eChapters

Introduction
Plants have been used for ages as animal and human health cures. Ethnoveterinary medicines, a phrase that primarily refers to folk skills, beliefs, knowledge, practices, and procedures related to animal health and the treatment of various disorders in rural regions, have acknowledged the ability of plants to combat a variety of diseases. The World Health Organisation (WHO) defines traditional medicine, also referred to as herbal medicine, as “When it comes to maintaining health and preventing, diagnosing, improving, or treating physical and mental illnesses, the entirety of the knowledge, abilities, and practices derived from indigenous theories, beliefs, and experiences whether or not they can be explained as illness”. Approximately 25% of contemporary medications are derived from plants that were once used in traditional medicine. The use of traditional medicine and its confirmation could result in the creation and discovery of more novel medications.

Marjoram is native of Southern Europe. It grows in West Asia, South and North America, France, Germany, Hungary, Spain, Portugal, England and North Africa. It is an important kitchen herb and its dried leaves with or without flowering tops in small proportion constitute the spice of commerce. In India, the crop finds its cultivation only in small scale in Karnataka, Andhra Pradesh and Tamil Nadu. France and Egypt are the main exporters of marjoram oil in the world.

Botany and chemical composition

Marjorana hortensis is an aromatic branched perennial, 30-60 cm high. Though a perennial, it is treated as an annual under cultivation. Main stem is woody with many softer branches. Leaves are round, soft, mat green and with a marvelous sweet smell. Flowers small, whitish or purplish in terminal clusters, seeds minute, oval and dark brown in colour.

ABSTRACT

According to WHO report, over 80% of the world population relies on traditional medicine, largely plant based for their primary healthcare needs. India has 15 Agroclimatic zones, 12 ecoregions and 47,000-plant sp. and is one of the 12-mega biodiversity centres. The Indian Systems of Medicine have identified 1500 medicinal plants, of which 500 species are used in the preparation of commercial drugs. These medicinal plants contribute to 80% of the raw materials used in the preparation of drugs.

1. Introduction

Herbarium is simply a dried and pressed collection of plants arranged in an accepted sequence of classification (Lawrence 1951, Shetler 1969). It can be a very useful teaching aid or an absorbing hobby (Cronquist 1966). According to Fosberg and Sachet (1965) “A modern herbarium is a great filing system for information about plants, both primarily in the form of actual specimens of plants and secondarily in the form of published information, pictures and recorded notes”. It is also a research, training and service institution that serves as a reference centre, documentation facility and data store house (Radford 1986). It is now well recognized that a herbarium is a vast reservoir of facts about plants. The word ‘Herbarium’ was originally applied, not to a collection of plants but to a book dealing with medicinal herbs. Tournefort in about 1700 used the term as an equivalent to ‘Hortus Siccus’ which was later on adopted by Linnaeus (Stearn 1957). The present concept and development of herbarium is due to efforts of botanists for more than four centuries. The concept of herbarium has been changing continuously, which in turn, has affected the gradual development of herbarium and herbarium practices.

For practical reasons, the classification of the world’s flora is primarily based on herbarium material and the literature associated with it. Despite its limitations, a herbarium has certain advantages over living collections. It is usually only in the herbarium that we can compare all the related species of a genus in the same place, in the same state and at the same time (Davis 1961).

The herbarium material, therefore, formed the foundation of all botanical studies. We should, therefore, realise that herbaria are the custodians of enormous data pertaining to plants. They are usually seen as old-fashioned and expensive “stamp collection” without realising their paramount role in biological sciences. However, the world-wide rise of interest in the field of conservation, biodiversity and bioprospection offer a new chance for herbaria. Furthermore, computers offer a golden opportunity to raise the status of herbarium taxonomy by making routine curatorial procedures more efficient.

Although Jain and Rao (1976) elaborately discussed the methods of field collections, identification and preservation in the herbarium, the salient features of herbarium in up dated form with various procedures followed in Indian context are discussed in this chapter.

14.1 Herbarium and Its Limitations
A collection of dried and pressed plants arranged according to a classification system and available for study or reference is known as herbarium (plural, herbaria), a name first applied by Linnaeus.
Plant specimens are usually mounted on a sheet of high quality paper. Properly dried, pressed and identified plant specimens are placed in thin paper folders (species covers) which are kept together in thicker paper folders (genus covers), and finally they are incorporated into the herbarium cupboards in their proper position. Some fleshy members (e.g. Cactaceae) are preserved in liquid preservatives instead of being pressed and dried. Bulky plant parts (e.g. dry fruits, cones of several gymnosperms, etc.) are dried without pressing and are stored in special bags.
A herbarium may contain a few hundred locally collected plant specimens kept in a small place, or it may contain millions of them collected from different parts of the world and housed in a very big building. Herbaria in different countries remain associated with colleges, universities, scientific societies, research institutes, botanical gardens or flora of a district, state, country, continent or several continents. There are also private herbaria.

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

Herbicide Application

Generally, herbicides are applied in the form of solution or granules. Of the two, spraying solutions of herbicides formulated as wettable powders, soluble powders and emulsifiable and solution concentrates is more common. When herbicides are formulated as granular or encapsulated materials, they are applied by hand or with the help of a granular applicator.

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

Herbicide History and Development

Common salt, ash, smelter waste, and like cheap materials have been used for centuries to control weeds on roadsides, fence rows, and pathways. But Chemical weed killing was born in 1896 when Bonnet, a French grape grower, observed that the Bordeaux mixture which he used against downy mildew of grape turned the leaves of Sinapis arvensis (a weed) black. Soon it was found that copper sulphate present in the Bordeaux mixture was responsible for its weed killing effect. Further tests in France, Germany, and U.S.A. established that copper sulphate could indeed be used for selective control of broadleaf weeds in small grains; wheat, barley, and oat. Between 1896 and 1908, several other inorganic salts, as also sulphuric acid, were found selective to small grain cereals. Of these, in Europe, a 6 to 10 per cent solution of sulphuric acid continued for considerable time as a satisfactory herbicide for broadleaf weed control in cereals, but it corroded the containers and sprayers. In the U.S.A., salts like sodium chlorate, carbon bisulphide, sodium arsenite, kainite, and calcium cyanamide were developed for non-selective eradication of perennial weeds, particularly, Convolvulus arvensis ‘field bind weed’ and Cirsium arvense ‘Canada thistle‘. In Hawaii, sodium arsenite solution was found highly effective for weed control in sugarcane plantations. Between 1930 and 1940, some boron compounds, thiocyanates, dinitro phenols (DNC and DNBP), ammonium sulphate, and certain mineral salts were developed in the west for selective and non-selective weed control. DNC and DNBP wereused extensively in Europe in small grains for broadleaf weed control, even though these chemicals dyed the hands and clothes of the users to yellow colour, almost permanently. Further milestones in weed control were introduction of organic chemical, 2-methyl-4, 6-dinitrophenoll (DMOC), in 1932 and discovery of hormone type selective weed killers. Selective residual chemicals such as substituted phenyl ureas and triazines, and non-residual chemicals diquat and paraquat are more recent discoveries.

The discovery of the herbicidal activity of 2, 4-D (2, 4-dichlorophenoxyacetic acid) first synthesized in 1941, triggered the development of modern herbicide technology. 2, 4-D proved to be an outstanding herbicide.

Herbicide Mixtures

A mixture of two or more herbicides could be more effective for controlling different weed species. In horticultural and plantation crops, weed free situation is needed during the entire year over several years. In such situations, herbicides are to be rotated to take care of all the species of weeds. A mixture of herbicides, due to chemical reaction, may enhance or reduce the efûciency of one or more compounds. Hence, knowledge of herbicides interactions is essential for efûcient use of herbicides in weed control.

Persistence of Herbicide in Soils

Most of the herbicides are applied to soil as pre-emergence for weed control under different situations. For effective weed control, herbicides must remain in soil in active and available form until their purpose is served. Larger persistence poses hazard to subsequent land use and is undesirable. The length of time that an herbicide remains active in the soil is called persistence or soil residual life. The quantity of herbicide that remains in the soil after its mission is accomplished is referred as residue. The term residue infers the continued presence of herbicide in the soil in very small quantities even though it may not be present in herbicidal quantities or available for plant absorption. Herbicide residues in soils are undesirable mainly because they may

Injure sensitive crops in a cropping system,

Be absorbed by succeeding crops and residues accumulated in unlawful amounts in the produce,

Result in building up of herbicide residues following repeated treatments that exceed their rate of dissipation, and

Inhibit growth of soil micro-organisms.

Knowledge of persistence and carry over residual effect of herbicides is essential to use them safely and effectively. Persistence of herbicides in soils pose hazard when

Highly persistence herbicides are used,

Crop failure necessitates replanting,

A susceptible crop follows a short term crop which received a persistence herbicide, and

Decomposition of the applied herbicide proceeds very slow.

Resistance

The intensive and continuous use of herbicides over the last five decades has resulted in the development and evolution of weeds resistant to the normally phytotoxic chemicals. Although herbicide resistance was reported as early as 1957 against 2, 4-D from Hawaii the first confirmed report of herbicide resistance was against triazine herbicide in common groundsel (Senecio vulgaris) was reported in l968 from U.S.A. Over the years, more than 150 weed species have been identified as having developed biotypes resistant to at least one or more herbicide classes. Resistance to at least 15 classes of herbicides have been noted. Moreover, the area of land infested with resistant weeds is increasing rapidly. Reports of evolution of newly resistant biotypes continue to emanate from all over the world, including developing countries, e.g., India, where extensive use of herbicides in grain crops began only in the late 1970s. These reports indicate that herbicide resistance problems are accelerating and, consequently, management of weeds is becoming increasingly more difficult and complex.

The phenomenon of herbicide resistance in plants, especially in weeds, is analogous to the evolution of changes that arise in insects and pathogens in response to the continuous use of insecticides and fungicides. Herbicide resistance is the result of selection for traits that allow weed species to survive specific herbicide usage, which would otherwise cause mortality. Herbicide resistance contributes a trait of resistance within the plant species to a herbicide and resistant weeds are those plant species that express the genetic variation required to evolve mechanisms to escape control. Like other crop pests (insects, pathogens, etc.) with reference to pesticides (insecticides, fungicides, etc.), herbicide-resistant weeds are the result of intensive selection pressure in weed populations.

Generally, resistance is defined as the ability of a plant species to withstand the phytotoxicity of a chemical. This is the trait normally found in crop plants, as against weeds, thus forming the basis for herbicide selectivity. Crop resistance to a herbicide is often different from the one that exists in the phenomenon of herbicide resistance in weeds.

Herbicide resistance in the context of weeds is defined as a characteristic of the weed species to withstand a herbicide dosage substantially higher than the wild type of the same plant species can withstand. It is the inherent or acquired ability to withstand the dosage of herbicide normally used for satisfactory weed control. Resistant weed populations are unharmed by a concentration of herbicide that completely kills all unselected populations. This herbicide concentration is the one that in field practice produces an effective kill.

Herbicide susceptibility represents the other end of the scale, encompassing natural variability in sensitivity to herbicides within the unselected populations. Tolerance, on the other hand, indicates reduced susceptibility (or conversely enhanced resistance) which may sometimes result from selection by herbicides. It is a response rather less than 100% survival accompanied by zero reduction in growth at herbicide concentrations, which normally give 100% Kill of susceptible biotypes. Tolerance may also be considered the natural or normal variability of response to-herbicides that exists within a species and can easily and quickly evolve.

1. Herbicide –herbicide interaction

Herbicides cause some effects as follow:

(i) Synergistic: Synergism is defined as the cooperative action of different chemicals in a mixture such that the total effect is greater than the sum of the independent effects (Green et al., 1997). In relation to herbicides, the total  induced by an herbicide mixture is greater than the sum of the responses by each herbicide alone (Anderson, 1996). Synergistic  is often used to describe the effect of drugs working together — where one drug increases the other’s effectiveness. Synergy is the interaction of multiple elements in a system to produce an effect different from or greater than the sum of their individual effects.

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

3.1 Introduction

Weed is defined as an unwanted plant growing at a place where it is not desired. According to Jethro Tull, the father of Weed Science, weed is defined as the unwanted, undesirable plant, growing out of their proper place, which interfere with the utilization of natural resources, prolific, persistent, competitive, harmful and even poisonous in nature and can grow in adverse climatic conditions. Weeds are considered major obstacle in agricultural production systems particularly in fruit crops. Weeds are a major problem to horticultural production as they take advantage of their initial slow growth rate. It has been reported that about 36-42% losses may occur due to inadequate management of weeds in apple (El-Metwally and Hafez, 2007). Fruits have a great potential but orchards are generally, infested with various types of annual, biennial and perennial weeds which compete with the fruit plants for nutrients, space, moisture, light and adversely affect growth, vigour, fruit set, flower initiation, yield, fruit quality and winter hardiness (Majek et al., 1993) and thereby directly reducing the productivity of fruit trees. Weeds also provide shelter to various pathogens by becoming an alternate or collateral host of invaded crops by a number of fungal, bacterial and viral diseases. Therefore, management of weeds in all agro-ecosystems is crucial to sustain our crop productivity and to ensure the food security to the rapidly increasing population. Weed control in orchard can be usually accomplished by various methods like manual, mechanical and chemical means. Yet the conventional hand weeding is the most common method of weed control which is not only laborious but also time consuming and expensive owing to high wage rates. If fruit orchards are located in high hilly areas with small and narrow routes, it would restrict the use of machinery which is also expensive and might injure the roots and stems of the fruit trees. Gradually, manual and mechanical weed control methods are being replaced by other alternatives such as herbicides and mulches as these are easier, cheaper and less time consuming. In recent years, the use of herbicide is becoming popular among the fruit growers all over the world.

SYNOPSIS

Flavor is the sensory impression of a food or other substance, and is determined mainly by the chemical senses of taste and smell. The flavor of the food, as such, can be altered with natural or artificial flavorings which affect these senses. Smell is the main determinant of a food item’s flavor. While the taste of food is limited to sweet, sour, bitter, salty, umami (savory), pungent or piquant, and metallic – the seven basic tastes – the smells of a food are potentially limitless.

1. Herbs and Spices
       
    1.    International Standards Organization (ISO) defines spices and condiments as: Vegetable products or mixtures thereof, free from extraneous matter, used for flavouring, seasoning and imparting aroma in foods.

    2.    Rosengarten describes a spice as a product which enriches or alters the quality of a thing, for example altering the taste of a food to give it zest or pungency; a piquant or lasting flavouring; or a relish. The term ‘spice’ is thus used to cover the use of spices, herbs and certain aromatic vegetables to impart odour and flavour to foods.

    3.    Herbs may be defined as the dried leaves of aromatic plants used to impart flavour and odour to foods with, sometimes, the addition of colour. The leaves are commonly traded separately from the plant stems and leaf stalks.

Dirying in India has traditionally been the preserve of landless agricultural labourers and small and marginal farmers, who have maintained very small herd sizes. However, of late, with increasing consumer awareness regarding milk quality, there has been a marked increase in the number of large, well-organized dairy farms which cater to predominantly urban markets. Terms like clean milk production, organic milk, microbial load of milk etc. are being used more frequently while referring to milk quality. Larger, intensive dairy farms not only profit from the economies of scale by way of optimum utilization of land, labour and resources, but also benefit from the fact that it is easier and cost-effective to implement more efficient technologies like machine milking, manufacture of by products, chilling, packaging, bulk transport etc. Further, most of these farms are able to realize a premium price for their products on account of high quality and brand identity, thus leading to greater profitability.

Herd A large number of animals that live and feed together in a group (Fig.197) is called as herd. In herd, all animals are considered as a unit rather than individual. Herd medicine, also known as herd health or production medicine, is the discipline of veterinary medicine that deals with the diagnosis, treatment and prevention of the diseases in the herd as a whole. Concept and Significance of Herd Health Herd health is a combination of regularly scheduled veterinary activity and management practices undertaken to maintain optimum health to achieve optimum production in the farm. Traditionally, the aim of the herd health is to control or eliminate diseases and rectify management inefficiencies impacting the welfare and productivity in the frame work of risk monitoring and assessment in conjunction with best farming practices. The main emphasis

Herd medicine considers groups of animals as a single management and health unit rather than focusing only on individual patients. This chapter explains herd health and production medicine, emphasizing disease prevention, productivity, animal welfare and economic efficiency. Major components include nutrition, hygiene, reproduction, vaccination, record keeping, biosecurity and environmental management. Identification of risk factors and subclinical disease is important for reducing production losses. Biosecurity measures include quarantine, sanitation, disease testing, vaccination and control of visitors, vectors and wildlife contact. The chapter promotes preventive veterinary medicine through practical, economical herd-health programmes designed to improve production and reduce disease.