eChapters

Origin of weeds : Weeds originated together with crop plants. They have been there since the man started cultivating crops about 10,000 BC. Man during his stage of development, explored certain crop plant to suit his own taste and fancy and cultivated them as ‘crops’. The unexplored / unwanted / troublesome plants which are interfering with his activities are considered as weeds. About 30,000 plants species have been identified as definite weeds in the World. Which are infesting crop lands, water bodies, gardens, orchards, road sides, railway lines, irrigation channels etc.

Plants are differentiated into

a) Crops: Which meet the needs of human being.

b) Weeds: Which compete or interfere in human affairs.

Jethrotull is the first person to use the word weed.

3.1. Cereals and millets

3.1.1. Rice

1. Major weeds

Grasses

Weeds are the plants growing where and when they are not desired. They compete with crops for soil moisture, nutrients, solar radiation and space, and thus reduce crop yields. Weeds also act as alternate hosts that harbour insect pests and diseases and other microorganisms. Some weeds release poisonous substances into the soil which may be harmful to crop plants, human and livestock. Weeds reduce the quality of marketable produce and render harvesting difficult, leading to increased expenditure on labours, equipment and chemicals for their removal.

Classification of weeds

A. Based on life cycle

Annuals-Complete their life cycle in a year or in a single growing season. Based on the season they may be summer annuals and winter annuals.
Summer annual e.g, Echinochloa crusgalli

Weeds are the plants, which grow where they are not wanted. Jethro Tull (1731) coined the word weed. Weeds can also be referred to as plants out of place.

Definition

Weeds are unwanted and undesirable plant that interfere with utilization of land and water resources and thus, adversely affect crop production and human welfare.

In organic agriculture weeds are treated as childrens of the soil.

In the world 30,000 species of weeds have been listed, of which nearly 18,000 cause serious damage to agricultural production. Eighteen weeds are considered as the most serious in the world and about twenty six species have been listed as principal weeds in crop fields of India, and are listed in annexure V

A. Answer the following questions:

1.    What is proximate analysis?

Ans: Proximate analysisis a systemforapproximatingthenutritive valueof a feedstuff without actually usingit in a feedingtrial.

2.    Why proximate analysis is called Weende analysis?

Ans: In 1865, two scientists namely Wilhelm Henneberg and FriedrichStohmanndeviseda methodcalledWeende analysis/ proximate analysis at Weende Experiment Station, near the University of Goettingen, Germany. Hence, it is called ‘Weende Analysis’.

3.    Write the six proximate principles?

Ans: Water (moisture), ether extract (crude fat), crude fibre, total ash, crude protein and nitrogen free extract (NFE).

4.    Why ether extract is also called as crude fat?

Ans: As it is composed of true fats (glycerides of fattyacids) along with other substances like hydrocarbons, free fatty acids, fat solublevitamins,pigmentslike carotene & chlorophyll,waxes, sterols,lecithin(phospholipids), alkali substances,volatile oils and resins.

5.    What is NFE?

Introduction

In a research laboratory, we frequently need weigh chemicals and prepare different solutions of varying strength, as per the requirements. Accuracy in weighing and preparation of solution, with respect to weight/volume and strength, determines the success of experiment. In turn, the accuracy depends on weighing of solid chemical and/or measuring the volume of liquid chemical/making up the volume. In this Chapter, weighing of chemicals using appropriate weighing balance, preparation of solutions of different strength, their dilution, and precautions while preparing will be discuss in brief.

Weighing of Chemical

The primary method to determine the amount of chemicals to be used is weighing the chemical by using a balance.

In general, there are two types of balances to weigh chemicals in a laboratory:

1. Standard laboratory balance

2. Analytical balance

Standard Laboratory Balance

Generally, a standard laboratory balance is used for weighing a chemical when an error of ±0.02 g is acceptable. It is also used for pre-weighing, where approximate mass needs to be determined. Precise mass of the chemical is then determined using an analytical balance. Following are the steps in using a weighing balance in a laboratory.

Introduction

Welding is a fabrication process in which two or more materials or metal pieces are joined or fused with the application of heat, pressure, or both allowing them to cool and this causes fusion. Besides the work piece, a filler material is also sometimes added to the joint to form a pool of molten material that cools to form a joint based on welding and that will be stronger than the parent metal.

Arc Welding and its Types

It is a process of joining two metals using an electric current generated by the power supply, which gives the required amount of heat to metal pieces through which the metals melt and when the metal cools, which results in the binding of the two metals. In the case of this type of welding, the power supply is given, which creates an electric arc between the electrode and the metal rod. Both A.C. or D.C. power supplies can be used in arc welding and both consumable and non-consumable rods can be used.

All farmed animals are transported at some stage in their lives, sometimes to places where food is more readily available, sometimes to a different owner or a different place of keeping and sometimes to slaughter. The handling, loading, transporting and unloading of animals can have very substantial effects on their welfare. Wherever   poor welfare associated with the transport of animals is prevented, there is an immediate financial advantage because mortality rates and carcass downgrading are reduced. The attitude towards animals has major consequences on animal welfare during transportation. Therefore, laws and codes of practice can also have significant effects on animal welfare during transport. In order to produce guidelines that can be used to prevent or minimise poor welfare in animals during transport, it is necessary to be aware of the biological functioning of the animals concerned and the attitudes and actions of the people involved in the handling and transport procedures.

Fish are Sentient Animals

There is strong increasing evidence that finfish, like other vertebrates are sentient animals. This means that fish are self-aware, they can feel pain and distress, they have long term and short-term memory and to some extent, they can experience emotions.

Fish are intelligent, sensitive creatures and like many other animals, they explore, travel, socialise, hunt and play. Some species care for their young and use tools as humans do. Fish are sentient animals capable of suffering and feeling pain. Most fish have highly developed senses with excellent taste, smell, hearing and colour vision. Until fairly recently, many people didn’t realise that fish were sentient or feel pain, and the mental abilities of fish were given limited attention by the scientific community. Now, recent discoveries open up a new world of understanding. Far more complex than we ever realised, f ish live rich social lives: communicating; hunting cooperatively; and, in some cases, developing cultural traits. Consensus arrived in the mid-2000s around science demonstrating high-level pain perception in fish, and examinations of fish behaviour are beginning to reveal a picture of fish as complex, social and emotional beings. Appreciation of these facts are not widespread in civil society, but identified in time for the principle of fish welfare to be recognised by legislation by the European Union.

In India, the cow is a worshipped as symbol of wealth, strength, abundance, altruistic giving and full of earthly life. Cows are traditionally treated as a sacred animal. Dairy products are extensively used in India and are one of the most essential nutritional components of meals.
 
The laws governing cattle slaughter is shown in entry 15 of the State List of the Seventh Schedule of the Constitution, meaning that State legislatures have exclusive powers to legislate the prevention of slaughter and preservation of cattle. Some States allow the slaughter of cattle with restrictions like a “fit-for-slaughter” certificate which may be issued depending on factors like age and gender of cattle, continued economic viability etc. Others completely ban cattle slaughter, while there is no restriction in a few states. Prohibition of cow slaughter is a Directive Principles of State Policy contained in Article 48 of the Constitution.

11.1 Introduction

The laws governing the flow of water in wells are referred to as the hydraulics of wells. Just like surface water flows from a higher elevation to a lower elevation by gravity, groundwater also flows from a region of higher water table to a region of lower water table. This difference of water table measured by any two piezometers divided by the longitudinal distance between them is called as hydraulic gradient. Hydraulic gradient plays a dominant role in deciding the flow of groundwater. This hydraulic gradient together with the hydraulic conductivity of the aquifer material forms the main law of well hydraulics called as Darcy’s law. An understanding of Darcy’s law together with some other laws as discussed subsequently in this chapter is essential in order to know the discharge of a well in a particular formation. Darcy’s law is valid for studying groundwater flow in alluvial formations. However, it is not valid for aquifers having hard rock areas.

15.1 Introduction

The laws governing the flow of water in wells are referred to as the hydraulics of wells. Just like surface water flows from a higher elevation to a lower elevation by gravity, groundwater also flows from a region of higher water table to a region of lower water table. This difference of water table measured by any two piezometers divided by the longitudinal distance between them is called as hydraulic gradient. Hydraulic gradient plays a dominant role in deciding the flow of groundwater. This hydraulic gradient together with the hydraulic conductivity of the aquifer material forms the main law of well hydraulics called as Darcy’s law. An understanding of Darcy’s law together with some other laws as discussed subsequently in this chapter is essential in order to know the discharge of a well in a particular formation. Darcy’s law is valid for studying groundwater flow in alluvial formations. However, it is not valid for aquifers having hard rock areas.

Introduction

Wells are vertical shafts excavated or holes drilled in earth to the level of water table for extraction. Digging of wells is an age old practice. Shallow dug wells supported communities in the past. Well water is drawn to the ground manually or mechanically using variety of containers made of metal, leather, canvass and wood or a combination of them. Draught animals or electrical power are used to draw water for irrigation.

Water table (Fig.6.1) wells extend below the groundwater table and extract free water. Pumping water from these wells lowers the water level. The well first gains water from the water bearing material in its immediate proximity. Subsequently a cone of depression is formed in the immediate vicinity of the well. Water outside the cone of depression but with in the area of influence is diverted to replace the body of groundwater finding its way in to pumping well.

Pulses are recognized as an integral part of Bengali as well as Indian diet and the ideal supplement of cereals by virtue of their high protein and essential amino acid content.  Pulses are inseparable ingredients of vegetarian diet and one of the cheapest sources of dietary nutrition protein in the state. The present emphasis on soil health, environmental quality and economic consideration, has stimulated a paradigm shift in cropping patterns leading to pulse based cropping systems. Any cropping system can become compatible and complete only when a pulse crop is included in it. Pulses won a strategic position in intensive as well as subsistence agriculture, as they are excellent source of dietary protein for millions of people, nutritional feed for livestock and having profound ameliorative effect on soil.

West Indian Cherry is a nutritive fruit mainly grown in semi dry and tropical parts of the country. It is native to West Indies and Central and South America and distributed in Southern Florida, Hawaii and other tropical and sub tropical regions of the world. West Indian Cherry received considerable attention in the 1950’s in its area of distribution because of its extremely high vitamin C content (2000-4600 mg / 100 gm of edible matter). It has been considered to be far superior to guava (Psidium guajava L.) as a potential source of vitamin c and it is richer than even the Indian gooseberry (Phyllanthus emblica L.), which is reported to contain roughly 800 mg of ascorbic acid per 100 g of edible matter. One fruit the size of a large cherry can furnish a man’s daily requirement of this vitamin. Thus the fruit of West Indian Cherry can rightly be called as the “pill of nature’s vitamin”. The fruit can be utilized for the production of crystalline vitamin C. The fruit is also rich in vitamin A, iron and can be consumed fresh or can be used in preparation of sherbet, ice cream, jelly and baby foods, fruit nectars and soft drinks. The juice can also be used to fortify ascorbic acid content of various other products and fruit juices to improve their nutritive value. It can withstand mild frost and drought. Fruits are good source of vitamin C and bark yields tannin (Chadha, 2001).

WNV was first identified in the West Nile district of Uganda in 1937. Reported in Western Hemisphere for the first time in 1999, in New York City. The virus had until that time been found only in Africa, Eastern Europe, West Asia and the Middle East.

Principle

Western blot analysis (also called protein immunoblot) is a useful tool for the detection of proteins in biological samples. It uses gel electrophoresis to separate native or denatured proteins by the length of the polypeptide (denaturing conditions) or by the 3-D structure of the protein (native/ non-denaturing conditions). The proteins are then transferred to a membrane (typically nitrocellulose), where they are probed (detected) using antibodies specific to the target protein.  It is a technique for analyzing and identifying protein antigens: the proteins are separated by electrophoresis in polyacrylamide gel, then transferred (“blotted”) onto a nitrocellulose membrane or treated paper, where they bind in the same pattern as they formed in the gel. The antigen is overlaid first with antibody, then with anti-immunoglobulin or protein A labeled with radioisotope, fluorescent dye, or enzyme. 

The method originated from the laboratory of George Stark at Stanford. The name “Western blot” was given to the technique by W. Neal Burnette and is a play on the name “Southern blot”, a technique for DNA detection developed earlier by Edwin Southern. Detection of RNA is termed northern blotting and the detection of posttranslational modification of protein is termed “Eastern blotting”.

Introduction

The western blot (alternatively, protein immunoblot) is an analytical technique used to detect specific proteins in a given sample of tissue homogenate or extract. It uses gel electrophoresis to separate native or denatured proteins by the length of the polypeptide (denaturing conditions) or by the 3-D structure of the protein (native/non-denaturing conditions). The proteins are then transferred to a membrane (typically nitrocellulose or PVDF), where they are probed (detected) using antibodies specific to the target protein.

There are now many reagent companies that specialize in providing antibodies (both monoclonal and polyclonal antibodies) against tens of thousands of different proteins. Commercial antibodies can be expensive, although the unbound antibody can be reused between experiments. This method is used in the fields of molecular biology, biochemistry, immunogenetics and other molecular biology disciplines.

Other related techniques include using antibodies to detect proteins in tissues and cells by immunostaining and enzyme-linked immunosorbent assay (ELISA).

The method originated from the laboratory of George Stark at Stanford. The name western blot was given to the technique by W. Neal Burnette and is a play on the name Southern blot, a technique for DNA detection developed earlier by Edwin Southern. Detection of RNA is termed northern blotting and the detection of post-translational modification of protein is termed Eastern blotting.

Introduction

Western blot analysis can detect one protein in a mixture of any number of proteins while giving you information about the size of the protein. It does not matter whether the protein has been synthesized in vivo or in vitro. This method is, however, dependent on the use of a high-quality antibody directed against a desired protein. So you must be able to produce at least a small portion of the protein from a cloned DNA fragment. You will use this antibody as a probe to detect the protein of interest.

Western blotting tells you how much protein has accumulated in cells. If you are interested in the rate of synthesis of a protein, Radio-Immune Precipitation (RIP) may be the best assay for you. Also, if a protein is degraded quickly, Western blotting won’t detect it well; you’ll need to use (RIP). See the section on RIP for more information, as well as a helpful comparative chart that illustrates the differences between these two techniques.

Introduction

Wet ashing is suitable for the determination of Ca, Cu, Fe, Mg, Mn, K, Na, Se and Zn in biological samples and may be applicable to the determination of other elements as well.

The organic matter of the sample is oxidized with concentrated nitric acid and perchloric acids. The acids are partially removed by volatilization and the solube mineral constituents remain dissolved in nitric acid. Any silica present is dehydrated and made insoluble.