eChapters

7.1 INTRODUCTION

Grafting and budding are horticultural techniques used to join parts from two or more plants so that they appear to grow as a single plant. In grafting, the upper part (scion) of one plant grows on the root system (rootstock) of another plant. In the budding process, a bud is taken from one plant and grown on another. The practice of grafting can be traced back 4,000 years to ancient China and Mesopotamia. As early as 2,000 years ago, people recognized the incompatibility problems that may occur when grafting olives and other fruiting trees.

7.2 ROOT STOCK

The part of the graft that provides root system to the grafted plant is known as rootstock. It is, normally, raised by seeds in the seedbed and then, transplanted in the nursery bed for budding and grafting. Rootstocks are also raised in pots and polythene bags.

6.1 INTRODUCTION

The ultimate success of an orchard enterprise largely depends upon the quality and genuineness of planting materials as nursery plants are the foundation of the orchard. Fruit crops, mostly being perennial in nature, call for utmost care in selection of cultivar, quality planting material and adoption of right technology for mass multiplication of planting material. Mistakes committed during the initial establishment of orchards cannot be corrected and will cause serious damage to production and productivity. The variation of scion-wood and rootstock has great bearing on the productivity of an orchard. Thus, it is of immense importance having all plants carefully labelled or otherwise marked. Cuttings taken from the mother plant will grow to have the same genetic qualities as the original plant. This is why the plants resulting from these cuttings are called “clones”. When a stem cutting is taken from a mother plant, the piece of stem will produce new roots if it is properly hydrated. Additionally, some plants can be grown from leaf pieces, or leaf cuttings and these will produce both stems and roots.

Thus, the progeny trees are the basic component for the multiplication of fruit plants and ultimately deciding the quality and productivity of the fruit crops. Hence, it is necessary to stock the true to type and best quality progeny trees.

In asexual methods of plant propagation, plant parts are being used as propagating materials. The plant from which the plant parts are collected is known as mother plant. There is every possibility of transmission of disease or pest which is present in the mother plant to the progeny. The mother plants have to be maintained properly to obtain disease free planting materials so that multiplication of disease/pest can be prevented. Thus, there is a need for the establishment of mother plant block/scion banks.

5.1 APOMIXIS

Apomixis is derived from two Greek words “Apo” (away from) and “mixis” (the act of mixing or mingling). It refers to the occurrence of an asexual reproductive process in the place of normal sexual processes involving reduction division and fertilization. During sexual reproduction, developmental steps occurring inside the ovule produce the female gametophyte (embryo sac) and following a double fertilization event give rise to embryo and endosperm structures. Apomixis can be best described as the reference to the asexual process. In some species, embryo sac is produced not as a result of meiosis and fertilization but by certain asexual processes. The occurrence of such asexual reproductive process in the place of normal seed reproductive processes of reduction division and fertilization is known as Apomixis. Such seedling plants produced in this manner is known as apomicts. ’’Apomixis’’ is used synonymously with ’’agamospermy’’ (Stebbins 1950), referring to the asexual production of seed.

Apomixis (asexual seed formation) is a phenomenon in which a plant bypasses the most fundamental aspects of sexual reproduction—meiosis and fertilization—to form a viable seed. Plants can form seeds without fertilization, and the seed genotype is consistent with the female parent. The development of apomictic technology would be revolutionary for agriculture and for food production as it would reduce costs and breeding times and also avoid many complications typical of sexual reproduction (e.g., incompatibility barriers) and of vegetative propagation (e.g., viral transfer). The application of apomictic reproductive technology has the potential to revolutionize crop breeding. Apomixis is widely distributed among higher plants. More than 300 species belonging to 35 families are apomictic. It is most common in Gramineae, Compositae, Rosaceae and Rutaceae. Among the major cereals maize, wheat and pearl millet have apomictic relatives. Apomixis is reproduction where only one parent passes genes to the offspring (King, 2006). Apomictically produced offspring are genetically identical to the parent (clones).The method is mostly seen in plants, especially flowering plants. Apomixis was defined by Hans Winkler (2008) as the replacement of the normal sexual reproduction by asexual reproduction, without fertilization. Propagation from cuttings or leaves, is not apomixis. Natural replacement of the seed by an asexual method is apomixis.

4.1 INTRODUCTION

The method of propagation in plants may be sexual or asexual. In sexual method of propagation, specialized reproductive cells called gametes are formed by the process of gametogenesis. Fusion of the male and female gametes leads to the development of an embryo and eventually the seed.

4.2 GAMETOGENESIS

The production of male and female gametes is known as gametogenesis. It occurs within microspores and megaspores. It involves only mitosis. It is of two types: (1) microgametogenesis and (2) megagametogenesis.

3.1 INTRODUCTION

A nursery is a place, where seedlings, saplings, trees, shrubs and other plant materials are grown under intensive care and maintained until they are ready for final transplanting in the main field. The importance of the best quality planting material as an initial investment is a well-realized factor for persons engaged in horticulture field. So, nurseries have great demand for the production of plants, bulbs, rhizomes, suckers and grafts. But in general, good quality and assured planting material at reasonable price is not available in most of the cases. Nursery is the basic need of horticulture. Plant propagation techniques and practices is the core of horticulture nurseries. The planting materials for horticultural plantations are raised from seeds and vegetative parts. The difficulty of procuring seeds and their rising cost makes it necessary to find means to increase seedling survival and growth.

2.1 INTRODUCTION

Several propagation structures are helpful in propagation of horticultural crops. These structures are helpful for seed germination, rooting of cuttings, layering, grafting etc. and other hardening operations. The structures which facilitate propagation of plants are called propagation structures. Propagation structures are required for propagating plants by seed, cuttings and grafting.2.2

GREENHOUSE

Greenhouse is a structure covered with glass or polythene for protection against adverse climatic conditions as well as to provide optimum environment for growth of the plants. Greenhouse has been used long back by horticulturists as a means of forcing rapid growth of plants and extending the growing season particularly in colder areas. Plants are grown or cuttings are rooted in a greenhouse when the atmospheric condition does not permit for raising them in outdoor conditions. Modern greenhouses are equipped with regulatory mechanisms for controlling temperature, light intensity, air, humidity etc. Plants in green house are grown in the ground bed or bench type raised beds. The size of the greenhouses and dimensions of beds vary according to the need of propagators. Glass covered greenhouses are expensive but they have long life. However, for short-term benefits, plastic covered greenhouses can also be made. Plastic covered greenhouses are lighter than glass covered ones but there is increase in humidity is such houses, especially in winters, which results in undesirable water drops on the plants. It can however be overcome by making adequate ventilation. Polyvinyl chloride (PVC) has also been used in construction of greenhouses but it tends to darken pre-maturely in sunlight. In India, construction of temporarily low-cost poly houses is in fashion for raising nursery of fruit plant in off-season. Such low-cost greenhouses are constructed either on wood or metal framework and are covered with polyethylene sheet of 0.10 to 0.15mm thickness, which is resistant to ultra-violet rays. These houses are equipped with thermostat, cooler or an air conditioner or humidifier etc for rigid control on temperature and humidity. Greenhouses made from fibre glass sheet are more durable than the polythene houses, but are quite expensive. In greenhouses, two types of beds are used for raising seedlings. In greenhouses, the beds may either be prepared on ground itself or raised beds or bench type beds are used. Greenhouse structures vary from elementary home constructed to elaborate commercial installations.

1.1 WHAT IS PLANT PROPAGATION?

Propagation of plant is defined as multiplication and perpetuation of new individuals from a selected plant having all the characters of the original one. It is the process of increasing the number of plants of a particular species or cultivar. It refers to the multiplication of an individual plant or group of plants, which have specific value to mankind. New plants or new individuals are required for establishing new plantings/new gardens/new orchards.

Ornamental plants that are adapted to an aquatic environment are commonly grown in water gardens and pools. They include those that are entirely submerged or floaters that are free living in the surface water or having roots anchored firmly in the ground beneath and marginal plants that thrive along the edges of water bodies and in shallow water. Spectacular flowering plants like the lotuses and water lilies to plants like the tape grass that are entirely submerged and grass like are grown in natural or structured fresh water habitats throughout the world. Many of these are also inhabitants of aquaria.

Some of the popularly grown water garden plants are listed below:

Acorus calamus

Araceae

Sweet Flag, Vayambu

Plants are rhizomatous herbs adapted to low lying and wet situations. The leaves are closely spaced, distichously arranged and resembling a fan, leathery, dark green, smooth and shiny. The inflorescence is a spadix that emerges from the middle of the terminal leaf. Plants are valued medicinally for their aromatic rhizomes and are also commonly grown as marginals of water gardens.

Grasses, bamboos, sedges and rushes are plants that are being used increasingly in xeri-scaping and in marsh gardens for getting the benefits of their unusual foliage textures and colours. Their hardiness, stature and canopy frame make them more suited for specimen planting in gardens and landscapes.

GRASSES

Grasses are the most successful of monocots belonging to the family Poaceae that are found the world over. Low growing perennial grasses are used to make attractive lawns in gardens and to provide a desirable turf cover for various situations. A number of species belonging to various genera differing in leaf colour, shape and growth pattern are used for this purpose. Mixtures of different varieties of grasses are also used for making turf having desirable blends of textures and hardiness. Tall bushy grasses having a mound-like or fountain–like habit and fine to velvety surfaces are grown for their textural and architectural features in landscaping. Many are grown as specimen plants for their display value at flowering. In selecting grasses for gardens, their potentially invasive nature is to be taken into account and seed dispersal controlled by timely cutting.

Grass species that thrive in the hot and humid tropics are called warm-season grasses and include Bermuda grass, Carpet grass and St. Augustine grass. Cool season grasses that are adapted to temperate regions and thrive at temperatures of 10 to 20^oC include Blue grass, Fescues and Zoysia.

Pteridophytes such as ferns belonging to several families, selaginellas popularly called ‘club mosses’ belonging to Selaginellaceae and the Lycopods which resemble both these, belonging to Lycopodiaceae are shade loving plants adapted to cool and moist or hot and humid ecosystems of tropical to temperate climates. They are mostly epiphytic or lithophytic and are grown as foliage ornamentals in a fernery or in shaded areas in gardens. Many are favoured indoor plants.

Popularly grown ferns, lycopods and selaginellas of gardens are listed below:

Adiantum capillus-veneris

Adiantaceae

Common Maidenhair fern

Plants are shade loving bushy lithophytes and have delicate looking thin black stems carrying light green oblique-ovate fronds. They are pot grown as ornamental foliage plants.

Adiantum decorum

Syn. Adiantum raddianum

Adiantaceae

Maidenhair fern

Terrestrial or epiphytic members of the family Bromeliaceae that are grown in gardens for their unusually coloured and patterned leaves or showy inflorescences and fruits are referred to as ornamental ‘Bromeliads’. Being low growing, they are ideally displayed in containers or as epiphytes. They are sun loving, suckering in habit and have xerophytic adaptations. The leaves are tough and fibrous often with spiny margins and sheathing leaf bases that hold water. A grayish-white waxy or powdery coating often covers the lamina. Certain bromeliads have a water collecting depression at the center. Inflorescences are sunken, erect or reclining, with condensed or long and much branched stalks carrying colourful bracts and usually, less showy flowers. In many, the terminal leaves become brightly coloured at flowering. These and the floral bracts remain showy even after the flowers are shed.

Ornamental bromeliads popularly grown in gardens include the following:

Aechmea blanchetiana

Copper leaf bromeliad

Plants have strap like leaves that develop streaks of coppery red colour on the upper surface in bright sunlight.

Aechmea burle-marxii

Burle-Marx bromeliad

These are a broad group of plants that have evolved in situations characterized by very high day temperatures and low night temperatures with very low available moisture in the growing medium. Their plant body is modified to conserve moisture with physiological adaptations that help to reduce moisture loss considerably and to survive in hot desert situations or drought conditions. Stems, leaves and roots of these plants are fleshy and rich in watery mucus. The unusual morphological features that these plants have developed to enable them to survive in their harsh native habitats, set them apart from other plants and have given them rarity value when grown as ornamentals. They are hence displayed individually or grown in a rockery where a landscape of rocks and stones highlight their features and at the same time provide desirable contrast with other garden plants. Many members of Cactaceae, Crassulaceae, Aizoaceae, Euphorbiaceae, Asphodelaceae and Agavaceae belong to this group and are commonly referred to as rock garden plants.

Among garden plants, herbaceous perennials that produce perennating structures like bulbs, corms, tubers, rhizomes or fascicled tuberous roots are called bulbous plants. They belong to various plant families such as Amaryllidaceae, Cannaceae, Heliconiaceae, Iridaceae, Liliaeceae, Musaceae, Ranunculaeceae and Zingiberaceae. The possession of perennating structures that are modifications of plant parts- mostly stems- is common to these plants. These modifications aid in their vegetative propagation as the dormant buds associated with them regenerate when conditions are favourable to result in new plants. In both tropical and temperate climate zones, bulbous plants have evolved and naturalized in several ecological ‘niches’. Many of these have been domesticated centuries ago and are familiar garden plants. Generally, bulbous plats are adapted to grow vegetatively putting forth shoots carrying a limited number of leaves. When further vegetative growth has ceased these shoots produce terminal or basal inflorescences. Bulbous plants are grown and displayed in clumps.

Based on the requirement of relatively low or high temperatures for sprouting and flowering they are classified into warm- season bulbous plants and cool-season bulbous plants. These groupings are not exclusive and many plants have evolved varieties that thrive in both seasonal conditions.

Pants that tend to climb vertically on to supports are called climbers. reepers are plants that tend to creep or ramble over the ground or other surfaces spreading horizontally. These have showy flowers or decorative foliage. Climbers are conventionally used in gardens to cover fences, bare walls and tree trunks. They are used to provide ornamentation in a vertical aspect. Creepers on the other hand are used as ground covers and function as decorative elements in a horizontal aspect.

CLASSIFICATION OF CLIMBERS AND CREEPERS

Depending upon their habit, vigour, duration, nature of flowering, adaptations for climbing and shade tolerance, they can be classified as follows:

H erbs include non-woody or succulent-stemmed plants that are relatively shorter in stature when compared to shrubs. Based on their ornamental nature they can be broadly grouped as Flowering Herbs and Foliage Herbs. Flowering Herbs can be further classified based on their duration into Annual Flowering Herbs and Perennial Flowering Herbs. Foliage herbs of a perennial nature are further differentiated into monocotyledonous and dicotyledonous foliage herbs.

ANNUAL FLOWERING HERBS

Annual herbs are grown in gardens for their spectacular beauty when they are in flower. They are seasonal in habit and have duration of up to four months. Most of them have a short vegetative phase, which is followed by continuous flowering for several weeks. They are used in gardens for obtaining various colour effects. Varieties of annuals having analogous or similar flower colours can be grouped in flowerbeds and flower borders for monochromatic effects. For contrasting colour effects, varieties having complementary or contrasting colours like violet and yellow or blue and orange as well as green and red can be used. For colour blending effects, flowers having different shades of the same colour can be grown.

Shrubs are the most diverse groups of ornamentals grown in tropical gardens. In habit they are hardy perennials having low spreading woody branches. They vary widely in stature and include dwarf bushes to those attaining the stature of small trees.

IMPORTANCE AND USES OF SHRUBS

Shrubs are quick growing and many of them flower continuously in the humid tropics. Their variability in flower colours and foliage characteristics and their easiness in propagation by vegetative means make them garden favourites. The various uses to which shrubs are put to in gardens are detailed below: -

In A Shrubbery : Grouping of shrubs in a shrubbery is done to display the attractiveness of their flowers and foliage. In temperate situations shrubs grown in shrubberies include Rhododendron, Peony, Fuchsia, Buddleia, and Camellia while in the tropics and subtropics, the range of shrubs available for planting are very wide.

As Focal Point Plants : Shrubs that are ever flowering like Hamelia and Hibiscus or those that have spectacular flowers such as Mussaenda, Neerium and Ixora are grown as focal point plants in small gardens. They are also grouped for mass effect in large gardens.

Trees are the largest plant components of gardens and landscapes. However much architectural features dwarf them, for human beings, they are the largest living entities in the environment. Profoundly influencing our habits, styles of habitation, culture and daily life, trees have been revered, sanctified and given symbolic importance and above all, depended upon as means of livelihood by entire communities through the ages. Through folklore, traditional knowledge and rituals, the usefulness of trees has been handed down from generation to generation-in societies all over the world. In India, cave paintings and carvings in addition to ancient literary works document the aesthetic and medicinal knowledge of our forefathers about trees found in the sub-continent.

Trees differ in stature, branching habit, girth of trunk and branches, canopy structure, outline and crown shape. The colour of the foliage, its texture, glaze, shape and size, foliage colour, floral features and season of flowering also differ among trees. These characteristics in addition to giving distinctiveness, also determine their ornamental use in gardens and landscapes. In tropical gardens evergreen dicotyledons and palms dominate among the trees, whereas in temperate situations evergreen conifers are selected over the deciduous dicots for tree planting. Palms among trees are universally grown as avenue trees or as clumps in areas where they can be easily grown while the other trees are grown as such or pruned and trained into various forms or as bonsai in gardens.

Introduction

Considering the accountable post-harvest losses which is approximately 30-35 percent, food processing becomes an extremely important sector for preventing the losses and feeding the growing population. The Indian food industry is poised for huge growth, as currently valued at US$ 1.3 billion with compound annual growth rate of 20 per cent per year, increasing its contribution to world food trade every year. In India, the food sector has emerged as a high-growth and high-profit sector due to its immense potential for value addition, particularly within the food processing industry. Increasing population of the country and high cost of fuels have also created a demand for new alternate sources of energies for post-harvest processing of foods. Solar food processing technologies may become a viable option that provides good quality foods at low or no additional fuel costs. The energy policy of the developing countries now focuses on the clean renewable energy to create a further reduction of the petroleum import and to alter the utilization of petroleum energy toward the utilization of solar energy. It is an interesting fact that most of the developing countries fall in the climatic zone where the insolation is considerably higher than the world average of 3.82 kWh m-2 (Majumdar 2015). The daily horizontal insolation of India is approximately 5.80 kWh m-2 (Visavale 2009, Visavale et al. 2011). Solar dyers are an alternative to traditional drying technique and a contribution towards the solution of the problems of the open sun drying from perspective of renewable and clean energy. The International Energy Agency (IEA) declared in its 2011 solar energy perspectives executive summary (SEP 2011): “Solar energy offers a clean, climate-friendly, very abundant and inexhaustible energy resource to mankind, relatively wellspread over the globe. Its availability is greater in warm and sunny countries that will experience most of the world’s population and economic growth over the next decades.

Introduction

The thermal performance of a building refers to the process of modeling the energy transfer between a building and its surroundings. For a conditioned building, it estimates the heating and cooling load and hence, the sizing and selection of HVAC equipment can be correctly made. For a non-conditioned building, it calculates temperature variation inside the building over a specified time and helps one to estimate the duration of uncomfortable periods. These quantifications enable one to determine the effectiveness of the design of a building and help in evolving improved designs for realizing energy efficient buildings with comfortable indoor conditions. The lack of proper quantification is one of the reasons why passive solar architecture is not popular among architects. Clients would like to know how much energy might be saved, or the temperature reduced to justify any additional expense or design change. Architects too need to know the relative performance of buildings to choose a suitable alternative. Thus, knowledge of the methods of estimating the performance of buildings is essential to the design of passive solar buildings.

Introduction

As the most of the conventional resources are depleting and can last only for about a few 30 to 50 years. Scientists worldwide are looking for alternative energy resources and they have come to an agreement that solar energy can provide much of our energy needs in the future. The major challenge before them is to store this energy. The radiation falling on the earth surface can be tapped and stored in no of ways. However, the most efficient way is done through the latent heat storage through PCM. The PCM has many added advantages i.e. high energy density, isothermal behavior, non-polluting and low cost. Nowadays, it gaining popularity worldwide and now seen as the most efficient way of thermal energy storage. There is a large number of PCM at use i.e. organic, inorganic, eutectic and salt hydrates. Their utilization depends on the user’s requirement technological constraints. They also serve the purpose of energy availability at night beside the uninterrupted supply during the day. They are seen as the materials for ensuring the environmental sustainability