eBook Chapters

A. Diseases

1. Anthracnose

Hemp anthracnose is caused by two different fungi, viz., Colletotrichum coccodes (=C. atramentarium) and Colletotrichum dematium (Saccardo, 1882; Cavara, 1889).

i) Anthracnose (Colletotrichum coccodes)

Occurrence & severity status

The anthracnose disease occurs on many plants, including hemp (Cannabis sativa). The disease causing fungus is well-studied and it is an important pathogen responsible for black dot disease on potato. The fungus is an unspecialized pathogen, infecting a wide range of host families. It is most common in Canada and commonly regarded as a minor pathogen or secondary invader, but the fungus may seriously affect yield where intensive cropping without rotation occurs. It primarily affects the growth rate of plants and diminishes harvest. Moreover, it becomes fatal occasionally. Hoffman (1958, 1959) reported heavy hemp losses in central Europe. Conversely, Gitman (1968b) considered the pathogen was of little importance in the USSR.

Introduction

There is concern that antibiotic-resistance in bacteria may make commonly used antibiotics less effective. Oral immunotherapy (passive immunization) with specific antibodies is a strategy that has been actively pursued in laboratory and clinical studies for the last two decades. Feeding of egg yolk antibodies to neutralize specific pathogens, especially enteric microorganisms, is a potential alternative to antibiotics. Oral administration of these antibodies has met with some degree of success in prevention of viral and bacterial enteric infections in humans, piglets, calves, fish and rabbits. It is proposed that the egg yolk antibodies may act against enteric pathogens by binding, immobilising and consequently reducing or inhibiting the growth, replication, or colony forming abilities of these pathogens. Three immunoglobulin classes (IgA, IgM and IgY) have been shown to exist in chickens. Chicken immunoglobulin G (IgG) has been designated as immunoglobulin Y(IgY) because it varies in several aspects from mammalian IgG. IgY is the main serum immunoglobulin in chickens. It is transported from the hen to the embryo via the egg yolk. The egg yolk thus contains high concentrations of IgY. Other immunoglobulin (Ig) classes are present only in negligible amounts in the egg yolk. It has been shown that the presence of immunoglobulins in eggs is an example of passive immunity. This is because these antibodies originated from the hen and are used to protect the offspring from various infectious diseases after hatch.

Hendra, a disease of horse has been recognized in Australia since 1994-95 with zoonotic importance. It is caused by a virus under the genus Megamyxovirus and subfamily Paramyxovirinae and family Paramyxoviridae. This virus is also endemic in certain species of bat. Another zoonotic bat virus called Nipah virus has been placed under the same genus and family. It is transmitted between the horses through contact. Infected horses can develop a severe and fatal respiratory disease characterized by dyspnoea, vascular endothelial damage, pulmonary oedema and neurological signs. Experimental infection of cats and guinea pigs showed fatal respiratory disease. The transmission of virus from horse to horse and horse to man is through close contact. One person died of the disease due to respiratory failure and another one due to delayed onset of encephalitis. A number of diagnostic methods are available to provide prompt, sensitive and accurate diagnosis of the disease.

History: In 1994-95, a new viral zoonotic disease was identified in Queensland, Australia resulting in death of 2 human and 15 horses in two separate incidents. Again, in 1999 another horse died at the same place. The term 'Hendra' has been derived from the name of a place, suburb of Brisbane where first outbreak took place. In September 1994, a total of 15 horses died due to hyperacute respiratory disease. The trainer of the horse also died. In 1995, a farmer died of meningoencephalitis after having contact with a Hendra positive horse. In the 1999, a mare died of Hendra virus infections.

Etiology: The Hendra virus is under the new genus Megamyxovirus and family Paramyxoviridae. The Hendra virus was isolated in Vero cells from lung specimens and produced CPE within 3 days. The virus can grow in MDCK, BHK, RK13, LLC-MK2 and MRC5 cells. It also grows in cells derived from birds, reptiles, amphibians, fish and in embryonated chicken eggs. The virus does not have haemagglutinin or neuraminidase activity. The virus is pleomorphic in shape, 38-600 nm in diameter and enveloped with two glycosylated transmembrane proteins of different lengths (15 and 18 nm). It differs from respirovirus and rubulavirus in not using sialic acid containing receptors. The virions are labile and infectivity is destroyed by heat, lipid solvents, non-ionic detergents, formaldehyde and oxidizing agents. Virions contain one molecule of negative sense ssRNA about 15 Kb long which codes 8 proteins. The Hendra virus is the largest of all known viruses under Paramyxoviridae. The genetic studies showed that Hendra virus is more similar to Morbillivirus or intermediate between Morbillivirus and Respirovirus. The amino acid homology between Hendravirus and Morbillivirus varies from 17-21% (P protein) to 40-42% (M protein) compared to 6-10% and 8% respectively for other members of Paramyxoviridae. A new Hendra like virus has been identified as a cause of respiratory and neurological disease in pigs and humans in Malaysia, called Nipah virus, after a village where the first human case occurred. (The amino acid homology of N protein between Hendra and Nipah is 92%, whereas in case of P&V it is 80-85%). Like, Hendra virus, the Nipah virus is thought to have emerged from a fruit bat (Pteropus hypomelanus).

Henna (Lawsonia inermis L.) is a multipurpose shrub also known as mehandi. It is grown through out the country as a hedge plant. In India, it was once grown extensively in Punjab and Gujarat. However, gradually major cultivation has shifted to the arid fringes of Rajasthan with the Pali district having the maximum area under henna cultivation. It is taken as an annual ratoon crop under rain fed conditions. Presently there are over 22,000 ha of henna plantations in the Pali district nearly 70 percent occurring in the Sojat area which produces around 20000 tonnes dry leaves worth Rs.40 crores annually. Sojat city is world famous for its mehandi or henna (Heena) powder.

Henna or Mehandi (Lawsonia inermis L.) a perennial shrub belongs to family Lythraceae. It is commonly cultivated as a commercial dye crop possess natural dyeing properties and are used for hair dyeing and for staining of palm, feet and other body parts since times immemorial. The plant finds their importance due to presence of orange red dye in its leaves and essential oil in its flower. Oil extracted from leaves and flower called ‘Otto of henna’ which is utilized as perfume (Jaimini et al., 2005). It can grow well in harsh climate of arid and semiarid regions. In India, over 90 percent of the henna production comes from Sojat region of Pali district of Rajasthan and Sojat is only center for its processing and trading in India. In India it occupies about 40,000 ha area out of which 35,000 ha alone is in Pali district (Sojat and adjoining tehsils).

Geographical distribution

It occurs naturally in North Africa mainly in countries of Algeria, Cyprus, Egypt, Eritrea, Ethiopia, Indonesia, Iraq, Iran, Jordan, Kenya, Kuwait, Lebanon, Libya, Malaysia, Morocco, Oman, Philippines, Qatar, Saudi Arabia, Syrian Arab Republic, Tanzania, Tunisia, Turkey, Sahara and Yemen. It is naturally occurring in many of these countries along the water courses and semi-arid regions where it can with stand dryness as well as drought. It has been introduced into countries like Australia, Benin, Burkina Faso, Cameroon, Central Africa, Chad, Congo, China, Gabon, Gambia, Ghana, Guinea, India, Liberia, Mali, Mauritania, Niger, Nigeria, Pakistan, Senegal, Sierra Leone, Spain, Sudan, Togo and Zanzibar (Suresh Kumar et al., 2005).

Distribution

Several countries grow henna on a commercial scale for its dye-bearing leaves, notably India, Egypt, Iran, Niger, Sudan and Pakistan. In India, it was once grown extensively in Punjab and Gujarat. However, gradually the major cultivation has shifted to the arid fringes of Rajasthan, with Pali district having the maximum area under henna. It is taken as an annual Ratoon crop under rainfed conditions. Presently over 39,000 ha of henna plantations in the district with nearly 70 per cent occurring in the Sojat area produce around 20,000 t dry leaves worth Rs. 40 crores. Besides this, leaf cuttings are also collected from existing farms and field boundary plantations in Gujarat and Madhya Pradesh. In Uttar Pradesh henna is grown for its scented flowers used in the essence industry. Kannauj, Lucknow, and Varanasi in Uttar Pradesh are reputed centres for the commercial extraction of mehndi oil from flowers and its use in traditional essence. Since henna is grown as a dryland crop under limited moisture conditions greater use of available moisture by the plants is possible.

Suits especially scrofulous and lymphatic constitutions that are inclined to have eruptions and glandular swellings. Unhealthy skin. Blondes with sluggish character and weak muscles. Great sensitiveness to all impressions. Sweating patient pulling blanket around him. Chilliness, hypersensitiveness, splinter-like pains, craving for sour and strong things are very characteristic. The tendency to suppuration is more marked, and ahs been a strong guiding symptom in practice. The side of the body on which he lies at night becomes gradually insufferably painful; he must turn.

Hepar Sulph is the medicine for abscess, for the tendency to suppuration. Every little injury suppurates. Accompanying this suppuration is shooting pain. Suppuration or pus formation can be on any part of the body. If throbbing and shooting pain accompany it, it requires a does of Hepar Sulph in a high potency of 200 and above. Hepar Sulph can abort pus formation if given at the earliest stage of suppuration. Later it will hasten the pointing and discharge and help in healing the ulcer.

Herbaceous border

In this system plant are arranged in irregular group of a kind for harmonious are contrasting colour effect, either all flowering at one time or successfully in such a way that those flowering latter should grow up and screen the all ready flowered. The planting of annuals in the border of a plot is called as herbaceous border. When the border is to be viewed from both side tall plant are planted in center followed by medium and dwarf planting in both side. Herbaceous border may include all the herbaceous plant including herbaceous perennial (Flowering and non flowering) bulbous and annuals (see plate 20 & 21).

The state of Jammu and Kashmir is highly mountainous except for a short belt joining the Punjab plains. Geographically, the state of Jammu and Kashmir is divided into three regions -alpine desert of Ladakh, subtropical region of Jammu and predominantly temperate region of Kashmir valley. The valley is rich in herbaceous flora with huge potential for landscape use, however, many of which are still not exploited much for the purpose. Plants which live and bloom year after year are known as perennials which have an importance of their own and are backbone of any well-planned garden. The stems of herbaceous perennials die at the ground level each winter. They comprise a vast group of plants widely differing in size, leaf texture, flower color and are found in all the gardening countries of the world. The monotonous spread of concrete and glass in cities can have a dehumanizing effect. Growing colourful flowers in the house compound and in the parks will greatly enhance the beauty of surroundings in the countryside, the towns and cities. Flowers also bring happiness to life and boast the sagging spirits. The assemblage and display of colourful and attractive herbaceous perennials can achieve very significant and telling effects on the environment particularly in the landscaping of the house compounds, gardens, parks, health resorts and hotels. Now a day herbaceous plants are also used therapeutically to cure several problems related to humans. Judicious selection of native and introduced herbaceous perennials should camouflage with the type of habitation, building pattern, colour of the countryside etc. These plants should occupy only well thought of position in the landscape. There are always a number of shady spots in our lawns/gardens especially towards north-east side of a structure where lawn grass fails to grow or show poor growth. These spots can be converted into perennial herbaceous border of foliage plants.

Trees and shrubs are often the most dominant plants in landscapes but ground covers and vines play an important role too. The low spreading form of ground covers can connect and unify major planting areas and even serve as a focal point when the plants are flowering. In contrast to annuals, perennials provide savings in time, labour and expenses each year because where adapted to a specific climate zone, they can successfully over come winter and re- establish for more than a single growing season. Perennials are probably the most diverse plant group, providing a huge variety of shape, form, colour, texture and scent with which to design a planting. Since there is an increasing trend and awareness of planned landscaping in the public and in view of its value in preserving the environment, there is an urgent need to identify and select the appropriate native, naturalized and exotic planting material for specific sites /locations. Information regarding herbaceous perennials surveyed and identified in Kashmir Valley with prospective use in landscaping are given as under:

The global herbal industry faces significant challenges due to varying regulatory frameworks, quality control standards, and traditional practices. This talk aims to bridge the gap by promoting “Herbal Harmony”- a unified approach to standardizing herbal products worldwide. Experts from diverse f ields will converge to discuss: Harmonization of regulatory frameworks, standardization of quality control and assurance, validation of traditional knowledge, innovative technologies for herbal analysis and global market trends and opportunities by fostering collaboration and knowledge sharing, “Herbal Harmony” seeks to: enhance consumer safety and confidence, promote sustainable herbal trade practices, support evidence-based herbal medicine and to facilitate international collaboration and trade.

Typically herbal pharmaceutics may include any medicinal or functional food preparations such as phytopharmaceuticals, single or poly herbal formulations, and nutraceuticals made out of botanical materials. This includes two broad categories. First, there are many evidence based formulations and mixures that may or may not be based on traditional knowledge or practices. The second group includes all the traditional or ethnopharmacological preparations. Bringing herbal medications from either group to the market will require a pharmaceutics approach balanced with an understanding of the original context in which the treatment was used.

As an example, Ayurvedic medicines have been used safely for many years on a wide variety of patients. Medications that have not been altered from their original form have de facto gone through a type of safety testing. When a traditional medicine is prepared differently, then it is essential to validate the drug safety to be sure that the effects of the new procedure don’t cause harmful effects. In this same way, the value of animal testing to establish safety and toxicity is not as critical if the botanicals are used in traditional forms. Suitable animal models help in understanding the mechanism of action or pharmacodynamics of medicines. However, it is well known that no good animal models exist for many human diseases, such as asthma, diabetes, and rheumatism. The use of modern technology in making traditional preparations more contemporary and scientific is important but it should not compromise the original basis and principles described in tracditional medicine. The following examples highlight some of the concerns of this approach.

Introduction

Wound is a disruption to the epithelial integrity of the skin, extended in-depth to subcutaneous tissue and other body parts such as ligaments, muscles, blood vessels, nerves, and bone (Robson et al. 2001). An appropriate wound healing is essential for the restoration of disrupted anatomical continuity (Begum, 2000). We have observed increasing interest in research based on traditional medicines of the world in the recent era (Medina-Franco et al. 2013). Traditional and complementary medicine regains popularity not only in developing countries but also in developed countries. Common and known practices across the globe of traditional medicines include Herbal, Ayurveda, Siddha, Unani, Iranian, Islamic, Vietnamese, Chinese, Acupuncture, African and other pseudo-medical knowledge (Dorai 2012). According to World Health Organization (WHO), traditional medicine ‘the health practices, approaches, knowledge and beliefs incorporating plant, animal and mineral-based medicines, spiritual therapies, manual techniques and exercises, applied singularly or in combination to treat, diagnose and prevent illnesses or maintain well-being’. Saxena et al. (2013) reported that phytochemicals present in plants are liable for preventing disease and promoting health. Antibiotics used in the treatment of wound infections are now proved to have adverse effects in the human body and in pathogens where resistance is emerging. Attention has, therefore, turned towards extracting biologically active compounds from plant species having wound healing property (Pattanayak and Sunita, 2008).

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.

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.

Estimates of heritability use statistical analyses to help to identify the causes of differences between individuals. Because heritability is concerned with variance, it is necessarily an account of the differences between individuals in a population. Heritability can be univariate–examining a single trait – or multivariate – examining the genetic and environmental associations between multiple traits at once. This allows a test of the genetic overlap between different phenotypes: for instance hair colour and eye colour. Environment and genetics may also interact, and heritability analyses can test for and examine these interactions (GxE models).

Polygenic characters exhibit a wide range of expression but the action of genes may be either additive or non-additive. According to Fisher et al. (1932), Smith (1936) Lush (1945), Panse (1946) and Mather (1949) the genetic advance can be achieved through selection of the heritable variation in only due to additive. So, selection for a particular character based on phenotypic variability without estimating the heritable part of it will not be successful. Heritability estimates along with genetic advance are normally more helpful in predicting the gain under selection than heritability estimates alone (Singh, 1997). Therefore, the heritability enters into every formula connected with breeding methods and many practical decisions are taken considering the heritability value.

Any phenotype is the result of interaction of genotype and the environment. Any genotype cannot express itself unless proper environment for its expression is made available. Likewise, environment cannot create any phenotype unless a genotype is there to be acted upon by the environment. However, the effect of genotype and the environment is not fixed, its keeps on changing depending upon the relative role of the genotype. Heritability therefore specifies the proportion of the total phenotypic variability that is due to genetic causes. In other words, heritability is defined as the ratio of genetic variance to the total phenotypic variance. Heritability is the degree to which the characteristics of a plant are repeated and expressed in the progeny. This can be expressed quantitatively as follows:

Heritability (h²) = Genotypic variance/Phenotypic variance

While dealing with polygenic traits and the continuous variation in plant breeding programs, it is important to know as to what extent the phenotype is decided by the genotype and to what extent by the environment. It is well known fact that what we observe i.e. phenotype is the result of genotype, environment and interaction between the genotype and the environment. The total variance is phenotypic variance or the variance of phenotypic values and various components of variance are as shown in Table 6.1.

Introduction

Apart from the general way of flood-flushing practiced at different sites of Indus Civilization, mention may be made of the following practices particularly undertaken in Sind. This is evident in the writings of inscriptions on seals from Mohenjo-Daro which state: ‘Two canals were constructed in the month of Kudam (Aquarius) and Mina (pisces). Another seal records that it took ‘thirteen months to construct a canal’. These canals were cut at low gradient and waters were allowed to merge ultimately into low ground in a direction oblique to the river so as to secure a great fall as possible. This fall varied from a foot to a few inches in a mile. They were up to hundred feet wide and about a dozen feet deep, not enough to draw off from the river except in flood. These were natural streams and probably seasonal. The perennial canals of the Indus system were cut to an extra depth and could receive water even when the main river was low, but their real purpose seems to increase the discharge during inundation.

Irrigation system

Irrigation system was consisting of lifting of water by water-wheel and by means of Shaduf from adjoining water sources. There was also provision of tank irrigation. Rice cultivation shows necessary moisture of soil probably retained by now using contour bunding for locking up monsoon rain-waters by tank-irrigation. Rainfall under vernal equinox or winter solstice has not been given much importance in the context of agriculture. Artificial rain making agents was the twin stars, Asvinis and Dadhici, described as horse headed sign. The exact time of their appearance cannot be ascertained definitely. Their association with cool season can be surmised from their name Dasra implying the same as referred to in the text of Panini. Moreover, their attributes as sender of hima (cold or snowfall) after the scorching heat of summer associates them as belonging to vernal equinox. That they appeared at the time of sun’s movement to another house, is explicitly mentioned in the Rigveda. It is a fact which shows the rising of these stars at the junction of two solstices, summer and winter. The Rigveda in one place described them as associated with winter solstice. They were found to have been associated with three kinds of watery discharges, viz. rain (vristi), dew (madhu) and snow (hima).

A hernia is the protrusion of an organ through a defect in the wall of the abdominal cavity in which it lies.

Classification
1. On the Basis of Anatomical Site
    Abdominal (umbilical and ventral)
    Diaphragmatic

Preamble

In India, agriculture plays an important role as it accounts for about 18% of the GDP and supports nearly 58% of the total working population for employment. Food grain production increased significantly from a low level of 50 million Tons during 1950-51 to a record of 230.7 million Tons in 2007-08. The demand for food is growing rapidly due to increasing population and rising income levels, hence we need to produce about 320 million Tons of foodgrains by the year 2025. It implies more pressure on our exhisting land, soil and water resources which are already in short supply, degraded, fragile and this similar situation is being faced by mainly developing countries today. Plant parasitic nematodes are of great economic significance. Since most of them live in the soil hence represent one of the most difficult pest problems in terms of identification, demonstration and management.

I. FILL UPS

1. _____ is the increased function of any biological quality in a hybrid offspring.
2. Heterosis is otherwise known as _____.
3. _____ is the reduced fitness in a given population as a result of breeding of related individuals.
4. In _____ heterosis type, naturally occurring mutants are sheltered.
5. The progeny posses superiority over parents in vegetative growth, but reduction in yield is known as _____.
   1. Average heterosis is mathematically expressed as _____.

1. HETEROSIS

1.1. Definition

Heterosis or hybrid vigor or outbreeding enhancement, is the increased function of any biological quality in a hybrid offspring. It is the occurrence of a genetically superior offspring from mixing the genes of its parents.

1.2. Inbreeding depression

Inbreeding depression is the reduced fitness in a given population as a result of breeding of related individuals. In general, the higher the genetic variation within a breeding population, the less likely it is to suffer from inbreeding depression.

13.1 Introduction

F₁ plants produced by crossing two parents with contrasting characters are called hybrids. Hybrids generally exhibit increased vigour and fitness over the parents. This phenomenon is called hybrid vigour or heterosis. Thus, heterosis is the phenomenon in which the hybrid of two genetically dissimilar parents shows increased vigour at least over the mid-parental value. Heterosis is just the reverse of inbreeding depression, which results after selfing the plants of the cross-pollinated crops. Kolreuter (1761-66) was the first to report hybrid vigour in the hybrids of tobacco, Datura, etc. Most of the early plant hybridizers including Mendel (1865) had noticed this phenomenon. Shull (1914) coined the term heterosis from two Greek words, hetero (different) and osis (condition), to replace his own earlier word ‘stimulus of heterozygosis’. In current usage, heterosis and hybrid vigour are used as synonyms and interchangeable.

13.2 Types of Heterosis

Depending on the nature, origin, adaptability, reproducibility and non-reproducibility, heterosis can be categorized into two: (1) euheterosis (true heterosis) and (2) pseudo-heterosis (false heterosis, i.e., luxuriance).

Heterosis or hybrid vigour is the condition where an F1 hybrid falls outside the range of the parents with respect to some character or characters. It is also defined as a manifestation of heterozygosity, expressed as increased vigour, size, fruitfulness and resistance to diseases, insects or climate extremes. It has been observed in nearly every crop including both self and cross-pollinated crops. It is converse of inbreeding depression. However, even the species that show little or no inbreeding depression, often benefit from crossing and resultant hybrids. Therefore, heterosis has been more emphasized than the inbreeding depression. It is defined in two basic ways:

The information under this section is primarily based on Yordanov (1983). It is almost unanimously accepted that heterosis manifestation in tomato is in the form of the greater vigour, faster growth and development, greater earliness, and productivity, higher resistance to disease and adaptability unfavourable environmental conditions. The first step towards a large scale extension of hybrid tomato cultivars in the practice and proper organization of hybrid seed production took place in Bulgaria. After the second world war tomato heterosis breeding developed quickly in the Netherlands, England France, USA, Japan and other countries. In India, tomato hybrid cultivar on commercial scale was introduced in 1973 by Indo American Hybrid Seed Company.

10.1. Heterosis

Occurrence of a genetically superior offspring from mixing the genes of its parents.

Superiority of F₁ hybrids over its both parents in terms of yield and vigour.

20.1 Introduction

A hybrid cultivar (also called hybrid) is the F₁ progeny of a planned cross between inbreds, cultivars, clones or populations. Depending upon the breeding approach, the hybrid cultivar may involve two or more parents. A critical requirement of hybrid production is that the parents are divergent. This divergence is the cause of superior performance of hybrids. The outstanding performance of crops is due to the exploitation of the phenomenon of heterosis (hybrid vigour) which is high when parents are divergent. Much of what we know about heterosis breeding (also called hybrid breeding) came from the work on maize hybrid cultivar development. However, commercial hybrids are now available in many crops including self-pollinated crops.

Abstract
The analysis of variance showed significant differences for all the traits studied. The best two combinations out of the 28 F1s produced by crossing eight diverse lines of capsicum in diallel fashion (excluding reciprocals) with respect to most of the traits were Osh Region x EC-119058 and California Wonder x Bonali.

Keywords: Heterosis, Capsicum annuum L.

Bell pepper (Capsicum annuum L.) also known as Sweet pepper or Spanish pepper is an important vegetable used in various delicacies and salads, the world over. The crop originated in New World tropics and subtropics (Greenleaf, 1986), and introduced in India by the British. Because of its excellent quality as obtained under Shimla hills conditions, it came to be called as Shimla Mirch. Its most notable feature is flavour and hence is appreciated worldwide. It is also an excellent source of pro-vitamin A and vitamin C. Bell pepper assumes a special significance in the mid hills of Himachal Pradesh as it is grown as an off season crop during summer and rainy seasons, which brings lucrative returns to the growers. 

INTRODUCTION

Heterosis has contributed significantly towards increased crop production and it has become the basis of multibillion dollar agro-businesses in the world (Phillips, 1999). Hybridization is the important way that can create genetic variability and make new options. The F1 population is obtained from the crossing of two homozygous but genetically dissimilar gametes or individuals (purelines in self pollinated crops or inbred lines in cross pollinated crops) that shows increased or decreased vigour over the better or mid parent value. Heterosis is maximum in F1, generation which diminishes gradually in later generations. Hence, production of F₁, hybrid seeds of different flower crops is considered as the extreme focused area in floriculture industry.

INTRODUCTION

Heterosis has contributed significantly towards increased crop production and it has become the basis of multibillion dollar agro-businesses in the world (Phillips, 1999). Hybridization is the important way that can create genetic variability and make new options. The F₁ population is obtained from the crossing of two homozygous but genetically dissimilar gametes or individuals (purelines in self pollinated crops or inbred lines in cross pollinated crops) that shows increased or decreased vigour over the better or mid parent value. Heterosis is maximum in F₁, generation which diminishes gradually in later generations. Hence, production of F₁, hybrid seeds of different flower crops is considered as the extreme focused area in floriculture industry.

Production of F₁ hybrids in ornamental crops was carried out even before Shull’s classical theory of hybrid vigour which was reported in 1971 for the first time in plant breeding. Benary Seed Company in Germany released F₁ hybrid in begonia (Begonia semperflorens) in the name of Prima Donna in 1909 (Reimann-Philip, 1983). But that time it did not attract the attention of plant breeders. It was during Second World War in 1942, when flower breeders were attracted towards heterosis breeding and started systematic F₁ hybrids. From 1950 onwards, numerous outstanding hybrids have been developed in many other flower crops in several countries like USA, The Netherlands, Denmark, Germany, United Kingdom and Japan, etc. First hybrid in single geranium was produced in 1960, in other flower crops like antirrhinum, pansy, marigold and zinnia in 1965, ageratum in 1966, geranium double in 1970, dianthus, begonia, impatiens and portulaca in 1976-77, gerbera in 1980 and carnation in 1981. In the present scenario of developed floriculture industry, in many countries F₁, hybrids are available in a number of annual flowers like ageratum, antirrhinum, anemones, calceolaria, dianthus, hollyhock, gazania, marigold, flowering tobacco, pansy, portulaca, stock, wall flower, zinnia, etc.

As emasculation is having the maximum share in cost of hybrid seed production, researchers have found several techniques in different flower crops as the alternative of emasculation and that can help in reducing the cost of hybrid seed production. The list of techniques being utilized commercially in different flower crops (Janakiram, 2004) is as follows:

Hybrid vigour is used as a synonymous of heterosis. In 1910, the term heterosis was first used by Shull who defined this phenomenon as the stimulus of heterozygous, and in his word, it has been the “interpretation of increased vigour, size, fruitfulness, speed of development, resistance to insect-pests and diseases or to the climatic rigors of any kind manifested by the out breeding organism as compared with corresponding inbreds as a specific result of the unlikeliness in the constitution of uniting parental gametes”. This definition is often interpreted as not implying a genetic basis for heterosis, because the definition basically describes the phenotypes that result from the crossing of two different inbred lines. Generally, heterosis is manifested as an increase in vigour, size, growth rate, yield, or some other characteristics but in some cases, the hybrid may be inferior to the weaker parent. This also represents as heterosis (average heterosis), and if heterosis is estimated over the superior parent, such an estimate is sometimes referred to as heterobeltiosis, hence, authors feel “heterosis refers a biological phenomenon in which the F₁ population obtained by crossing of the two genetically dissimilar gametes or individual shows increased or decreased vigour over better parent or over the mid-parental value. Earlier, Power (1944)also suggested that the term heterosis should be used only when the hybrid is either superior or inferior to both the parents. Other situation should be regarded as partial or complete dominance. It can be easily explained with the help of Table 5.1.

Heterosis, hybrid vigor, or outbreeding enhancement, is the improved or increased function of any biological quality in a hybrid offspring. The adjective derived from heterosis is heterotic.Heterosis is the occurrence of a superior offspring from mixing the genetic contributions of its parents. These effects can be due to Mendelian or non-Mendelian inheritance.

The commercial exploitation of heterosis started only after the rediscovery of Mendel’s law of inheritance and consequent understanding of the theoretical basis of hybrid vigour. Heterosis is considered as a major revolution in classical plant breeding era. Utilization of heterosis has substantial influence in genetics to provide hybrid vigour, consequently high yielding hybrids in different crops and plants. Yield increase from heterotic hybrids due to the expression of heterosis is up to 30% superior to conventional varieties. The term heterosis was first used by Shull (1914) and represents the increase or decrease in fitness and vigour of the F₁ hybrid over the mean or mid parent values, produced by crossing two genetically different individuals for one or more traits. Generally, positive heterosis is desirable but in some cases like maturity duration and presence of toxic substances, negative heterosis is condiderable as desirable. Heterosis can be estimated in three different ways. When the heterosis is estimated over mid parent, it is called as relative heterosis or mid parent heterosis. Estimation of heterosis over better parent out of the two parents involved in the cross is referred as “Heterobeltiosis”, the term which was coined by Fonseca and Patterson (1968). “Standard Heterosis”, often called as useful heterosis which was coined by Meredith and Bridge (1972) and denotes the superiority of F₁ over the standard commercial check.

Hybrid vigor or heterosis is opposite and complementary to inbreeding depression (reduction in fitness as a direct result of inbreeding). In theory, the heterosis observed after crossing is expected to be equal to the depression upon inbreeding, considering a large number of crosses between lines derived from a single base population. In practice, plant breeders are interested in heterosis expressed by specific crosses between selected parents, or between populations that have no known common recent origin. Furthermore, because heterosis is subject to the interactions between genotype and environment, it is desirable to describe the heterosis of a particular hybrid line for a specific trait at a specific location or under specified environmental conditions.

Introduction

Flowers speak millions of unspoken words. Presenting a bouquet and making arrangements with flowers in most of the drawing rooms, offices, hotels and hospitals have become the style of the day in the fast – moving modern world where there is hardly any time for exchange of sweet memories. Since time immemorial, the importance of such a delicate creation of nature has always been appreciated. Tamil Nadu ranks first among the flower producing states of India, contributing 25% of the country’s flower production with an area of 31, 970 ha under flowers. Of this, around 700 ha are under protected cut flower cultivation. In Nilgiri district alone, it has an area of around 70 ha under protected cut flower production which is inclusive of around 11.2 ha of lilium.

The genus Lilium (Lilium spp.) is a herbaceous flowering plant normally grown from bulbs, about 110 species world over belongs to lily family Liliaceae. It is native of the northern temperate regions. The species in this genus are the true lilies while the other plants with lily in the common name are related to the other groups of plants. Lilies are usually erect leafy stemmed herbs. The majority of species form tunicless scaly underground bulbs from which they produce flowers. The large flowers have three petals along with three sepals, look like petals.