eChapters

Introduction

Crop discrimination is the process of using remote-sensing technologies to identify and characterize different types of crops based on their electromagnetic behavior at different wavelengths. Each crop has a unique spectral signature that reflects its response to the incident radiation. However, the spectral signature can also vary depending on the season, the angle of the sensor, crop’s features, illumination intensity, weather phenomenon, and topography among other external factors (Parida et al., 2023).

Introduction

Agriculture is a vital sector in the world economy, as it helps to reduce poverty and promote sustainable development, especially in developing countries. However, agriculture also faces challenges such as increasing productivity and reducing environmental impacts. Therefore, new technologies and methods are needed to improve agricultural practices. One of these methods is precision agriculture (PA), which is based on the principle of sustainable agriculture and healthy food production. PA is a science that uses high technology sensors and analysis tools to improve crop yields and support management decisions. PA is a new concept that aims to increase production, reduce labor time, and optimize the management of fertilizers and irrigation processes.

Introduction

Site-specific nutrient management (SSNM) is the dynamic, field-specific management of nutrients in a particular cropping season to optimize the supply and demand of nutrients according to their differences in cycling throughsoil–plantsystems(Sarkar etal.,2017).Thisnewmethodofnutrient recommendationsisprimarilybasedontheinitialnutrientstatus(INS)from thesoil andthecrop’sneedfornutrients toachieve thedesiredyield.

Introduction

To address the escalating food demands of the global population, a transformation in the agricultural sector is imperative (Velten et al., 2015; Lampridi et al., 2019). The current overdependence on finite resources is leading to their overexploitation, largely due to irresponsible usage (Velten et al., 2015; Lampridi et al., 2019). By adopting a site-specific approach, farmers can apply inputs only where they are necessary in the field (Velten et al., 2015; Lampridi et al., 2019). This method can enhance output, decrease labor costs, and mitigate the environmental damage caused by excessive input use (Velten et al., 2015; Lampridi et al., 2019).

Introduction

In order to cater to the nutritional needs of a rapidly growing population, it is imperative to increase food grain production on the same land while maintaining the soil’s productive capacity. This necessitates comprehensive research to establish a scientific foundation for enhancing and sustaining food production and soil productivity with minimal environmental impact (Rathore et al., 2010). Balanced nutrition extends beyond the application of nitrogen, phosphorous, and potassium in specific quantities through fertilizers. It entails ensuring that the soil contains the right proportions of available nutrients to meet the crop’s requirements for optimal yield (Rathore et al., 2010).

Introduction

Precision farming, also known as precision agriculture, prescription farming, and site-specific farming, is grounded on the principle of managing fields based on their heterogeneity (Nowak 2021). In the past, crop management decisions were made for the entire field, treating it as a homogenous unit, despite significant variations in soil characteristics, weed infestations, and plant growth within a field (Nowak 2021). Precision agriculture integrates modern technology with past experience to manage farming on a grid-by-grid basis (Nowak 2021).

Introduction

Nanotechnology is a scientific and technological field that manipulates matter at the nanoscale to create, design, characterize, and use structures, systems, and devices with novel properties (Sattler 2016). Nanoparticles are one of the most important products of nanotechnology, as they exhibit different features from their bulk counterparts due to their size and shape (Sabir et al., 2014). Nanoparticles have applications in various disciplines, such as materials science, medicine, agriculture, physics, and chemistry.

Introduction

Nanofertilizers are products of nanotechnology that are created or modified from conventional fertilizers, bulk fertilizer materials, or plant extracts. They use different methods such as chemical, physical, mechanical, or biological processes to produce nanosized particles that can enhance soil fertility, crop productivity, and quality (KhetiGaadi 2022). Nanofertilizers have a size range of 0.1–100 nm, which is similar to the size of plant cell wall (20 nm), making them easier to be absorbed by plants (Tiwari 2022).

Introduction

Nanopesticides are pesticides that use nanomaterials or nanotechnology to improve their effectiveness and safety in agriculture. Nanomaterials are materials that have at least one dimension between 1 and 200 nm. Nanomaterials have different properties than their bulk counterparts, such as higher surface area, reactivity, and mobility. Nanopesticides can be formulated in various ways, such as nanosized active ingredients, molecular active ingredient nanocarrier complexes, or active ingredients encapsulated or coated by nanomaterials (Deka et al., 2021; Xu et al., 2022).

Introduction

Crop models can be broadly classified into two categories: dynamic or process-based crop simulation models (CSMs), and reduced form statistical models. Since simulation models are based on various plant-related processes, they develop or alter in tandem with plant growth (Chetty 2009); as a result, they are inherently nonlinear (Olmstead 2009). To run, calibrate, and validate, they require a significant amount of date input. However, statistical models are helpful in situations where there is a lack of data because they describe the relationships between a subset of variables while keeping the others constant. (Chetty 2009).

• General considerations

 • Collection of blood

 • Storage

 • Examination of blood

 • Coagulation time

 • Bleeding time

 • Determination of movement of parasites under wet film

• Total erythrocyte count

 • Total leucocyte count

 • Differential leucocyte count

 • Hemoglobin

 • Erythrocyte sedimentation rate

• Hematocrit value

 • Mean corpuscular volume

 • Mean corpuscular hemoglobin

 • Mean corpuscular hemoglobin concentration

 • Erythrocyte fragility test

• General considerations

 • Blood glucose

• Total serum protein

 • Serum albumin

 • Serum globulin

 • Serum gamma globulin

 • Serum calcium

 • Serum inorganic phosphorus

 • Serum magnesium

 • Serum cholesterol

 • Serum creatinine

 • Serum urea

 • Serum chloride

 • Serum sodium

 • Serum potassium

 • Serum Glutamic Oxaloacetic Transaminase

 • Serum Glutamic Pyruvic Transaminase

 • Serum alkaline phosphatase

• General considerations

 • Indications

 • Limitations

 • Techniques of bone marrow examination

 • Cell types

 • Cellular composition of bone marrow

 • Morphology of the cells

 • Interpretation of bone marrow examination

• General considerations

 • Collection

 • Preservation

 • Examination

 • Physical examination

 • Chemical examination

 • Microscopic examination

 • Organized sediment

 • Unorganized sediment

 • Cultural examination

• General considerations

 • Collection of feces

 • Storage

 • Examination of feces

 • Gross examination

 • Microscopic examination

 • Examination of feces for flukes

 • Examination of feces for blood

 • Culture of feces for nematode larvae

 • Sporulation of coccidia.

• General considerations

 • Collection of milk sample

 • Storage

 • Examination of milk

 • Physical examination

 • Chemical examination

 • Cytological examination

 • Bacteriological examination

• General considerations

 • Examination of skin scrapings for mange

 • Examination of skin scrapings for fungi

 • Cultural examination

General Considerations

The skin scrapings are examined for the diagnosis of skin diseases, including parasitic, fungal and bacterial infections and infestations.

 

• General considerations

 • Collection of synovial fluid

• Examination of synoival fluid

 • Physical examination

 • Chemical examination

 • Cytological examination

 • Microbiological examination

 • Examination for immune complexes

 • Miscellaneous examination

 • Inflammatory conditions of joints

 • Non-infectious arthritis

 • Infectious arthritis

 • Immune complex mediated arthritis

• General considerations

 • Indications

 • Collection of cerebrospinal fluid

 • Sub-occipital puncture

 • Lumbar puncture

 • Examination

 • Physical examination

 • Chemical examination

 • Cytological examination

 • Microbiological examination

• General considerations

 • Volume

 • Colour

 • Reaction

 • Concentration of spermatozoa

 • Motility

 • Live and dead count

 • Microbiological examination

• General considerations

 • Direct examination

 • Culture methods

 • Some important tests used in identification of bacteria

 • Characteristics of some organisms

 • Gram positive cocci

 • Gram positive rods

 • Gram negative rods

 • Mycobacteria

 • Leptospira/spirochete

 • Rickettsia

 • Chlamydia

 • Mycoplasma

 • Fungi

 • Virus

 • Antibacterial sensitivity testing

• General considerations

 • Scope

 • Exfoliative cytopathology

 • Interventional cytopathology (Biopsy)

 • FNAC

 • Imprint cytopathology

 • Crush smear cytopathology

• General Consideration

 • Post-mortem examination of large animals

 • Post-mortem examination of poultry

 • Steps in post-mortem examination

 • Writing of post-mortem report

 • Collection, preservation and dispatch of specimens for laboratory

diagnosis

• General considerations

 • Scope

 • Microscopic examination techniques

 • Smear

 • Vital staining

• Routine histopathological techniques of sectioning

 • Collection of tissues

 • Fixation

 • Washing

 • Dehydration

 • Clearing

 • Impregnation

 • Casting of blocks

 • Trimming

 • Section cutting

• General considerations

 • Agglutination

 • Slide agglutination test

 • Tube agglutination test

 • Capillary tube agglutination test

 • Plate agglutination test

 • Hemagglutination test

 • Hemagglutination-inhibition test

 • Coagglutination test

• Allergic Tests

 • Single intradermal test

 • Tuberculin test

 • Johnin test

 • Double intradermal test

 • Comparative test

• Mallein test

 • Immunofluorescence Techniques

 • Direct method

• Indirect method

 • Immunoperoxidase Techniques

 • Detection of antigen

• General considerations

 • Cyanide poisoning

 • Nitrate poisoning

 • Nitrite poisoning

 • Oxalate poisoning

 • Strychnine poisoning

 • Arsenic poisoning

 • Lead poisoning

 • Thalium poisoning

 • Ergot poisoning

 • Carbon monoxide poisoning

 • Phenothiazine poisoning

 • Pesticide poisoning

• General considerations

 • Polyacrylamide gel electrophoresis (PAGE)

 • SDS-polyacrylamide gel electrophoresis (SDS PAGE)

• Nucleic acid hybridization

 • Radio labelled probes

 • Biotin labelled probes

 • DNA finger printing

 • Polymerase chain reaction (PCR)

 • Reverse transcriptase polymerase chain reaction (RT PCR)

• General considerations

 • First hand information and constitution of a team

 • Gathering the disease information from records and the owner

 • Animal data

 • Previous illness

 • Present disease

 • Proforma for animal examination report

 • Observation of team

• Logical clinical examination of animals

 • Disease investigation kit

• General considerations

 • Tuberculosis

 • Johne’s disease

 • Brucellosis

 • Infectious bovine rhinotracheitis

 • Campylobacteriosis

 • Tichomonosis

• General considerations

 • Steps in validation

 • Step1- Feasibility studies

 • Step 2- Assay development and standardization

 • Step 3- Determining assay performance characteristics

 • Step 4- Monitoring validity of assay performance

 • Step 5- Maintenance and enhancement of validation criteria

 • Measurement of uncertainity of a diagnostic test

• General considerations

 • Ethics for veterinary diagnostic laboratory personnel

 • Safety measures in the laboratory

 • Accidents

 • First aid

 • Acid burns

 • Alkali burns

 • Poisoning

 • Burns caused by heat

 • Injuries caused by broken glass

 • Contamination by infectious materials

 • Bodily damage by electric shock

 • Precautionary measures

• General considerations

 • Biosafety levels-1 and -2

 • Biosafety level-3

 • Biosafety level-4

General Considerations

Biosafety is a combination of laboratory practices, techniques, equipments and other facilities appropriate for the protection of hazards posed by infectious agents handled in the laboratory. There are guidelines for maintaining the biosafety in laboratory at various levels described as under:

• General considerations

 • Quality management principles

 • Objectives of 9001:2008

 1. Scope

 2. Normative reference

 3. Terms and definitions

 • Main clauses and sections of ISO 9001:2008

 4. Quality management system

 5. Management responsibility

 6. Resource management

 7. Product realization

 8. Measurement, analysis and Improvement

• General considerations

 • Purpose and goals of laboratory

 • Standards, guides and references

 • Accreditation for competence

 • Identification of scope

 • Test methods

 • Benefits of ISO17025 accreditation

 • Processing of application

• General considerations

 • Purpose

 • Scope

 • Five pillars of GLP

 • Good laboratory practice principles

• Test facility organization and personnel

 • Quality assurance programme

 • Facilities

 • Apparatus, materials and reagents

 • Test systems

 • Test and reference items

 • Standard operating procedures

 • Performance of the study

• Nutritional diseases

 • Viral diseases

 • Prion, Mycoplasmal, Rickettsial, Chlamydial, Spirochaetal and Bacterial

diseases

 • Fungal diseases

 • Parasitic diseases

 • Toxic conditions

 • Miscellaneous conditions

• Epidemiological definitions

 • List of tests for international trade

 • OIE listed diseases

 • Solutions and reagents

 • Age and body weight of animals

 • Rectal temperature of animals

 • Normal values of blood vascular system

 • Vaccination schedule

India is basically an agrarian economy where 57.8% of rural households are engaged in agriculture (Situation Assessment Survey of Agricultural Household, 2021). 48.9 per cent of the Indian work force is employed in the agricultural sector, (ILO, 2016). The estimated Indian population for the year 2050 is 1.7 billion which will raise our food demand to ∼400 million tonnes (Rao et al., 2018). In this context, Indian agricultural production system will have to take up the challenge to feed l7.5% of the global population with only 2.4% of land and 4% of the available water resources at its disposal.

Weeds are diverse plant species of the ecosystem which can survive adverse condition and reproduce quickly. The global compendium of plants has listed 28000 species as weeds. According to Holm et al (1977) about 8000 weeds species have been reported from agricultural fields in 124 countries and of these, 250 species are considered to be problematic. It is also to be noted that weeds from 12 families constitute 68% of the world’s worst weeds. Within these 12 families, weeds from poaceae, asteraceae and cyperaceae constitute 44% of the world’s worst weeds.

Weeds have specific characters which helps them to adapt to any stressful situation and successfully, compete with the crop. They have survival strategies which help them to overcome vagaries of nature like extreme cold, heat, drought, biotic stresses and soil abnormalities. Their most important characteristic is the ability to succeed in any adverse situation even in disturbed soils. The age old war between man and weeds makes it pertinent to understand the characteristics of weeds which make them better competitors in the field.

Weeds have been a problem to agriculture ever sine man started cultivation. Weed species by and large invade cropped areas and account for large economic losses to the farmer. Weeds are economically more important than insects, fungi or other pest organisms (Savary et al. 2000, 2006). Globally, weeds cause the highest potential loss to crop production (34%), with animal pests and pathogens being less important (losses of18% and 16% respectively). The loss in production due to weeds has been estimated as 5% in developed countries. It is around 10% in developing countries and 25% in least developed countries. (Oerke, 2006)

Deliberate use of natural enemies to control invasive pest in an ecosystem is known as biocontrol. To control invasive weed species, selective pathogens and weed seed predators are employed to reduce the population of the weed to non competitive numbers rather than total eradication of the weed species (Appleby, 2005) These can be insects, herbivorous fish, other animals, disease causing organisms or even competitive plants. This method is comparatively safer to the ecosystem, is cheaper and has long lasting impact. Difficulty in f inding host specific bio-agent with minimum adverse effect on other crop and the environment is a challenge.

Herbicides are chemical substances that are capable of either killing or injuring plants and so used for elimination of unwanted plants. In Latin, the term ‘herba' means plant and ‘caedere’ means to kill. There are many reasons for the increased use of chemicals for weed control. Shortage and high cost of agricultural labour prevent economic control of weeds by manual and mechanical means. Benefits offered by herbicides include efficient weed control, higher crop yield, better soil, water and energy conservation and higher income.

A large number of herbicides are currently available in the market hence selection of suitable herbicide needs judicious understanding of the product and the requirement. When large number of chemical options are available it can make the process of selection a bit confusing. So it is important to know the crops in which a herbicide can be used, the weeds it will control, the appropriate rate, adjuvants included in the formulation. The different uses of the chemical and the different situations for which it will be useful. In addition to these it is important to understand the mode of action of the herbicide and also the mechanism of action of the chemical.

Effectiveness of spray mixtures can be increased by addition of adjuvants. Weed Science Society of America (WSSA1994) have defined adjuvant as a material in a herbicide formulation or added to the spray tank to modify herbicidal activity or application characteristics. Adjuvants enhance activity of a herbicide in different ways viz., wetting, spreading, deposit building, emulsifying or deflocculating the active ingredient. In many cases cost of adjuvant will be less than that of active ingredient. In such cases it helps to reduce the cost of the final product.

Herbicides have received wide acceptance from farmers mainly due to ease of application and effectiveness. After application, herbicide molecules should penetrate plant tissue and get translocated to the target site. Once they reach the target protein they bind to them and disturb metabolic processes in plants by disrupting biosynthetic pathways and damaging cell structures by generating cytotoxic molecules that ultimately kill the plants. In this, the first step is penetration of herbicide into the plant system.

In a cropping systems there may be simultaneous or sequential application of herbicides, insecticides, fungicides, fertilizers, PGR during a single cropping season. The different chemicals will undergo physical and chemical changes as they interact with plant, soil and other chemical substances already applied to the plant or soil. The interaction effect of such chemical substances will be visible only at the later end of the cropping season. The responses observed in the plants can be.

Major advantage of chemical herbicides over other methods of weed control is its ease of application, which saves the cost of labour for the farmer. Effectiveness of herbicide depends on how long it remains in active form in the plant /soil. The form in which any herbicide is available in the market is known as herbicide formulation. The technical active ingredient (ai.) of the herbicide is converted to a formulations so as to improve easiness of handling, retention on leaf surface, absorption and movement in the plant. Herbicides are available in different formulations.

When a herbicide is applied to the soil, it is subjected to various interactions with soil and surrounding environment which ultimately determines its persistence. Dissipation of these compounds from soil system is by three main processes viz., physical (volatilization, leaching and runoff), chemical (photochemical decomposition, adsorption by organic and inorganic colloids and chemical decomposition) and biological (microbial decomposition and plant uptake) 

1. Physical Processes

a) Volatilisation