eChapters

1. Neutron activation analysis

This technique is used in qualitative and quantitative analysis. If an element present in a sample is to be identified by neutron activation analysis, the sample will be bombarded with slow neutrons or other charged particles and converted into radioisotope. It is one of the most sensitive and specific methods available for the determination of trace quantities of a wide range of elements. From the half life measurement, it is possible to identify the element from which the radioisotope has resulted. Also the quantity of element present in a given sample can be calculated by this technique.

Stable isotopes are chemical isotopes that may or may not be radioactive,but if radioactive, have half-lives too long to be measured. These isotopes decay into stable products. Eg. ¹⁴C having 6protons and electrons with 8 neutrons.

Most elements of biological interest (including C, H, O, N, and S) have two or more stable isotopes. Among the stable isotopes, the most useful as biological tracers are the heavy isotopes of carbon and nitrogen.

Radiation emitted from the radioactive isotopes can be detected and quantified by using several equipments and the details are furnished below:

A. Radiation Detection Devices

1. Electroscope

The electroscope is a simple device comprised of a metal rod with two thin leaves attached to one end. If the electroscope is given a negative charge, the metal leaves will separate from each other. It is the characteristic that makes the electroscope useful as a detection device. A negatively charged electroscope will discharge when ions in the air remove electrons from it, and consequently, a positively charged electroscope will discharge when it takes electrons from the air around it. The rate of discharge of the electroscope is a measure of ions in the air and can be used as a basis of measurement and detection.

Radiation Chemistry is a branch of nuclear chemistry that deals with the study of chemical effects of radiation on matter.

Radio activity is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing radiations (a, b, g radiations). It may be of

Chromatography is the set of laboratory techniques used for the separation of molecular mixtures by developing chromatograms. Chromatogram is a collection of different bands on the chromatographic column. The mixture is dissolved in a fluid called the “mobile phase”, which carries with it another material called the “stationary phase”. The various constituents of the mixture travel at different speeds, causing them to separate. Chroma (colour) and graph in (to write) contribute to the word chromatography, as coined by Mikhail Tswett (1903). Solute moves only when it is in stationary phase. In chromatography, the mobile phase flowing into the column is called eluent, the solution emerging from the column is elute, and the process by which solutes moves and separate is called elution.

This method employs the differences in absorbability of components of mixtures and the differences in the mobility rate. The molecules of a substance which interact strongly with the fixed phase will move slowly through the column whereas substances which do not interact strongly are carried through more rapidly. It is used to separate different substances having similar chemical properties.

Absorption and Emission

Absorption techniques – It measures the absorption of abundance of light due to electrons going to a higher energy level.

Emission techniques - It measures the intensity of light that is emitted as electrons return to the lower energy levels.

Colorimetry is the quantitative analysis of a coloured constituent. It is determined by measuring the relative amount of absorption of light passing through a solution of a constituent.

When a monochromatic light is passed through a homogeneous medium, a part of the incident light is absorbed and part of the light is reflected and part could be transmitted. This can be mathematically expressed as

Potentiometry

Potentiometry is based on measurement of potential of an electrode system

Principle

When a metal electrode is immersed in a solution containing its own ions, the metal atom pass into the solution in the form of metal ions and a potential difference is established between the metal and the solution. This potential is called as electrode potential.

Potential on an electrode depends on the ions present in solution and their concentration which can be determined by using electrochemical cells and expressed by Nernst equation

I. Filtration

Filtration is a process of separation of precipitate from solution. Filtration is used to remove impurities from a solution (or) to isolate a solid.

Precipitation

An ionic phenomena wherein the product of the ionic concentrations of a substance in a solution exceeds the solubility product

Precipitate is often ignited before weighing to convert it into substance of definite chemical composition and chemical stability

Compound precipitated –– precipitated form

Example: Magnesium ammonium phosphate

Gravimetric analysis

Techniques – analyte is determined by quantitative isolation of substance by precipitation and weighing the precipitate

Volumetry / Titrimetry

Process of determining the volume of solution of known concentration required to complete reaction with a solution of unknown concentration (test solution) by titration.

Indicator

A substance which indicates the end point on completion of the reaction.

Helps in the visual determination of the completion of titration.

Secondary standard solution

Solution of chemicals which lack one (or) all the properties for a primary standard

A solution standardised by titrating a primary standard

Less accurate than a primary standard

Volumetric Analysis

Measurement of volume of reagents required for the completion of reactions

Also called titrimetry – most widely used techniques of chemical analysis

Rapid, accurate, convenient and inexpensive

Standard solutions

Standard solutions are solutions of accurately known concentration

Different standard solutions are

Laboratory analysis is an important part in any branch of chemistry and analytical chemistry in particular. To undertake the analysis, both apparatus and equipments are needed.

Analytical Chemistry

The science involving the determination of the constituents in terms of elements and compounds is called Analytical Chemistry. It is used to identify the substances found in a material and to quantify the exact amount of substances in them.

The basic principles involved in Analytical Chemistry are changes takes place in the substances by the process of combination, decomposition, replacement and double decomposition.

Astro-meteorology is considered as one of the branches of Astronomy along with Astrophysics, Astrobiology and Astrometry. Astronomy is the science that deals with the material universe beyond the earth’s atmosphere. It studies the nature and constitution of Celestial (heavenly) bodies and the laws which govern them including the effect they produce upon one another. It seeks to unravel the probable past history of heavenly bodies and their development. There exists a confusion between the branches of Astronomy viz., Astrophysics and Astro-meteorology with the term Astrology. Astrophysics uses principles and laws of physics to explain how Celestial bodies form and function or in other words it will help to ascertain the nature of the astronomical objects, rather than their positions or motions in space. However, the Astrology and Astro-meteorology are the subjects deal in future prediction and often considered as pseudo-science which uses position and movement of stars and planets for that purpose. Astrology links these to predict the human behaviour, while that of Astro-meteorology links the same to predict the future weather.

From ancient days, these predictions are based on one’s wisdom and knowledge in astronomy and often these astrologers are astronomers who keenly watch the stars and planets movement and guide their rulers and farmers with their guesstimates. Till date it is being lore, mainly passed to followers of this group and the methodology is not documented clearly and properly. There are many incidences of falsified predictions of astrology as reported by many reviewers elsewhere and we are not discussing the same here, owing to our interest in weather prediction i.e., astro-meteorology only. However, we have to recognize the works of the ancient astrologers who helped in developing the astronomical science.

Basically, there are two approaches in astrology viz., geocentric and heliocentric as used by the practitioner of astrology worldwide. As the name implies the Geocentric astrology is based on the calculation of planetary position as seen by the observer from the earth and thus earth is centre, while Heliocentric astrology bases its interpretation upon position within solar system with reference to the sun as centre. Though in true sense, the sun is the centre, the effect of motion as manifest on the earth is the basis of most astrological interpretation. Hence, vast majority of astrologers employs the geocentric calculations of the planetary positions for their predictions.

Livestock population meet the protein requirement of humans in addition to meeting from plants. The food chain starts from fodder crops to animals and from animals to humans. In human physiology, digestion of plant protein is much easier than animal protein, but however the digestion depends on climate (temperate climate, sub-tropical climate, tropical climate etc.,) wherein human kind live. Similar to crops, there is strong interaction between livestock and meteorological weather elements (temperature, relative humidity, wind etc.). But detailed study has not been published elaborately in scientific journals in the past. The weather elements have greater influence on livestock productivity in terms of milk, meat, skin, wool etc., pest and disease infestation and their housing needs. In this chapter how weather elements influence shed management, pest and disease problem and animals’ productivity and are discussed. In majority of the Veterinary and Animal Science University in India, they have one division on animal climatology, wherein both research and extension aspects are being attended. However, in depth research is the need of the present decade, since little works have been done in the past on animal climatology.

Irrespective of weather elements, the heat stress due to the combination of temperature and relative humidity plays important role in affecting the productivity of animals. There is a range of thermal conditions within which animals are able to maintain a relatively stable body temperature by means of behavioral and physiological means. Heat stress results from the animal’s inability to dissipate sufficient heat to maintain homeothermy (Sejian et al., 2017). High ambient temperature, relative humidity and radiant energy compromise the ability of the animals to dissipate heat. As a result, there is an increase in body temperature, which in turn initiates compensatory and adaptive mechanisms to re-establish homeothermy and homeostasis. Homeostasis refers to the tendency to maintain a balanced or constant internal state that is optimal for functioning. Animals have a specific balanced or normal body temperature. When there is a problem with the internal functioning of animal body, this temperature may increase, signaling imbalance. As a result, body attempts to solve the problem and restore homeostasis for normal body temperature. These readjustments generally referred as adaptations and this is essential for survival of the animals.

8.1 Climate Change

Climate change is a broad term of global negative phenomena as created predominantly by burning of fossil fuels, which add heat-trapping gases to earth’s atmosphere. The over accumulation of greenhouse gases in the atmosphere lead to increased temperature and this is called as global warming. As a result, sea-level rise; ice mass loss in Greenland, Antarctica, Arctic and mountain glaciers worldwide; shifts in flowering/ plant blooming; and extreme weather events occur.

7.1 Importance of Weather Forecast in Agriculture

In India, agriculture is in reality to be a “gamble activity” with the monsoon rain, that means the productivity and profit from agriculture depend upon the goodness of the season. If any malevolent weather situation that happens during a crop season, whether it is at the beginning of the crop season or at the mid of the crop season or at the terminal of the crop season or at the whole of the crop season, the productivity of the crops raised would be under stake. In practice the irrigated crop area is lesser than the area under unirrigated crop in India in any region except the regions where irrigation is routed through perennial rivers. Normally the production from unirrigated crop is 30 to 40 per cent of the same crop grown under irrigated condition in an environment in the same season.

In India, in a region or in a taluk, if the irrigated area is lesser than 30 per cent of total cultivable area, there is every opportunity for the occurrence of food shortage. That means assured production depends upon irrigation rather than managing the crops with seasonal rainfall alone. This clearly indicates that the higher probability of occurrence of crop production risks falls under rainfed/dry land situation. The crop production risk is also common to irrigated area like unirrigated crop but the intensity gets varied. In this context one example that happened in India can be quoted. During December- January of 1982, with the occurrence of heavy rain/snow as a result of prevalence of western disturbance weather system, the wheat crop stood for harvest at Punjab got damaged with a loss of 124 crore of rupees. If this was anticipated earlier through weather forecast development, (which is common in all developed countries) and communicated to the farmers in advance, then the yield loss would have been reduced by following some tactical decisions to be taken either by the farmers or by the concerned Government. At that time, India did not have medium range weather forecast system and hence Indian farmers met with greater losses.

Under normal weather situation, agriculture depends on timely occurrence of rainfall for crop management activities irrespective of different farming situations namely, irrigated and unirrigated agriculture. Changes in temperature and rainfall pattern together with frequent occurrence of extreme weather events are major anticipated threats from the climate change that occurs now around the world. This threat in long run, if not addressed properly, would affect food security of a country. Pratap Narain et al., (2000) observed an increase in moderate and severe drought occurrence numbers in the arid zone of India during last decade (1991-2000) as compared to the earlier decades of the last century. Similarly, Pasupalak (2008) reported daily maximum rainfall of 400.3 mm in the last decade against earlier record of 256.4 mm (1969–78) in a location at Odisha State. Further the inter- annual variation within the decade did increase and also the number of rainy days with very heavy rainfall > 125 mm also found increased in the location against the daily mean rainfall of 20 mm/day in India.

A day may be with heavy rainfall or with bright sunshine or windy or in combination of these. When heavy rainfall continues for more than a week with some system like cyclone, floods may be the result. Similarly, if dry spell continues during a cropping season for more than 15 days, drought would initiate in that region. This is again depending upon the nature of the soil water holding capacity and nature of soils, topography and green cover of that region. In between these two extremes, we have normal season, where we get normal seasonal rainfall during a cropping season. Hence like dress code, in agro-climatology, there are three weather codes, namely floods code, drought code and normal code. The jargon weather code was developed by Dr.M. S Swaminathan in India. Across the countries of the World, if these weather codes occur, the impact would be universal. The strength of adaptation capacity to maneuver these extreme events by the farming community rests with their past experience made for similar situations, financial support and also the technology options that are available from the scientific institutions.

5.1 Introduction

A Crop Simulation Model is a mathematical model which describes crop growth and development processes as a function of environment, soil conditions, and crop management. Simulation model is a schematic representation which works on set of underlying assumptions, equations and algorithms, closely replicating the behaviour of the agricultural systems. A crop growth simulation model predicts the harvestable yield. Apart from this final state of crop production, the model also provides a host of quantitative information about major processes involved in the various stages of crop development. The information covers each component of the crop such as leaves, stems, roots and harvestable products as they change over time, including the changes in soil moisture and nutrient status.

An increase in the population, demands an increase in agricultural production with available resources. Efficient management of available resources under varying weather conditions is important for increasing agricultural productivity. Besides that, the emphasis of agricultural production changes from quantity to quality and sustainability (Aggarwal et al., 2000). Solution of these new challenges lies in understanding the interaction of the numerous elements affecting the plant growth and generating a crop growth model. This extremely complicated information needs to be processed and interpreted on a spatial scale. Information technology which has unleashed new frontiers in data analysis and automation is the driving force behind this model generation. These powerful computer programmes simulate the crop growth or yield of crops under various management regimes and provide near real time information to help farmers to make strategic decision in the management of their crops.

4.1. Introduction

Many countries have set up a network of agrometeorological observatories to regularly record important weather parameters such as clouds, rainfall, surface temperature, humidity, wind and wind direction, solar radiation, soil moisture, temperature and humidity profile of the atmosphere, etc. The observation process is performed either manually or through Automatic Weather Stations (AWS).

This recorded information is used for weather forecasting, natural resources management and for tracking agricultural production. However, these networks, which handle data of high spatial climate variability, are typically less robust than they should be. Moreover, the agrometeorological data collected from different ground stations is not transmitted in real time to a central collection point which limits the use of information.

Satellite remote sensing technology is an alternative system that is gaining popularity in the recent times which has allowed us to obtain frequent and precise measurements of vital agrometeorological parameters such as rainfall, solar radiation, temperature, evapotranspiration, albedo etc. Satellite data has many advantages over traditional ground stations, such as high spatial resolution (50 m–5 km), wide spectral bandwidth range (0.4–3.75 um) and high temporal frequency (even half an hour) and the prospect of collecting data from remote areas. In addition to routine repeated observations, satellites often provide synoptic views of the earth’s surface from space on a wide scale and have archive of information to create baseline data.

The preparation, planning and use of agricultural technologies for agriculture, needs application of agricultural meteorology. The role of agrometeorology in the last three decades has increased in terms of increasing food and nutritional security for the burgeoning population and natural resource management particularly in the context of global climate change. Agrometeorology can help to minimize inputs, thus clarifying the contribution of ecosystems and agriculture to the carbon budget in the event of global change. Agrometeorological information needs to be disseminated to users in time and space quite accurately, as agricultural activities are linked to the very local situation where the outputs of modern tools such as local area models, climate models, and dynamic crop simulation models are reduced to finer grid resolution and combined using GIS to extract practical suggestions. This chapter describes the recent applications of remote sensing in Agrometeorology.

The subject on micrometeorology deals with small scale meteorology of near ground surface with its related elements of both physical and biological processes. When this micrometeorology is integrated for crop production purposes, then it becomes crop micrometeorology, which is very important in the science of agricultural climatology. This crop micrometeorology gets varied with the architecture of the crops grown, available soil moisture, agronomical practices followed, soil texture, topography of the area, the nature of climate and weather that prevails etc. The soil surface heat, exerts a profound frictional effect on wind movements and hence it is different from the air layers at higher levels. These special features constitute the microclimate, which is modified compared to a flat bare surface by factors like topography, nature of soil surface, presence of vegetation and type of vegetative cover. The presence of crop canopy leads to distinct differences in the thermal and humidity regimes of the soil, the air layers immediately above it and the distribution of radiation and wind profiles inside the canopy. The study on the physical exchanges of the transfer of heat, momentum and moisture in the microclimatic region is called as micrometeorology (Venkataraman and Krishnan, 1992).

Radha Krishna Murthy (2002) reported that the micrometeorology is the micro scale of both the physical and meteorological factors that are taking place within the ecosphere. The ecosphere means the area between just above the crop canopy and just below the root zone of a crop. Further he was on the opinion that the microclimate of valley is important as compared to the entire climate of the mountain for the bio-life of valley. For the crops purpose, the microclimate is the climate of the ground surface to top of the crop canopy or otherwise it can be called as crop’s climate, a modified one from the Stevenson’s Screen climate/weather observation.

The climate, the past weather event that existed over larger region and covering long years of more than 30 years is very important for the emergence and successful sustenance of an organism including human kind. Normally scientists talk about environment and this includes not only the soils but also the climate of the particular region. Based on this, during 1989, the Planning Commission of India divided the entire India in to 15 agro-climatic zones based on physiography and climate. This division is only for planning purposes. Subsequently under NARP, the Indian Council of Agricultural Research (ICAR), New Delhi in consultation with the Planning Commission, requested all State Agricultural Universities (SAU) to divide their State in to different sub climatic zones considering soils, temperature and other weather parameters preciously with in the major agroclimatic zone of India in which the concerned State falls. Accordingly, each SAU has divided their State into different agro-climatic sub-zones and this resulted in 129 agro-climatic sub zones in India and limited to 127 and these all fall within 15 agro climatic zones of India as done by the Planning Commission of India.

The National Bureau of Soil Survey and Land Use Planning (NBSS&LUP), Nagpur not satisfied with this division, considering soils, temperature, rainfall, vegetation and all factors responsible for ecosystem (bio-climate, length of growing period, moisture index) divided the whole India in to 20 agro-eco regions by 1992 and revised preciously again by 2015 (Mandal et al., 2016) and the revised approach is being considered as scientific tool and taken for micro-level planning in India now and those are discussed at this chapter.

1.1 Weather Parameters

The atmosphere is a gaseous component surrounding the earth as an integral part and its interaction with ocean (water bodies), other planets of the solar system and land (Earth) generates one physical product namely weather elements (temperature, pressure, wind, humidity, precipitation, etc.,) and these form the weather and climate of the Earth. The process of generation of weather and climate of the region is purely natural and cannot be modified by the human being. But they can do adaptation to the existing climate and weather for their sustainable life. The weather can be defined as day to day change in the atmosphere in terms of heat and moisture exchange, while the climate is average of long period weather covering larger area or a region.

The particular climate of a region dictates/permits the genesis of a particular bio-organism in that domain and this selected organism’s growth and multiplication are triggered by the prevailing weather of that particular climate. Hence weather parameters of the atmosphere are very important to human being and other organisms of the Earth. The details on weather elements are given in question and answer section of this book (Annexure-I)

All higher plants have some kinds of aroma or flavor in their various parts, which includes roots, stems, leaves, flowers and fruits. This flavor and aroma in a particular plant part due to the presence of some specific essential oils present in special glands in it (Chadha and Choudhury, 1989). Essential oils arethe concentrated liquid, which is highly concentrated and water insoluble liquid (hydrophobic) and it is also known as ethereal or volatile oils, which are fragrant oily liquid that are extracted from the various parts of the plants. Generally they are organic compounds like hydrocarbons likealcohols, aldehydes, esters, ketones and phenols. An essential oil is “essential” in case that it contains the essence of the different fragrance, and the properties of the plants from which they are derived. All though all ornamental plants have some aroma but only few of them are used commercially in perfumes, flavor and cosmetic industries. The essential oil demand by fragrance industry is 60%, flavour industry 20% and pharmaceutical industry 20%. In all the perfumes, rose oil is one of the best and costliest perfume. The first recorded reference of rose perfume is in CharakSanghita. The credit for discovery of rose perfume was given to Queen Noor Jehan mentioned in the book written by Md. Achem of King Jahangir’s regime.

The volatile oils showed the different kinds of biological activities including the antibacterial, antioxidant, antiviral, insecticidal, etc. These oils are also used for cancer treatment, while some other has been used for the food preservations, aromatherapy, and in the perfumery industries. Thus, in the day to day life a large spectrum of usage the essential oil and aroma industry has a bright future. Yet the known applications of essential oilsare opening up ofmore areas which will benefit the industry.

Flower arrangement is the art of using plant materials and flowers to create an eyecatching and balanced composition or display. Among all art forms, flower arrangements today take as prominent a place. The art engages ones personal involvement in welcoming guests and bringing cheer to the surroundings. It is rightly said, “Flowers are the music of the ground. From earth’s lips spoken without sound. “Professionally designed floral designs, arrangements or artwork incorporate the elements of floral design: line, form, space, texture, and color, and the principles of floral design: balance, proportion, rhythm, contrast, harmony, and unity.

Composition of Arrangements

There are a few compositions of flower arranging that should be considered. Once we understand these we can create so many different styles and our floral designs will have that professional look.

Floriculture has flourished with a considerable growth and a useful crop diversification option, particularly for small farmers over the past three decades. The commercial production of the cut greens has started in India in recent years and has huge demand in the market. They are suited for year round production with low investment and less care and maintenance. Cut greens or fillers are an important component of the floricultural industry and their commercial value depends on vegetative characters, such as stem length, leaf colour, density and side branching. Cut foliages (leaves and stems), which are attractive in form, colour and freshness, are lasting and in great demand. They have various other uses in making attractive fresh floral designs and floral arrangements, such as bouquets, wreaths, decoration of house interiors, etc. Evergreen plants with green, silver or variegated leaves are usually used and species with berries are now also becoming popular. Fillers are critical components in most arrangements as the flowers themselves,used to increase the volume and size of the bunch and provide colour contrast. These floral produce have various other uses in making attractive fresh floral designs and floral arrangements, such as bouquets, wreaths, decoration of house interiors, etc. Colour, freshness, stem length, freedom from pests, fragrance and vase life are important quality aspects of fillers. In the International market, fillers accounts for about 16 percent of the total trade by volume with an annual turnover of more than Rs 800 crores including selling of ornamental leaves, filler flowers, dry and dyed flowers along with berries and capsules. On the contrary, fillers representvery less quantum with poor quality in the domestic market and are unsuitable for cut flower bouquets. Their share in the market is very low and fetches nominal rates.

Flowers and various parts of the plant have been used for decoration and to commemorate various religious, festive, matrimonial and social gathering events in day to day life. The main drawback of fresh flowers and foliage is being highly perishable and delicate which cannot retain their beauty for longer durations. Moreover fresh flowers are not available round the year which can be overcome by the dehydration and drying techniques. Since ancient times, in Egyptian pyramids, fragrant dried flowers and herb garlands were encased along with mummified bodies. Japanese people created “Oshibana”, the “preserved flower art” of enduring designs to retain the exquisite beauty of the living plants centuries ago.

Later on, this craft making technique spread from Japanese to Victorian England because of their beautiful long lasting appearance. During middle ages monks dried flowers, foliage, and herbs for use in decorative motifs or for colouring their handprinted books.

Dried flower arrangements have been popular in Europe for centuries, and as early as 1700 AD, colonial Americans used dried flowers to brighten their homes, especially during the dark winter months.

Earlier botanists practiced dried flowers in the form of herbarium for the purpose of identification of various plant species. Though drying of flower was well known even in the past but for the first time the flowers were dried commercially in Germany (Sankari and Anand, 2014).

Floriculture is a high value industry. It is increasingly regarded as a feasible diversification option from traditional field crops due to increased per unit returns and increasing habit of ‘Greeting with Flowers’ during all the occasions. With increasing awareness among consumers and pressure from the artificial floral products on the fresh flower industry, and continued competition even amongst the growers, whole salers and retailers, quality is becoming increasi ngly important. The aspects related to visual quality of the product are the main determining indices of consumer’s acceptability of flowers.

The important flower crops in the international market are rose, carnation, lisianthus, chrysanthemum, gerbera, hydrangea, gladiolus, gypsophila, bird of paradise, orchids, anthurium, tulip and lilies etc. Cut flowers have the highest economic value and are the most perishable. Their high respiration rates, rapid deterioration, and susceptibility to damage require the utmost care during postharvest handling for quality maintenance. The post-harvest losses can be both, quantitative as well as qualitative, which ultimately result in loss in terms of its monetary value.

Floriculture industry is facing main problem due to highly perishable nature of its flowers which demand for appropriate post-harvest handling techniques to maintain the quality. With changing scenario in international floriculture trade, perfection in post-harvest technology is mandatory to offer quality plant products to the consumers round the year. The post-harvest life of cut flowers and flowering pot plants can be extended relatively by a range of treatments and technologies. Quality factors that influence the post- harvest keeping quality and flower longevity are environmental factors as well as the influence of the pathogenic organisms. Due to perishable nature of cut flowers, huge post-harvest loss is there which ranges from 30-50 per cent. Qualitative losses which include consumer acceptability of fresh produce are much more difficult to measure than quantitative losses. Quantitative losses can occur during the entire post-harvest and marketing chain due to lack of proper post harvest handling (Bhattacharjee, 2006). These losses could be on a higher side, which might be due to lack of knowledge on ‘post-harvest handling’ of cut flowers and proper infrastructure for post-harvest management and storage. However, all these losses can only be minimized by proper technique of harvesting, post-harvest handling, packaging, storage, marketing and value addition of flowers.

Lotus being a national flower of India, is closely associated with religion and culture. It is a perennial, aquatic crop that is grown and consumed throughout Asia. The edible parts of lotus are Leaves, flowers, seeds and rhizomes, and the flowers are also used in religious ceremonies. Lotus flowers are also, used for extraction of perfumes. It is one of the oldest plants in the world Archaeologists in China found Lotus seeds with estimated ages of 5,000 years in 1972 in Yunnan Provincelagoons.

During the pre-historic period, the South India Dravidians used lotus flowers (pundarika) as their food, much earlier than the people of the Indus Valley civilization (3000-2000 BC). However, there is no evidence of lotus being present during the Indus Valley culture of the Mohenjo Daro and Harappa period in northern India. The Rigveda reference that lotus was made by the Aryans (2000-1500 BC) wherein it is also mention that lotus can be used as food. Subsequently, lotus was mentioned in the Vedas, Upanishads, Puranas, Slokas, plays and other ancient Sanskrit literature. The lotus symbol is not only mentioned in the scriptures of Hinduism but it also occurs in the Buddhist and Jainism literature.

In the Arthasastra (350-300 BC) by Kautilya, the great diplomat during the golden age of Chandra Gupta, it is recorded that one of the varieties of sandal wood possesses the fragrance of lotus. The Mughal kings were also attracted towards the beauty of lotus. While describing Agra, the Mughal king Jehangir (1605-1627 AD) in his memories Tuzuk-i-Jehangiri, mentioned a memorable scene of a tank full of exquisite red lotus flowers, the like of which he had not seen before.

Marigold (Tagetes spp.) is an important annual flower crop; native to Central and South America especially Mexico and belongs to family Asteraceae (Compositae). It is commonly known as “Gainda” in India and also called as “Friendship Flower” in United States of America. Loose flowers of marigold are in great demand throughout the year. It is commercially grown in tropical and subtropical regions of India owing to its ease in cultivation, hardy nature, wider adaptability and year round availability of single, semi-double and double flowers of vibrant colours. Marigold is grown over an area of about 66.09 thousand hectares with production of 603.18 thousand MT loose flowers in India. Major states involved in loose flower production of marigold are Karnataka, Madhya Pradesh, Gujarat, Andhra Pradesh, West Bengal, Maharashtra, Haryana and Chhattisgarh. In India, Assam is the only state, which produces marigold for both cut as well as loose flower purpose on an area of about 0.61 thousand hectare (Anonymous, 2016a).

Marigold is a cross-pollinated flower crop and it is pollinated by insects (Kaneko et al., 1990). It bears terminal and solitary inflorescence, known as head or capitulum, which possesses long and hollow peduncle with swollen apex and campanulate involucres (Setshogo, 2005). Capitulum consists of peripheral ray florets and central disc florets. Ray florets are pistillate, ligulate, sessile, epigynous and zygomorphic, whereas, disc florets are bisexual, tubular, sessile, epigynous and actinomorphic (Subrahmanyam, 1996 & Setshogo, 2005).

African marigold (Tagetes erecta L.) is a diploid species (2n = 2x = 24), while, French marigold (Tagetes patula L.) is a tetraploid species (2n = 4x = 48) with basic chromosome no. of x = 12 as revealed by breeding work of various researchers (Towner, 1961, Chen and Lin, 1981, Chen and Lin, 1982, Serrato-Cruz et al. 2000, Zhang et al., 2011). Tagetes erecta and Tagetes tenuifolia are diploid species, whereas, Tagetes patula, Tagetes minuta, Tagetes biflora and Tagetes remotiflora species are tetraploid in nature (De, 2017). On the basis of floral morphology; three different types of male sterile systems i.e. apetaloid, petaloid and gynomonoecious types was observed in African marigold (Prakash et al., 2016). Out of these, apetalous male sterility (femina type) is more reliable and preferred over petalous male sterility because later is more prone to break down (Goldsmith, 1968 & Janakiram, 2004). Apetaloid male sterility was controlled by single recessive gene (Prakash et al., 2016). A monogenic recessive male sterile apetalous mutant was detected from T. erecta population by Khoshoo (1979). Cyto-genetic male sterility is also found in marigold (De, 2017). Petaloid and gynomonoecious male sterile systems were controlled by cytoplasmic inheritance (Prakash et al., 2016). In marigold, cytoplasmic genetic male sterile lines were also developed for commercial production of F_l sterile hybrids (Pratibha et al., 2000).

Jasmines constitute a group of traditional flower crops which are commercially grown for their fragrant flowers and essential oil production. There are trailing, climbing, and erect growing species and cultivars in the genus Jasminum. The genus Jasminum comprises of more than 200 species which are known to occur in different tropical and subtropical regions of the world. The countries growing Jasmines on a commercial scale are India, France, Italy, Morocco, Algeria, North Africa, Egypt and Spain. More than 80 Jasminum species are found in India, of which only four species viz., Jasminum sambac (Mogra / Gundumalli), Jasminum auriculatum (Jui / Mullai), Jasminum multiflorum syn Jasminum pubescens (Kunda / Kakda) and Jasminum grandiflorum (Jai / Pitchi) are widely used for commercial cultivation. Jasmines are commercially grown in many parts of the country as a dry land crop. The leading states in jasmine production are South Indian states like Tamil Nadu, Karnataka and Andhra Pradesh. In India, the commercial cultivation of jasmines are popular in Athoor, Coimbatore, Dharampuri, Dindigul, Erode, Krishnagiri, Madurai, Nilakottai, Periakulam, Salem, Thiruchirapalli, Thirunelveli, Thiruvallur, Tirumanagalam, Vellore, Virudhunagar etc. in Tamil Nadu; Bangalore, Bellary, Kolar, Mysore, Shimoga, Tumkur etc. in Karnataka ; Hyderabad, Khammam, Mahbubnagar, Mancherial, Ranga Reddy, Sangareddy, Vikarabad, Warangal Rural, Yadadri etc. in Telangana; Anantapur, Chittoor, Cuddapah, East Godavari, Guntur, Krishna, Kurnool, Nellore, Prakasam, West Godavari etc. in Andhra Pradesh; Ahmednagar, Aurangabad, Pune, Sangli etc. in Maharashtra; Ahmedabad, Anand, Bharuch, Bhavnagar, Kutch, Vadodara etc. in Gujarat; Gazipur, Jaunpur, Kannauj etc. in Uttar Pradesh; Ajmer, Jaipur, Kota, Udaipur etc. in Rajasthan; Panskura Ranaghat etc. in West Bengal; Guwahati, Hoja, Jorhat etc. in Assam ; and parts of Punjab and Delhi. Jasmines contributes markedly to the national economy and it is estimated that annually more than 20 crores worth of jasmine flowers are produced and traded in India and are also exported to countries like Malaysia, Singapore, Sri Lanka, UAE and United States (Safeena et al., 2017).

Statice, botanically known as Limoniumis very highly demanded ornamental plant. It is also known as ‘Sea Lavender’ owing to its color and place of growth. The genus name Limonium is from Greek name ‘leimon’ which translates to origin ‘a meadow’, most suitable as many species are found growing near marshy lands or salty areas of sea shore. The statice plants have very wide adaptability and can be seen growing under a wide range soil and climatic conditions like sea shores, marshy lands, deserts and plains etc. Statice figures in top 20 cut flowers sold worldwide but information on its trade, volume, export-import and number of stems sold etc. is not available. The reason for this may be attributed to classification systems, data collection categories and frequently changing nature of the assortments in the international flower market. Comprehensive trade statistics are difficult to locate for Statice. However, Statice figured in top 10 imported products in the Netherlands way back during 2013, 2014 and 2015. Though it is presently not among the top 10 flowers category, still it enjoys the immense popularity among the growers owing to its ease in cultivation and other characteristics. It is cultivated as annual as well as perennial crop, as different species have been domesticated for this purpose.

Lily is one of the most beautiful and popular ornamental bulbous flowers. They belong to the genus Lilium of the family Liliaceae, which comprises of 110 species classified into seven taxonomic sections: Lilium, Pseudolirium, Martagon, Sinomartagon, Archelirion, Leucolirion and Oxypetalum. All species are distributed over the mountainous area in the Northern Hemisphere (10° to 60°), mainly in Asia, North America and Europe. Especially, China, Nepal, Korea and Japan are the major centres of lilium gene pool around the world. Being second amongst the bulbous flower crops in the commercial market, Lilium has 4^th position among cut flowers in Flora Holland (Flora Holland Annual Report 2017). In the language of flowers lily is known as symbol of purity and innocence. Majority of cultivated lilies are either hybrids or selections. A large number of species and hybrids can be used in ornamental gardens even though the lily requires little more attention than any other bulbs. Many species of lily (L. leichtlinii, L. lancifolium, Lilium candidum and L. auratum) are also edible and having medicinal value.

Importance and uses

Lilies are one of the most important bulbous ornamental plants with varies uses, grown in border, beds, pots, landscape gardens and are excellent cut flowers of magnificent appearance and beautiful flowers. Roman naturalist and writer, Plinius, recorded that salves and oils were prepared from leaves and flowers of the Madonna lily, or L. candidium. Some species are also known for medicinal and food values, which increased its economic importance many folds. The mucilaginous substance coming out from the bulbs while cooking is used as an ointment for tumours, ulcers and inflammations. The plant was really more of a miniature household pharmacy. Different compounds have been reported in this genus, such as carbohydrates, proteins, fats, amino acids, vitamins, alkaloids, phenolics, flavonoids, carotenoids, sterols, steroidal saponins, and steroidal glycoalkaloids. Alkaloids, steroidal saponins, flavonoids and polysaccharides have been isolated from L. lancifolium and L. brownii var. colchesteri bulbs. Flowers of Lilium candidium contain an alkaloid. Extract of Lilium polyphyllum bulb has been used as refrigerant, expectorant, aphrodisiac, diuretic, antipyretic and tonic (Warrier et al., 1997; Dhyani, 2007). In the customary system of medicine, this species reported to restore health immediately and works as antioxidant in the body. Lily oil is an aid in childbirth. The white lily was also renowned as a cosmetic.

Dahlia (Dahlia variabilis Desf., family: Asteraceae, origin: Mexico) is regarded as a premium specialty cut flower besides its utilization for garden decoration and growing as a potted flowering plant. The dahlia flower symbolizes elegance, inner strength, creativity and dignity. It is herbaceous rooted perennial valued for their majestic and attractive display of colourful spectacular flowers. The generic name “Dahlia” was coined by Swedish botanist “Andreas Dahl”. Dahlia was introduced in India during 1857 under the auspices of the “Agri-Horticultural Society of India”, Calcutta. Dahlia exhibit wide range of flower from and size ranging from miniatures (less than 2.5 cm across), to giant (more than 40 cm in diameter). Dahlia flowers profusely and its easy cultivation have made these very popular worldwide. The commercial value of this crop has been exploited in certain countries only. The Netherlands is claimed to be the largest producer of tuberous rooted dahlias. Other countries cultivating Dahlia as a specialty cut flower are Japan, France, South Africa, the U. K., Italy, Germany and the United States. The commercial cultivation of dahlia in Indian subcontinent is limited to hills and plains of Eastern India (Misra and Misra, 2017).

Holland takes the lead in dahlia bulb production cultivation neeary 400 ha, followed by France and Chile. There are 41 international associations concerned with the cultivation and spreading awareness about dahlia as a potential specialty cut flower and flowering potted perennial. Societies such as National Dahlia Society in the UK, the American Dahlia Society (ADS), other groups of New Zealand in European countries, France and Germany have been maintaining Dahlia germplasm for developing novel flower colour and breeding dahlias for their uniform and profuse flowering, longer flower duration, stem sturdiness and longer vase life.

Zingiberales is an important order in Kingdom Plantae with eight families in which most of them are important as far as commercial horticulture is concerned. The order includes fruits (bananas and plantains), spices (ginger, turmeric, cardamom), medicinal (arrowroot, galangal) and ornamental (Heliconias, Bird of Paradise, Marantas, Canna, Costus, etc) plants. Among the ornamental zingiberales, plants of Strelitziaceae and Heliconiaceae are gaining popularity for its aesthetic preferences and marketable cut flowers. The unique colour and enhanced vase life of inflorescences makes them as flowers of choice. The plants of other families such as Marantaceae, Cannaceae, Costaceae, Zingiberaceae, Lowiaceae and Musaceae are also gaining momentum in floriculture business for their cut foliages and inflorescences. Some plants such as calathias are admired as potted plants and for indoor gardening.

Tuberose is an important half-hardy, perennial bulbous flowering plant. It belongs to the Amaryllidaceae family and having basic chromosome number (n=30). It is one of the important cut flower among the top ten cut flowers due to its beauty, elegance and sweet pleasant fragrance (Sadhu and Bose, 1973). It is cultivated for its long lasting spike as cut flower as well as loose flower purpose. Tuberose also known as Rajanigandha in Bengali, Gulchari and Galshabbo in Hindi, Sukandaraji and Nelasanpengi in Telegu, Nilasompangi in Tamil and Sugandharaja in Kannada. It is suitable under protected cultivation as well as open field condition (Brundell and Steenstra 1985). It has a huge economic potential and more demand for cut-flower purpose (Usman, 2013) and essential oil industry (Singh, 1995). Due to its immense export potential, cultivation of tuberose is gaining momentum day by day in our country.

Origin and distribution

Tuberose is cultivated all over the world and it is originated from Mexico. Tuberose is commercially producing in various countries such as India, China, Bangladesh, Mexico, Kenya, Italy, France, Morocco, USA, Hawaii and South Africa. In India, it is commercial growing in West Bengal, Karnataka, Tamil Nadu, Maharashtra, Uttar Pradesh and North Eastern part of India. At present scenery tuberose is cultivation in India 7. 95 lakh hectare and cut flowers is estimated to be 27.71 ‘000 MT and loose flowers1560.70 lakh (Anonymous, 2013).

Botanically aster belongs to the family Asteraceae and scientifically known as Callistephus chinesnsis which is basically native to China aster and annual aster. It is native to China and Japan and it is cultivated worldwide as cut flower, loose flower, bedding plant, for flower decoration and for making floral ornaments. It can easily cultivate in the open fields and green houses for the production of cut-flowers. The genus Callistephus derives from two Greek words that is ‘Kalistos’ and ‘Stephos’ meaning ‘most beautiful’ and ‘a crown’, respectively. The name Aster comes from the Ancient Greek word acx^p (aster),, meaning “star”;, referring to the shape of the flower head (Janakiram, 2006).Among various flowering annuals, China aster is having an important position in Indian floriculture industry. It holds the position next to chrysanthemum and marigold among the traditional flowers. In fact, it has widely replaced an already grown annual Chrysanthemum up to greater extent in Indian floriculture industry.

This flower is most preferred for wide cultivation by virtue of its wide variation in attractive color and longer vase life. It is also very much used for beautification in landscape gardening which create mass effect. In India it is cultivated in about 1,020 ha with a production of flower 800 million tonnes. It is commercially cultivated in Karnataka, Tamil Nadu, West Bengal and Maharashtra. In Karnataka it account for 6 % of the total area and 8.8 % of the total flower production.

Gladiolus, commonly known as ‘Sword lily’ which derives its name from latin word Gladius meaning sword shape foliage. The name gladiolus was originally given by Pliny the Elder (A.D.23-79). It is an important florist crop, cut flower in the domestic and international flower trade. It is relatively easy to grow, suitable for cut flower, pots, hanging basket, bedding and exhibition. An engrossing cut spikes bear a large number of florets on rachis, which exhibit various sizes, forms, with smooth, ruffled, deeply crinkled or laciniated tepals. As a genus it was first proposed by Tournefort and which was accepted in botanical litreture by Linnaeus through his description “Species Plantarum” in 1753 and “Genera Planterum” in 1754. The gladioli are said to be cultivated since the days of ancient Greece. The genus Gladiolus, at present comprises with 255 species (Mishra et al.,1995; Goldblatt and Manning,1998) with wide distribution occurs in Central Europe, Mediterranean region, Central and South Africa are primary centre of origin. Campbell and Bower (2003) mentions about one more species Gladiolus scabridus- a new species 1978 from the mountains of northern Kwa Zulu- Natal and southern Swaziland, restricted to well- drained rocky habitat and where it is endemic. This species has enormous commercial potential have large number of pink flowers. So now number of recorded gladiolus species are more than 260. The gladiolus was brought into cultivation first during Greek period. Gladiolus has been documented in literature since 1578, as evidenced from the record Lyte’s Nievve herbal. This was first time introduced in France and soon after spread to England, Germany, Holland and North America. In India, its cultivation dates back to 19^th century as mentioned in the ‘Firminger’s Manual of Gardening in India (1863)’ that Mr. Charles Gray of Conoor grew some gladioli from corms and seeds at his garden. The European Union gladiolus importing countries are Germany, Belgium, Luxembourg, Denmark, Spain, France, United Kingdom, The Netherlands, Italy and Portugal.

Anthurium is commonly known as anthurium/tail flower/oilcloth flower (Anthurium andraeanum) and flamingo flower/flame plant (Anthurium scherzerianum). The word anthurium is derived from two Greek words viz, anthos meaning flower and aura meaning tail, referring to the spadix. Anthurium plants were growing undisturbed for hundreds of centuries in the rainforests of South America. Samuel Damon, a businessman and politician in the Kingdom of Hawaii brought one species out of hundreds of species of anthurium to Hawaii in 1889 for cultivation in his garden. The plants were introduced by various people in their gardens from Samuel Damon’s garden. It is a tropical ornamental plant valued for its flowers and unusually attractive foliage. In India, it is grown commercially in Assam, Kerala, Tamil Nadu, Karnataka, Sikkim, West Bengal, Meghalaya and Maharashtra. In India, total anthurium flower production is 3230 tonnes with Assam producing highest anthurium production of 2050 tonnes followed by Meghalaya 740 tonnes (Seemanthini and Chandrashekar, 2018). Major markets in the world for per capita consumption of anthurium flowers are Europe (47.80%), United States of America (21.80%) and Japan (16.80%) (Misra and Misra, 2017). In anthurium, various ploidy levels exist like diploid (Anthurium andraeanum and A. hookeri), triploid (A. scandens) and tetraploid (A. digitatum and A. wallisii). Basic chromosome number varies in different species of Anthurium. Most of the Anthurium species have 2n = 30 chromosomes while in some polyploids, it is 2n = 60. However, a few species have 2n = 20 to 124 chromosomes (Petersen, 1989). In Anthurium andraeanum, somatic chromosome number has been found as 2n = 30 + 2B and this species has high percentage of meiotic abnormalities and karyotype differences suggesting its hybrid origin. Anthurium plants need medium care and reach up to a height of 45-50 cm bearing pale white to yellow coloured flowers with orange to red coloured bracts.

Orchid is a valuable flowering plant belongs to family Orchidaceae. It is considered that the family recognise for maximum number species ranged between17,000 and 35,000 worldwide (Garay 1960; Willis 1973). The word orchid is derived from a Greek word orchis for testicle because of the shape of the root tubers in some species of genus Orchis. India is a reservoir of 1300 orchid species from 184 genera, accounts for nearly 7 per cent of worlds orchids genetic diversity (Arora, 1983; Rampal and Nagrare, 2006) and 1150 species belonging to 164 genera (Satish Kumar and Manilal, 1994) of which about 800 species are found in the North Eastern region of the country (Nagaraju et al., 2006). Apart from species, more than one lakh hybrids developed in orchids. It is found all over the world from tropical to temperate and even alpine region. People always think that orchids are epiphytic only but it is not. It can grow in soil as terrestrial, on tree trunk (epiphytic) and on dead organic matter (saprophytes) and on rocks (lithophytes). Orchids produce unique flowers, affluent for their uniqueness in shape, size and colour, exquisitely attractive; remain fresh condition for long period of time in comparison to other flowers. Vase life of its flowers varied among species and hybrids ranged up to 40-45 days. Orchids are cultivated for trade of orchid species, cut-flowers, potted plants, flower basket, bouquet, stage decoration in high profile meets and functions and also used in many other value-added products (Kuehnle 2007). Many orchid species are used as food like Cymbidium hookerianum, Dendrobium chrysotoxum, D. kingianum, D. cathenatum and many more (Singh et al., 2016), spices (Vanilla planifolia and V. pompona) and medicinal uses (Dactylorhiza hatagirea, Flickingeria macraei, Vanda tessellata and Dendrobium macraei as reported by Ram Pal et al., 2020). The most popular and commercially cultivated genera are: Cymbidium, Dendrobium, Oncidium, Phalaenopsis, Vanda, Paphiopedilum, Mokara, Arundina, Paphiopedilum, Ascocenda and Cattleya in the country and even in the world.

Gerbera (Gerbera jamesonii Bolus), commonly known as Transvaal Daisy, Barberton Daisy or African Daisy, belongs to the family Asteraceae is one of the most important cut flowers in domestic as well as global market. It ranks sixth among the top ten cut flowers. Gerbera can successfully be grown in the plains as well as in the hills. In India, its cultivation is confined mostly to Kalimpong, Bangalore and Pune. The flowers are known for long vase life (Chauhan, 2005) and good rehydration capacity suitable for long distant transportation. It is a diploid species with somatic chromosome number 50 (n=25).

Importance and Uses

Gerbera is very fashionable and widely used as a decorative garden flower and cut flower (Kanwar and Kumar, 2008). It is ideal for garden decoration as a bedding plant, pot plant and suitable for growing in rock gardens. It is also used in interior decoration in vases, flower arrangements and in bouquets.

Gerbera viridifolia is referred as ‘the herb of milk’ in the eastern Cape and is probably used to stimulate milk production in cattle (Dold and Cocks, 2002).

Chrysanthemum takes its name derived from the Greek word chryos meaning gold and anthos meaning a flower, as many species have yellow flower heads. The genus Chrysanthemum belongs to family Asteraceae. It is herbaceous perennial plant. The genus comprises some 200 species of annuals, perennials and shrubs from northern temperate zone (chiefly Europe and Asia), whereas some researchers claim it was originated only from China. Though botanists have retained only the annual species under the genus Chrysanthemum (Beckett, 1983; Dole and Wilkins, 1999).

Annual chrysanthemums which are propagated through seeds. Annual chrysanthemum comprise ofthree species viz, Chrysanthemum segtum (corn marigold), Chrysanthemum carinatum (tricoloured chrysanthemum) and Chrysanthemum coronarium (crown daisy or garland chrysanthemum). The crown daisy or garland chrysanthemum (C. coronarium) is a native from Southern Europe, branching annual with finely cut foliage reaching a height up to a metre, size of flowers varies from 2.5 to 4 cm and colour is usually in shades of yellow and white with cream zone at the center (Vishnu Swarup, 1967).

Importance and Uses

Chrysanthemum is the number one dollar earning flower in the United States and cultivars suitable for growing throughout the year have been evolved there. The members of National Chrysanthemum Society run into thousands in several countries. It ranks second (next to rose) in the international cut flower trade. In India, it occupies a place of pride both as a commercial flower, garden plant, pot plant and as a popular exhibition flower.

Large number of chrysanthemum cultivars which exhibit wide variation for characters like growth habit, size, colour and shape of blooms makes chrysanthemum suitable for varied purpose. Its erect and tall growing cultivars are suitable for background planting in borders and as cut- flowers. The dwarf and compact growing ones are suitable for front row planting or pot culture. The decorative and fluffy bloomed small flowered cultivars are ideal for preparation of garland and hair decoration. The extra large- bloomed cultivars are prized for their exhibition value. Certain species like Chrysanthemum cinerariifolium and Chrysanthemum coccineum are cultivated as sources of pyrethrum, a natural insecticide.

Carnation (Dianthus caryophyllus L.) is one amongst the commercially important cut flowers traded worldwide. The genus Dianthus has about 300 species of annual, biennial and perennial herbs of which Dianthus caryophyllus is the most important species commercially. The genus Dianthus in Greek means ‘Flower of Zeus’ or ‘Divine Flower’. Linnaeus chose the species name, caryophyllus, after the genus of Clove, as the fragrance from carnation is reminiscent of clove. It is genetically a quantitative long day plant based on its photoperiod requirement (Blake, 1955). The Dianthus species are adapted to the cooler Alpine regions of Europe and Asia and are also found in Mediterranean coastal regions. Carnations were the first flowers to be cultivated on commercial scale in high altitude areas of tropics for export to Europe and North America.

It is cultivated throughout the world. The largest growing areas of carnation are in Bogota and Colombia. Carnation is also grown in Italy, Spain, Kenya, Sri Lanka, Canary Islands, France, Holland, Germany, Israel and USA. In India, main production areas are located around Pune and Bangalore. It is also being grown in Solan, Shimla, Mandi, Kullu, Chamba, Sirmour, Bilaspur and Hamirpur districts of Himachal Pradesh. As per the State Department of Horticulture - Himachal Pradesh, carnation occupied 44.07 hectares out of 705.77 hectare total area under floriculture in the state during 2018-19. The acreage of carnation is still expected to increase because of the favourable climatic conditions for its cultivation in different parts of Himachal Pradesh and other hilly states of the country.

In India, depending upon the regions, there is a wide difference in temperature, light intensity and humidity which not only affect the yield and quality of the flowers but also limit their availability for a particular period of the year. To produce quality flowers, carnation needs to be grown under cover, that is, in greenhouse which provides the plants with the optimum condition of light, temperature, humidity and carbon dioxide for proper growth and to achieve maximum yield of best quality flowers. Though, there are different types of the greenhouses, naturally ventilated polyhouses are preferred in mild climate in which temperature is reduced by ventilation (Ryagi et al., 2007).

Rose (Rosa x hybrida L.) is the most beautiful creations of nature and is commonly known as queen of flowers. It occupies first position in the international trade. Rose is known for its beauty and is used in worship, bouquets, cut and loose flowers, preserves, garlands, decorations, landscaping, etc. It has gained wide acceptability due to varied growth habits, beautiful shape, dissimilarity in size and form, attractive colour, pleasant fragrance and abundant varieties. These can fulfill the requirement of climbers, trees, hedges shrubs, and edges in the landscape gardening. Commercial products of rose such as rose water, rose attar, gulroghan, gulkand, rose dry petals, rose oil, etc play a vital role in international and national market. Rose hips are one of the imperative sources of Vitamin C and are used for preparation of rose tea. With the ever-increasing demand of novel varieties in the world trade, a large number of varieties are being bred every year with many novel traits. Its share is around 51 per cent of the whole of European markets. In India, 29.41 thousand ha area, producing 301.95 thousand MT is under rose cultivation in the states of West Bengal, Karnataka, Gujarat, Chhattisgarh, Maharashtra (NHB database, 2017). Cultivation of rose such as Rosa damascena, R. bourboniana, R. centifolia is also done for essential oil extraction from rose petals.

Origin and Taxonomy

Rose belongs to the family Rosaceae. The genus is divided into four sub genera of which sub genus Rosa includes nearly all the species (Gudin, 2000). The sub genus Rosa is further divided into different sections of which the actual number is arguable. There are about 100 to 300 species in rose based on various reports. The rose genome is complex consisting of five haploid chromosome sets each made of seven chromosomes. (Nybom et al., 2005). The chromosome number of wild species varies from 2n = 2x=14 to 2n= 8x=56, with most of the species being diploid or tetraploid (Nybom et al, 2005). Rosa x hybrida L. is not a species in botanical terms, however, is a highly complex artificial species (Gudin, 2003) that may be used to describe the modern rose cultivars.

Bonsai is an astonishing art-form, combining horticultural approaches and Asian aesthetics in a distinct way, which reflects the nature’s beauty (Pietraszko and Sobota 2008). The art of bonsai is considered to be originated in Chinese empire (Doyle et al., 2019) and was later adapted by the Japanese, where it has become the integral part of their culture (Ching 1990, Roth 2014). The word ‘Bonsai’ is derived from two Japanese words ‘Bon’ (Shallow pan) and ‘Sai’(plant) which literally means “planted in a container”. The Chinese started creating miniature landscapes in the form of Bonsai during Han Dynasty over 2000 years ago. During the Kamakura period (700 years ago) the Japanese adopted the bonsai art-form and subsequently a different Japanese style form came into existence. This art of bonsai was further redeveloped under the influence of Japanese Zen Buddhism (Doyle et al. 2019).

A bonsai is a nature’s replication of plant in its miniature form, without depicting the human interference too clearly. Thus, they are normal trees and shrubs which are dwarfed by a specific system of pruning-training-wiring. Techniques such as pinching buds, pruning and wiring branches, and carefully restricting but not abandoning fertilizers are used to limit and redirect healthy growth in bonsai. They are different from the pot plants which are mainly grown for either their foliage or floral beauty, but in case of bonsai the whole artistic look of the plant in its miniature form is maintained for years. Bonsai can be grown both outdoors and indoors, especially they are ideal for display in living rooms, verandas, terraces and window-sills etc. The good bonsai specimens are usually hardy species that can be kept outdoors the year round wherever winters are mild. They can be brought into the house occasionally for appreciation and enjoyment. In Japan, they are customarily displayed in a recess area or on small tables in a living room and later returned to their outdoor bonsai stands.