eChapters

Introduction

Development of improved crop varieties is vital for sustained increase in agriculture production and productivity. Timely supply of quality seed is equally significant since the contribution of quality seed alone is estimated to be 15-20 per cent to total crop production. Seed quality attains more significance in view of emerging biotic and abiotic stresses, issues related to quality and phytosanitary measures, competition in domestic and international markets and emerging food needs. Measures of seed legislation with respect to quantity and quality were initiated in the country by establishment of National Seed Corporation during 1963 under Ministry of Agriculture. The seed sector in India during the period was dominated by the Public sector. The National Seed Corporation was the Central Body to produce seeds of superior dwarf varieties in rice, wheat, and superior hybrids in maize, pearl millet and sorghum. This was followed by various seed legislations enacted by Government of India. Further, AICRP-NSP (Crops), popularly known as National Seed Project was launched during 1979-80. The NSP-Project came into operation in three major phases and continues to produce breeder seed to cater the needs of the Indian farmers. The project resulted in achieving breeder seed production surpassing the indents in all major crops. The seed programme of the country was further strengthened with NSP II (World Bank) Project starting in 1989-90, which not only supported the ICAR and SAUs, but also Department of Agriculture, Seeds Corporations, Seed Certification Agencies and Private Seed Industries to a great extent in production, processing and in providing quality seeds to the country.

Organic agriculture or farming is very much native to India. Whosoever tries to write a history of organic farming will have to refer India and China. The farmers of these two countries are farmers of 40 centuries and it is organic farming that sustained them. This concept of organic farming is based on following principles:

• Nature is the best role model for farming, since it does not use any inputs nor demand unreasonable quantities of water.
• The entire system is based on intimate understanding of nature’s ways. The system does not believe in mining of the soil of its nutrients and do not degrade it in any way for today’s needs.
• The soil in this system is a living entity.
• The soil’s living population of microbes and other organisms are significant contributors to its fertility on a sustained basis and must be protected and nurtured at all cost.
• The total environment of the soil, from soil structure to soil cover is more important.

Introduction

Organic seeds are produced by purchasing conventional non-treated seeds and growing them on organic plot / farm for one season without the use of any synthetic chemical. The seeds harvested are then sold on to organic farmers as organic seeds.

Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species, because they are sprayed or spread across entire agricultural fields. Runoff can carry pesticides into aquatic environments while wind can carry them to other fields, grazing areas, human settlements and undeveloped areas, potentially affecting other species. Other problems emerge from poor production, transport and storage practices.

Production of organic seeds without the use of pesticides like herbicides (weeds), insecticides (insects), fungicides (fungi), nematocides (nematodes), and rodenticides (vertebrate poisons) is a matter of skill and expertise. For this purpose, the seeds used for planting, the soil where they are planted, the water used for irrigation and even the air, need to be kept free of pesticides in order to prevent their contamination.

Seed

Introduction

Germination is the process by which a plant grows from a seed or similar structure. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. Quick germination is the various ways and means that really fastened the process of seed germination. Through various ways, it is possible to reduce the time of germination by 70 per cent and also the success rate of germination can also be doubled.

Archaeobotany

Botany as far as it is relevant in archaeology mainly denotes all types of ancient organic material (in particular ancient plant remains) collected from excavation sites. The deliberate study of the interrelationship between humans and plants and the environmental context in which this occurred has been called archaeobotany.

Introduction

Since beginning of this century genetic diversity of agricultural crop has been lost due to several reasons (Marla, 2012). Genetic erosion is caused by human intervention, mono culture, green revolution especially due to commercialization of plant breeding. So there is urgent need to collect, conserve plant genetic & genomic resource for further use.

A seed bank stores seeds to preserve genetic diversity. There are many reasons to store seeds. One reason is to have on-hand the genes that plant breeders need to increase yield, disease resistance, drought tolerance, nutritional quality, etc. of plants used in agriculture (i.e., crops or domesticated species). Another reason is to forestall loss of genetic diversity in rare or imperiled plant species in an effort to conserve biodiversity ex situ and in situ. Many plants that were used centuries ago by humans are used less frequently now and seed banks offer a way to preserve that historical and cultural value. Collections of seeds stored at constant low temperature and moisture guard against loss of genetic resources that are otherwise maintained in situ or in field collections. These alternative ‘living’ collections can be damaged by natural disasters, outbreaks of disease or war. Seed banks are considered seed libraries and contain valuable information about evolved strategies to combat plant stress or produce novel products. The work of seed banks spans decades and even centuries. Most seed banks are publicly funded and seeds are usually available for research that benefits the public.

Introduction

Synthetic seeds are defined as artificially encapsulated somatic embryos, shoot buds, cell aggregates, or any other tissue that can be used for sowing as a seed and that possess the ability to convert into a plant under in vitro or ex vitro conditions and retained its potentiality also after storage (Capuano et al., 1998). In other words, synthetic or artificial seeds defined as somatic embryos engineered seed used in the commercial propagation of plants (Gray and Purohit, 1991; Redenbaugh, 1993).

Artificial seeds have great potential for large scale production of plants at low cost as an alternative to true seeds (Roy and Mandal, 2008). An artificial seed is often described as a novel analogue to true seed consisting of a somatic embryo surrounded by an artificial coat which is at most equivalent to an immature zygotic embryo, possibly at post-heart stage or early cotyledonary stage (Bekheet, 2006). There are various advantages of artificial seeds such as better and clonal plants could be propagated similar to seeds, preservation of rare plant species extending biodiversity could be realized, and more consistent and synchronized harvesting of important agricultural crops would become a reality, among many other possibilities (Khor and Loh, 2005). In addition, ease of handling, potential long-term storage and low cost of production and subsequent propagation are other benefits (Bekheet, 2006).

Introduction

Seed as an input is the precursor for agricultural development as it alone can guarantee 20-30 per cent share of crop productivity (Koudinya and Kumar, 2014). Rigveda, the world’s most ancient scripture available, prescribes the importance of seeds as “Subeejam Sukshetre Jayate Sampadyate” which literally means, “A good seed in a good field can lead to the prosperity and posterity of the entire human race”. Seed production is indeed important to take care of a country’s food and nutritional security needs. At the same time, seed export across countries is vital for ensuring competitiveness in the domestic seed industry besides generating employment and valuable foreign exchange which in turn can be used for scaling up the seed sector’s efficiency itself (Poonia, 2013). As a matter of fact, seed trade is one of the reasons for huge advances made in the Indian seed industry through development and exchange of genetic transformation, marker-assisted breeding and nanotechnology (Nandi et al., 2013). As of 2014-15, global seed industry has reached USD 45 billion in which international seed export alone was worth USD 10 billion. Further, with the estimated growth rate of 9.2 per cent during 2015-2020, the world seed business is expected to be over USD 92 billion. Presently, USA, China, France, Netherlands and Brazil are the top markets comprising more than 66 per cent of the global share in seed trade. Corn, soybean and vegetables account for more than 75 per cent of the total global seed market volume. As of 2014-15, the value of the Asian vegetable seed market was USD 6.75 billion in which China had a major share (41 per cent) and the Indian share was around 7 per cent. Moreover, the world vegetable seed market alone is expected to grow at the rate of 7 -8 per cent per annum and reach USD 8.8 billion by the year 2020 (Parashar and Kumar, 2016).

A

Abnormal seedling: Abnormal seedlings are those seedlings which do not show the capacity for continued development in to normal plants when grown in good quality soil under favourable conditions of water supply, temperature and light.

Abortion: Loss of reproductive structures (e.g. a flower or an ovule) during development or arrest of development of any organ so that it remains imperfect or fails to reach maturity.

Absolute humidity: The amount of water vapour present in a given volume of atmosphere, usually expressed in g water per kg dry air, or g water per cubic meter air.

Human being as a hunter has depended mostly on animal food and some fruits. With the progress of civilization, he settled down and

started agriculture around 7000-10,000 B.C. He started depending on plant grains to take care of his energy and nutritional requirements in addition to animal foods. Initially cereal grains must have mostly accounted for his staple food requirements. Taste and health requirements must have prompted him to diversify his crop production programme. It is this need that must have made him to cultivate oilseeds, fibre and other crops.

Oilseeds, thus, have been under cultivation since antiquity. Rapeseed and sesame have been described in the Indian Sanskrit writings of 2000 BC. Historically, extraction of oil seems to have been a batch process. Seeds kept in gunny bags or boxes were pressed to remove oil. The separated oil on clarification was used for food and non food purposes. The resulting cakes were utilized as animal feed or thrown away into fields which helped in improving the soil fertility. Human beings slowly discovered the uses of oil and other oilseed products for various food and non-food purposes.

There are several species of plants in the world whose oil can be utilized for human consumption. Though around 40 oilseeds are known, only around a dozen oilseed crops have become commercially important. There are ten seed crops and three tree crops. The seed crops are groundnut, rapeseed- mustard, sesame, soybean, sunflower, cottonseed, safflower, niger, castor and linseed. These are mostly annual crops. The three major tree oil crops are palm, olive and coconut.

Groundnut

Groundnut roundnut is believed to have originated in Brazil and later spread to many countries all over the world. It is known to humanity since 950BC. Groundnut crop and its products have multiple uses. Being a leguminous crop it enriches the soil with nitrogen through symbiotic biological fixation by rizhobium. The economic product, groundnut in shell, contains the seeds, which are edible. The shell as well as the haulms serve as fuel and fodder. The seed oil serves as a good cooking oil while the cakes are good sources of protein for animals and even humans. Groundnut (Arachis hypogaea L,) belongs to leguminosae family and papilionacea sub family. It consists of two sub species each with two varieties. The first one hypogaea has the variety hypogaea (virginia group) and variety hirsuta kohla while the second one fastigiata has the variety fastigiata (valencia group ) and the variety vulgaris (spanish group). Hypogaea varieties are spreading types with branching and lack infloresence on the main stem. They are of longer duration and have fresh seed dormancy . Varieties of the fastigiata are of erect type with branching and flowering on the main stem also. The crop is of shorter duration than hypogaea types, but with little fresh seed dermancy.

The major groundnut producing countries of the world are China, India, Nigeria, U.S.A. Indonesia, Argentina, Sudan, Senegal and Myanmar. The cultivation is spread in tropical and sub-ropical regions. Groundnut is a self- pollinated crop and pollination takes place in the morning. After fertilization an elongated stalk namely peg develops which enters the soil, bends horizontally and swells to become a pod. Within the pod, two, three or four kernels are formed. The crop can be grown under rainfall conditions ranging from 50-125cm, with good distribution during flowering and pegging stages. Sandy loams, loamy soils, and black soils with good drainage are suitable for growing the crop.

In addition to cultivated oilseeds, many other seeds and related plant products serve as sources of vegetable oils. They are obtained from large trees, shrubs or from different crops and their products. It may be the seeds or the husk, or the germ or other parts of the fruit or seed which are rich in oil. These are in general, referred to as non-conventional vegetable oil sources. They are highly important for the food/feed and non-food industries. Non- food and industrial uses are plenty.

But for the availability of these non- traditional oilseeds and their products, there would have been great pressure on the cultivated seeds. The products, mainly oil, help run our machines and protect them from getting rusted. Some of them protect our crops from pests and deseases. They even serve as beauty aids in the form of cosmetics. Some of them serve as sources of medicine for men and animals.

In recent years, some non-conventional/ non-edible oilseeds have become the raw material for biofuel/bioenergy. They have gained prominence, due to shortage of conventional oils. Seeds of more than 100 species occurring in the wild or cultivated are known to contain oil in considerable quantities. There is a vast scope for production and utilization of oil from these sources (Ambasta, 1986, Bhattacharya, 2002 and Vimal and Naphade, 1980).

In this chapter, the major non-conventional oilseeds of tree origin, by product oilseeds or other minor sources, are being dealt with. They are ricebran, corn, sal, mahua, jatropha, kokum, melia, rubber, mango kernel, kusum, simarouba, neem, karanj, crambe, moringa, tumba, jojoba and tobacco seed etc. Emphasis is given to the composition and quality of oil, cake and other plant parts. Their food, non-food and medicinal uses are presented. Oil extraction and related post harvest technological aspects are also discussed.

Post Harvest Technology

Introduction

The demand for edible oil has grown with the increase in world population. Improvement in living standards have made the population increase the consumption of oils and fats. It also has become more discriminating with respect to the oil quality. Oil producers, have to meet the increasing demand for edible oil, and improve product quality and variety as these have become major factors in the market-place.

Agriculture has been tuned through selective seed breeding and improved crop production practices to take care of the increasing demand. The emphasis has been to improve yield per hectare or tolerance to climatic variations. The ability to modify seed through traditional breeding and biotechnological approaches promises a revolution in agriculture. Using various approaches, not only quantitative improvement but also the qualitative changes especially fatty acid changes have been brought about. Customer support is needed for the genetically modified crops. A lot of controversy exists at present in accepting genetically modified crops. This aspect has to be studied in depth and needs to be resolved at the appropriate level as quickly as possible.

A prerequisite for the production of top quality oils and meals is a high quality raw material. Some attempts have been made to improve the physical characteristics of oils and meals through genetic, agronomic as well as through post production handling and processing technologies. The harvested quality grain should not be damaged during transportation, storage and processing. To produce a crude oil, the industry uses a number of processing steps, the application of which depends on the type of seed and the scale of the operation.

The purpose of Post Harvest Technology of oilseeds is to recover the maximum quantity of good quality oil and also make the deoiled cake useful as food or feed. Oil in oilseeds is located in spherosomes, which are the oil bodies (Salunkhe et al, 1992). When seeds are broken into small particles and the cells get ruptured the oil becomes available and is easily extracted. From the time of harvest, till the seeds are fed to the oil extracting machines, various processes are carried out to make good quality of oil available to the consumer apart from providing remunerative prices to the producer, namely, the farmer. The various steps involved in the oil extraction are proper harvest, drying, storage, seed cleaning, heat treatment and different types of machinery. The basic objective of every step in the post harvest technology is to minimize losses and to sustain or improve the quality of the product.

Nutritional Quality of Edible Oils

Fats improve the taste and flavour of foods. Fatty foods satiate a hungry person fast because fats remain in the stomach for a longer period than either protein or carbohydrate (sugar) foods. Fats also carry essential vitamins like A, D, E and K. They also provide the body with essential fatty acids. Thus, fats have a very important role to play in human nutrition.

Spectrum of Fats and Oils

It is not just the butter and ghee that provide us the necessary fats. Vegetable oils, meat and fish too add fats in our diet. There is an array of vegetable oils available to human beings. They are groundnut, rapeseed, sesame, sunflower, safflower, soybean, niger, cotton seed, coconut, palm and rice bran oils. Ghee(butter fat), however, is the main animal fat utilized widely. The quality and composition of these oils vary as also the preference of people.

Antinutrients

Safety is the most important aspect among all the quality attributes of food. Food can be considered safe, only if it does not contain any factor which is hazardous to human or even animal health. The various factors which affect the safety of the foods may be broadly classified into three categories. The first category includes the toxic factors occurring naturally in foods. The second category comprises a group of incidental contaminants which find their way at various stages of processing, manufacture, preservation and storage of foods and the third category includes harmful intentional additives or adulterants.

Various categories of anti-nutritional factors are present in the traditional and non-traditional oilseeds, oils and oilcakes. Some of them are heat-labile and do not pose any harmful effects in the body, while the heat-stable factors may cause deleterious effects in human beings and animals. They belong to different groups of compounds. It is necessary to know their behaviour, significance and toxicities. Their avoidance or elimination is important to protect human and animal health.

Methods of Analysis

Organic material especially, seeds, grains, fruits and nuts contain mainly three groups of compounds. They are carbohydrates, proteins and fats/oils, mostly in that order. They also contain 3-5% minerals and smaller quantities of vitamins and other minor constituents. Cereal grains contain more of carbohydrates while oilseeds contain more oil. Tree nuts and even oilseeds may contain 30-50% protein while cereal grains contain 5-8% protein. The starch and sugar contents of oilseeds may be less than 10% while the oil content of cereal grains ranges around 5%. The actual content and the composition of these groups of compounds really account for the quality as well as their commercial value.

The composition and quality of grains and other plant products vary with respect to their genetic background, location or the soils under which they are grown, season or the environment, the maturity of the grain/product or its harvest stage and the post harvest processes including storage etc. Crop scientists have in recent years been bringing out made to order or designer seeds, whose quality and composition need to be examined to satisfy the needs of the quality conrol and consumer requirements. Keeping this aspect in view this chapter has been designed.

As this book deals with oilseeds, emphasis has been placed on methods of evaluation relating to thier composition and quality. This chapter deals with methods of oil, protein and sugar analysis. Oil being the major constituent of oilseeds, importance has been given to methods of oil quality evaluation including fatty acid profile. Antinutrients especially aflatoxins, glucosinolates, ricin, oxalate, phytic acid, oligosaccharides, etc. also find a place. Analytical methods of some vitamins and minerals have also been included. Only a few important and most essential procedures relating to oilseed quality have been presented. The analyst can find more details and methods of evaluation of other constituents in standard laboratory analytical manuals.

PESTS OF CEREALS

Rice (Oryza sativa)

Rice is the staple food of a vast majority of people throughout the world, especially in India. Rice crop is grown in about 75 million acres, which is about one-third of the total world area under rice. The warm and humid environment for the rice crop is best suited for invasion by several insect pests and as many as 85 species of insects are known to infest this crop. The damages caused by different pests extend from the seedling to harvest stages of the crop. Some of these pests are widely distributed and cause extensive damage. The more important pests are described below:

1. Rice stem borer or Rice yellow stem borer

Scirpophaga (Tryporyza) incertulas

Order - Lepidoptera

Family - Pyraustidae

Among the pests, which ravage rice crop, ‘rice stem borer’ is a major one and infests rice crop at all growth stages, from seedling to flowering. It is a specific pest of rice alone and is more serious during the months of October-January. The pest has a wide distribution in all Asian countries. The damages caused by this pest ranges from 5-20 per cent. Generally, late varieties of rice are more severely infested than the early maturing varieties, because of the possibility of the pest multiplying in larger numbers by the time the late varieties come to maturity. Cold weather with high humidity and low temperature prevalent during October-December is found to be conducive for the multiplication of the insect.

Mango (Mangifera indica)

1. Mango hoppers

(i) Amritodes atkinsoni (ii) Idioscopus niveosparsus and (iii) I. clypealis

Order - Hemiptera

Suborder - Homoptera

Family - Cicadellidae

Nature of damage. Three different species of hoppers are found to cause damage to mango trees. During some years, especially during the months of November-February, when the mango trees come to flowering, the pest appears in large numbers. During the other months, the pests are seen in much lesser numbers in an active form, while the other insects hibernate under the bark of the trees. Even in the peak period of pest occurrence, after a few heavy showers, the number of insects is considerably reduced.

During the cold season, when the trees put out the flower spikes, thousands of hoppers, young and adults appear in large numbers, pierce, suck and feed on the sap from the tender shoots, flower stalks, flowers and buds. This drain of the sap causes the buds and flowers to dry, wither and they are shed in large numbers, as a result fruit production may go down by 25-60 per cent. When a severely infested tree is approached, thousands of hoppers hop or fly about and make a rustling noise, as they dash against the foliage. The hoppers exude a sweet, sticky fluid excretion and this fluid thrown out by myriads of these insects after feeding on the tree sap, wets the soil underneath the trees and on the surface of the leaves of the trees. In case of severe infestation, the fluid may fall down in drops. The secretion attracts scores of flies, bees and other insects, which come to feed on the secretion. The infested tree presents a sickly appearance. The trees get devoid of buds and blossoms. The leaves appear shiny and are covered by ‘sooty mould’, a fungal disease. Thousands of caste skins of the nymphs are found on the shoots and leaves. The continuous damage caused to the trees year after year by the pest makes them loose their vigor gradually and eventually leads to severe reduction in their yielding capacity.

Life cycle of the pest. The female hopper inserts spherical, pale whitish eggs singly into the plant tissues through slits made in the young shoots, flower stalks and flower spikes. The eggs hatch in 4-6 days and the young nymph hatching out of the egg looks quite similar to the adult. The nymphs are very active and move about rapidly along the flower spikes and shoots, suck and feed on the plant sap. They are smaller in size, wingless and unable to fly or jump. The young ones moult their skin a few times during their growth and become adults in 10-15 days. The adult hoppers are small insects, about 3.0 mm. in length with a wedge-shaped body. The head is broader and the body gradually narrowing backwards. The legs are well developed, especially the hind legs. The general color is light greenish-brown. They are extremely active and can fly and hop around. They have a tubular, sucking mouthpart by which they puncture the tender plant parts and floral parts. The adults of Idioscopus clypealis are smaller, with two black spots on the prothorax and a few black spots on the front portion of the head, while those of Idioscopus niveoparsus are slightly bigger with three black spots on the prothorax and whitish, distinct cross bands on the light brownish forewings. The adults of Amritodes atkinsoni are bigger than the other two species, about 5.0 mm. in length, with two black spots on the prothorax. Two or more generations may appear during the flowering season of mango trees (Fig.71).

Insect and non-insect pests cause extensive damage to standing crops, stored grains and stored products resulting in huge economic loss. Besides these, several pests cause annoyance, as well as attack livestock such as, cattle, poultry and pet animals. Some others damage household articles such as, clothing, upholstery, carpets, paper, books, leather articles, wooden and bamboo furniture and all sorts of wooden structures. These obnoxious creatures besides consuming any kind of food materials, spoil them by contaminating and polluting them with their faecal matter and urine and impart a repulsive, bad odor and make them unfit for consumption by humans and livestock. The damages caused by them pave the way for easy access and infection by some of the saprophytic microorganisms, which hasten the deterioration process. A few of these microorganisms produce mycotoxins, which are poisonous and may even be fatal to the consumers.

Among the household pests, cockroaches, crickets, silver fish, ants, white ants, carpet and powder post beetles and clothes moths are quite important. These insects not only cause annoyance but different types of flies, mosquitoes, bugs, fleas and lice either suck and feed on the blood from humans, cattle, poultry etc. but are also responsible for disseminating several disease causing microorganisms.

“Hydrology is the science that treats the waters of the earth, their occurrence, circulation and distribution, their chemical and physical properties, and their reaction with their environment, including their relation with living things. The domain of hydrology embraces the full life history of water on the earth.” (Federal Council for Science and Technology, “Scientific Hydrology”, Washington, 1962)

This definition puts in a nutshell what is most often inadequately done before undertaking exploitation of water resources. In short, it is the scientific inputs that are likely to be missed while planning water resources management projects. It is the “full life history of water” part of the above definition that is of specific relevance to the theme of this book, Isotope Hydrology.

Conventional hydrology is strong on measurement and quantification of different parts of the hydrological cycle (Fig.1.1), be it precipitation, run-off, evaporation, transpiration, infiltration, groundwater dynamics etc. Through chemistry and isotopes, we try to understand the processes themselves in order to delineate the history of that part of the hydrological cycle that is being studied. For example, if we are measuring river flow, we would like to know the contribution of different components; base flow, rainfall run-off and snow melt, if any.

Let’s see what we know and what do not know in the conventional hydrological practice. We know surface waters evaporate, form into clouds and precipitation occurs under favourable weather conditions. What we often do not know is the source of moisture, oceanic or inland.

In the last chapter, we have broadly introduced the concept of tracer hydrology and also the concepts of isotopes as tracers, their characteristics and measurement techniques. In this chapter let us see the basis of application of each group of isotope tracers, injected and environmental.

What are the different groups of isotope tracers used in hydrology and how are they classified?

The range of isotope applications in surface water hydrology is not as wide as in groundwater hydrology as the surface waters are more easily amenable to conventional hydrological methods. Following are the areas in which isotopes have a significant role in either improving the accuracy of measurements or in providing additional information, which is otherwise not easily available.

After precipitation, run-off and surface water storage in lakes and man-made reservoirs, the next steps in the hydrological cycle are infiltration through the unsaturated zone and groundwater dynamics in the saturated zone. Well-established applications of isotopes in groundwater hydrology are

5.1 The Need

In spite of the considerable experience and quite a few facilities available in the country, the growth of application of isotope techniques is not commensurate with India’s size, its climatic and hydrogeological diversity and the sheer range of its water resources problems.

The situation may not be unique to India and other developing countries. Australia also appears to be facing a similar problem. A recent publication [1] says ‘the limited uptake of the method may be due to a number of factors. Until relatively recently, isotope hydrology has remained a largely academic pursuit, or measurements were the domain of national atomic energy agencies. A large fraction of information lies buried in the grey literature or in arcane technical journals. Interaction with local or regional water resources agencies has been the exception rather than the rule’

India has probably a stronger case for a more effective use of isotope techniques. A large portion of groundwater occurs in hard rocks in India. Normal hydrogeological and geophysical methods cannot fully describe such groundwater regimes to effectively plan their exploitation. It is essential to apply tracer hydrology methods, especially isotope geochemical techniques, for a comprehensive understanding of the systems. The examples of Manikaran geothermal springs, seepage studies in Salal tunnel and in some dams, given in the earlier chapters come under this category. Studies on percolation tanks in basaltic terrain and on recharge processes need isotope support.

It will not be long before we would be planning to exploit very deep ground waters (>500 m), both in the hard rock terrains of peninsular India as well as in the Ganga plains to meet our ever growing need for water. We would need good understanding of the recharge processes to these deep ground waters. Isotopes will have a large role in such investigations.

Arid zone hydrology is yet another area where the potential of isotope techniques has been effectively demonstrated for the characterization of the recharge processes, both palaeo and modern, and including the role of ancient rivers.

India is a second largest producer of fruits and vegetables after China. These share are 10% and 16% respectively in total world production. Horticulture crops occupy 23.548 million ha and production is estimated around 260.063 million tones. Total area of fruits, vegetable, plantation crops, spices, loose flower and aromatic plant are 7012, 9083, 3606, 3092, 218 and 537 thousand ha, respectively and production are 79400, 156445, 16388, 5786, 1421 and 622 thousand tones, respectively with productivity are11.32, 17.22, 4.54, 1.87, 6.59, 1.19 thousand tones per ha, respectively (2012-2013). The total productions of cut flowers are 74305 Lakh stem (2012-2013). The annual horticulture export volume is 2733145 metric tonnes (2010-2011) with total exported value of Rs 696461 lakh. In terms of volume, fresh fruits & vegetables comprised about 76 % of exported horticulture produce followed by processed fruits & vegetables (23 %) and floriculture & seeds (1%). After that losses found 20-30 % in fruit and 30-40 % in vegetable while harvesting to consumption in India. It’s due to the perishable nature of horticulture commodity, non availability of appropriate post harvest infrastructure transportation, inadequacy of the market or lack of processing.

India is a major horticulture producer, even though processing is less than 2 %. This is very low as compare to 80 % of Malaysia, 78 % of Philippine, 70 % of Brazil and 30 % of Thailand. The most of developed country 40-60 % fruits and vegetables utilize in processing.

Proper handling, packaging, transportation and storage reduce the post harvest losses of fruits and vegetables. For every one percent reduction in loss will save 5 million tons of fruit and vegetable per year. Processing and preservation technology helps to save excess fruit and vegetable during the glut season. The technology has become a necessity to improve the food safety and strengthen nations food security. The technology helps to boost export of agricultural commodities in the form of preserved and value added products.

Fruits and vegetables are important part of our dietary, which are rich source of nutrient (carbohydrates, protein, fat, vitamins, minerals, and dietary fiber). Carbohydrates, protein and fat are macronutrients, considered as energy sources. Vitamins and minerals are micro nutrient, play important role in body building. Fibers have several direct and indirect advantages. ICMR, New Delhi recommends 125g of leafy vegetables, 100g of root and tuber vegetables and 75g of other vegetables (total 300g/day) and 85g of fruits per capita every day for balance diet.

Maturity

It is derived from Latin word ‘Maturus’ which means ripen. It is that stage of fruit development, which ensures attainment of maximum edible quality at the completion of ripening process.

Maturation

It is the developmental process by which the fruit attains maturity. It is the transient phase of development from near completion of physical growth to attainment of physiological maturity. There are different stages of maturation e.g. immature, mature, optimally mature, over mature.

Maturity Indices

The factors for determining the harvesting of horticulture commodities according to consumer purpose and type of commodity.

Maturity Indices is two type

Fruits and vegetables are living tissues subject to continuous change after harvest. Some changes are desirable from consumer point of view but most are not. Post-harvest changes in fresh fruit cannot be stopped, but these can be slowed down within certain limits to enhance the shelf life of fruits. The post-harvest handling plays an important role in extending the storage and marketable life of horticultural perishables.

Post Harvest Treat ment of Fruits and Vegetables Washing

It is useful in removing surface adhering material water. Mechanically, it is also accomplished by passing the fruits/vegetables through machine arranged with water tank equipped with rotating brush. In some produce washing improves appeal by facilitating removal of sap as case in mango, papaya, jackfruit, kronda, dirt in case of carrot, reddish, turnip, sugar beet, sweet potato, etc. and for removal of debris in case of banana. The water use for the purpose should be cleaned otherwise fungal and bacterial levels may build up. Disinfected treatment using ultraviolet light, ozone, chlorine (100 ppm), calcium hydroxide, etc. help to clean water for washing purpose.

Flowers are highly perishable unlike other horticultural or agricultural crops. Owing to poor keeping quality the post harvest losses in floriculture are significantly higher than any other sector. Although there has been significant increase in the area, production and productivity of flower crops in the last two decades, there is an urgent need to minimize the huge post harvest losses in terms of the value of the produce which are estimated to be 30-40 per cent of farm value. The post harvest behavior of flowers is an outcome of the physiological processes, occurring in leave, stem, flower bud, leafless peduncle or scape connecting bud to the stem. Some of these processes may act independently to affect the senescence and vase life of cut flowers but most of them are inter-related. The nature and extent of post harvest damage is typical for each crop or cultivar. The post harvest losses become important especially when dealing with the export of fresh flowers to distant and foreign market. Therefore, patient, soft and expert handling of flowers is of utmost importance after harvest.

Since time immemorial, spices have played a vital role in world food trade, due to their varied properties and applications. We primarily depend on spices for flavour and fragrance as well as colour, preservative, inherent therapeutic, medicinal and appetizing properties. The spices that India can offer in abundant quantities are pepper, ginger, turmeric, chili, cardamom, celery, fenugreek, fennel, cumin, dill, coriander, cinnamon, ajowan, cloves, nutmeg, mace etc.

Ripe

This word is derived from Saxon word ‘Ripi’, which means gather or reap. This is the condition of maximum edible quality attained by the fruit following harvest. Only fruit which becomes mature before harvest can become ripe.

Ripening

Ripening involves a series of changes occurring during early stages of senescence of fruits in which structure and composition of unripe fruit is so altered that it becomes acceptable to eat. Ripening is a complex physiological process resulting in softening, colouring, sweetening and increases in aroma compounds so that ripening fruits are ready to eat or process. The associated physiological or biochemical changes are increased rate of respiration and ethylene production, loss of chlorophyll and continued expansion of cells and conversion of complex metabolities into simple molecules.

Ethylene (C₂H₄ also known as ethene) is a gaseous organic compound that is the simplest of the alkenes chemical structures (alkenes contain a carbon-carbon double bond). The hormone effects of ethylene on general plant growth were first noted in 1864 when leakage from gas street lighting systems caused stunting and deformation of nearby plants. In 1901 Neljubow identified the active component of the gas to be ethylene but it was not until 1934 that Gane identified that plants could synthesize ethylene and in 1935 Crocker proposed ethylene to be the hormone responsible for fruit ripening and senescence of vegetative tissues.

Ethylene play important role in many plant during development processes, including seed germination, vegetative growth, leaf abscission, flowering, senescence and fruit ripening. Ethylene also plays a role in response to water stress, chilling and mechanical injury.

It is a most deteriorating biological process of the harvested fruits and vegetables that leads to the oxidative breakdown of the complex material (carbohydrates or acids) of cell into simpler molecules (CO₂ & water) with production of energy. Respiration includes glycolysis metabolism, aerobic metabolism, anaerobic metabolism, trycarboxilic acid cycle and electron transport metabolism processes.

Proper marketing of perishable commodities such as fruit and vegetables often requires some storage to balance day-to-day fluctuation between harvest and sale or for long term storage. Storage of horticulture produce is attempeted with a view to extend period of availability. Storage controls shelf life of produce by controlling rate of respiration, transpiration, ripening and biochemical changes all of which are responsible for shelf decomposition/deterioration of produce. Further, different types of storage have different attributes in minimizing microbial infection and thus add to better storability of produce.

Packaging is an important consideration in vegetable and fruit market. The use of properly designed containers for transporting and marketing of vegetables is significantly reduce losses and maintain their freshness succulence and quality for longer period. Packaging also provides protection from mechanical damage and undesirable physiological changes and pathological deterioration during storage, transportation and marketing.

Many vegetables are transported in gunny bags and bamboo baskets. Packaging material such as polythene films, paper boars, and boxes lived with polythene and other materials can effectively prolong the shelf life of vegetables. By using plastic films vegetables can be protected from dry air. Polythene packaging provides modified atmosphere and consequently reduces decay, softening, and loss of solids. The thickness and permeability to CO₂, O₂ and water vapour of films needs to be standardized for each vegetable.

Physiological disorders refer to non-parasitic or inanimate disease of fruit crops, or it is the breakdown of tissue that is not caused by either invasion by pathogens or by mechanical damage. They may develop in response to an adverse environment, especially temperature or to a nutritional deficiency during growth and development. Physiological disorder is broadly classified into two broad categories. They are:

Preservation means just protect the foods against the spoilage, but scientifically it may be defined as a science which deals with the process for prevention of decay or spoilage of the food is called preservation.

In other words, just controlling the physical, chemical or microbial changes in the foods is called preservation.

Physical Changes: Colour, flavour, texture and taste etc.

Chemical Changes: Carbohydrate, fats, proteins, vitamins and minerals.

Microbial Changes: Mould, yeasts and bacteria

Food additive is any chemical substance that is added to food during preparation or storage. A food additive either becomes a part of the food or affects its characteristics for achieving a particular effect. For instance, substances that are used to enhance the appearance, texture, or to keep qualities of a food are considered food additives.

Canning is a process of sealing food stuffs hermatically in containers and sterilizing them by heat for long storage is known as canning.

Principle of Canning

Destruction of spoilage organism within the sealed container by means of heat.

Selection of Fruit and Vegetable

For canning fruit should be ripe but firm and uniformity mature and vegetables except tomato should be tender.

Grading

Selected fruit and vegetable are graded according to size and colour to obtain uniform quality. This is done by hand or machines such as screw grader and roller grader.

Removal of water from the food by non-conventional energy source like sunlight, wind, and a smoky fire. Drying (dehydrating) food is one of the oldest and easiest methods of food preservation.

Dehydration

Dehydration is the process of removing water or moisture from a food product under controlled condition like temperature, relative humidity, air flow, etc.

Principles of Drying and Dehydration

Drying removes the moisture from the food so that bacteria, yeasts and moulds cannot grow and spoil the food. It also slows down the action of enzymes, but does not inactivate them. Dried food items can be kept almost indefinitely, as long as they are not rehydrated.

Freezing is one of the easiest and least time consuming methods of food preservation. The freezing process is a combination of the beneficial effects of low temperatures at which microorganisms cannot grow, chemical reactions are reduced, and cellular metabolic reactions are delayed.

Methods of Freezing

1. Sharp freezing (slew freezing)

In sharp freezing commodities are exposed at -15 to -29⁰C. It required 3-72 hrs. Here the thawed tissue cannot regain its original water content. The ice crystals formed are large and rupture the cells. The thawed tissue cannot regain its original H₂O content.

Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions.

Fruit juices which do not undergo alcoholic fermentation are termed as unfermented beverages. They include natural and sweetened juices, RTS, nectar, cordial, squash, crush, syrup, fruit juice concentrate and fruit juice powder. Barley waters and carbonated beverages are also included in this group.

A dilute solution of acetic acid produced by a two-stage fermentation process in the first stage, fermentable sugars is converted into ethanol by the action of yeasts and in the second stage, bacteria of the genus Acetobacter oxidize the ethanol to acetic acid.

Vinegar is a liquid produced from the fermentation of ethanol in a process that yields its key ingredient, acetic acid. The acetic acid concentration ranges typically from 4 to 8 percent by volume for table vinegar (typically 5%) and higher concentrations for pickling (up to 18%). Natural vinegars also contain smaller amounts of tartaric acid, citric acid, and other acids.

The preservation of food in common salt or in vinegar is known as pickling. It is one of the most ancient methods of preserving fruits and vegetables. Pickles are good appetizers and add to the palatability of a meal. They stimulate the flow of gastric juice and thus help in digestion. They are prepared with salt, vinegar, oil or with a mixture of salt, oil, spices and vinegar.

Jam is prepared by boiling the fruit pulp with required quantity of sugar to thick consistency, firm enough to hold fruit tissues in position. It should contain not less than 68.5 per cent soluble solids. Jam may be made from a single fruit (apple, strawberry, banana, pineapple etc.) or from combination of two or more fruits. Jam contains 0.5-0.6% acid and invert sugar should not be more than 40%.