eChapters

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.

Aquarium hardscaping is the craft of arranging rocks, driftwood, and other structural elements to create a natural-looking and visually appealing underwater environment. This design process goes beyond aesthetics—it’s about crafting a balanced habitat that mimics nature and supports aquatic life. Aquarium plants and hardscape form the foundation of aquascaping. While plants add color, texture, and movement, they also play essential ecological roles by producing oxygen, absorbing nutrients, stabilizing water conditions, and offering shelter and breeding sites. Whether it’s low-growing carpets like
Hemianthus callitrichoides or tall background plants like Vallisneria, aquatic flora turns a simple tank into a dynamic ecosystem.
Hardscaping uses inanimate materials—rocks, driftwood, and decorative structures—to simulate riverbeds, forests, or mountain-like terrains. It shapes the aquascape’s layout, provides hiding spots, and defines territories, helping to reduce stress among fish.
A successful aquascape depends on harmony between plants and hardscape. Selections should be based on tank dimensions, lighting, water chemistry, and the needs of the species being kept. Materials must be safe, stable, and non-toxic. Knowing how plants grow—whether rooted or floating—and how they interact with their surroundings is vital to achieving a sustainable, beautiful aquarium.
IMPORTANCE OF AQUATIC PLANTS IN OXYGENATION
AND AESTHETICS
Aquatic plants are essential components of an aquarium, offering both ecological and visual benefits. Functionally, they improve water quality by producing oxygen and removing excess nutrients such as nitrates and carbon dioxide. Aesthetically, these plants create a more natural and appealing underwater environment, enhancing the overall visual experience of the aquarium.

2.1 INTRODUCTION

Several propagation structures are helpful in propagation of horticultural crops. These structures are helpful for seed germination, rooting of cuttings, layering, grafting etc. and other hardening operations. The structures which facilitate propagation of plants are called propagation structures. Propagation structures are required for propagating plants by seed, cuttings and grafting.2.2

GREENHOUSE

Greenhouse is a structure covered with glass or polythene for protection against adverse climatic conditions as well as to provide optimum environment for growth of the plants. Greenhouse has been used long back by horticulturists as a means of forcing rapid growth of plants and extending the growing season particularly in colder areas. Plants are grown or cuttings are rooted in a greenhouse when the atmospheric condition does not permit for raising them in outdoor conditions. Modern greenhouses are equipped with regulatory mechanisms for controlling temperature, light intensity, air, humidity etc. Plants in green house are grown in the ground bed or bench type raised beds. The size of the greenhouses and dimensions of beds vary according to the need of propagators. Glass covered greenhouses are expensive but they have long life. However, for short-term benefits, plastic covered greenhouses can also be made. Plastic covered greenhouses are lighter than glass covered ones but there is increase in humidity is such houses, especially in winters, which results in undesirable water drops on the plants. It can however be overcome by making adequate ventilation. Polyvinyl chloride (PVC) has also been used in construction of greenhouses but it tends to darken pre-maturely in sunlight. In India, construction of temporarily low-cost poly houses is in fashion for raising nursery of fruit plant in off-season. Such low-cost greenhouses are constructed either on wood or metal framework and are covered with polyethylene sheet of 0.10 to 0.15mm thickness, which is resistant to ultra-violet rays. These houses are equipped with thermostat, cooler or an air conditioner or humidifier etc for rigid control on temperature and humidity. Greenhouses made from fibre glass sheet are more durable than the polythene houses, but are quite expensive. In greenhouses, two types of beds are used for raising seedlings. In greenhouses, the beds may either be prepared on ground itself or raised beds or bench type beds are used. Greenhouse structures vary from elementary home constructed to elaborate commercial installations.

Role of Bioinputs explains how biological inputs contribute to soil health, plant performance, ecological interactions, and long-term agricultural sustainability. It introduces the conceptual framework and classification of bioinputs before examining their effects on soil microbial populations, enzyme activities, organic carbon, nutrient availability, soil structure, rhizosphere activity, and soil-fertility indicators. The chapter further explores plant–microbe interactions and plant–faunal relationships involving earthworms, beneficial nematodes, arthropods, microarthropods, protozoa, and the soil food web. By linking biological processes with physiological and agronomic outcomes, the chapter presents bioinputs as important components of resilient, ecologically balanced, and sustainable farming systems. across sustainable and natural farming systems.

Lighting and water quality are closely linked elements of aquarium maintenance that significantly affect both the well-being of aquatic organisms and the tank’s overall appearance. Proper lighting enhances visibility, influences fish behavior, supports plant growth through photosynthesis, and helps manage algae levels.
The choice of lighting should correspond to the specific type of aquarium—be it a simple freshwater setup, a densely planted tank, or a reef environment. Key factors to consider include light intensity, color temperature (in Kelvin), and the duration of daily exposure. LED lighting has become a favored option thanks to its energy efficiency, adjustable settings, and minimal heat production. Maintaining water quality involves regulating essential parameters such as temperature, pH, general and carbonate hardness (GH/KH), ammonia, nitrite, nitrate, and oxygen levels. Neglecting these can lead to fish stress and illness.
Routine care includes water changes, effective filtration, gravel cleaning, and regular testing.
Coordinating lighting and water conditions prevents issues like algae overgrowth, plant decline, and fish loss. A balanced, integrated strategy promotes a healthy and visually appealing aquatic environment.
TYPES OF LIGHTS: FLUORESCENT, LED, FULL-SPECTRUM
In its most basic role, aquarium lighting allows hobbyists to view the tank’s inhabitants. However, its more essential purpose is supplying necessary energy for photosynthetic plants and animals. As the main—often only—light source, appropriate lighting is crucial in aquariums containing organisms like corals, anemones, and aquatic plants. It also affects the behavior and physiology of fish, playing a significant role in maintaining the health and balance of the entire aquarium environment.

Proto – first; Zoon – animal

Protozoa are single celled eukaryotic organisms, which lack cell wall and ability to move at some stage of their life cycle.

They are referred as the first animals.

There are about 65000 described species grouped into 7 phyla. Among them, 50 per cent are not available as living forms (as fossils) and out of remaining 50%, 22,000 species are free-living and 10,000 species are parasitic forms.

The protozoa are distinguished from other organisms by following characters

Sterilization refers the complete removal or elimination of microorganisms from an environment. Physical and chemical agents are available to remove the microorganisms from the environment. Heat, irradiation and filtration are the three physical agents and various chemicals are available for sterilization.

Terms related to control of microorganisms

Cide or cidal means to kill the microorganism (Ex. Bactericidal refers the killing of bacteria).

Static or stasis means inactivation or inhibition, but not killing. They prevent multiplication of the organism. (Ex. Fungistatic refers the inhibition of growth of fungi.).

Sepsis refers break down of a living tissue by organisms and is accompanied by inflammation and pus formation.

Antispetic is an agent applied externally on living tissues to kill or inhibit the growth of the organisms.

Disinfectant is an agent applied externally on inanimate objects (not living tissues) to destroy harmful pathogens in their vegetative stage.

(Antiseptics are milder than disinfectants because to avoid the side effects)

Sanitation refers removal of organisms from a location by cleaning but not by sterilization.

Specialized aquariums are designed to meet particular environmental conditions or aesthetic preferences, presenting both distinct opportunities and challenges for aquarists. The three primary categories include planted tanks, biotope aquariums, and marine (saltwater) systems.
Planted tanks are densely populated with live aquatic plants and require precise management of lighting, CO? levels, nutrient-rich substrates, and fertilizers. These aquariums closely resemble natural freshwater environments and are especially favored in the aquascaping community. In addition to their beauty, they help improve water quality by producing oxygen and absorbing excess nutrients. Biotope aquariums aim to authentically recreate specific natural ecosystems like the Amazon basin, African Rift Valley lakes, or Southeast Asian freshwater streams. These tanks feature native fish, local plants, appropriate substrates, and water chemistry specific to the chosen habitat, making them ideal for education, conservation, and scientific observation.
Marine aquariums support saltwater life and involve more complex care. They require strict control of salinity, buffering capacity, and filtration using advanced systems such as protein skimmers. These setups may be dedicated to fish, coral reefs, or a mix of marine species. Though more expensive and demanding, marine tanks offer vibrant biodiversity and striking visual appeal. Each of these aquarium styles has unique care requirements, attracting hobbyists with different goals—whether artistic expression, ecological simulation, or marine biology.

INTRODUCTION
Tyres serve as the essential contact points between your vehicle and the ground. Without tyres, the power generated by the engine would be ineffective in producing movement. This power transfer is known as traction, and the effectiveness of a tyre’s interaction with the surface significantly influences how much of the engine’s power can be utilized. Traction becomes even more critical when operating heavy machinery, particularly for farm and field applications. Tractors, for instance, are built for rugged and demanding conditions, requiring more traction compared to regular tubeless car tyres.
A tyre consists of a torus, made of a complex, flexible, reinforced composite material that surrounds a steel hub and is filled with air under pressure. The tyre’s rolling tread usually features expanded ribs. The design and shape of the torus, as well as the construction materials, are chosen based on the specific application of the tyre. Generally, a tyre is characterized by its construction type, mounting details, ply rating, and other key dimensions, as illustrated in relevant diagrams .

The paper deals with the historical perspective of the tsunamis, much widely discussed Kumari Kandam and Lemuria continent and the palaeo-time series changes on the past continents and oceans, disastrous tsunamis since 16^th century and archeological evidences indicating shore line changes along Tamil Nadu coast.

Keywords: Ancient tsunamis in history, Kumari Kandam and Lemuria, Past shore line changes.

INTRODUCTION

A tsunami is a natural phenomenon consisting of a series of waves generated when water in a lake or the sea is rapidly displaced on a massive scale. Earthquakes, landslides, volcanic eruptions and large meteorite impacts all have the potential to generate a tsunami. The effects of a tsunami can range from unnoticeable phenomenon to large scale devastation.

The term “tsunami” is derived from the Japanese language meaning harbour (“tsu”) and wave (“nami”). The term was coined by fishermen who returned to port to find the area surrounding the harbour devastated, although they had not been aware of any wave on the high seas. A tsunami is not a sub-surface event in the deep ocean; it simply has a much smaller amplitude (wave heights) offshore, and a very long wavelength (often hundreds of kilometers long), which is why they generally pass unnoticed at sea, forming only a passing “hump” in the ocean.

Tsunamis were historically referred to as tidal waves because when they approach land they take on the characteristics of a violent onrushing tide rather than the sort of cresting waves that are formed by wind action upon the ocean (with which people are more familiar). However, since they are not actually related to tides the term is considered misleading and its usage is discouraged by oceanographers.

Genotype × environment interaction underlies the efforts of crop ecologists, agronomists, and plant breeders to define ecological regions, mega-environments, and ecotypes and to specify the adaptation and yield stability of individual cultivars. Multi-location testing or multiple year testing gives rise to an important term, genotype x environment interaction. “Interaction” is a statistical term signifying differential response of genotypes over the environments. The environments could be in terms of more numbers of diverse locations or years. Multi-location trials (MLTs) are also called as multiple environment trials (METs) and these have been adequately reviewed by Yan and Hunt (1998) and Kang et al. (2004). The following sections of this chapter derive extensive information on MLT/MET from these two sources.

Introduction

The genotype-environment-interaction (GEI) is a complex phenomenon that undermines the repeatability of experimental results and consequently reduces the selection efficiency. Agricultural researchers have long been concerned of the various implications of GEI in plant breeding programmes. Understanding of the implications of GEI structure/nature is important in crop breeding programmes as a significant GEI can seriously impair selection of superior genotypes in new crop introduction and cultivar/hybrid development programmes. Crop breeders of field and vegetable crops, etc. are in better position to decide whether crop cultivars should be developed for all the environments of interest or if the breeders should develop specific cultivars for specific target/mega environments. Variation among genotypes in phenotypic sensitivity to the environment may require the development of locally adapted varieties.

Genotype-by-environment is widely observed and reported issue. Large numbers of publications both on GEI and stability parameters are pointers to the facts that it is a complex and intriguing issue and these are expected to be more relevant in the light of the fact that greater emphasis is going to be placed on sustainability of agricultural systems.

Blood Cholesterol

(Colorimetric Method of Lieberman, 1885: Burchard 1889 Modified by Watson, 1960).

Introduction

According to Liebermann-Burchard reaction, treatment of chloesterol with acetic anhydride and concentrated sulphuric acid in a water-free environment, polymerized unsaturated hydrocarbon with an intense blue-green colour are produced. The values for cholesterol esters may be calculated by deducting free cholesterol from total cholesterol.

Introduction

Indian major carps viz. Catla catla, Labeo rohita and Cirrhinus mrigala are the fast growing, consumer preferred and the stay component species in Indian pond aquaculture system. These carps breed spontaneously in natural water viz. river and bundh type tanks where fluviatile condition prevails (Hora, 1945; David 1959; Quasim and Qayyam, 1962; Natarajan, 1971). Above three species under culture condition attain sexual maturity but do not spawn in confined water (Chaudhuri, 1960; Chaudhuri and Singh, 1984). Khan and Jhingran (1975) in their review described several factors viz. temperature, run off water, photoperiod, turbidity and water depth that are playing important roles in initiating natural spawning in ‘bundhs’ and rivers. They further described that no single factor can be considered responsible for spawning separately. The act spawning involves a chain of interrelated conditions as prerequisite to spawn. Monsoon, flood forms the spawning ground and initiates natural spawning. Although fish bred in its natural environment, it was difficult to understand why some species do not breed in confined water where as other species in the same environment breed somoto.

The initial attempt to induce breed IMC (mrigal) was made during 1937. Khan (1938) was able to induce ovulation in Cirrhinus mrigala by administration of mammalian pituitary extract but eggs were not fertilized. No remarkable success on induced breeding of Indian major carps was made till 1957. Indian major carps were induced to breed for the first time on 10th July, 1957 by the injection of aqueous carp pituitary extract at Govt. Fish Farm, Angul of Orissa state by the scientific team from pond culture substation, Cuttack (Chaudhuri and Alikunhi 1957). Eversince 1957, the induced breeding of carps have been tried by many permutation and combination, addition and alteration of inducing agents.

Introduction

Global diversity in domestic animals and aquatic organisms is considered to be under threat worldwide. Worldwide 11 % birds, 25 % mammals and 34 % of fish species are threatened (Lovell-Badge, 2001; Vemuganti and Balasubramanian, 2002) and aquatic ecosystem is becoming more vulnerable to disasters due to run off from agriculture and industrial sources, oil spills or sudden environmental changes leading to total elimination of stocks from different ecosystems. The multifarious human activities in open waters have threatened the fish diversity all round the world. Fish worldwide are in crisis. The effective population sizes in fish hatcheries are getting smaller and smaller that causes loss to farmers worldwide. The World Resources Institute has reported that nearly 70 percent of the world’s marine fish stocks are over fished or are being fished at their biological limit. Apart from fish, across all live stock species there is a shrinking pool of genetic diversity. For instance, the effective population size for all dairy cattle breeds is less than 60 animals. To preserve the gene pool of unique populations by protecting them from extinction, loss of genetic variability (inbreeding) and dilution due to inter breeding with unrelated populations (hybridization) gene banks or germplasm repository can play a vital role. Germplasm repositories in fisheries could be used for: 1) restoration of threatened species, 2) brood stock improvement through genetic modification of a targeted population, and 4) information and technology development including gene pool database management.

Abstract

The recent tsunami occurred on 26^thDecember 2004, caused great devastation along the east coast of Tamil Nadu, India. As the said tsunami has caused colossal damages, the impact assessment has become essential for tsunami mitigation measures. In this context, the extent of tsunami inundation, loss of lives, property loss and damages to physical and natural resources have been assessed in the tsunami affected area between Ennore and Mahabalipuram along the east coast of Tamil Nadu.

IRS LISS III PAN merged satellite data and IKONOS data were used for mapping the pre-tsunami geomorphology and land cover conditions and IRS-P6 PAN merged satellite data were used to map the post – tsunami terrain conditions including the inundations. From the study it is inferred that wherever buildings and population are denser the loss is more. Hence, vertical expansion may be needed as an alternative or to supplement horizontal expansion. Bio-shield along coastal areas, involving raising of mangrove forests, planting of casurina, salicornia, palms, bamboo and other tree species and halophytes which can grow near the sea will serve as speed-breakers for the up rising waves.

Keywords: Tsunami, Damage Assessment, Mitigation Measures, Chennai region.

Introduction
Using short, single-stranded oligonucleotide strands complementary to the targeted mRNA, as RNA technology can regulate gene expression, leading to changes in phenotype, disease resistance, and other traits associated with protein expression profiles. Since gene function depends on expression, this technology can be used to silence genes and inhibit their expression. Because it can manipulate and regulate protein expression during its translation, it can knock out or down the expression of a gene of interest. As such, functional genomics can benefit from this technology as it allows for the regulation of protein expression.
Gene expression involves two main steps: transcription, in which the DNA sequence serves as a template to create an mRNA molecule, and translation, in which the mRNA is used as a template to synthesize a protein. The genes in DNA provide the instructions for making proteins, which are essential for the functions of the cell.
Polymer chain that transforms into an effective protein. The triplet code, which forms the basis of the genetic code, designates an amino acid for each codon made up of three nucleotides. Several enzymes, including together, enzymes such as polymerase, exonuclease, ligase, etc., unravel the DNA double helix and match RNA base pairs with DNA bases to create an RNA copy of the original DNA.

The soil is a heterogeneous, polyphasic viz., solid, liquid and gaseous, particulate, disperse and porous system (Fig. 3.1). The solid phase constitutes the soil matrix, the liquid phase consists of soil water, which always contains dissolved substances so that it should properly be called as soil solution and the gaseous phase is the soil atmosphere.

Objectives

• Chi-square test for goodness of fit of genetic ratios.

Introduction

Karl Pearson developed the chi square test of statistical significance which is commonly used in Mendelian and population genetics. Chi square (χ²) test is a test of statistical significance which is used to test the significance difference between observed and expected frequencies or ratios. The purpose of χ² test is to decide if a set of observed data is according to an expected ratio or if it agrees well with an expected or theoretical distribution.

The chi square test of independence allow us to evaluate whether the segregation of alleles at one locus is independent of the segregation of alleles at another locus. To distinguish between inheritance patterns that obey Mendel’s laws versus those that do not, a conventional strategy is to make crosses and then quantitatively analyze the offspring’s. Based on the observed outcome, an experimenter may make a tentative hypothesis. For example, it may seem that the data are obeying Mendel’s laws. Hypothesis testing provides an objective, statistical method to evaluate whether the observed data really agree with the hypothesis.

The underlying principles behind a statistical approach is to evaluate the goodness of fit between the observed data and the data that are predicted from a hypothesis. This is sometimes called a null hypothesis because it assumes there is no real difference between the observed and expected values. A high deviation would be found between the observed and expected values. If this occurs, the hypothesis is rejected. Hopefully, the experimenter can subsequently propose an alternative hypothesis that has a better fit with the data.

The null hypothesis is a particular claim concerning how the data is distributed. More will be said about the construction of the null hypothesis later. The null and alternative hypotheses for each chi square test can be stated as

Introduction Agricultural extension plays a pivotal role in the advancement of agriculture in any nation. It encompasses the dissemination of knowledge, guidance, and assistance to farmers, rural communities, and various stakeholders involved in the agricultural domain. The primary objective of agricultural extension is to empower farmers to enhance their productivity, income, and overall quality of life. The concept of agricultural extension has undergone significant transformations across various countries, including India. This article will delve into the historical progression of agricultural extension both internationally and within the Indian context.

Introduction The world of agriculture stands at the crossroads of innovation and tradition, and at the heart of this dynamic sector lies the crucial role of farm journalism. In the backdrop of evolving technologies, shifting market dynamics, and the everpressing need for sustainability, farm journalism emerges as a vital conduit of information, education, and advocacy for farmers and rural communities. This chapter delves into the multifaceted realm of farm journalism, exploring its definition, scope, guiding principles, and its indispensable functions and roles in the sphere of rural development.