eChapters

Digestion Mixure : This is a mixture of two salt. That is potassium sulfate and cupper sulfate with 9:1 ratio (90 g Potassium sulfate + 10 g Copper sulphate).

In the detection of soil organic carbon a known weight of soil is heated with an excess volume of standard K2 Cr2 O7 in the presence of Con. H2 SO4 . The soil is slowly digested at the low temperature by the heat of dilution of H2 SO4 and the organic carbon in the soil is thus oxidized to CO2 . The highest temperature attained by the heat of dilution reaction produced with the addition of Con. H2 SO4 is approximately 12o C which is sufficient to oxidize the active forms of the soil organic carbon but not the more inert forms of carbon that may be present.

100 ppm ‘P’ : By dissolving oven dry KH2 PO4 salt. Take 0.4393 gm of KH2 PO4 and volume to 1 ltr that gives 100 ppm ‘P’.

Phytochemicals are chemical compounds that occur naturally in plants (phyto means “plant” in Greek). Some are responsible for color and other organoleptic properties, such as the deep purple of blueberries and the smell of garlic. The term is generally used to refer to those chemicals that may have biological significance, for example antioxidants, but are not established as essential nutrients. Scientists estimate that there may be as many as 10,000 different phytochemicals having the potential to affect diseases such as cancer, stroke or metabolic syndrome. The potential of the phytochemicals have large scale pharmacological and biological activities such as antioxidant constituents (hydrolysable tannins, phenolic acid and flavonoids) of the plant materials for the care of health and protection from coronary heart diseases, cancer, anti-carcinogenic and anti-mutagenic effects. Varieties of herbaceous vegetables are protective against various diseases, particularly cardiovascular diseases. These herbaceous plants and species are harmless sources for obtaining natural antioxidants. Antioxidant constituents can delay or inhibit the oxidation of lipids and other compounds by inhibiting the propagation of oxidation chain reaction (Hussain et al., 2011)

Primarily, antioxidant effect is due to phenolic compounds such as phenolic acid, flavonoids and phenolic diterpenes and their mode of action for antioxidant compounds is due to its redox reaction properties which can absorb and neutralize free radicals by quenching singlet and triplet oxygen. Vitamins are organic substances necessary for metabolism. Human diet does not always contain the required amount of vitamins for the normal growth and maintenance of the body function and as such cannot produce enough quantity for their body metabolism, so it can be obtained from fruits, vegetables and foods. Deficiency of vitamins can cause serious human health diseases and sometimes, very small concentrations are required for maintenance of good human health.

Take 5 ml/2.5 ml aliquot in a 25 ml volumetric flask.

Objective

To determine the pH of a soil sample, which provides insight into the soil’s acidity or alkalinity, influencing nutrient availability, microbial activity, and plant growth.

Materials Required

• Soil sample

• Distilled water

• pH meter or pH paper

• Beakers (100 mL)

• Measuring cylinder (50 mL)

• Stirring rod

• Filter paper and funnel (if needed) • Mortar and pestle (for soil grinding, if necessary)

Determination of soil texture mainly depends on the complete dispersion of soil aggregates into their individual primary particles without triturating the particles themselves, accurate fractionation of the sample into various separates, sedimentation of different particles in the viscous medium as well as measurement of individual particle by the hydrometer.

Stomata are pores formed between two specialized epidermal cells, the guard cells, which are found on the surface of aerial parts of higher plants (leaves). They control the gas exchange between the leaf and the ambient air. Their main functions is to facilitate the entry of CO² into the leaf for photosynthesis and loss of water vapour for evaporative cooling of the leaves.

The guard cells are formed by the transverse division of stomatal mother cells that differ morphologically and biochemically from other epidermal cells. The middle lamella disintegrates and the two walls separate leaving an opening between them the stomatal pore. The walls bordering the pore become considerably thickened. They are generally cutinised. This radial thickening of the inner wall plays an important role in stomatal movement. Stomata control 95 per cent or more of CO² and water vapour exchange between the leaf and atmosphere.

Location and occurrence of stomata: Stomata are found in all higher plants down to the evolutionary level of the phylum Bryophyta. Stomata are not found in liverworts. In the leaves of most herbaceous plants the stomata are found in both upper (Adaxial) and the lower (Abaxial) surfaces. Such leaves are known as Amphistomatus. Usually in tree species, stomata are found only on the lower surface of the leaves. Such leaves are called Hypostomatus. Aquatic plants with floating leaves such as water lilies have stomata only on the upper surface and such leaves are called Epistomatus. Most of submerged aquatic plants do not posses stomata and diffusion of gases occurs between water and plant tissues across a thin cuticle. In many cases subsidiary cells are present adjacent to the guard cells. These are specialized epidermal cells which are usually different in size and shape from other epidermal cells. They are usually smaller than the epidermal cells and have more dense cytoplasmic contents and a greater frequency of cell organelles. In grasses and some other species, subsidiary cells are intimately involved in stomatal mechanism.

Diffusion of gases through stomata is governed by the two important parameters associated with the stomata, viz., the stomatal frequency and the extent of opening of the stomata. Stomatal frequency is defined as the number of stomata per unit leaf area (no.mm ^-2 ). Apart from the stomatal frequency, yet another parameter that reflects the stomatal distribution is the stomatal Index. It is the ratio of the number of stomata per unit leaf area to the total number of epidermal cells and is generally expressed in percentage.

6.25 HNO3 (for 2 ltr) : Take 181 ml of conc HNO3 and diluted to 2 ltr in a volumetric flask.

Field capacity may be defined as the amount of water held in soil after excess water has drained away and the rate of downward movement of water was materially decreased which usually taken place within two to three days after heavy rain or irrigation. In this condition water was moved out of the macropores and air has moved into take its place. 

Infiltration is the entry of a fluid from one medium into another. Soil water plays an important role in nature. The entry of rain or irrigation water into soil is called infiltration. Infiltration rate is defined as the amount of water entering into a soil per unit area per unit time under one atmospheric pressure. The infiltration rate depends upon initial moisture content of soil, condition of soil surface and permeability of various layers.

The maximum water holding capacity is the amount of water, expressed as percentage on oven dry basis held by a soil when it is completely saturated with water. At this moisture content, all the pore spaces are completely filled with water.

Object: Determination of the viability of seeds by tetrazolium test. 

Material required: Healthy seeds, tetrazolium solutions, beakers, water and petridishes. 

Theory: Viability of seeds shows their potential towards germination.

Primary particles tend to adhere under natural condition so as to form secondary unit called aggregates. It is very difficult to determine the diameter of the individual aggregated particle. So the mean weight diameter is calculated as a single value constant, which indicate the wetted average value for a group of aggregates.

Soil texture is the relative proportion of sand, silt and clay in soil by weight. As per the classification of the inorganic soil particle by the International Society of Soil Science, diameters of the sand, silt and clay particles vary from 2 to 0.02 mm, 0.02 to 0.002 mm and less than 0.002 mm, respectively. There are 3 broad textural groups i.e sand, loam and clay and each broad textural group is subdivided into different textural classes depending upon the proportion of sand, silt and clay.

World population is expected to cross 8.5 billion by 2025 and it will be a gigantic task to produce enough to meet the future food demand by growing same set of crop varieties on anticipated reduced area. Most of the land that could be brought under cropping has been utilized with exception of some land in Sub-Saharan Africa and South America (Borlaug and Doswell, 1993). Therefore, it is warranted to produce more from less land, less water and less inputs which can be achieved by enhancing the efficiency of production system by devising more efficient crop management practices and developing input use efficient cultivars.

1. Introduction

Among three major functions identification, classification and nomenclature of taxonomy (Fig. 1), identification is a core activity and one of the major objectives of taxonomy, which determines whether other two elements are the same or different. Classification and nomenclature are two separate methods in taxonomy, however, both are totally dependent on the correct identification of the objects. The identification of an unidentified plant with a correctly identified specimen also involves classification. So, both identification and classification, involve comparison and judgment of similarities and differences. Therefore, the identification is a primary function in classification involving nomenclature which performs an essential role as a means of communication. According to Blackwelder (1967) “identification enables us to retrieve the appropriate facts from the system (classification) to be associated with some specimen at hand” and is “better described as the recovery side of taxonomy.” The identification of plants is very important for proper assessment and characterization of biodiversity on which the whole life of human beings is dependent starting from birth to death. The use of biodiversity for various purposes like food, nutrition, pharmacognosy etc. requires accurate and reliable identification and naming of plants (Nesbitt et al. 2010).

Introduction

The phytohormone abascisic acid (ABA) was discovered in connection to studies related to shedding of fruits and leaves, also called abscission, and the dormancy of buds. It was first identified and characterized by Frederick Addicott and his associates in 1963 while studying the compounds responsible for the abscission of cotton fruits. Inhibition of growth and maintenance of the dormancy of buds are the most important visible effects of ABA. The concentration of ABA does not remain constant as its concentration decreases in the buds significantly after sprouting and rises during seed and fruit production. Its concentration in dormant seeds is very high and considered as an efficient inhibitor of germination. The role ABA plays during the abscission of fruits and leaves is not clearly understood as its effect is very clear in case of fruit abscission where as it is not very clear on the abscission of leaves. However, the regulatory effect of ABA on the water balance is established in plants. It also induces stomatal closure to inhibit further loss of water. Being a growth inhibitor, ABA also reverses the effect of growth-stimulating hormones like auxin, gibberellins and cytokinin in different tissues of a plant. One of the main goals of phytohormonal ecology is to study the interactions between biotic and abiotic stress at hierarchical levels of biological organization.

Digital technologies are transforming horticultural production by enabling data-driven crop management and precise decision-making. This chapter introduces agricultural informatics, sensors, Internet of Things, remote sensing, drones, artificial intelligence, machine learning, geographic information systems, robotics, and precision technologies. These tools can support crop monitoring, disease detection, irrigation scheduling, nutrient management, yield prediction, phenotyping, and resource optimization. AI-based image analysis can identify symptoms and assist in early crop diagnosis, while sensors provide continuous information about soil and plant conditions. The chapter emphasizes the integration of digital data with practical horticultural knowledge to improve productivity, profitability, sustainability, and resilience while reducing unnecessary inputs and improving decision-making.

Introduction

In agriculture, plant diseases have always been a major problem, as they cause crop quality to decrease, resulting in yield. Plant disease has a range of effects from minor symptoms to serious damages in whole crop areas, which lead to high financial costs and significantly impact the agricultural economy, particularly in developing countries dependent on a single crop or on a few crops.

Various approaches have been developed to detect disease in order to avoid significant losses. Causal agents have been precisely defined by methods developed in molecular biology and immunology. However, for many farmers these techniques are inaccessible and require detailed knowledge of the field or substantial time and energy to be used. According to the United Nations Food and Agriculture Organization, most farms in the world are small and family-owned in developed countries. Such families provide food for a significant proportion of the population of the planet. However, hunger and food insecurity are not rare and there is restricted access to markets and services. For the above reasons, a great deal of work has been undertaken in order to establish methods that are sufficiently reliable and available to most farmers. Where Plant disease is an essential factor contributing to a major decline in plant production quality and quantity. Plant disease identification and classification are a significant role in improving plant production and economic development.

1. Introduction

India, as a party to the Convention on Biological Diversity (CBD), has obliged to document a whole range of organism diversity within her territorial boundaries, make all attempts to conserve these bio-resources and monitor the efficacy of the conservation measures adopted. With its diverse ecological conditions and unique geographical location, Indian landmass supports rich diversity of algal flora. However, this algal wealth needs to be systematically surveyed and documented from all possible habitats. Ecological patterns emerged from recent studies within India are assessed with the identification of knowledge gaps and conservation implications in algal systematics.

During last one decade, great advances have been made in the field of Algology/Phycology throughout the world. Over the years algae has attained a greater reputation and popularity because of its economic importance, particularly as food, for commercial products, water contamination, toxin production, sewage oxidation, municipal water purification in fisheries and above all for the study of fundamental scientific information. But before the algae put in to such important use, it is imperative to have a baseline data about the material in question. Without knowing the status of algal resources of any area one cannot have projections for their utilization or gain knowledge of their ecological role and functions. The taxonomy of algae is, therefore, a prerequisite for all applied fields of algae apart from academic interest. Recent global surveys have revealed that there is lack of knowledge about fresh water algal diversity of tropical countries including India.

1. Introduction

The gymnosperms constitute a distinct subdivision of spermatophytes, the seed bearing plants. The term ‘gymnosperm’ is derived from Greek words, gymnos, naked and sperma, seed, which indicates that these are naked-seeded plants, i.e., those in which the seeds are not enclosed within the fruits but are borne freely exposed on an open carpel. In contrast in the angiosperms the seeds are enclosed within a closed carpel (ovary). The first known use of the term gymnosperm was given by Theophrastus in 300 BC in his book “Enquiry into Plants” to describe “plants with unprotected seeds”. Goebel (1905) rightly described gymnosperms as “Phanerogams without ovary”. The Scottish botanist, Robert Brown in 1825 first distinguished gymnosperms from angiosperms. At one time they were considered to be single class of seed plants, called Gymnospermae, but taxonomists are now tend to recognise four distinct divisions of extant gymnospermous plants - coniferophyta (Pinophyta), Cycadophyta, Ginkgophyta and Gnetophyta. Geological history reveals that all divisions of gymnosperms have been distinct groups since their origin.

Among the gymnosperms are plants with stems that may barely project above the ground and others develop into the largest trees on the earth. The extant gymnosperms are a small group of plants comprising ca. 1026 species belonging to 83 genera and 12 families (Christenhusz et al. 2011). They are distributed throughout the world, with extensive latitudinal and longitudinal ranges. Economically, gymnosperms are of outstanding value, fulfilling the greater proportion of our timber as well as resin requirements. They are also the dominant forest makers of the world and in addition they play a leading role in the preservation of the environment (Sahni 1990). By far the largest group of living gymnosperms is the conifers (pines, cypresses and relatives), followed by cycads and Gnetales (Gnetum, Ephedra and Welwitschia).

1. Introduction

Fungi are ubiquitously present in air, water, soil and organisms, or on organism surfaces. They are a group of eukaryotic system that are of great applied and scientific interest to common man, microbiologists, agriculturists and industrialists. They are a diverse group of organisms with respect to taxonomy, size, morphological appearance, mode of nutrition and reproduction. Fungi are eukaryotic spore bearing protists that lack chlorophyll. Fungi comprise the molds and yeasts. Yeasts are usually unicellular measuring only several microns in diameter, whereas molds are filamentous and multicellular which may grow up to several meters in diameter like the extremely large polypores. Fungi generally reproduce both sexually and asexually (Gow and Gadd 1995).

Although it is not easy to define fungi, biologists currently use the term “Fungus” to include nucleated, spore bearing, achlorophyllous organisms with absorptive nutrition which generally reproduce sexually and asexually, and whose filamentous branched somatic structures are typically surrounded by cell walls containing cellulose of chitin or both. A feature which all fungi have in common is their mode of nutrition. Like animals, fungi are heterotrophic organisms, which must consume preformed organic matter. They may live as saprophyte or parasites. They are of great economic importance to man and play an important role in the disintegration of organic matter and affect us directly by destroying food, fabric, leather and other commercial goods. They are responsible for a large number of diseases of plants, animals and man.

UNTIL THE 1940S BIOLOGISTS ARGUED ABOUT WHETHER DNA OR PROTEIN WAS THE MOLECULE OF HEREDITY

Nuclei observed to divide when cells reproduced themselves

Large amounts of both DNA & protein in the nucleus

Many though protein was most likely molecule of heredity

Proteins made of 20 different amino acids- could have more variety than DNA (made of only 4 different bases)

DNA replication. The double helix is unwound and each strand acts as a template. Bases are matched to synthesize the new partner strands.

DNA replication, the basis for biological inheritance, is a fundamental process occurring in all living organisms to copy their DNA. This process is “replication” in that each strand of the original double-stranded DNA molecule serves as template for the reproduction of the complementary strand. Therefore, following DNA replication, two identical DNA molecules have been produced from a single double-stranded DNA molecule. Cellular proofreading and error toe-checking mechanisms ensure near perfect fidelity for DNA replication.

In a cell, DNA replication begins at specific locations in the genome, called “origins”.

Unwinding of DNA at the origin, and synthesis of new strands, forms a replication fork. In addition to DNA polymerase, the enzyme that synthesizes the new DNA by adding nucleotides matched to the template strand, a number of other proteins are associated with the fork and assist in the initiation and continuation of DNA synthesis.

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

The study of abiotic stresses in plants has advanced significantly in recent years. However, the majority of experiments testing the response of plants to changes in environmental conditions have focused on a single stress treatment applied to plants under controlled conditions. In contrast, in the field, a number of different stresses can occur simultaneously. These may include conditions such as high irradiance, low water availability, extreme temperature, or high salinity and may alter plant metabolism in a novel manner that may be different from that caused by each of the different stresses applied individually. The response of plants to abiotic stresses in the field may therefore be very different from that tested in the laboratory (Cushman and Bohnert, 2000).

1. Introduction
Drought’ which apparently means lack of water, is one of most vulnerable natural hazards. It alone causes a huge crop loss annually. But history says it not only affects crop but destroys human lives.in the year 1972 almost 600000 people died due to starvation caused by huge drought in Northern India. In simple language drought means shortage of water mainly caused by abnormal climatic condition and damaging to the environment. Ideally there is no such proper definition of drought because it should be region specific and circumstances specific. A per McMahon and Diaz Arenas (1982) define drought as “a period of abnormally dry weather sufficiently prolonged for the lack of precipitation to cause a serious hydrological imbalance, carrying connotations of a moisture deficiency with respect to man’s usage of water”. Apart from these several general definitions have been provided by many authors. Beran and Rodier (1985) gave a definition based on hydrological aspect of drought that, ‘The chief characteristic of a drought is a decrease of water availability in a particular period and over a particular area’. India meteorological department (IMD) has defined drought as a situation in a subdivision in a year when the actual rainfall is less than 75% of the normal annual rainfall. Basically, to define drought the impact on environment and society and their complex interaction must be considered. Drought is defined as a state of total water capacity being within the range of 12-20% for a period of 16 days and can be distinguished from water deficit, which is the state of water capacity falling below 30%. Drought affects crop development, production, productivity and quality and on other hand soil physical, chemical and biological properties.
2. Classification of Drought
As per the hydrological point of view drought can be classified into different Categories: i) On the basis of source from which water is available: -a. Meteorological Drought b. Hydrological drought c. Agricultural Drought. ii) On the basis of time of occurrence: - a. permanent drought area b. Seasonal Drought Area contingent drought. iii) On the basis of medium: - a. soil drought atmospheric drought.

Introduction

Drought is the most common adverse environmental factor which limits crop production in different parts of the world. Often drought is accompanied by relatively high temperatures, which promote evapotranspiration, and hence could accentuate the effects of drought and thereby further reduce crop yields. Since these events occur more frequently in tropical and semitropical regions where most of the developing countries are situated, droughts are often associated with food shortages and an overall setback to developmental activities. Therefore, raising of drought-resistant crops is common sense to achieve stability in production and to enhance the possibility of self-suficiency in food. Consequently, breeding for drought resistance is a major objective of many research programmes in the international and national institutions. This has been so for the past several decades. But, it is disappointing that, there has not been any measurable success in these programmes compared with the success achieved in breeding for yield; or breeding for disease resistance or breeding for quality attributes. In fact, this was amply expressed by Arnon (1980) when he stated “Breeding for drought resistance has been a consistent theme for as long as I remember and probably the greatest source of wasted breeding efforts in the whole field of plant breeding.” However, the fact remains that we do hear of drought resistant varieties in many crops. For example, C-306 in wheat, Lalnakanda in rice and M 35-1 in Sorghum are some of the better known examples in India. It is also claimed that a large number of cultures among the Assam Rice Collection exhibit a considerably high degree of drought tolerance. Many land races and wild relatives of several crop species are said to contain drought resistant traits, which could be profitably utilised in breeding programmes. This situation is not unique to India alone but is a common experience in different parts of the world. However, to afirm a conviction a short questionnaire to assess the current state-of-art on breeding for drought resistance was distributed to 75 distinguished plant breeders and plant physiologists all over the world. The questionnaire and a summary based on the responses is as follows:

Introduction

Chickpea, the world’s third most important food legume, is currently grown on about 10 m ha worldwide, with 95% cultivation in the developing countries. India is the largest producer of chickpea in the world. Chickpea is grown under rainfed conditions in winter in India subjecting it to abiotic stresses. Consequently it experiences water deficit stress at one or the other growth stage(s) which affects the crop productivity.  Among the abiotic stresses to which chickpea is subjected to drought stands to be the number one problem in major chickpea growing regions because the crop is grown on residual moisture and the crop is eventually exposed to terminal drought (Johansen et al., 1994). A distinctive variation exists between the plant in sensitivity to water stress. Chickpea is considered relatively more tolerant, possibly because of its deeper root system is and its smaller leaves and canopy. Several adaptive mechanisms are evoked by plants in response to water stress (Chaves et al., 2003). These traits enable chickpea to ensure its survival in different environmental conditions.

4.1. INTRODUCTION

Water stress is the single most severe limitation to the productivity of rice in the rainfed ecosystem (Widawsky and O’Toole, 1990). Drought has been defined as the inadequacy of water availability, including precipitation and soil moisture storage capacity, in quantity and distribution during the life cycle of the crop to restrict expression of its full genetic yield potential. Drought is actually a meteorological event which implies the absence of rainfall for a period of time, long enough to cause moisture-depletion in soil and water deficit with a decrease of water potential in plant tissues. Under drought conditions, water stress develops in the plants as the demand exceeds supply of water; this may occur either/or both due to atmospheric or soil conditions, and is reflected in a gradient of water potentials developed between the soil or soil-root interface and leaf, the transpiring organ. Moisture stress is likely to develop to a different rate in different plant organs along with the gradient. Drought like many other environmental stresses has adverse effects on plant growth and yield.

Partitioning of assimilated carbon among sink organs is a critical factor that controls the rate and pattern of plant growth. Environmental stress often restricts resource availability while successful acclimation sets in motion processes that restore the supply. A key mechanism contributing to regulation of carbon partitioning is an expression of genes that control activity of the enzymes which initiate sucrose metabolism at specific sites and stages of ontogeny. Drought stress not only limits the size of the source and sink tissues but the phloem loading, assimilate translocation and dry matter portioning are also impaired. However, the extent of effects varies with the plant species, stage, duration and severity of drought. Crop production faces many challenges, due to changing environmental conditions and evolving needs for new plant-derived materials. 
The extreme temperatures those are consequences of present-day global climate changes are considered as major abiotic stresses for crop plants. Temperatures exceeding the limits of adaptation substantially influence the metabolism, viability, physiology, and yield of many plants. Plants exposed to extreme temperatures often show a common response in the form of oxidative stress. However, the extent of damage caused by extreme temperatures depends greatly on the duration of the adverse temperature, the genotypes of the exposed plants, and their stage of growth. Numerous research findings support the notion that induction and regulation of antioxidant defenses are necessary for obtaining substantial tolerance against environmental stress. Plant adaptation to either high temperature or low temperature is a multigenic response which is very complex in nature. Plant response to continuous light depends on plant tolerance and can be modified by alteration in temperature, light intensity, CO2 level, and other environmental factors.

Introduction

While experimenting with chemicals, sometimes we need to dry the chemical/ solution (solid, liquid or gas) using a process like evaporation or distillation, mainly to remove water or different solvents. Drying is the process of evaporation or distillation to remove water/solvent from a solution, solid or even from gas. Generally, a drying agent (usually an anhydrous inorganic salt) is used for this process, which reacts with the water (present in the chemical/ solvent to be dried) to form a hydrate. For example, anhydrous MgSO4 is one of the drying agents. The drying agents are recognized by their capacity (the rate at which they absorb water) and their intensity (the amount of water left behind in the solvent at equilibrium). No chemical reaction or change in phase occurs during the drying process.

Type of Solvents

Apart from water (a universal solvent), there are three families of organic solvents used in laboratories.

1) Oxygenated solvents: Alcohols, Ketones, Glycol ethers, Glycol esters, etc.

2) Hydrocarbon solvents: Aliphatic and Aromatic hydrocarbons.

3) Halogenated solvents: Chlorinated hydrocarbons.

Dryland agriculture refers to cultivation of crops entirely under natural rainfall without irrigation. It is a form of subsistence farming in the regions where deficit of the soil moisture retards the growth of water consuming crops like rice (Oryza sativa), sugarcane etc. Dryland areas are characterized by low and erratic rainfall and no assured irrigation facilities. Dryland agriculture is important for the economy as most of the coarse grain crops, pulses, oilseeds, and raw cotton are grown on these lands. Dryland areas receive annual rainfall between 500 and 1200 mm.

Types of Dryland Agriculture

Depending on the amount of rainfall received, dryland agriculture has been grouped into three categories:

Dry farming: It is production of crops without irrigation in areas where annual rainfall is less than 750 mm. Crop failures are more frequent under dry farming condition owing to prolonged dry spells during crop period. The growing season is less than 200 days. It is generally practiced in arid regions of the country

The Dumas combustion method, named after the renowned French chemist Jean-Baptiste Dumas, is a widely recognized analytical technique employed in the determination of the elemental composition of organic compounds. This method involves the complete combustion of a sample in an oxygen rich environment, followed by the separation and subsequent analysis of the resulting combustion products.

Principle

The Dumas combustion method involves the complete combustion of a sample in the presence of excess oxygen. The nitrogen present in the organic compound is converted into nitrogen gas (N2 ), which is then measured quantitatively. The process can be summarized as follows:

i. Combustion: The sample is combusted at high temperatures (typically around 900-1000°C) in the presence of oxygen. This results in the conversion of all organic material into carbon dioxide (CO2 ), water (H2 O), and nitrogen gas (N2 ).

ii. Removal of Interfering Gases: The combustion products are passed through various reagents to remove interfering gases such as CO2 and H2 O.

iii. Detection of Nitrogen: The nitrogen gas is then measured, often using a thermal conductivity detector (TCD) or another suitable detection method.

Ectodormancy: A kind of dormancy which is due to environmental factors.

EDTA: An important chelating agent often used in modern nutrient solutions. It forms soluble complexes with metal ions such as that of iron and prevents from precipitation in the solution.

Elaiosomes: Greek élaion means “oil” and sóma means “body” , are fleshy structures that are attached to the seeds of many plant species. The elaiosome is rich in lipids and proteins, and may be variously shaped. Many plants have elaiosomes that attract ants, which take the seed to their nest and feed the elaiosome to their larvae and by which the seed get dispersed.

Electrical conductivity: Electrical conductivity is the measure of a material’s ability to allow the transport of an electric charge. It is used to measure the level of salinity in water or soil. When electrical conductivity is more, then salinity is more since as salt concentration is more in water or soil, then those salts will conduct more of electricity. Normally measured in μS/cm.

Electrical impedance: The application of alternating electrical current to pre-frozen or frozen plant tissues to predict damage or measure injury, respectively.

Early identification of crop diseases enables timely management interventions and can reduce losses in agricultural production. This chapter investigates the use of artificial intelligence and sensor data for detecting crop diseases at an early stage. It introduces the fundamentals of crop disease detection and reviews AI techniques applicable to agricultural monitoring. Sensor technologies provide continuous information about crop and environmental conditions, while AI models analyze these data to identify disease-related patterns. The chapter presents an AI- and sensor-based framework, including implementation and experimental procedures, followed by performance analysis. Challenges and limitations are examined, together with future research directions aimed at improving accuracy, reliability and real-time disease monitoring.

1.1. What is Earth?

The Earth is a layered body consisting of three parts: core, mantle, and crust. The radius of the Earth is nearly 6370 km of which crust, mantle and core share a depth of 40, 2850 and 3480 km, respectively (Figure 1.1). Exterior of the Earth contains the outer lithosphere which is surrounded (70% of surface) by water (hydrosphere). Solid and liquid sphere are surrounded by gas (atmosphere). The atmosphere is of 320 km above the lithosphere / hydrosphere. It is believed that there is a progressive increase in temperature with depth, if one goes to the core from the Earth crust. There is a rise of approximately about 1°F for every 64 feet depth on an average. Therefore, one could imagine that the interior of the earth is in molten condition.

1. Introduction

If we want to know what kind of plants and animals are in a particular habitat, and how many they are of each species, it is obviously (usually) impossible to go and count each and every one present. It would be like trying to count different sizes and colors of grains of sand on the beach. This problem is usually solved by taking a number of samples from around the habitat, making the necessary assumption that these samples are representative of the habitat in general. In order to be reasonably sure that the results from the samples do represent the habitat as closely as possible, careful planning beforehand is essential.

The usual sampling unit is a quadrat. Quadrats normally consist of a square frame, the most frequently used size being 20×20 m² for trees, 5×5 m² for shrubs, 1×1 m² for herbs. The purpose of using a quadrat is to enable comparable samples to be obtained from areas of consistent size and shape. Rectangular quadrats and even circular quadrats have been used in some surveys. It does not really matter what shape of quadrat is used, provided it is a standard sampling unit and its shape and measurements are stated in any write-up. It may however be better to stick to the traditional square frame unless there are very good reasons, because this yields data that are more readily comparable to other published research. (For instance, you cannot compare data obtained using a circular quadrat, with data obtained using a square quadrat. The difference in shape of the sampling units will introduce variations in the results obtained.)

Effect of Air Pollutants on Plants
 
Elements of those air pollutants which accumulate in plants (S from SO2, heavy metals from anthropogenic emissions etc.) may be used for specific bio-indication of possible effects caused by these pollutants, and for mapping their spatial and temporal distribution. Measuring accumulated components in plants rather than directly in the environment, provides the dual advantages of an integrated rather than a momentary value, and of a biological content rather than a mere concentration (Stocker and Gluch, 1990).

Abstract

Abiotic stresses lead to the overproduction of reactive oxygen species (ROS) in plants which are highly reactive and toxic and cause damage to proteins, lipids, carbohydrates and DNA which ultimately results in oxidative stress. The arbuscular mycorrhizal fungi (AMF)-symbiosis can confer a greater degree of tolerance against drought stress in many cash crops. The significance of heat shock proteins (Hsps) and chaperones in abiotic stress responses in plants, and co-operation among their different classes and their interactions with other stress-induced components is well known. Soil salinity is a major abiotic stress adversely affecting plant growth and crop production worldwide. Phyto-mycoremediation utilizing AMF as plant inoculants is regarded as a promising strategy to heavy metal pollution remediation. Plants have stress specific adaptive responses as well as responses which protect the plants from more than one environmental stress. The potential of phytoremediation of contaminated soil can be enhanced by inoculating hyper-accumulator plants with mycorrhizal fungi most appropriate for the contaminated site.

Agriculture plays a pivotal role in India’s economy, it shares 18.2 % (202324) in country’s GDP at current prices and employs 42.3 % of the Indian workforce, particularly in rural areas, making it one of the largest sources of livelihood (Anon., 2024). With 1.41 billion peoples, India is the world largest populous country and agriculture is crucial for ensuring food security. India’s agricultural exports also significant in boosting its economy through generating foreign exchange of 53 billion dollars in 2023 and contributing around 11.8% to total exports (Statista, 2023). India is the largest producer of milk, millets, banana, sapota, cashew nuts, coconuts, tea, ginger, turmeric, black pepper and second largest producer of wheat, rice, sugar, groundnut and in the world (APEDA, 2024). The sector also provides raw materials for many industries, such as textiles and food processing. India achieved self-sufficiency in food grains after Green Revolution, using introduction of high-yielding varieties (HYVs) of crops, especially wheat and rice, chemical fertilizers, pesticides, and improved irrigation techniques, which dramatically increased crop productivity. The improved productivity also helped to increase farmers’ incomes, raise living standards in rural areas, and support the development of rural infrastructure. Moreover, surplus food production allowed India to build buffer stocks, which could be used to manage food shortages or price fluctuations.

Object: Effect of ethylene on regulation of stomata.

Material required: Plant leaves, ethaphon, ACC, double distilled water, measuring cylinder, beaker and electric balance.

Theory: Ethylene is a plant hormone that regulates many aspects of growth and development. Despite the well-known association between ethylene and stress signalling, its effects on stomatal movements are largely unexplored. Here, genetic and physiological data are provided that position ethylene into the Arabidopsis guard cell signalling network, and demonstrate a functional link between ethylene and hydrogen peroxide (H₂O₂). In wild-type leaves, ethylene induces stomatal closure that is dependent on H₂O₂ production in guard cells, generated by the nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidase AtrbohF. 

Though the pesticide application represents viable solution to pest control, however indiscriminate use poses threat to target as well as non-target crops. The side effects of pesticides therefore have to be considered based on their use and on the agricultural system to which particular pesticide is used. Studies should be implied on effects and persistence of pesticides in crops and is consequent effects on soil microbial flora and associated nitrogen metabolism. Safe alternate methods like development of relatively cheaper biopesticide should be encouraged. More efficient methods have to be developed and validated for dissipation of pesticide residues in food grains. Human health and environment has gained great importance in the modern world. The widespread use of insecticides has resulted in problems caused by its interaction with the natural biological systems. Study showed that higher amounts of acetamiprid have some negative effects on corn plant physiology. Thus, the use of pesticide should be controlled following the standards of developed countries to protect health and the environment.

Water is indispensable for human, animal and plant life. It is a major component of all organisms some of which contain more than 90% of water. Water is a constituent of protoplasm. It maintains turgidity of cells which is essential for stomatal opening, expansion of cells and for different physiological processes. Water is also required for translocation of nutrients and dissipation of heat.

16.1 Irrigation

Irrigation is generally defined as the artificial application of water to soil for the purpose of supplying the moisture essential for plant growth.

However, a broader and more inclusive definition of the term irrigation is the application of water to the soil for any number of the following six purposes —

1. To add water to soil to supply the moisture essential for plant growth.
2. To provide crop insurance against short duration drought.
3. To cool the soil and atmosphere, thereby making more favourable environment for crop growth.
4. To wash out or dilute salts in the soil.

18.1 Determination of Electrical Conductivity of Soil Solution

The conductivity or more precisely the specific conductance of a soil at a given soil-water ratio is the reciprocal of the specific resistance offered by the solution at 25ºC between the electrodes of 1 sq cm cross section kept 1 cm apart. Thus, the electrical conductivity of any solution depends on the amount of soluble salt present in it. Knowledge on the extent of salinity is important for management of saline soil including the choice of the crop suitable for that soil. Soluble salt content in saturation extract is more reliable index of salinity level than in soil: water ratio of 1: 2 or 1: 2.5, because it simulates the extent of salinity experienced by crop in field moisture condition.

Salinity class of soil is based on the electrical conductivity (EC) of saturation extract at 25ºC. However, EC of water extract from 1:2 soil-water suspension can be transformed into the EC of saturation extract following the formula (except for soil containing gypsum).

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).

Electrophoresis is an important separation technique for the charged molecules. Biologically important molecules, such as amino acids, peptides, proteins nucleotides, nucleic acids which carry electrical charge as they possess certain ionizable functional groups may be separated and identified from a mixture with the help of this technique. Some compounds that are non-polar in nature and do not possess any charge may be transformed to charge carrying derivatives. Thus, phosphate derivatives of carbohydrates may be separated and characterized utilizing electrophoretic techniques.

Technology Scouting and Innovations in Technology Incubation
Technology scouting and innovations in technology incubation have a symbiotic relationship, fuelling each other for the benefit of budding startups and the broader technology ecosystem. Let’s dive deeper into their individual roles and how they interact:
Technology Scouting
Technology Scouting is the process of discovering, analyzing and evaluating new or existing technologies that will help them with their innovation process. In simple terms, it is a process for companies to find the necessary technology outside the company.
Hunting for promising technologies: Scouts actively search for emerging technologies, patents, research advancements, and market trends across various sectors.
Evaluating potential and fit: They assess the technical feasibility, market potential, and compatibility with the needs of incubators and their supported startups.
Connecting innovators and ventures: Scouts bridge the gap between technology creators (researchers, inventors, startups) and potential users (incubators, established companies).
Fuelling innovation pipelines: Technology scouting helps incubators access a wider range of technologies and ideas, enriching their portfolio and diversifying the innovations supported.

Abstract

Variously defined endophytes are highly diverse in plants in natural ecosystems, and most of them are symbiotic with of them are Asymptomatic presence of endophytic fungi in internal tissues on healthy host plants are able to play vital roles in physiology and biochemical processes. As a result of this interaction endophyte produces chemical substances having various applications. This chapter provides a brief review of certain grass and non-grass endophytes capable to extend beneficial impacts on host plants to sustain the unfavourable conditions of abiotic stresses. However, biotic stresses are also a matter of great concern, where endophytes can play important roles in combating the unfavourable situation. Endophytic fungi used in bio-control and other agriculture related sectors are also  highlighted in this review. Endophytic fungi producing volatile organic compounds reported from all over the world and their various applications find place in this article which has opened new frontiers of bioprospecting of endophytic fungi.