well as human diets. The comparative production per unit area of horticultural crops is much higher than field crops. They are not only a source of nutrients, vitamins, minerals, flavour, aroma and dietary fibres, but also contains health benefiting compounds and medicines. Ornamental horticulture have aesthetic value and protects the environment. These crops are also useful for cultivation in wasteland, poor quality soil, slopy, uneven or undulating lands. Mango and cashew nut are cultivated on a large scale in hilly and hill back areas. Such crops are of high value, labour intensive and generate employment throughout the year. Further they have national and international demand and are a good source of foreign exchange.

10.1 Introduction

Biomass fuels are a potential source of renewable energy. One of the major barriers to their widespread use is that biomass has a lower energy content than traditional fossils fuels, which means that more fuel is required to get the same amount of energy. When combined — low energy content with low density -the volume of biomass handled increases enormously. Compaction or densification is one way to increase the energy density and overcome handling difficulties.

Densification means compaction of loose material or to increase density of loose biomass so that its volumetric efficiency can be increased. Densification essentially involves two parts; the compaction under pressure of loose material to reduce its volume and to agglomerate the material so that the product remains in the compressed state. The resulting solid may be a briquette, a pellet and a cube. It will be briquettes if roughly, it has a diameter greater than 30 mm. Smaller sizes are normally termed pellets though the distinction is arbitrary. The process of producing pellets is also different from the typical briquetting processes. The densified product can be developed in the cubical shapes as well.

If the material is compacted with low to moderate pressure (0.2-5 MPa), then the space between particles is reduced. Further, increasing the pressure will, at a certain stage particular to each material, collapse the cell walls of the cellulose constituent, thus approaching the physical, or dry mass and more, density of the material. The pressure required to achieve such high densities are typically 100 MPa plus. This process of compaction is entirely depending on to the pressure exerted on the material and its physical characteristics including its moisture content.

9.1 Introduction

The rapid growth of industrialization and population significantly affect on the demand of ethanol as an alternate fuel. Generally, conventional crops like sugarcane and corn become unable to meet the demand of bioethanol, due to their primary role in food and feed. Therefore, lignocellulosic biomass from agriculture waste is attractive precursor for bioethanol production. Biomass is renewable organic material, abundant and cost effective. Ethanol production from agriculture waste has been projected an economically attractive option for industrial sector. However, sugar and starch derived ethanol have a more theoretical yield as compared to lignocelluloses, theses sources are insufficient for bioethanol production. The major agricultural wastes including rice straw, corn straw, wheat straw and sugarcane bagasse etc. can subsequently used for ethanol production. Rice straw has a highest worldwide potential for bioethanol production (205 giga liter) followed by wheat straw (104 giga liter), corn straw (58.6 giga liter), and finally for sugarcane bagasse (51.3 giga liter)¹.

A bio fuels is environmentally friendly options for power generation. Most of the fossil fuels are biological in nature. These are plant forms that, typically, remove carbon dioxide from the atmosphere and give up the same amount when burnt. The bio fuels are therefore considered to be “CO₂ neutral”, not adding to the carbon dioxide level in the atmosphere. The type of bio fuel used will depend on a number of factor, chief amongst them being the available feedstock and the energy that can be used locally.

India import 70% of the oil it uses, and the country has been hard by the increasing price of oil, uncertainty and environmental hazards that are concerned with the consumption of fossil fuels. In this context, bio fuels constitute a suitable alternative source of energy for India. There are two examples of bio fuels are Ethanol and Bio diesel (Renewable Diesel)

Ethanol can be made from biomass material containing sugar, starches, or cellulose (starch and cellulose are complex from of sugar)

8.1 Introduction

Rising petroleum prices, increasing threat to the environment from exhaust emissions and global warming have generated an intense international interest in developing alternative non-petroleum fuels for engines. The use of vegetable oil in internal combustion engines is not a recent innovation. Rudolf Diesel (18581913), creator of the diesel cycle engines, used peanut vegetable oil to demonstrate its invention in Paris in 1900. In 1912, Diesel said, “The use of vegetable oils as engine fuel may seem negligible today. Nevertheless, such oils may become, in the passing years, as important as oil and coal tar presently.” Nowadays, it is known that oil is a finite resource and that its price tends to increase exponentially, as its reserves have being decreasing¹.

India ranks sixth in the world in total energy consumption and needs to accelerate the development of the sector to meet its growth aspirations. The country, though rich in coal and abundantly endowed with renewable energy in the form of solar, wind, hydro and bio-energy has very small hydrocarbon reserves (0.4 % of the world’s reserve). India, like many other developing countries, is a net importer of energy, more than 25 percent of primary energy needs being met through imports mainly in the form of crude oil and natural gas. The rising oil import bill has been the focus of serious concerns due to the pressure it has placed on scarce foreign exchange resources and is also largely responsible for energy supply shortages. The sub-optimal consumption of commercial energy adversely affects the productive sectors, which in turn hampers economic growth².

7.1 Introduction

Biomass gasification is age old technology originated in 1800 century for lighting and cooking purposes (Sansaniwal et al., 2017). Biomass typically contents biopolymers such as cellulose, hemicellulose and lignin in addition to the presence of average composition of C₆H₁₀O₅ which depends upon physical characteristics of biomass¹. Oxygen is required for combustion of every fuel. For complete combustion of biomass stoichiometric air to fuel ratio required varies from 6:1 to 6.5:1 with CO₂ and H₂O as end product.

Biomass gasification is an efficient and environmentally friendly way to produce energy². Gasification process is nothing but it is a conversion of solid fuel into gaseous fuel for wide applications. This whole process completed at elevated temperature range of 800-1300 ^oC with series of chemical reaction that is why it come under thermo chemical conversion³. Thermo chemical processes are most commonly employed for converting biomass into higher heating value fuels⁴. Major thermal conversion route is include direct combustion to provide heat, liquid fuel and other elements to generate process heat for thermal and electricity generation is summaries in Fig. 7.1.

6.1 Introduction

Torrefaction is a thermophilic process of biomass conversion into a solid, friable, homogenous coal-like material, which has better fuel characteristics than the original biomass. Torrefaction involves the heating of biomass material in the absence of air at 250 to 300°C temperature. Torrefaction produces high-grade hydrophobic nature solid biofuels from various streams of woody biomass or agro residues.Torrefied biomass has high energy density then the original biomass which make torrefied biomass as renewable alternate source for power generation in coal power plant. Torrefied biomass being hydrophobic in nature can be stored easily for longer duration with negligible biological degradation. At 250-300°C temperature volatilization has been taking place and around 30% mass of the biomass is reduced as compared to original untorrefied biomass with net energy loss of approximately around 10%.The end product is a predictable, homogeneous, hydrophobic, high value solid biofuel with far higher energy density and calorific value than the original biomass feedstock. During the torrefaction process a combustible gas is released, which can also utilised to provide heat to the process. The process diagram of torrefaction process is shown in Fig. 6.1.

5.1 Introduction

Today, energy distribution and environmental issues have developed into international threats. Demand for alternative fuels increases every day due to rapid population growth, rising living standards, and economical sustainability. With its massive population, India has become the fourth largest energy consumer country in the world after the United States, China, and Russia. Because most nations use fossil fuels to fulfill their energy demands, they create negative impacts on the environment including raising global temperatures, pollution, acid rain, and other effects. As such, the quest for alternative fuels derived from renewable resources has captured significant attention throughout the world¹. Biomass as a renewable energy sources is an important asset for achieving economic development is due to the availability of biomass at a low cost, a good conversion efficiency, the addition of jobs, and an increase in the biodiversity^2,3. Typically, biomass is composed of cellulose (40-50%), hemicelluloses (25-35%), and lignin (15-30%). Large amount of resources for biomass are available such as woody biomass, crop residues and their by-products, food processing waste, municipal solid waste, aquatic plant etc.

In the present context, pyrolysis process has been received a remarkable identity as a potential method for the conversion of any organic biomass into valuable energy rich products due to its simple in operation and also required a reasonable cost for conversion process. Pyrolysis is the thermal decomposition of any organic material at a specific temperature in absence of air/oxygen; the process ends with three resulting products, namely liquid (bio-oil), solid (biochar), and syngases⁴. Recently, biooil produced through pyrolysis process and further it up grading has been attracted a significant attention due to its major use as biofuel and as a precursor material for making chemicals⁵. The pyrolysis process also classified in three different types as per its operating conditions; slow, fast and flash pyrolysis.

4.1 Introduction

Biomass is referred to as an indirect source of solar energy and considered a source of stored chemical energy. Biomass is renewable organic material derived from plants and animals serving as sources of energy. Biomass produced from agricultural sector is big challenges for all over the world due to its improver disposal. Mitigating greenhouse gas emissions and ensuring adequate global food supplies represent two of the last decade’s mostdifficult challenges.Although global food production has benefitted from chemical fertilizers, environmental problems have emerged as a result of their use. Additionally, overuse of fertilizers can result in hardened soil, decreased soil fertility, polluted air and water, and the release of greenhouse gases. There is an urgent need to find an alternative to chemical fertilizers that, ideally, can be sourced in abundant amounts, promotes global food production, enhances CO₂ capture , and does not affect soil health or damage the environment¹. To sustain agricultural productivity, it is crucial to maintain adequate levels of organic matter in the soil to preserve its physical, chemical, and biological integrity. Biochar, a pyrogenic black carbon, may play an important role in improving soil health, resulting in higher crop yield and absorbing atmospheric carbon dioxide. Biochar is the most auspicious straw management measures and have highest carbon abatement and economic profit².

Biochar is produced by heating biomass at high temperatures (300 – 600 °C) in a closed reactor containing no to partial levels of air. Under these conditions, biomass undergoes thermo-chemical conversion into biochar. Because of its numerous potentials uses in agriculture, energy, and the environment, much attention has been given to biochar in both political and academic areas. Biochar can be used in a variety of applications such as energy production, agriculture, carbon sequestration, waste water treatment, and bio-refinery; additionally, biochar provides an alternative strategy for managing organic waste. These advantages have renewed the interest of agricultural researchers in producing biochar from bio-residues and using the product as a soil amendment.

3.1 Introduction

Nature has a provision for destroying and disposing off wastes and dead plants and animals. This decay or decomposition is carried out by tiny micro-organisms called bacteria. Making of farm-yard manure (FYM) and compost is also through decomposition of organic matter (OM). When a heap of vegetable or animal waste and weeds etc., die or decompose at the bottom of backwater or shallow lagoons, bubbles can be noticed rising to the surface of water. Sometimes these bubbles burn with dancing flame at dusk. This phenomenon has puzzled man for a long time. It was only during the past hundred years that Scientists unlocked this secret as the decomposition process. The gas thus produced was and is still called “Marsh Gas.” The technology of harnessing this gas under artificially created conditions is known as Biogas Technology.

2.1 Introduction

Biomass store solar energy in the chemical form and it is most precious and versatile resources on earth. Biomass, unlike fossil fuels, is a renewable energy resource that is available where the climatic conditions are favorable for plant growth and production¹. The term biomass is used for all organic materials which are combustible in nature, mainly plant and animal origin present in land and aquatic environments. Biomass is considered carbon neutral, because the amount of carbon it can release is equivalent to the amount it absorbed during its life time. There is no net increase of carbon to the environment in the long term when combusting the lignocellulosic materials. Therefore, we can say that biomass is a renewable source of energy and can play vital role in responding to concerns over the protection of the environment and the security of energy supply^2,3.

Biomass energy accounts for about 15% of the world’s primary energy consumption and about 38% of the primary energy consumption in developing countries⁴. Furthermore, biomass often accounts for more than 90% of the total rural energy supplies in developing countries⁵. It is the main source to meet out domestic energy in developing countries⁶. The efficient use of fuel wood is much more eco-friendly than the use of efficient and conventional fuels like kerosene and liquefy petroleum gas (LPG). LPG emits 15 times more CO₂ per kg than wood, and kerosene emits nearly 10 times as much. CO₂ is the prominent candidate for global. It is commonly assumed that biomass fuel cycles based on renewable in nature and greenhouse-gas (GHG) neutral because the combusted carbon in the form of CO₂ is soon taken up by re-growing vegetation⁷.

1.1 General

The term “biomass” generally refers to renewable organic matter generated by plants through photosynthesis. Materials having organic combustible matter is also referred under biomass.Biomass is an important fuel source in our overall energy scenario. Biomass is produced through chemical storage of solar energy in plants and other organic matter as a result of photosynthesis. During this process conversion of solar energy in sugar and starch, which are energy rich compounds takes place. The chemical reaction of photosynthesis can be written as:

6CO₂ + 6H₂O + sunlight → C₆H₁₂O₆ + 6O₂ + 636kcal

It indicates that the storage of 636 kcal is associated with the transfer of 72 gm carbon into organic matter. Biomass can be directly utilized as fuel or can be converted through different routes into useful forms of fuel. In fact, biomass is a source of five useful agents, which start with ‘F’ like food, fodder, fuel, fiber and fertilizer. Further, biomass has many advantages like.

(1) It is widely available

(2) Its technology for production and conversion is well understood.

(3) It is suitable for small or large applications

(4) Its production and utilisation requires only low light intensity and low temperature (5 to 35°C)

(5) It incorporates advantage of storage and transportation

(6) Comparatively, it is associated with low or negligible pollution.

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.

TROPICAL AND SUBTROPICAL FRUITS

2.1 Mango
 

Mango is considered to be an allopolyploid. The chromosome number is 2n =40. The polyembryonic seedlings of cv. Vellaikolumban, earlier reported to be 2n= 80 was later shown to be a diploid. In Canary Island, a putative tetraploid viz Gomera-1 has been identified.

Floral biology

Flower starts opening early in the morning from 4-7 a.m. and maximum flowers open between 9.30-10.30 a.m. and complete 11 a.m. Dehiscence of anthers takes place at 11.30 a.m. and it continues up to 3.45 p.m. The pollen grains are oval, or triangular or oblong. Stigma becomes receptive even 18 hours before flower opening. Mode of pollination is entomophily; nectar is present to attract the insects.

The flowering duration is usually of short i.e. 2 to 3 weeks. The mango inflorescence or panicle bears mainly two types of flowers - male and perfect. The number of flowers per panicle varies between 1000 to 6000 depending upon the variety and climatic factors. The percentage of perfect flowers varies between 0.74 per cent in Rumani, 16.41 to 55.7 per cent in Neelum and up to 69.8 per cent in Langra.

Horticultural crops include the fruit crops, vegetables, spices, plantation crops, medicinal plants, aromatic plants, commercial flower crops and ornamental plants.

Knowledge on the methods by which these reproduce is of primary importance from the standpoint of plant breeding. Besides, their annual or perennial nature also decides the methods of breeding to be adopted to get desired improvement.

Two divisions of methods of reproduction commonly recognized are:

1. Asexual i.e. vegetative parts of the plants are utilized to produce new individuals.

2. Sexual i.e. gametic fusion, the resultant zygote develops into seed which is utilized to produce new individual.

This group can be further placed in several sub divisions according to the mode of pollination. They are

a. Naturally self pollinated crop - (e.g. tomato, pepper, brinjal) wherein cross pollination occurs less than 4 % only.

b. Often cross pollinated crop- (e.g. chillies, bhendi) wherein though self pollination is more frequent, cross- pollination may occur so frequently that some methods of preventing cross pollination between varieties and strains of different genotypic constitution must be followed throughout the breeding programme.
Common breeding methods can be applied to the above two groups, however, the parents chosen for breeding under often cross pollinated crop need to be selfed for few generations to select desirable, homozygous lines.

An area with similar soil, climatic conditions and resource availability resulting in similar type of crops and cropping systems. Ex. Rice based cropping system, Ragi based cropping system, Wheat based cropping system, Cotton based cropping system etc.

Efficient cropping zone: An analysis of productivity efficiency of crop was made by Kanwar (1972) using relative yield index (RYI) and relative spread index (RSI).

A zone where both yield and spread indices are maximum that is above 90 per cent is called most efficient and in case of indices below 90 is the least efficient zone of a crop.

Agriculture is the most important sector in India in terms of the population dependent on it. Although agriculture now accounts for on 14 per cent of GDP, it is still main source of livelihood for the majority of the rural population. Rapid growth of agriculture is critical for development of rural economy and viable development of rural economy will leads to overall development of country. Diversification in agriculture is need of the hour, any cropping system comprising crops with varied maturity period, crop canopy and high yielding potential is need for an average farmer. Again cropping systems depending upon the soil type, total rainfall and arrival of monsoon in the region. Low cost technology is essential for reducing financial burden on farmers and to increase production on sustainable manner.

The crop production is affected by the plant type, climatic condition, soil type and management factors. The production of the plant might be increased by changing plant type and increasing the grain filling period under certain climatic condition where management and soil factors are not limited. There is a direct relationship between the plant type and crop yield because the orientation and number of leaves play an important role in carbon fixation (photosynthesis). Again any variety/cultivar will contribute 21-25 per cent to the total yield of any crop in general. In recent years due to development of photoinsensitive varieties and hybrids which are more fertilizer responsive and high yielding varieties lead to increase overall production in the country.

Plant ideotypes

Refers to plant type in which morphological and physiological characteristics are ideally suited to achieve high production potential and yield reliability. The concept of ideotype was given by Donald in 1968 and he illustrated that there should be minimum competition between the crops and crop must be competent to compete with weeds. Ideotype is defined as a biological model which is expected to perform or behave in a predictable manner within a defined environment. On the basis of environment, Donald and Hamblin (1976) identified two forms of ideotypes that is isolation ideotypes and competition ideotypes. Isolation ideotypes are suitable for mono/single cropping and competition ideotypes are suitable for mixed cultivation.

Crop diversification refers to the addition of new crops or cropping systems to agricultural production on a particular farm taking into account of the different returns from value-added crops with complementary marketing opportunities.

Major driving forces for crop diversification

Crop diversification provides better conditions for food security and enable farmers to grow surplus products for sale at market and thus obtain increased income to meet other needs related to household well being. Crop diversification enable farmers to gain access to national and international market with new products, food and medicinal plants. Diversification from the monoculture of traditional staples are important for nutritional benefits of farmers in developing countries and can support a country to become more self reliant in terms of food production. Diversification also manages price risk and compared to monoculture techniques. For diversification crops generally consists of more sustainable natural resources and again, diversified farms are usually more economically and ecologically resilient.

The stability of yield is an important characteristic to be considered when judging the value of a cropping systems when compared to others cropping systems. Here, we focus on multiple cropping and how this agroecological practice can be used to increase the sustainability of crop production. Strip, mixed and relay intercropping can be used to increase crop yields through resource partitioning and facilitation. In addition to achieving greater productivity, diversifying cropping systems through the use of strategic cropping systems will increase yield stability, reduce weeds, pests, disease and improve soil health. Several multiple cropping systems are already implemented in industrialized agricultural landscapes, including mixed intercropping with perennial grasses and legumes as forage and relay intercropping with winter wheat and red clover. Because multiple cropping systems will provide numerous benefits, researchers should be clear about their objectives and use appropriate methods so as not to draw spurious conclusions when studying multiple cropping systems. In order to advance the practice, experiments that test the effects of multiple cropping systems should use standardized methodology and researchers should report a set of common criteria to facilitate cross-study comparisons. Multiple cropping systems with two or more crops appears to be less common with annuals than perennials, which is likely due to differences in the mechanisms responsible for complementarity. One area where intercropping with annuals in industrialized agricultural landscapes has advanced is with cover crops, where private, public and governmental organizations have harmonized efforts to increase the adoption of cover crop mixtures.

When crops are grown in either intercropping or sequential cropping interaction between different component crops occurs which is essentially a response of one species to the environment as modified by the presence of another species is commonly referred to as interference or interaction.

The interaction are classified into three groups

1. Competitive interaction: One species may have greater ability to use the limiting factor and will gain at the expense of the other and this is called competitive interaction or when one or more growth factors are limiting, the species that is better equipped to use the limiting factor(s) will gain at the expense of the other and this is called competitive interaction.
2. Non competitive: If the crops are grown in association and the growth of either of the concerned species is not affected, such type of interaction is called non competitive interaction or if resources (growth factors) are present in adequate quantities, as a result of which, the growth of either of the concerned species is not affected, then it is non-competitive interaction or interference.
3. Complementary: If one species is able to help the other, it is known as complementary interaction or if the component species are able to exploit growth factors in different ways (temporal or spatial) or if one species is able to help the other in supply of factor (like legumes supplying part of N fixed by symbiosis to non-legumes), it is complementary interaction or interference and also referred to as Annidation.

Various types of cropping systems are practiced in a farm or region. They should be evaluated to find out their stability and relative advantages in yield. Again, comparisons may be made with reference to land use efficiency, biological potential and economics. Following are the important indices for assessment of competition and yield advantage:

1. Relative yield total (RYT): The oldest establishment measure of the yield advantage of crop mixtures is the Relative Yield Total. The RYT index was designed as a measure of the extent to which various crop components shared common resources, rather than as a direct measure of yield advantage.

Classifications of cropping systems

Depending on the resources and technology available, different types of cropping systems can be adopted on farms and which are as below.

Mono cropping /single cropping: Mono cropping refers to growing only one crop on a particular land year after year or practice of growing only one crop in a piece of land year after year. Example, growing only crops during kharif in rainfed areas and this is due to lack of irrigation facilities and crops depend on rainfall alone.

In sustainable agriculture the word sustain is derived from the Latin word sustinere (sus-from below and tinere-to hold), to keep in existence or maintain, implies long term support or performance. As it pertain to agriculture, sustainable describes farming system that are capable of maintaining their productivity and their usefulness in society indefinitely. Such system should be resource conserving, socially supporting, commercially competitive and environmentally sound. Systems approach is essential for understanding sustainability and it gives us tools to explore the interconnections between farming and other aspects of our environment and sustainability implies at the following,

1. Meeting the basic needs of all people and giving this priority over meeting the greeds of a few
2. Keeping population densities if possible below the carrying capacity of the region
3. Adjusting consumption patterns and the design and management of systems to permit the renewal of renewable resources
4. Conserving, recycling and establishing priorities for the use of non- renewable resources
5. Keeping environmental impact below the level required to allow the systems unaffected to recover and continue to evolve.

Various definitions have been provided for what constitutes sustainable agriculture ranging from the narrow focus on economics or production to the incorporation of culture and ecology. Wendell Berry has simply said A sustainable agriculture does not deplete soils or people.

Multiple cropping includes both inter and sequential cropping systems and here the main objective is to utilize the available resources effectively in a given environment. Number of indices are available for assessing land use and the yield advantage of crop mixtures compared to pure stands. These indices not only reflect the difference in criteria used to appraise advantages often encompassing aspects of quality or values as well as yield, but also reflects the different reasons for which an assessment is made.

1. Rotational intensity (RI): Crops are grown in a recurring sequence on the same piece of land with sufficient diversity and intensity. Crop rotations to control erosion/ to improve or maintain soil fertility and to manage weeds, insects and disease. Lower values of rotational intensity indicate mono cropping and higher values of rotational intensity indicates more rotation.

The main objective of any cropping system is to utilize available resources efficiently viz., land, water, solar radiation by maintaining stability in production in order to obtain higher net returns. The efficiency is measured by the quantity of produce obtained per unit resource used in a given time. The objective of traditional agriculture was to increase the production by two means

1. By increasing area under cultivation
2. By increasing the productivity per unit area of the crop

But two more dimensions are added to modern agriculture

1. To increase the production per unit time
2. To increase the production per unit space

In the traditional cropping systems, mixtures and rotations were developed by the farmers over years of experience by trial and error to suit specific ecological and sociological conditions to attain yield stability, whereas modern scientific cropping has three pillars viz.

A system is a unit which possess a group of interacting components, operating together for a common purpose, capable of reacting as a whole to external stimuli. It is unaffected directly by its own outputs and has a specified boundary based on the inclusion of all significant feedbacks. For example, the human body is a system-it has a boundary (skin) enclosing a number of components (heart, lungs) that interact (the heart pumps blood to the lungs) for a common purpose (to maintain and operating the living body).

Ecosystem: Any collection of organisms that interact or have the potential to interact along with the physical environment in which they live form an ecological system or ecosystem. Ecosystems are not static entities but, they are dynamic systems with characteristic pattern of energy flow, nutrient cycling and structural change.

Agro ecosystem: Agro ecosystems are ecological systems modified by human beings to produce food, fibre or other agricultural products. Like the ecological systems, agro ecosystems are structurally and dynamically complex. But their complexity arises from the interaction between socio economic and ecological processes.

Crop system: An arrangement of crop population that transform solar energy, nutrients, water and other inputs into useful biomass that produce food, feed, fuel and fibre. Crop system comprise of soils, crop, weed, pathogen and insect subsystems. The crop can be of different species and variety, but they only constitute one crop system if they are managed as a single unit.

Cropping systems: It is defined as the order in which the crops are cultivated on a piece of land over a fixed period of time. Cropping system is the way in which different crops are grown. In the cropping systems, sometimes a number of crops are grown together or they are grown separately at shorter intervals in the same field.

Growing more than one crop in sequence or simultaneously as a mixed crop is an ancient practice. In Indian Vedas, there is a mention about double cropping. In early periods, the objective to adopt sequential cropping practices was to reduce the risk of total crop failure due to uncertain monsoon and to have a variety of produce to meet food requirement of farmer’s family, fodder to animals and to meet his cash requirements. Other benefits of yield increase was due to complementary effects of the component crops in improving the soil fertility, spreading the labour requirement throughout over a period of time and to reduce damage caused by weeds, pests and diseases were only incidental.

Multiple cropping in simple terms refers to the practices that increase production in a unit area of land through two or more growing crops simultaneously. The importance of intensive cropping in sustainable agriculture has been well understood by the agricultural scientists of late and there has been surge of interest in the research community to explore these complex systems in detail and to see what can be learnt from the farmers in our quest to make cropping system more sustainable progress made in the past through intensive research carried by the various agricultural universities, ICAR, research institutes/ coordinated research projects and international research institutes such as IRRI, ICRISAT, IITA and CIMMYT, it has shown that and more efficient utilization of the natural resources is possible by suitably modifying the present cropping systems in the various regions of the world.

The present cropping intensity in India is 136 per cent. There is a great prospect for increasing the cropping intensity both in irrigated and rainfed areas. In many irrigated areas, cropping intensity can be increased to 200-300 per cent. There is good scope to increase cropping intensity to 180-200 per cent with proper policies and technology options in rainfed conditions also.

Agricultural extension is a term that has long been used to describe a non-formal educational system aimed at improving the livelihood of farmers. Extension education aims at three main types of behavioural changes in relation to knowledge (things known), attitudes (things felt) and skills (how to implement the things). This can be achieved through persuasion and motivation for the changes. The core activities in extension are education and training. Extension is now being regarded as a much wider task of integrating indigenous and new skills and techniques, derived from study or research, into an overall framework of discussion and cooperation between the people and the extension organisation. The extension worker is primarily engaged in the ‘selling’ of ideas to bring about changes in the knowledge, attitudes and skills of the individual. Functions of extension in a broader sense include

Economic analysis provides a rational basis for making decisions in allocating scarce resources among various options to achieve competing goals. If resources were not limiting, there would be no need for economic consideration.

PRINCIPLES OF ECONOMIC ANALYSIS

Optimization criteria

The additional return obtained from using one additional unit of an input should be considered to optimize net income from several possible production options. If option ‘x’ gives a higher return to land than other options, then additional units of land should be allocated to option ‘x’.

Agroforestry systems are more complex than the agricultural systems. The long-term nature of trials involving woody species and the varying objectives of agroforestry trials demand that adequate caution be exercised in their design. Several characteristics of the trees like slow growth, long term effects on their surroundings, long life, age of trees, the area over which the influence of trees extend, etc. complicate the issue of designing experiments for these systems. Agroforestry experiments are often established on marginal sites which include sloping lands, and sites with infertile and degraded soils. It is thus difficult to find homogeneous sites of such problem areas, especially sloping lands where plots along contour lines are long and linear. Germplasm of many agroforestry tree species are usually collected from different origins which lack uniformity. Therefore, experimental materials in an agroforestry experiment may not be of uniform quality.

There are several features of agroforestry systems that require some modification of the methods usually used in agricultural experiments. Important issues related to agroforestry experiments include

In agroforestry systems the various components like tree, crop and pasture exist in different proportions and orientations. It is difficult to find out which agroforestry system is the best suited for a given land situation. Similarly, it is to be decided which technologies are required for refinement and improvement of the existing agroforestry practices. But without sufficient knowledge of the existing system in a particular land situation, it is very difficult to set the research priorities for modification and development of this system.

Diagnosis and Design (D & D) is a systematic and objective methodology developed by International Centre for Research in Agroforestry (ICRAF) to initiate, monitor and evaluate agroforestry programmes. D & D is based on the philosophy that knowledge of the existing situation (diagnosis) is essential to plan and evaluate (design) meaningful and effective programmes in agroforestry research for development. The methodology plays a strategic role in all the phases of the agroforestry research process. D & D in agroforestry is unique and it has been specially developed for the following purposes.

Human societies over the ages have depleted natural resources in different ways and degraded their local environments. Indiscriminate cutting down of trees and accelerating the construction works lead to global warming and climate change. Climate scientists believe that human-induced deforestation is responsible for 18-25% of climate change. Accumulation of greenhouse gases in the lower atmosphere is the main cause of global climate change. The concentration of these gases in the earth’s atmosphere is increasing, mainly due to deforestation and the combustion of fossil fuels which release carbon dioxide.

The earth receives heat energy constantly from the sun through radiation. Some of the heat is absorbed and some is reflected. Carbon dioxide works like an invisible blanket that wraps around the earth and traps the heat inside, similar to the function of a greenhouse. A greenhouse is a structure that is used in colder climates to grow plants. Even when outside temperatures drop below freezing point, greenhouses are still warm enough inside to grow plants. Greenhouses are made of glass, which allows solar radiation to enter. The heat is trapped inside the greenhouse, allowing plants to grow all the year round. Increasing concentrations of carbon dioxide in the earth’s atmosphere insulate it like a greenhouse, leading to a gradual warming of the earth’s atmosphere. Carbon dioxide is the major greenhouse gas, but there are others as well, including methane and nitrous oxide.

India shares 17.4% of the world population, while its land is only 2.4% of the total geographical area of the world. Naturally, the pressure on the land is often beyond its carrying capacity. Therefore, the productive lands, especially the farmlands in India are in the constant process of various degrees of degradation and are fast turning into wastelands. At present, approximately 63.85 million hectare area of the land is lying as wastelands in India (NRSA, 2005). Out of these lands, about 50% lands are such non-forest lands, which can be made fertile again if treated properly. In the last 50 years India’s lush green village forests and woodlots have been deforested to the maximum. To restore this ecological imbalance by developing the degraded non-forest wastelands, Government of India had created the Department of Wasteland Development during July, 1992 under the Ministry of Rural Development, which has been subsequently reorganized and renamed Department of Land Resources, with a broader mandate.

National Wasteland Development Board was established in 1985 mainly to tackle the problem of degradation of lands, restoration of ecology and to meet the growing demands of fuelwood and fodder at the national level. The Board was reconstituted in August, 1992 and was made responsible for development of wastelands mainly in non- forest areas in totality by involving local people at every stage of development. It aims at creating a scenario where the Government acts as a facilitator and the people at the grass root level become the real executioner of the programme. The degradation of environment in the fragile Indian subtropical ecosystem is basically attributed to the following factors.

A watershed is a geohydrological unit or all the land and water area bounded by a divide which contributes runoff to a common point. Watershed is considered to be synonymous with ‘catchment basin’ and ‘drainage basin’. In watershed management approach, development is not only confined to agricultural lands but also covers the area, starting from the highest point of the land to the outlet of the natural stream. Watershed management becomes increasingly important as a way to improve livelihood of people while conserving and regenerating their natural resources.

Watershed management is the process of creating and implementing plans, programmes and projects to sustain and enhance watershed functions that affect the plant, animal and human communities within a watershed boundary. It implies the judicious use of all the resources i.e. land, water and vegetation in an area to prevent soil erosion, improve water availability and increase food, fodder, fuel and timber on sustained basis.

Ecology of a place is influenced by a number of biotic and abiotic factors. An agroecological zone is broadly homogeneous in climatic and edaphic factors, but not necessarily contiguous, where a specific crop exhibits roughly the same biological expression. On the other hand, the characteristics of an agroecological zone influence the crops and cropping patterns of the zone. Thus, there are considerable variations in the types and management practices of agroforestry systems being followed in different agroecological zones.

AGROFORESTRY FOR HUMID AND SUBHUMID TROPICS

Humid and subhumid tropical regions have much variation in biological, social and economical parameters. The characteristics of humid tropics include high mean annual rainfall of more than 1500 mm, dry season of less than four months in a year and mean annual temperature of more than 22oC. Rainfall usually exceeds the evapotranspiration. However, demographic pressure has caused excessive deforestation and overgrazing which developed soil related problems like low soil fertility, low organic matter, high acidity and high rainfall erosivity. The agroforestry practices designed for this region should aim for improved fallows, soil fertility improvement and conservation, food production, etc. Thus, the common agroforestry systems in this zone are taungya, homegardens, alley cropping, plantation-crop combination, windbreaks, silvipastoral systems and various intercropping systems. Shifting cultivation is a common practice in tropics which should be discouraged as it causes environmental degradation and ecological imbalance, soil erosion and soil nutrient loss.

Agroforestry is a land use system that involves two or more plant species at least one of which must be a woody perennial. When perennial woody and herbaceous components are grown together on the same piece of land their performance would largely depend on their ability to share various growth resources in a given environmental situation. Due to difference in growth pattern and resource requirement of the components in agroforestry situation, a close interactive relation is obvious. Thus, careful management practices for the components are required to establish a successful agroforestry system. The characteristics of the trees and crops, and their interactions, can be modified with good management practice in order to take advantage of the positive characteristics and minimize the effects of the negative ones. Effective and efficient agroforestry management may be divided into two groups - tree management and agricultural crop management.

Trees that provide materials for propagation are called mother trees. Selection of mother trees is important because the young trees will be expected to inherit the favourable characteristics from the mother tree, such as fast growth, upright or spreading shape of the tree crown, good flowering and fruiting, and tolerance of diseases or pests. There may be sexual propagation by seed or vegetative propagation by using other parts of the tree. The genetic make-up of the seeds differs due to recombination of the genes, resulting in seedling variation. Thus, all the seedlings may look like the mother tree in some respects, but no two seedlings are the same. In case of vegetative propagation through cutting, layering, grafting or budding, the genetic make-up of the young tree is exactly the same as that of the mother tree. Consequently, all new trees grown vegetatively from one mother tree have the same set of gene pairs and therefore the same characteristics; they form a so called clone. Differences between plants of a clone can only be caused by different growing conditions.

Farmers have been growing trees for different purposes for thousands of years. Tree species that are grown to provide more than one significant function are called multipurpose trees. These functions may be productive such as producing fuelwood, timber, fibre, fodder, food, medicine, etc. and/or protective such as soil conservation, shade, shelterbelt, microclimate amelioration, land sustainability, biodiversity preservation, etc. All trees are multipurpose; some, however, are more multipurpose than others. Tree species can be multipurpose in two ways.

1. A single tree can provide more than one function. For example, Gliricidia sepium is grown as living fences that provide fuel, fodder and green manure for agricultural crops - all at the same time.
2. Trees of the same species, when managed differently, can provide different functions. For example, Leucaena leucocephala is managed so that some trees will mainly yield wood while others mainly produce leaf fodder.

Farmers can grow multipurpose trees (MPT) in various combinations with other crops, as in agroforestry, in block plantations of trees or in naturally regenerating tree farms. In certain cases, multipurpose trees are grown and managed for only one purpose. For example, Gliricida sepium is grown only to provide shade in coffee plantations. The same species may be planted in some other places and is managed differently for a very different use.

Agroforestry systems are not simply systems where trees and crops or animals give useful products to the farmers, rather systems where trees and crops and/or animals interact. Interaction literally means influence or mutual or reciprocal action. So component interaction refers to the influence of one component of a system on the performance of other component as well as the system as a whole.

In agroforestry systems, trees are grown in close proximity to crops and pasture. Their performance would largely depend on their ability to share various growth resources in a given environmental situation. Various interactions take place between the woody trees and herbaceous plants (crops or pastures) which is referred to as tree-crop interface. These interactions take place through the media of soil and microclimate and may exert favourable or adverse effects on the crop. Study of interaction helps to know how the components of agroforestry utilize and share the resources of the environment, and how the growth and development of any of the components will influence the others. Interaction occurs both above and below the ground and includes a complex set of interactions relating to radiation exchange, the water balance, nutrient budget and cycling, shelter and other microclimatic modifications.

The success of an agroforestry system relies heavily on exploitation of the component interactions. In an ideal relationship, production of trees as well as crops or grasses in combination could be comparable to their sole performance. Agroforestry could be even more advantageous if the production of associated components is increased due to influence of trees. This is possible because trees are capable of improving productivity of soil in many ways. A large number of trees are known to fix nitrogen symbiotically. Nevertheless, instances of crop inhibition in association of trees are not uncommon. Such inhibitions are primarily caused by shade effect as well as competition for belowground resources such as nutrients and water. In some cases inhibitory effect may also result from allelochemicals secreted by some of the tree species.

Management approaches to soil, including problems of soil degradation and low soil fertility, have recently undergone major changes. The earlier concept was to concentrate on achieving high levels of production from the more fertile areas, leaving the marginal lands for extensive use only. Steeply sloping and highly drought-prone areas were mostly left without any cultivation as production from these areas was hardly cost effective. Soil constraints were to be overcome by inputs like improved crop varieties, fertilizers, chemical control of pests and diseases, and the use of irrigation.

The approach of use of newly developed high yielding crop varieties, improved agronomic management practices, use of chemical fertilizers, efficient water management and timely plant protection measures has been successful in achieving large increases in crop productivity in recent years. On the other hand, continuous application of fertilizers at higher rates leads to environmental problems. Yield responses to fertilizers have declined because of soil physical degradation and micronutrient deficiencies. Above all, large numbers of poor farmers simply can neither afford high levels of fertilizers and other purchased inputs, nor do they have the capital to take on the risk involved in their use. Increasing the area under irrigation has also run into severe constraints in the form of limits to available freshwater resources.

The word 'social forestry' was coined by Westoby and used in the ninth Commonwealth Forestry Conference at New Delhi in 1968. In India the term was first used by the National Commission on Agriculture, Government of India in 1976, to denote tree raising programmes to supply firewood, small timber and minor forest products to rural population. Prasad (1985) defined social forestry as forestry outside the conventional forests which primarily aims at providing continuous flow of goods and services for the benefit of people. This implies that the production of forest goods for fulfilling the needs of the local people is social forestry. Thus, conceptually it deals with the people to produce goods such as fuel, fodder, small timber, etc. to meet the needs of local community particularly the underprivileged section (Shah, 1988).

The words ‘system’, ‘sub-system’ and ‘practice’ are commonly used in agroforestry literature. In a broad sense, a system is defined as a group of associated elements forming a unified whole and working together in a well defined regular relation for a common goal. An agroforestry system refers to a type of agroforestry land-use that extends over a locality to the extent of forming a land utilization type of the locality. Sub-system and practice are lower-order terms in the hierarchy with lesser magnitudes of role, content and complexity. However, these terms are used loosely, and almost synonymously.

Classification of agroforestry systems is necessary in order to understand and provide a practical framework for evaluating systems and developing action plans for their improvement. Any classification scheme should satisfy the following criteria (Nair, 2008).

Agroforestry is a new name for a set of old practices. The general concept of agroforestry is to integrate trees and agriculture so as to create a more diversified landscape, while providing the producers with new environmental and economic benefits. In other words, agroforestry is a method of farming that allows trees and shrubs to grow along with crops and/or livestock, therefore blending agriculture and forestry in the same production system. In fact, man's association with forest is much older than with agriculture. First man was a food gatherer and hunter in forests. Then he realized that the seeds of the fruits he collected germinated, grew into plants and bore the fruits again and thus man started to cultivate foods. Man's desire to live in a community created settled agriculture.

The pressure on the agricultural lands has increased manifolds due to the increasing population, expansion of urban area and the industrialization process. The environment has also been disturbed. Soil is losing its productivity and the biodiversity is threatened. Farming community is trying all means to increase the land productivity. Chemical fertilizers and pesticides are applied in higher proportion, causing environmental pollution hazards. Under all these circumstances agroforestry has shown that besides sustainable agriculture it can also help promote a better environment. Trees have always played an important role in mankind's survival. This relatively young science known as agroforestry was brought from the realm of indigenous knowledge into the forefront of agricultural research three and half decades ago and was promoted widely as a sustainability-enhancing practice that combines the best attributes of forestry and agriculture.

Abstract

Anaerobic microorganisms occur in oxygen-free environments as they possess biomolecules and metabolic processes that have adapted to sustain them in the stressed environments. These biomolecules and metabolic processes are harnessed and employed in various biotechnological applications. Anaerobes are abundant in various ecological niches such as freshwater or marine sediments, subsurface aquifers, deep thermal vents etc. where, in the absence or limitation of oxygen, they utilise reduced ions such as nitrate, sulphate, ferric, carbonate and certain organic compounds like degrading organic matter, fatty acids or alcohols as electron acceptors during respiration/fermentation to produce more or fewer reduced products such as, alcohols, ammonia, organic acids, hydrogen and carbon dioxide as the oxidised product. Diversity of substrates that can be fermented and the wide range of products that can be formed make anaerobic processes useful in biotechnological applications. Their substrate versatility and flexibility, for example, they can utilize simple sugars as well as many of them can utilise complex renewable biomass make their biotechnological applications sustainable and environment friendly. Anaerobes have been employed in food, chemical and material industries for the production of food items, preservative, additives, chemical intermediates, solvents, catalysts and polymers. They find widespread usage in energy sector for generation of various kinds of biofuels that can mitigate our reliance on non-renewable sources for fuel production. An emerging aspect of anaerobic biotechnology is waste valorization that involves treatment of any kind of waste (industrial, municipal, agricultural, pharmaceutical), where organic fraction of the waste is converted into valuable products. Anaerobes play key role in maintaining the global cycles of carbon, nitrogen, and sulfur, and also facilitate bioremediation by breakdown of persistent compounds. Lately, role of anaerobes in medicine and health care sector is widely explored as they are found to produce several bacteriocins, antibiotics, immunomodulators, vitamins and anti-tumor compounds. Some of the anaerobes have also been employed as probiotics. In the present chapter, we discussed these and many more biotechnological applications of anaerobes in white, green, red and blue biotechnology.

Abstract

Hundreds of bacterial taxa makes up human gut microbiota and it is comprised primarily of anaerobes belonging to four main phyla which are Firmicutes, Bacteriodetes, Actinobacteria, and Proteobacteria. Anaerobes colonizes the human body, including oral cavity, small intestine, vagina, skin but the majority of them are housed in the colon. The composition and distribution anaerobes varies along the length of gastrointestinal tract because of variation in oxygen gradient, anatomy of intestinal tract and other host physiological factors. Human gets colonized by anaerobes during the birth and these initial colonizers have impact on infant’s health status. The colonization and development of the gut microbiome is responsive to variety of factors including the mode of delivery, feeding methods, environment etc. The human gut microbiota plays an important role in healthy status of host. It plays an important role in nutrient metabolism and absorption, synthesis of vitamins and production of short-chain fatty acids (SCFAs). In turn these metabolites have positive effect on host immunity and overall host fitness. Studying, the anaerobes using culturing method remains critical in microbiology. However, culturomics approach, combined with sequencing technology, provides new insights in studying anaerobes of human gut microbiota. In this chapter we have discussed that, how human gut is an ideal habitat for the colonization and growth of anaerobes and their impact on host health. We also tried to shed light on latest technical advancement in sequencing culturing technology and their application in studying gut anaerobes.

Abstract

Gastrointestinal tract (GIT) harbors mixed microbial community, these are highly diversified, as revealed by molecular and phylogenetic studies. It is also estimated that microbiota of the GIT is composed of over 35,000 species and play a crucial role in human health and diseases. Thus are now of great interest to both the industrial and scientific communities. The microbes exhibit health benefits are known as probiotics. Anaerobic bacteria dominate in the GIT environment and genera like Bifidobacterium, Clostridium, are strict anaerobes while Lactobacillus, Lactococcus, is facultative anaerobes implicated in the probiotic effects.

For developing anaerobic bacterial based bio-products, it is necessary to cultivate large-scale biomass production that could be done using a modern manufacturing practice. Information on detailed understanding of the perfect growth medium and other bioprocessing parameters for the growth and viability is must. Also high cell viability is a prerequisite during downstream processing and storage of probiotic formulation. In this work we review the latest information about the history, mechanism of action, benefits of probiotic, selection criteria, sources of anaerobic probiotic bacteria, industrial cultivation medium along with biomass production, downstream processing.