eChapters

Introduction

Date palm (Phoenix dactylifera L.) is a monocotyledonous and dieocious species belonging to the family Palmae. The Latin name of the date palm, Phoenix dactylifera, is derived from the Phoenician name “Phoenix,” which means date palm, and dactylifera is derived from the Greek word “daktulos,” which means a finger. In India, generally, two species of Phoenix are found, of which, Phoenix sylvestris Roxb. called “desi khajoor,” is found throughout the country but t produces inferior quality fruits. The fruit contains large stones with less pulp content.

Date palm is considered one of the world’s oldest cultivated fruit trees. Archeological evidence suggests that the date palm was domesticated some 6000 years ago in the Mesopotamian region. It is widely cultivated in arid regions of the Middle East and North Africa. It is also one of the most appropriate fruit trees, and it can be easily grown under saline soil and water conditions. It grows well in poor, arid soils due to its hardy plant characteristics and deep root system. Date palm is believed to be indigenous to countries around the Persian Gulf. In the Indus Valley, date palm is believed to have been introduced by the soldiers of Alexander the Great in the fourth century B.C. and during the Muslim invasions at the beginning of the eight century AD. Date palm was commercially cultivated in Iraq, Saudi Arabia, Algeria, Iran, Egypt, Morocco, Tunisia, Pakistan, and Sudan, among many other Near East and North African countries. In India, dates are grown in the states of Gujarat, Rajasthan, Punjab, Haryana, and Tamil Nadu (Table 1).

Background

Water is the most precious input for dryland horticulture, and therefore, its use should be planned judiciously. Rainwater harvesting and its management play a significant role in horticultural production. The rainwater can be diverted either directly to tree basins in situ or in suitable structures ex situ, which can later be utilized as lifesaving irrigation. In sandy soils, in situ conservation should be popularized, while in heavier soils, ex-situ conservation should be popularized. The water thus collected remains stored deep into the soil profile, escapes from evaporative losses, and is available during critical periods of demand. Perennial fruit trees, once established, get the advantage of any time it rains during the year, unlike annual crops. Water harvesting in khadins in parts of the Jaisalmer district of Rajasthan and its use in raising crops and trees is the age-old practice of in situ water harvesting. The hilly, rocky, and sloppy lands generate runoff, which can be collected in ponds or tanks and recycled for the establishment of fruit plantations and lifesaving irrigation at critical stages. In the same stance, nutrient management also plays an important role in the successful cultivation of horticultural crops under dryland. The arid zone soils are very poor in the majority of nutrients except potash. Enrichment of soil with organic and inorganic sources is essential for optimum production of fruits and vegetables. The application of chemical fertilizers has made miracles initially in agriculture and horticulture. However, increasing awareness of environmental degradation due to various anthropogenic activities has been expressed worldwide about the over-reliance on mineral fertilizers, which causes environmental penalties. It has also led to a deficiency of several micronutrients. Therefore, the option left is whether to revert back to traditional farming using organic input or to follow some middle path by integrating both organic and inorganic. So far as present knowledge is concerned, organic manuring alone cannot maintain the required productivity and demand for food.

The Indian arid zone is one of the largest subtropical deserts in the world, of which 20% is arid and the rest is semi-arid. A hot arid zone is spread over 31.7 million ha and confined to Rajasthan, Gujarat, Andhra Pradesh, Punjab, and Haryana. The major part of the hot arid region of the country lies in western Rajasthan (19.62 million ha), followed by north-western Gujarat (2.16 million ha). It is characterized by a high aridity index, extremes of temperature, low and variable precipitation, very high wind velocity and dust storms, high soil pH, a high infiltration rate, and minimal availability of groundwater and saline ground irrigation water. Under such harsh climatic conditions, cultivating vegetable crops in open conditions results in meager and poor-quality yield, which fetches less return per unit area. By creating a suitable microclimate for plant growth throughout the year, vegetables can be cultivated under adverse climatic conditions. It is possible through protected cultivation, which has tremendous scope in peri-urban areas of the country. It is the best way to increase the productivity and quality of vegetables, especially cucurbits. India is the world’s second-largest producer of vegetables, next only to China.

Introduction

The ill effects of chemicals used in agriculture have changed the mindset of consumers in different countries, who are now buying organic products with a high premium for health. Policymakers are also promoting organic agriculture for the restoration of soil health and the generation of the rural economy, apart from making efforts to create a better environment. The world principles of organic farming have emerged in the form of biological farming, ecological farming, permaculture, biodynamic agriculture, green farming, bio-intensive farming, zero-input agriculture, etc..

Organic agriculture is one of the broad spectrums of production methods that are supportive of the environment. Organic production systems are based on specific standards precisely formulated for food production and aim at achieving agroecosystems that are socially and ecologically sustainable. Organic farming practices help in increasing carbon sequestration, soil and water conservation, and minimizing risk in agriculture. The important aspects of organic farming with respect to water conservation are mentioned in this chapter.

Nutraceuticals have received considerable attention for their expected safety and potential nutritive and therapeutic effects. These were used as alternatives to modern medicines that promote quality of health, increase the nutritional value of the diet, and prolong life expectancy. Major constituents of nutraceuticals are herbals; various nutrients and dietary supplements are involved in preventing different diseases and minimizing the pathophysiology of the disease too. It also acts as an immune boosting, natural antioxidant, anticancer, anti-inflammatory, anti-diabetic, cardioprotective, and organ protective agent, in addition to different health-promoting effects. Ultimately, they ensure a better quality of life.

The scope of the nutraceutical field is plenty both in terms of type and the varieties. The nutraceuticals industry in India is one of the rapidly growing markets. Higher- and upper-middle-class consumers are perceiving nutra ceuticals as alternatives to prescribed drugs and exclusively for their beneficial properties without any side effects. Consumers are showing sharp interest in nutraceuticals for boosting energy and improving their physical endurance and mental alertness. Nutraceutical industries are focusing on developing new products with innovative formulations and using proper advertisements to choose the right products. Nutraceuticals have significant promise in the promotion of human health and the prevention of disease. They are widely accepted by all age groups due to their safety, higher quality, purity, efficacy, health-promoting, and disease-curing activities. The newest trend is moving toward nutraceuticals, leading to a new era of medicine and health. It is still in its infancy in India. But in this hype era, we must say, “let food be your medicine” and “proper nutraceuticals daily can keep the medicine away.”

Water is a very essential component for human civilization, living organisms, and natural habitats. It ma.kes up a major part of plant biomass (about 90% of plant cytoplasm; Singh, 2014). Irrigation, the largest water user sector, is currently under pressure to produce more with higher quality by using limited water to feed the increasing population of the country. The highest proportion of water is consumed by agricultural crops, which is called the blue water footprint, and it is assumed that the water scarcity will increase in the future in view of the changing climate. India has 18% of the world population; however, the water resources are only 4%. Even with all the planning and development, the country has not even been able to provide sufficient drinking water to all at the end of the 20th century. The water sector is facing a number of challenges regarding the availability, accessibility, use, and sustainability of its fresh water resources. Further, the distribution of water in the country is also uneven over space and time. Unfortunately, Rajasthan is the driest state in the country and has been water scarce (with per capita water availability below 1000 m3/year) since 1991. The efficient use of water in agriculture/ horticulture without affecting crop productivity or quality by adopting water saving irrigation techniques is the foremost need. Fruit crops, which have gained commercial attention in recent years, are an important component of Indian agriculture. Due to low irrigation and water use efficiencies, irrigation managers are looking for the introduction of effective water-saving devices and practices for water management in fruit crops.

In irrigated agriculture, water is the most important and precious input among all the inputs required for the biological activities of the plant. It is also a key input not only for ensuring food security but also for sustainable socio economic development. Water plays a crucial role in enhancing agricultural production and provides food security. On a global scale, 97.5% of water resources are salty ocean water, with only only 2.5% being fresh water. The bulk of the latter occurs in the polar ice and glaciers, as well as deep aquifers, some in water bodies like rivers and lakes, and in soil moisture. On the whole, less than 1% of the world’s fresh water resources are available for human use. The world’s average annual precipitation of about 1100 mm, marked by wide variation in water availability, is creating a great divide in regions, resulting in plenty of regimes and scare/acute shortage regions.

In India, the average annual precipitation, including snowfall, is 4000 billion cubic meter (bcm), of which water availability in the river systems is estimated at 1869 bcm, and out of which only 1122 bcm can be used. About 690 bcm is surface water and 432 bcm is ground water. As compared to the world’s average annual rainfall of 1100 mm, India receives 1170 mm, which is highly erratic and uncertain in both time and space. Thus, in India, very limited fresh water is available for use because of competitive and conflicting demand from the agriculture, industry, power, and domestic sectors, which is expected to increase from 10.7% in 1990 to 22.5% in 2025. While that of agriculture will decrease from 89.3% in 1990 to 77.6% in 2025. The projected requirement of water for use by the different sectors shows an increase in energy and industry as compared to the domestic and irrigation sectors by 2025, indicating a growing scarcity of water availability in the future.

A laboratory is essential for research work in science and development. Most of the research institutes have dedicated laboratories for researchers and students to conduct experiments, perform research work, as well as to provide hands-on learning/training to students. There are certain rules and regulations laid down by the laboratory in-charge which need to be followed strictly for safety purposes. Some of the laboratories keep ‘safety manual’ for researchers to read before entering into the laboratory to conduct experiments. Whenever safety is compromised in a laboratory, there is increase in risk of unwanted incidents in the laboratory. Storing food/beverages in the same refrigerator where laboratory chemicals are kept may lead to disastrous effects on health. This chapter aims to provide instructions in brief on the things to be performed (Do’s) before and after entering onto a laboratory as well as the things never to be done (Don’ts) in a laboratory for the safety reasons.

Good Laboratory Practices (Do’s)

• P Wear apron/labcoat while working in the laboratory.
• P Use gloves/respiratory mask/fumehood while handling toxic/volatile/inflammable chemicals/reagents.
• P Use pippet or pippetor for safety in transfer of solutions.
• P Protect eyes, face and naked parts of the body from UV radiations. Use safety goggles or face mask/apron.
• P Keep your eyes away from Liquid Nitrogen and use cryogloves while handling it.
• P Arrange all the necessary materials/solutions before starting the experiment.
• P Periodically fumigate/ozonize culture and inoculation rooms.
• P Autoclave all contaminated materials before discarding.
• P Pre-treat gel or solution containing Ethidium Bromide (EtBr) before discarding into laboratory waste-disposal bin, and use gloves while handling them.
• P Burn all the transgenic plant materials in an incinerator after taking necessary observations.
• P Make entry in the designated log-book and clean the instrument after using it properly.
• P Switch-off the instrument after use or when not in use.
• P Wash hands with soap and remove the labcoat before leaving/going out of the laboratory7.
• P Ensure that switches for fans/lights, and water taps are off while leaving the laboratory.
• P Follow the biosafety guidelines suggested for handling and disposal of the hazardous chemical.

Introduction

Several hazardous chemicals, microbes, and techniques like recombinant DNA technology are used for research and development work in research Institutes and universities. Therefore, the researchers, technical, helping and supporting staffs as well as the laboratory outputs must be kept free from contaminations. Thus, biosafety is necessary to prevent unintentional exposure/ release of hazardous chemicals, microbes/pathogens, and toxins to the laboratory staff and environment. Following the biosafety guidelines and ethical considerations are essential to maintain safety standards for the researchers as well as the environment. This chapter deals with various biosafety measures and ethical issues to be strictly followed while working in a research laboratory. The required safety level needs to be determined as per the chemical/biological materials are used in the laboratory to keep the researcher/environment safe for sustainable research and developmental activities.

Biosafety

The term biosafety is used to describe the procedure and policies needed to ensure environmental and personal safety. Biosafety refers to the containment principles, technologies and practices that are implemented to prevent unintentional exposure to pathogens, toxins, or their accidental release into the environment. A fundamental objective of any biosafety program is the containment of potentially harmful chemical/biological agents as precautionary safety measures.

Why Biosafety?

With the increasing number of countries adopting molecular biology tools and techniques in life science research and development activities, especially in the areas of agriculture and medicine, the biosafety issues are gaining importance to ensure biological safety for the public and the environment. Conducting research in safe and sustainable manner is not only a personal requirement but essential collective efforts to ensure biological safety for a clean and safe environment. This requires rules, regulations, monitoring bodies, and awareness among the workers as well as the public. Therefore, biosafety per se is an integral part of laboratory research and requires awareness among the researchers so that biological safety can be well taken care from the grassroot level.

For a researcher, laboratory is another home where he/she spends much time every day. As we take care of cleanliness, safety, and design of our home, we must take care on these aspects of laboratory too. It is the responsibility of the laboratory personnel to ensure cleanliness/safety of the laboratory. Since every laboratory chemical and equipment have the potential to cause harms if not used with appropriate precautions. Hence, as a laboratory user, it is our responsibility to follow the basic safety/biosafety rules and regulations set up by the Principal Investigator of the laboratory, Institutional Biosafety Committee, as well as by other regulatory authorities, if any. We must be aware of the general/personal protective measures, cleanliness and laboratory waste disposal prior to joining a research laboratory. In this chapter we will briefly discuss about personal safety, chemical safety, cleanliness, waste disposal, etc.

A. Personal Safety

1. Personal Protective Equipment (PPE)

Personal protective equipment (PPE) is special arrangement to protect the worker from specific hazards because of using a hazardous substance. PPE does not reduce or eliminate the hazard, but protects the wearer from exposure to hazardous material. PPE should not be reused or brought outside the laboratory as these might increase the risk of spread hazardous material or contamination. Used PPE must be kept inside the laboratory in a designated waste storage area adjacent to the work area.

Introduction

Proper electrical wiring and earthing are crucial for laboratory safety and functionality. A laboratory houses several installations/equipment that demand stable/continuous power supply. Inappropriate or faulty wiring and earthing may lead to significant risks, including electrical shocks, damage to equipment, and even incidence of fire. Therefore, understanding the requirements of electrical wiring and earthing is essential for designing, construction, and maintenance of laboratory. This chapter aims to provide a basic knowledge of electrical wiring and earthing necessary for a laboratory. Importance of earthing in mitigating electrical hazards and ensuring integrity of electrical installations are also described.

Basics of Electrical Wiring

Basic understanding of electrical wiring is necessary for laboratory safety and efficient electrical functioning. The potential difference between two electrical points (negative and positive) is known as Voltage, which drives the flow of electric current. This is measured as volt (V). The rate of flow of electricity in a circuit is known as Current (I), which is measured as ampere (A). Current can be either direct (DC) or alternating (AC). Opposition/resistance experienced in the flow of current in circuit is known as Resistance (R) and it is measured in ohms (Ω). Higher the resistance means lesser the current flows at a given voltage. The rate at which electrical energy is transferred/utilized in an electric circuit is known as Power (P), which is measured in watt (W). The Power can be calculated as the product of voltage and current (P = V × I).

Introduction

We come across a variety of chemicals every day in a laboratory. While some of them are relatively safer, others are extremely hazardous. Thus, it is very important to know the potential hazards that can be caused by the chemicals present in the laboratory and the safety measures needed to be followed to avoid the hazards. Additionally, we should also be aware of the steps necessary to be taken on such hazardous situations. According to IUPAC, a hazardous chemical mean the chemical which has the potential to cause damage in various ways. In a laboratory, there are chemicals that might be irritant, carcinogen, respiratory fibrogen, systemic poison, asphyxiant, flammable, etc. which have the potential to cause hazard to the workers or environment. Therefore, it is important to use appropriate procedure to reduce the risk and protect the health/safety of laboratory personnel, the public and the environment.

Types of Hazards Associated with Chemicals

Chemical hazards: The hazards caused by chemicals can be broadly classified into three categories.

1. Health hazard: This is also known as toxic effects of chemical. The risk associated with a chemical in laboratory depends on the extent of exposure and the inherent toxicity of the chemical. Many chemical reactions form the product that might be much more toxic than the reacting chemicals. For example, inadvertent mixing of formaldehyde (a common tissue fixative) and hydrogen chloride results in the generation of bis(chloromethyl) ether, a potent human carcinogen. For most of the chemicals, the route of exposure (through skin, eyes, gastrointestinal tract, or respiratory tract) is more important (Figure 17.1) that must be considered during risk assessment.

Introduction

Flowering plants (Angiosperms) are identified by their morphological characteristics like flower, fruit and seeds that help their taxonomic characterization into different species, genera, families and orders. The floral characters which are used for taxonomic characterization of plants include the type of inflorescences, perianth structure, floral symmetry, arrangement of floral leaves, type of androecium, stamens, gynoecium, carpel, ovule, etc. The type of fruit and seed also play important roles in taxonomic classification. In this chapter we will briefly discuss about various morphological features of flowering plants (in botanical terms) that are useful in taxonomy.

Nomenclature of Plant

Nomenclature of plant is the formal and scientific naming of plants. It is related to but distinct from taxonomy for grouping and classifying plants and provide botanical name.

The scientific/botanical nomenclature started with Species Plantarum by Carolus Linnaeus in 1753. Botanical nomenclature is governed by the International Code of Nomenclature for algae, fungi, and plants (ICN), which replaces the International Code of Botanical Nomenclature (ICBN).

ICBN and ICN

International Code of Botanical Nomenclature, (ICBN) was adopted by the VIIth International Botanical Congress held in Stockholm, July1950. While the International Code of Nomenclature for algae, fungi, and plants (ICN) was adopted by the XVIIIth International Botanical Congress held in Melbourne, Australia in July 2011.

Introduction

Test of pollen viability (extent of pollen viability) is important in pollination experiments to ensure fertility/seed setting. It is also important in monitoring state of pollens during storage in ecological/ taxonomic studies as well as during research on pollen biochemistry, genetics, stigma interactions, and incompatibility studies. Pollen viability refers to the ability of pollen to accomplish post-pollination events to achieve fertilization. Pollen viability test has gained importance particularly in plant breeding and hybrid seed production experiments/ practices. In this chapter, you will be acquainted with the basics of pollen viability test. However, for more professional knowledge on the topic readers are suggested to refer specialized books.

Pollen Viability Test

It is important to know the extent of viability of pollens used in pollination experiment, in finding fertility of a plant of interest, to monitor state of pollen on storage, in ecological/taxonomic studies, as well as in research on biochemistry, genetics, stigma interaction, incompatibility assay, etc. of pollen. Several pollen viability tests have been developed time-to-time. It is recommended to initially use different tests for a given pollen type to find out the most appropriate method that provides reliable result on pollen viability. It is important to note that every procedure requires standardization of protocol according to the sample used. Following different tests are used for assessing pollen viability.

1. In-vitro Pollen Germination Test

It is a simple, speedy, and quantitative test for assessing pollen viability. In this method, a collection/sample of pollen is germinated in vitro and observed under microscope. The percentage of germinating pollens (producing pollen tube) after appropriate treatment and a given period of time is determined. The percentage provides an index of viability of the pollen sample.

Introduction

Seed is a living entity (mature ovule) consisting of a tiny plant in embryonic stage along with the stored food protected by an outer layer known as seed coat. Seed is an important biological input in agriculture, which is economically important for successful crop husbandry. Cotyledons serve as the source of nutrients (proteins, carbohydrates, and oils) that not only nurture the plant at the early developmental (seedling) stages of plant but also the vegetarian (heterotroph) organisms. Being one of the important inputs in agriculture, viability of seed needs to be assessed to know the germination percentage of seeds used to raise a crop. Since viability of seeds may deteriorate on storage depending on the storage conditions. Therefore, often it becomes important to test viability/germinability and vigour of seeds before being used for raising a crop or conducting an experiment. In this chapter, we briefly discuss about the different methods which can be used for testing the viability of seeds.

Seed Viability

Seed viability can be defined as the capability of the seed to germinate and produce a normal seedling within a specified period. In other words, seed viability indicates how many seeds in a lot are alive and could develop into plants under appropriate field conditions. It is very important that most of the stored seeds are capable of germinating when sown in a field. They must possess higher viability at the beginning of storage and maintain it over the storage. A seed with high initial viability survives longer in storage; however, the viability deteriorates slowly at first and then rapidly as the storage prolongs. It is important to know the duration of storage after which a considerable decline in viability occurs under given storage conditions so that to take necessary action to revive the seeds. Excessive deterioration in vianility of seeds may lead to loss of the seed/material/ germplasm.

Introduction

Tissue culture refers to the technique of growing cells, tissues, or organs under controlled, artificial conditions. This allows propagation of tissues from a small sample of cells/tissues under sterile conditions. Plant tissue culture is widely used for various purposes, including the production of disease-free plants, rapid multiplication of plants with desirable traits, genetic modification, conservation of rare or endangered species, etc. Tissue culture is a valuable technique because it enables consistent and large-scale production of plants, ensures genetic uniformity, and allows manipulation of plant biology at cellular level. In this chapter, we will discuss about the major types of tissue culture techniques and their advantages, disadvantages, as well as applications in brief.

Different Types of Tissue Culture

Callus culture involves induction and growing of unorganized, undifferentiated cell masses from an explant on a nutrient/culture medium. The part of plant used to induce callus is called explant which can be tissue, organ or part of a plant.

Organ culture is used to maintain or grow an entire organ or a part of organ in vitro. It preserves the structure and function of the organ for studies or transplantation.

Embryo culture involves isolating and growing embryos from seeds or ovules in a nutrient medium. It is used to bypass seed dormancy or rescue embryos from hybrid crosses that may not develop naturally.

Cell suspension culture involves growing dispersed cells or small cell clusters in a liquid medium under continuous shaking. This is used for large-scale production of cells, secondary metabolites, and studying cell biology..

Introduction

Different types of culture media are used for culturing microbes and plant tissues. Preparing as well as sterilizing them properly following appropriate method with safety for the desired purpose are important parts of research work. In this chapter, we will discuss briefly about different types of media, their composition, preparation and sterilization in laboratory for microbial or plant tissue culture.

Culture Medium

Ingredients mixed to prepare solid, liquid or semi-solid substance to support the growth of microorganism or plant tissue in vitro (outside the body) is called culture medium. Frequently, it becomes important to grow microorganism or plant/animal tissue in vitro for any or all of the following purposes:

• To study characteristic features or properties of microorganisms.

• To identify the causal organism(s) of infection in a clinical sample, so that appropriate remedy can be determined.

• To culture/multiply microorganism or plant/animal tissues in vitro for research or commercial purposes.

• To prepare/produce biological molecules, vaccines, antigens, proteins, metabolites, etc. in vitro for research or industrial purposes.

Introduction

Use of acid/base is common in laboratories for experiments like titration and proper safety in their handling laboratory is necessary. In this chapter we will briefly discuss about the safety measures necessary to be adopted while using acids/bases in laboratory for any experiment.

Handling of Strong Acid/Base

There are four major points that need to be taken care of while working with strong acids or bases that might be quite harmful if any accident happens.

1. Protect Yourself

Wear a lab-coat and acid-resistant gloves: Always use lab-coat/apron and make it sure that the sleeves properly cover your arms. More importantly, use gloves made of acid-resistant materials and also wear shoes to protect your feet while wearing long-pants/jeans. Female with long hair, must tie her hair properly (with rubber band) to avoid any disturbance caused by appearance in between.

Wear safety goggles: It is important to wear safety goggles to protect your eyes using larger and fitting goggles that cover front as well as sides of your eyes. Always use properly fitting and adjustable goggles because smaller/ loose goggles may not protect the areas around your eyes against accidental acid spills and it may fall down from your face, if it is too loose.

Locate emergency wash area: There must be an emergency washing area nearby the work place or laboratory containing lab spill management kits. All the workers in the laboratory must be aware of using the kits and emergency plans.

Neutralize acid: Don’t panic even if an acid or chemical spill happens. Stay calm and act as quickly as possible. In case an acid spills, neutralize it by using sodium bicarbonate so that they can be cleaned and disposed safely. If acid comes in contact of skin, wash it off under running tap water but do not use/ apply sodium bicarbonate on skin.

Introduction

Measurement of pH of a solution and preparation of different types/strength of buffers are common practices in a laboratory, particularly in the Biochemistry and Molecular Biology laboratories. Therefore, in this chapter you will be acquainted with the procedures of measuring pH of a solution as well as preparation of some of the commonly used buffers in a laboratory.

Potential or Power of Hydrogen Ion (pH)

Measurement of pH of a solution is measuring the molar concentration of hydrogen ion [H+] in the solution, which is an indication of the acidity or basicity of the solution. The symbol pH stands for “power of hydrogen” and numerical value for pH is just the negative logarithm of the molar concentration of hydrogen ions [H+]. The ionic product of water (Kw ) is the basis for the pH scale. The total hydrogen ion concentration from all the sources and it can be experimentally measured.

The pH scale designates the concentration of H+ (and thus of OH−) in an aqueous solution, which ranges between 1.0 M H+ and 1.0 M OH−. The term pH is defined by the expression

Thus, the ionic product of water makes it possible to calculate the concentration of H+, with given concentration of OH−, and vice versa. The value of 7 for pH of a neutral solution is not an arbitrarily chosen figure; it is derived from the absolute value of the ionic product of water. A solution having pH greater than 7 is basic, and the concentration of OH− is greater than that of H+. A solution having a pH less than 7 is acidic.

Introduction

For agricultural applications as well as for research work, often we need to prepare solutions of different agrochemicals of varying strength, as per the requirements. Agrochemicals are used to help crop plants grow, produce, and protect them from biotic/abiotic stresses. Many of the agrochemicals (insecticides, herbicides, fungicides, rodenticides, molluscicides, nematicides, etc.) are used to protect the crop from insect pests and diseases. However, some of them (fertilizers and soil conditioners) are used to augment crop yield. While in the previous chapter (Chapter 8) we discussed about preparation of laboratory solutions, in this chapter we will briefly discuss about the preparation of different agrochemicals.

Agrochemical/agrichemical is a generalized term used for the chemicals applied in agriculture. In general, it also includes the feed-supplements used in f isheries and animal husbandry.

Agrochemicals

Fertilizers

Fertilizers are used to augment growth of crop plants and to mitigate nutrient deficiency in the soil. Fertilisers can be organic (containing natural substances, prepared through natural processes) and inorganic fertilisers (synthetic fertilizers, manufactured artificially using chemical processes using natural deposits, by chemical alterations).

Soil Conditioners

Soil conditioners include manure, livestock and leaf compost, peat that help making the soil in good condition. They are laid on the top soil and then mixed properly. They not only increase nutrient contents in the soil but also improve aeration and water holding capacity.