eChapters

Introduction

The western blot (alternatively, protein immunoblot) is an analytical technique used to detect specific proteins in a given sample of tissue homogenate or extract. It uses gel electrophoresis to separate native or denatured proteins by the length of the polypeptide (denaturing conditions) or by the 3-D structure of the protein (native/non-denaturing conditions). The proteins are then transferred to a membrane (typically nitrocellulose or PVDF), where they are probed (detected) using antibodies specific to the target protein.

There are now many reagent companies that specialize in providing antibodies (both monoclonal and polyclonal antibodies) against tens of thousands of different proteins. Commercial antibodies can be expensive, although the unbound antibody can be reused between experiments. This method is used in the fields of molecular biology, biochemistry, immunogenetics and other molecular biology disciplines.

Other related techniques include using antibodies to detect proteins in tissues and cells by immunostaining and enzyme-linked immunosorbent assay (ELISA).

The method originated from the laboratory of George Stark at Stanford. The name western blot was given to the technique by W. Neal Burnette and is a play on the name Southern blot, a technique for DNA detection developed earlier by Edwin Southern. Detection of RNA is termed northern blotting and the detection of post-translational modification of protein is termed Eastern blotting.

Northern Blot

The northern blot is a technique used in molecular biology research to study gene expression by detection of RNA (or isolated mRNA) in a sample.

Eastern blotting is a technique to detect protein post translational modifications (PTM) and is an extension of the biochemical technique of western blotting. There are multiple versions of the method, but in general proteins or lipids are blotted from one or two-dimensional SDS-PAGE gel on to a PVDF or nitrocellulose membrane are analyzed for post-translational protein modifications using probes that may detect lipids, carbohydrate, phosphorylation or any other protein modification. Eastern blotting should be used to refer to methods that detect their targets through specific interaction of the PTM and the probe, distinguishing them from a standard Far-western blot. The most common application is lectin blotting, however, a variety of other probes can be used for detecting different PTMs.

History and Multiple Definitions

Definition of the term Eastern blotting is somewhat confused due to multiple sets of authors dubbing a new method as Eastern blotting, or a derivative therof. All of the definitions are a derivative of the technique of Western blotting developed by Towbin in 1979. The current definitions are summarized below in order of the first use of the name, however all are based on some earlier works. In some cases, the technique had been in practice for some time before the introduction of the term.

DNA Sequencing

DNA sequencing is the determination of the precise sequence of nucleotides in a sample of DNA. Sequencing can be done on a short fragment of DNA to cover the entire genome. The maps thus constructed using the nucleotide sequences in the correct order is called as sequence map.

In 1977, twenty-four years after the discovery of the structure of DNA, two separate methods for sequencing DNA were developed: the chain termination method (Sanger et al., 1977) and the chemical degradation method (Maxam and Gilbert, 1977). Both methods were equally popular to begin with, but, for many reasons, the chain termination method is the method more commonly used today. In chemical degradation method, chemicals specific to each base remove the last base, which has been labelled. The method uses toxic chemicals which required high care while handling.

In chain termination method, DNA polymerase extends a DNA strand in which dideoxynucleotide becomes incorporated terminating the chain extension (phosphodiester formation) at the 3’OH site making an array of fragments differing in length. This method is based on the principle that single-stranded DNA molecules that differ in length by just a single nucleotide can be separated from one another using polyacrylamide gel electrophoresis.

The transfer foreign gene to the plant cell is a very crucial method to production of transgenic plant. So improvement of plant quality requires to transfer our interest gene or we can say useful for production of our interest product. To achieve genetic transformation in plants, we need the construction of a vector (genetic vehicle) which transports the genes of interest, flanked by the necessary controlling sequences i.e. promoter and terminator, and deliver the genes into the host plant. The two kinds of gene transfer methods in plants are.

1. Vector-mediated or Indirect Gene Transfer

Among the various vectors used in plant transformation, the Ti plasmid of Agrobacterium tumefaciens has been widely used. This bacteria is known as “natural genetic engineer” of plants because these bacteria have natural ability to transfer T-DNA of their plasmids into plant genome upon infection of cells at the wound site and cause an unorganized growth of a cell mass known as crown gall. Ti plasmids are used as gene vectors for delivering useful foreign genes into target plant cells and tissues. The foreign gene is cloned in the T-DNA region of Ti-plasmid in place of unwanted sequences.

To transform plants, leaf discs (in case of dicots) or embryogenic callus (in case of monocots) are collected and infected with Agrobacterium carrying recombinant disarmed Ti-plasmid vector. The infected tissue is then cultured (co-cultivation) on shoot regeneration medium for 2-3 days during which time the transfer of T-DNA along with foreign genes takes place. After this, the transformed tissues (leaf discs/calli) are transferred onto selection cum plant regeneration medium supplemented with usually lethal concentration of an antibiotic to selectively eliminate non-transformed tissues. After 3-5 weeks, the regenerated shoots (from leaf discs) are transferred to root-inducing medium, and after another 3-4 weeks, complete plants are transferred to soil following the hardening (acclimatization) of regenerated plants. The molecular techniques like PCR and southern hybridization are used to detect the presence of foreign genes in the transgenic plants.

What is FISH ?

Fluorescent in situ hybridization is a technique in which single-stranded nucleic acids (usually DNA, but RNA may also be used) are permitted to interact so that complexes, or hybrids, are formed by molecules with sufficiently similar, complementary sequences. Through nucleic acid hybridization, the degree of sequence identity can be determined, and specific sequences can be detected and located on a given chromosome. Fluorescent in situ hybridization (FISH) is a powerful technique for detecting RNA or DNA sequences in cells, tissues, and tumors. FISH provides a unique link among the studies of cell biology, cytogenetics, and molecular genetics.

Principle of FISH

FISH involves the preparation of short sequences of single-stranded DNA, called probes, which are complementary to the DNA sequences the researchers wish to paint and examine. These probes hybridize, or bind, to the complementary DNA and, because they are labeled with fluorescent tags, allow researchers to see the location of those sequences of DNA. Unlike most other techniques used to study chromosomes, which require that the cells be actively dividing, FISH can also be performed on non dividing cells, making it a highly versatile procedure.

The biological diversity of each country is a valuable and vulnerable natural resource. Sampling, identifying, and studying biological specimens are among the first steps toward protecting and benefiting from biodiversity. Knowledge about biodiversity and the ability to identify organisms that comes with it are global public goods. That is, this knowledge can create benefits for all countries - benefits that no one country can create by itself.

DNA Barcoding: Documenting Biodiversity with a Gene Sequence

“DNA barcoding” is an exciting new tool for taxonomic research. The DNA barcode is a very short, standardized DNA sequence in a well-known gene. It provides a way to identify the species to which a plant, animal or fungus belongs. The Consortium for the Barcode of Life (CBOL) is promoting international partnerships that will enable people in all countries to better understand and protect their biodiversity.

DNA barcoding is a taxonomic method that uses a short genetic marker in an organism’s mitochondrial DNA to identify it as belonging to a particular species. It is based on a relatively simple concept: most eukaryote cells contain mitochondria and mitochondrial DNA (mtDNA) has a relatively fast mutation rate, which results in significant variance in mtDNA sequences between species and, in principle, a comparatively small variance within species.

In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells These organelles range from 0.5–10 micrometers (µm) in diameter. Mitochondria are sometimes described as “cellular power plants” because they generate most of the cell’s supply energy in form of adenosine triphosphate (ATP), used as a source of chemical energy. In addition to supplying cellular energy, mitochondria are involved in a range of other processes, such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth. Mitochondria have been implicated in several human diseases, including mitochondrial disorders and cardiac dysfunction, and may play a role in the aging process.

Several characteristics make mitochondria unique. The number of mitochondria in a cell varies widely by organism and tissue type. Many cells have only a single mitochondrion, whereas others can contain several thousand mitochondria. The organelle is composed of compartments that carry out specialized functions. These compartments or regions include the outer membrane, the intermembrane space, the inner membrane, and the cristae and matrix. Mitochondrial proteins vary depending on the tissue and the species. In humans, 615 distinct types of proteins have been identified from cardiac mitochondria; whereas in Murinae (rats), 940 proteins encoded by distinct genes have been reported. The number of proteins encoded in plant mitochondrial DNA is probably not much higher than the number encoded in mammalian mitochondria.Experiments have shown that most of the protein synthesis in isolated maize mitochondria can be accounted for by some 18-20 polypeptidesThe mitochondrial proteome is thought to be dynamically regulated. Although most of a cell’s DNA is contained in the cell nucleus, the mitochondrion has its own independent genome. Further, its DNA shows substantial similarity to bacterial genomes.

In genetics, microRNAs (miRNA) are single-stranded RNA molecules of 21-23 nucleotides in length, which regulate gene expression. miRNAs are encoded by genes from whose DNA they are transcribed but miRNAs are not translated into protein (i.e. they are non-coding RNAs); instead each primary transcript (a pri-miRNA) is processed into a short stem-loop structure called a pre-miRNA and finally into a functional miRNA. Mature miRNA molecules are partially complementary to one or more messenger RNA (mRNA) molecules, and their main function is to down-regulate gene expression. They were first described in 1993 by Lee and colleagues in the Victor Ambros lab .

MicroRNAs can be encoded by independent genes, but also be processed (via the enzyme Dicer) from a variety of different RNA species, including introns, 3' UTRs of mRNAs, long noncoding RNAs, snoRNAs and transposons.

The genes encoding miRNAs are much longer than the processed mature miRNA molecule; miRNAs are first transcribed as primary transcripts or pri- miRNA with a cap and poly-A tail and processed to short, 70-nucleotide stem-loop structures known as pre-miRNA in the cell nucleus. These pre- miRNAs are then processed to mature miRNAs in the cytoplasm by interaction with the endonuclease Dicer, which also initiates the formation of the RNA-induced silencing complex (RISC). This complex is responsible for the gene silencing observed due to miRNA expression and RNA interference. The pathway in plants varies slightly due to their lack of Drosha homologs; instead, Dicer homologs alone effect several processing steps. The pathway is also different for miRNAs derived from intronic stem-loops; these are processed by Dicer but not by Drosha. Either the sense strand or antisense strand of DNA can function as templates to give rise to miRNA.

After the DNA is run on the gel, the polymorphic bands or the bands cosegregating with a target trait are tagged. The bands identification is either done by calculating their relative mobilities (Rm / Rf values in case of isoenzymes) or by calculating their molecular weights (in case of proteins and DNA).

There are several methods to calculate molecular weights of DNA bands on the gel. Graphical approach is one of them. The approaches include (1) use of computer software to generate molecular weights and (2) running unknown DNA fragments with the fragments of known molecular weights (standard markers available from private companies, see examples in the figure). An example is given here (see figure) to illustrate the method to calculate molecular weights of unknown DNA fragments. This method is usually called as Graphical Approach.

NTSYSpc 2.0 software is used for various types of analysis including calculation of similarity index values and construction of dendrogram. Construction of dendrogram using gel data in the form of bands. This software accepts zero-one data.

Among the vast resources of plants, aromatic and medicinal plants are highly beneficial to mankind for supplying medicines and essence. Olfactory gland bearing aromatic plants are few and many of them are located mainly in tropics and sub-tropics. Ecological conditions in the tropics are so conducive for such plants that out of 75,000 edible plants, majority are found in this region. (Chai et al., 1979, Jong, 1979)

Among the aromatic plants, kewda (Pandanus fascicularis Lam.), a common species of screwpine, is commercially important for its highly aromatic male spadices used in the production of highly prized kewda perfumes. Kewda attar, water and oil (rooh kewda) are the important perfumery products. Kewda attar blends well with most of the fancy perfumes, in preparation of lotions, cosmetics, soaps, hair oils, agarbatis (incense sticks), scenting clothes and flavouring betel masala, chewing tobacco and bouquets. Kewda water is used for flavouring various foods, confectionaries, sweets, syrups and soft drinks. The oil and attar are considered as stimulant, antispasmodic and administered for headache and rheumatism (Chopra et al., 1956). The kewda is mentioned frequently in Tamil classics as having flowers which neutralize the foul fish odour pervading the sea coast with their strong perfume. Jehangir in his memoirs, Tuzuk-i-Jahangiri, described kewda flower for its strong and penetrating scent, which even obscures that of musk (Gandhi, 1989).

Odisha state lying between 17^o 52′ N to 22^o 45′ N latitude and 81^o 50′ E to 87^o 50′ E longitude has a prosperous agriculture. Nearly 75 % of its working population are either cultivators or agricultural labourers and remaining 25 % are engaged in the categories of household industry and other works (Anonymous, 1988). The wastelands occupy 13.79 % of the total area of Odisha and are mostly scattered throughout the state. The areas of wastelands in the state mainly accounted for the hilly slopes, degraded forests, over grazed revenue wastelands, oil eroded valleys, drought stricken pastures, saline and marshy lands, etc. The changes in land use leading to creation of wastelands include overgrazing forest degradation and development of marginal cropland due to flood, drought and soil erosion etc. (Fig. 1).

Kewda (Pandanus fascicularis Lam.) is a native of the old world extending from Africa to Australia (Chittenden, 1956; Lorus and Milne, 1967; Mott, 1975). About 600 species of Pandanus are widely distributed in the moist tropics of the old world and kewda is the most widespread species being recorded from Mauritius Islands in the west to Polynesian and Micronesian Islands in the east (Deshaprabhu, 1966).

It occupies an important position in the mythology of Melanesian, Polynesian and Micronesian Islands (Massal and Barrau, 1956). Kewda has been mentioned in the Indian mythology with several available legends. In Skandha Puran, it is mentioned that Ketaki (P. odorattisimus L.f.) flower is unfit to worship Shiva (Bhattacharjee, 1987). As regards to popularity of Kewda, one of the Gujarati tribal songs says that the sun rises behind the Kewda tree, the moon applies antimony to its eyes, the night is lit with soft moon light. Another mythological legend mentioned that during Satya Yuga, there was a fight between Brahma and Vishnu to know, to prove their greatness. Lord Shiva decided a simple method that the one, who can see his head or his feet, shall be greater than the other. Shiva disappeared and became so great that Brahma and Vishnu couldn’t see his head or feet and searched in different directions. Vishnu went up to patal, but couldn’t find his feet and Brahma had gone up to the highest peak and could not see the head of Shiva. On the returned way, Bramha found a Kewda flower and claimed that he had brought the flower from the head of Lord Shiva. On questioning by Vishnu, Kewda flower also replied that she was adorned by Shiva (Gandhi, 1989).

Botany

Several vernacular names of kewda are reported in different languages all over the world ; viz.

Keora, Ketgi, Keura, Gagandhul in Hindi; Keya, Ketaki, Kea, Ketkikea in Bengali; Kiya, Kia in Odia; Kewoda in Gujrati; Ato, Keto, Covasso in Konkani; Keoda, Keora in Marathi; Talemara in Kannada; Gedaji, Gedangimogali, Gojjangi, Ketaki, Mugali, Mogali in Telugu; Kaidai, Talhai, Thasai, Thazh, Kechiya, Kedagi, Kedagai, Muchali in Tamil; Kaita, Ketaki, Palliyambu in Malayalam; Gandhapuspa, Dalapushpa, Shivadvishta, Ketaki, Suchika pushpa in Sanskrit; Leram in Nicoberese; Mudukeyiya, wetakey in Sinhalese; Keora in Urdu; Gulkiri, Kader, Kadi in Persian; Satthapu, Tsatthapu in Burmese; Nalu in Nepalese; Togenashiadan in Japanese; Kadar, Kadhi, Kazi in Arabic Kaide, Kedige, Ketaki, Gedege, Mundige in Canarese; Kedgi in Deccan; Vaquois odorant in French and Schrauben palme in German. (Kirtikar and Basu, 1935; Randhawa and Mukhopadhyay, 1986; Kapoor, 1990).

The screwpines are tropical shrubby plants grown for the highly scented flowers or the ornamental foliage. The ornamental foliage types are generally cultivated in the green house and protected from direct sun. The variegated types loose the colour in a rich soil and hence should be grown in a rather poor soil containing just sufficient nutrients and moisture. Some species are good for potting and indoor decoration. The common screwpine is used as a hedge also (Randhawa and Mukhopadhyay, 1986)

The screwpine (Pandanus), is highly polymorphic with numerous forms and varieties and selected in various countries for specific uses as maintained by vegetative propagation, e.g. P. leram (Plate 14), the Nicober-bread fruit, is grown in the Andaman Islands for its edible fruit providing a starchy food that is enjoyed locally; another species, P. utilis (Plate 15), on the remote Island of Mauritius, provides fibre from the leaves, used in making bags and a species from Polynesia, P.veitchii (Plate 16) is most commonly grown in green houses and outdoors as an ornamental, where the winter weather is mild and in the species the prop roots and branching stems are particularly well developed attracting attention from many people who might not otherwise notice the stranger from the tropics (Lorus and Milne, 1967). However, these three species give a striking foliage effect and especially useful in seaside gardens as P. utilis with green leaves; P. veitchii with banded white and P. leram with even longer leaves (Thomas, 1965). An unarmed form, forma laevis warb., is cultivated for the fragrant bracts of the inflorescence, while forma samak, a group of prickly Pandanus, is preferred for the tough leaves suitable for matting; another form with longitudinal yellow bands on leaves (forma variegatus) is grown for ornamental purposes (Deshaprabhu, 1966; Ambasta, 1986). In the Pacific Islands, some of the forms (e.g pulposus) are cultivated for their edible fruits (Purseglove, 1975; Ambasta, 1986). Burkill (1966) states that the common wild armed form of the sea-coasts was var. littoralis and that flower growers had selected various races for cultivation, which included the prickly var. samak and thronless var. laevis, grown in India, Malay and Indonesia, are used for making mats.

No breeding work has so far been done on kewda except selection of some promising morphotypes. Varietal improvement in kewda by breeding poses problems mainly due to dioecious nature and long life cycle of the plants, besides heterozygosity. Lack of promising strains is a major drawback. The wild growing population of kewda has a measure of variation and this has never been documented and utilized, which naturally offer a good scope for improvement of kewda by resorting to selection and subsequently propagating them vegetatively. Since a wide range of variation is available and the plants are mostly propagated by vegetative means, it is worthwhile to collect genetic stocks, access variability in morphological characters and attempt a breeding programme after selecting the desirable types for high flower production as the ultimate economate economic value of the plantations depends on the quantity of flower production to be used industrially in the distillation units.

Soil

Soil has a pronounceed effect on the plant growth and productivity in kewda. Well drained sandy-loam soil with adequate supply of moisture is best suited for its vigorous growth and flower production. Thickly distributed profitableKewda plantations with normal flowering are found in the lateritic belts with deposits of silty loam soil and adequate moisture supply. In heavy clay soil with inadequate moisture supply, the plants grow vegetatively with poor flowering. At places close to the Bay of Bengal like Rangiagarh, Kujang, Paradeep of Jagatsinghpur district, where a silt-loam soil deposit is found over the clay zone, the dense plantations of kewda with free flowering ability are noticed. But surprisingly, the female plants are more at few places close to the Paradeep port, which may be due to seed propagation by drifting of ripe fruits from the uplands; while in Ganjam district, the farmers are used to plant the selected male plants in their field resulting in high flower production.

The tentative age of the natural plantations is estimated from the rates of leaf production, stem and branch growth (5-50 cm / year) and development of branching pattern (primary and secondary) in conjuction with the interactions made with the local farmers of kewda (Fig. 9). The plants of different age groups (1 to 5 years) are observed for growth characters and flower production at Tulu of Ganjam and Konark of Puri districts under farmers’ field condition and it is observed that the initiation of flowers started at 5 years of age and the rate of flower production was 1.7 to 2.2 per plant (Table 9).

Kewda is exclusively propagated through ground suckers and leaf bearing terminal cuttings. In kewda growing areas, predominantly the terminal shoot cuttings are used in commercial plantations. However, the seeds are also capable to germinate and give rise to plants, but it is not in practice due to hard mesocarp and seed coat (Bailey, 1950, Deshaprabhu, 1966, Mott, 1975, Maharana and Jagadev, 1993).

Seed propagation

In kewda, the flowers develop into berries, which fuse to form a multiple fruit. The receptacle and bracts are included in the fruit. The seeds are deep seated and very difficult to extract, hence seeds are sown along with the fibrous drupes. Each drupe contains 2-9 seeds. Seeds collected from ripe fruits are sown during spring. The seeds normally, take about 3 months for germination due to the hard seed coat and impervious fibrous covering. Experimentally, it was observed that one hour sulphuric acid scarification treatment of the drupes reduced the germination period by about one month increasing the germination percentage as compared to direct sowing, however, scarification for more than one hour was deterimental (Table 14) (Maharana and Jagadev, 1993). Bailey (1950) reported that seed soaking in tepid water for 24 hours would aid the germination. The seed propagated plants (Plate-27) take about 2-3 years more for flowering as compared to vegetatively propagated plants.

In practice, flowers are collected from wild plantations. Recently kewda has emerged as one of the important commercial commodities. A systematic cultivation practice is essential to develop a successful plantation and to increase the productivity.

Planting

Kewda suckers or crowns are generally planted during June-July. i.e. in the beginning of the monsoon, when the soil is not too wet. Planting in wet soil delayd the root formation and reduces the success level. Just after the first shower of rain or during the summer shower close to monsoon, kewda is planted.

In a full grown plant, stilt roots originate at a few feet above the ground to render a support for the huge canopy of the plant. Each part of the stem is capable enough for development of root initials, but it is retarded once the stem became old and leafless. The root initials develop at the terminal portion, where more leaves cluster, but they do not grow. Hence, the stem cuttings collected from the flowering or non-flowering shoots bear the rudimentary roots and when planted, they establish quickly.

In practice, the cuttings are collected and scattered on the ground for two to three days. Before planting, a few leaves closed to the base of the cuttings are removed to expose the root development sites. The cuttings are planted in trenches of 45 cm depth horizontally or at an angle of 30^o. The new leaves appear on the growing points one month after planting.

Kewda plants are usually planted on the field bunds for fencing and subsequently used for collection of flowers. A 30 years old plant can produce a crown of 6-7 m, for which it is difficult to develop a commercial plantation in a close spacing. It has been observed in the natural plantations that the plants may be spaced at 8-10 m distance to achieve a full length of plantation life. It is, therefore, suggested by the authors to follow a paired row method of planting maintaining a spacing of 4 m between plants and rows of a paired row and 6 m between two paired rows; which provides all facilities for plant growth upto 10-12 years and then pruning of a few branches are required. Hence, a plant population of 500 plants in the field and 150-200 plants on field bunds are maintained in a land of one hectare.

Kewda plant occurs wild in the entire coastal belt of Odisha , but abundant in Chhatrapur and Keluapalli areas of Ganjam district. There were about 3-4 lakhs trees of kewda in Ganjam district (Deshaprabhu, 1966). Main season of flowering starts from July-August and lasts for 2-3 months and a few flowers also come during November-December and March-May (Haines, 1961). Averagely, a plant produces 15-20 flowers per season depending on branching of the tree (Plate 32). A fully matured tree bears 30-40 spadices in a year (Deshaprabhu, 1966). Flowering is also dependant on rainfall, being better in years of high rainfall. Size of flower is bigger during rainy season. The spadices take a fortnight to mature, depending upon the weather condition. Ripe spadices, creamy in colour, give higher yield of perfume and of better quality than immature ones (Plate 33). The kewda flower of Ganjam district is also registered under the geographical indications (GI) of goods (Registration and Protection) act (Panigrahy, 2019).

The volatile oil in the flower determines the odour and flavour of kewda and it has been of particular fascination to the chemists. There are only a few reports on the chemical composition of kewda essential oil (rooh or otto) Dhingra et al. (1954) distilled the kewda flowers collected from five places of Ganjam (Odisha) and Ghazipur (Uttar Pradesh) districts. He found the oil yield to vary from 0.015 to 0.031% and the compounds identified were methyl ether of β- phenyl ethyl alcohol (65.97%), d-linalool (18.70%), dipentene (8.31%), phenyl ethyl acetate (3.48%) and citral (1.82%). The oil was of light to golden yellow in colour having the following physico-chemical properties viz., specific gravity (d20o) 0.932-0.958; refractive index (n20o) 1.485-1.491; optical rotation ([α]D) + 1.350 to + 2.080; acid value 1.4 – 6.7; ester value 15.9 – 40.9 and soluble in equal volume of 80 % alcohol (Deshaprabhu, 1966). Sadgopal (1959) also reported the major constituent of oil as methyl ether of β-phenyl ethyl alcohol (65 – 80%) and minor constituents as dipentene, α-linalool, phenyl ethyl alcohol, citral and some terpene esters.

According to Chandra (1985), the oil contained dipentene (6.0%), d -linalool (19.0%), phenyl ethyl acetate (4.6%), citral (1.8%), caproic acid (0.5%) and stearoptene (0.2%) besides the major constituent methyl ether of β-phenyl ethyl alcohol (67.0%).

Kewda plants are hardly attacked by the insect pests and diseases. However, a few fungal and bacterial diseases are found to reduce the yield of flowers significantly. Some important insect pests and diseases of this plant with their nature of damage and suggested control measures are discussed here as reported by Jagadev et al. (2001).

Pests

1. Bag worm

During the dry season, leaves are found to be attacked by bag worm (Manatha albipes; Fam. Psychidae; order- Lepidoptera) (Plate 36). The larva, a foliage feeder, feeds on the chlorophyll and veins of leaves leaving the mid-rib resulting in perforation of leaves. In case of heavy infestation, the leaves become dry. Extensive damage arrests the vegetative growth resulting in significant reduction of flowering. Thus, the insect is considered to be of economic importance, but till date neither the extent of economic loss caused to the crop nor its control measures have been worked out.

French author Jean Giono once remarked, “The God creates the Odours, but the men manufacture the perfumes”. In today’s world, fragrances play bigger role than just being associated with a tiny bottle of liquid. It now serves the larger purpose of linking itself with anything you can imagine, from soaps to your favourite sweater knitted by your grandmother (Biswas, 2012). In the modern day, these products find their applications in items for personal sophistication to culinary delights and beverages, to a host of industrial products (Dev, 1993). India, a country known for its vast range of fragrant flowers and herbs, has used extracts from such raw material to produce incense sticks, medicines, body massage oils and sweet savouries.

The word ‘perfume’ is derived from the Latin term ‘perfumen’, meaning ‘through smoke’. Perfume is a fragrant liquid mainly distilled from natural oils, aromatic chemicals and resinoids; cologne is a lightly scented liquid used to cool the skin and deodorant contains chemicals to counter offensive body odour. Perfume is basically used by women, cologne by men and deodorant by both (Saha and Sareen, 1997). Throughout antiquity there was a continuous demand for incense, to mark the rites of scenting passage from birth to the grave, for the daily rituals of incensing rooms, linen and clothing. The South Asian synonym for perfume, ‘attar’, on the other hand, is derived from the Arabic word ‘aettr’ meaning ‘fat’ or ‘extract’. Almost all attars are basically aromatic oils extracted from flowers, plants and herbs through steam distillation. Some fragile flowers and oils that can not stand the heat of distillation are, however, crushed and the oil expelled by mechanical force (Mahmud, 1992).

The world trade in flavour and fragrances in 1987 was US $ 7,000 million and at present, it is estimated at more than $ 10,000 million annually. In 1975, perfume was used by one woman in ten, but today it is used by eight out of ten women; even reticent Japanese women are adopting the habit (Anonymous, 1995 c). The average annual industry growth rate in perfumes of India is valued at about US $ 20 million with an annual growth rate of 12% (Murty, 1993),while the UK market is Rs. 2000 crores and the US market supersedes it by Rs. 4000 crores (Walia, 1997). However, the domestic luxury perfume market is estimated to grow at a rate of 20-25 % (Biswas, 2012). Besides domestic market, India earns a lot of foreign exchange from the export of total essential oils and perfumes and is fast growing as it is showed from the trends in export earnings of Rs. 11.1 corers in 1982-83 rose to 4-fold in 1986-87 of Rs. 41.1 crores (CHEMEXCIL, 1988). According to a market survey report, Ahmed (1999) reported that the daily turn over of the attar market in India is more than 50 crores.

Middle East countries continue to be the big buyers of our traditional perfumes. Kewda flavour which is used in pan masala and tobacco is a familiar one in this part of the world. Kewda essence, being one of the few flavouring oils, has a good scope for export to other developed countries where the food flavouring industry is well developed. India is the leading producer of kewda perfumes in the world and the market for kewda perfumes is fast expanding specifically in the Arab countries. India exported the kewda water of Rs. 266.2 lakhs in 1986-87 which rose to Rs. 276.4 lakhs in 1987-88 (CHEMEXCIL, 1990). Anonymous (2007) reported that about 140 distilleries (bhattis), both local and outsider, earn about Rs.1.3 crore by way of extraction charges and annually they extract 332 kgs of kewda oil (Rs.8.3 crore), 7823 kgs of kewda attar (Rs.15.65 crores) and 150 MTs of kewda water (Rs.4.47 crore), the total coming to around Rs.28 crore. For extracting attar , the extractors use about Rs. 8 crore worth of sandal wood oil procured mainly from other states, while Rs.18 crore goes to the plantation owners as flower cost and to the flower collectors.

Kewda plants are mostly propagated through vegetative means. The common propagating materials used are ground suckers. The planting materials are planted in paired-row method maintaining a spacing of 4m from plant to plant and row to row keeping a spacing of 6 m between paired rows. In a field of one hectare, a minimum plant population of 500 plants in the field and 150 plants on the field bunds with a total of 650 plants are maintained. A fertilizer dose of 30:15:15 kg NPK/ha and 4 cartloads (100 cft) of FYM/ha are applied. The planting of collected ground suckers is normally done in the field just before monsoon after thorough land preparation under rainfed condition.The earthing-up of the plants are done up to five years of planting for quick initiation of flowering at the age of 5 years after planting. During the first year, the operational cost per hectare comes to Rs.28,900/- and from 2^nd to 5^th years, it comes to Rs.6,600 per year and then the maintenance cost from 6^th year onwards comes to Rs.6,000/- per year. The details of the operational cost per hectare of kewda cultivation under rainfed condition of coastal Ganjam district is given at Table 23. Kewda plant comes to flower on the 5^th year of planting, but the annual net profit begins on the 6^th year of planting and the cumulative net profit starts on the 10^th year (Table 24). The economic viability of kewda plantations is observed from 10^th to 30^th year of planting and after 30^th year, the net profit declines. A farmer can earn an annual profit of Rs.61,000/- per hectare of kewda cultivation from 11^th to 15^th year, which goes on increasing and from 26^th to 30^th year, the annual net return reached to Rs.1,23,400/- with a cumulative return of Rs.4,04,970/- on the 30^th year of planting. Then at the age of 35^th year, it declines to Rs.1,07,800/ - and at 40^th year to Rs.87,000/- per annum (Table 24). Although the profit was calculated only on the basis of sale of flowers yield, some additional profit can be obtained from other plant parts like leaves and stilt roots. After distillation of one lakh flowers, the spent over flowers and plant parts can be utilized as fertilizer/manure by selling at a rate of Rs.1000/- per batch. In the two blocks (viz., Chhatrapur and Rangeilunda) of Ganjam district, about 7,000 women are engaged for collection of flowers, leaves and stilt roots and they prepare ropes and other household items from the roots and leaves. It has been observed that one female can prepare 12 bundles of ropes each of 12 m length and the sale rate of rope is about Rs.10/- per metre. The ropes are sent to the markets of Visakhapatnam (Andhra Pradesh) and Chennai (Tamil Nadu) for sale. The profit can also be increased by incorporating some inter-crops like Casuarina, coconut, Agasti and medicinal crops like Patchouli etc. Further, kewda can be taken on the sand dunes and waste saline land of the coastal lines, where no other crops can be grown profitably. Hence, kewda needs better attention for its extensive cultivation with a foresight on the perfume industry.

1. House Plant

The screwpines or kewda plants are characteristics of many tropical regions with long ringed trunks, bracing roots and crowns of Dracaena-like foliage. The young plants are amongst the most popular foliage plants for home decoration as the plants do not flower at early stages (Wickham, 1950). They are also grown as pot and tub specimens for green house, residence, veranda and lawn decoration where their stiff clustered foliage gives them a formal decorative character. They may be kept as indoor ornamental foliage plants in the warm and semi light places of a house. (Wickham, 1982a).

2. Fence

The plant is useful for binding the soil, so checks soil erosion and not browsed by the cattle due to its spiny leaves; hence sometimes used as fence around the crop field in the coastal districts of Odisha, Andhra Pradesh, Tamil Nadu, Kerala and Gujrat. The plants are often used for hedges as in the Casuarina plantations at Puri of Odisha (Haines, 1961a) (Fig. 17).

Principles to create effects

Balance

It is a visual equilibrium of different garden elements.

Formal Garden : Balance is achieved by positioning plants, other landscape objects at equal distance from a real (or) imaginary plane (or) axis.

Informal Garden : Balancing is mainly a neutralizing effect. (eg.) Opposite colours in the colour wheel, contrasting texture, different numbers, shapes, forms, line and pattern are cleverly employed to neutralize one another.

Proportion

It refers to the share of the different parts (or) components to the whole. It refers to all ingredients being mixed in right measure, not essentially in equal measure.

I. General information

1. Lalbagh garden is located at Bangalore
2. Founder of Lalbagh garden is Hyder Ali and his son Tipu Sultan
3. Total area of Lalbagh garden is 50 hectares and developed during 1760
4. Brindavan garden is located at Mysore
5. Government botanic garden, Ooty was established during 1848
6. Total area of Ooty botanic garden is 20 hectares

I. General information

1. Formal type of garden is laid out in a symmetrical or a geometrical pattern
2. Features of a formal garden are trimmed formal hedges, cypress, ashoka trees
3. Informal type of garden in which all plants and features are arranged in a natural way
4. Wild garden was laid out by William Robinson
5. Examples for formal type of gardens are Mughal, Persian, Indian and French style
6. Examples for informal type of gardens are English and Japanese garden
7. Main features of English garden are lawn, herbaceous border and rockery
8. Main features of Italian garden are massive flight of marble stairs, decorative urns, fountains
9. Mughal type of garden is a replica of ancient Persian garden

I. General information

1. Common names of trees

• Acacia nilotica – Black babool, Indian gum-Arabic tree
• Acacia auriculiformis – Golden shower
• Adansonia digitata – Baobab, Monkey bread
• Adenanthera pavonina – Red sandal wood, bead tree, red wood
• Ailanthus excelsa – tree of heaven, paradise tree
• Albizia julibrissin – Pink siris, silk tree

I. General information

1. Shrub is a woody or semi-woody perennial plant with little or no trunk and grows up to a height from 50 cm to less than four meters.
2. Shrubbery border is an area of the garden devoted exclusively for growing shrubs planted in a row of rectangular fashion.
3. Plants suitable for shrubbery border.

I. General information

1. Climbers which climbs up with the help of tendrils are Antigonon leptopus, Bignonia gracilis, Pyrostegia venusta, Clematis paniculata
2. Climbers which climbs up with the help of thorns or prickles are Bougainvillea spp., climbing rose
3. Climbers which climbs up with the help of root and rootlets are Campsis grandiflora, Ficus repens
4. A climber which climbs up with the help of sticky substances from growing points is Ficus repens
5. A Climber which climbs up with the help of hookers is Combretum comosum
6. Climbers which climbs up with the help of clingers are Passiflora caerulea, Passiflora quadrangularis and Hydrangea petiolaris
7. Climbers which grow well under sunny situation are Pyrostegia venusta, Quisqualis indica, Antigonon leptopus, Adenocalymma alliaceum, Bougainvillea spp., Campsis grandiflora and Wisteria sinensis

I. General information

1. A group of ornamental plants which complete their life cycle in one season or in a year is called annuals
2. Time of sowing of summer annual seeds is February- March
3. Time of sowing of rainy season annual seeds is June- July
4. Time of sowing of winter annual seeds is September- October
5. Based on growing season, annuals are classified into summer, rainy & winter
6. Based on hardiness, annuals are classified into hardy, half hardy & tender
7. Based on photoperiodic requirement annuals are classified into short day, long day, day neutral, long short day, short long day & intermediate

I. General information

The nature of roots

The roots of palms are usually tough and thick, although slender and wiry types are existing. Some roots creep over the soil’s surface, while a few palms even develop aerial roots that may eventually make them appear to be growing on stilts.

A few palms develop aerial roots at or near the base of the trunk or stems. These include Crysophila warscewiczii (Rootspine palm) and Clinostigma exorrhizum. Other palms with aerial roots include Pinanga aristata, Verschaffeltia splendida (Seychelles stilt palm) and Socratea exorrhiza. Some of these develop into stilt or prop roots, which often form a cone and give the palm extra support, they usually occurs on plams native to wet soils and humid conditions, whereas the base of the palms is at risk from decay. Indeed, in a few instances, the lower part of the trunk withers and the palm is entirely supported by these roots.

I. General information

1. Plants propagated through modified underground stems are grouped into tubers, bulbs, rhizomes
2. An example of a bulbous plant propagated through tuber is dahlia
3. Bulbous plants which are propagated through corms are Gladiolus, Freesia, Tetonia and Tigrida
4. Bulbous plants propagated through bulbs are Amaryllis, Tuberose, Zephyranthes and Crinum
5. Bulbous plants propagated through rhizome are Alstroemeria, Bamboo, Canna, Convallaris, Hydechium, Iris and Zantedeschia
6. Bulbous plant propagated through tubercle is Bowiea volubilis
7. Bulbous plants propagated through tuberous roots are Dahlia, Eranthis, Ipomoea, Mirabilis, Ranunculus and Tapioca
8. Bulbous plants propagated through tuberous stem are Begonia and Cyclamen
9. Bulbous plant propagated through offsets are daffodil, tulip and iris

I. General information

1. All cacti are succulents
2. All succulents are not cacti
3. All the genus belonging to the family Cactaceae are native of America
4. A genus in Cactaceae family which is not native of America is Rhipsalis
5. Sedum and Sempervivum are native to temperate Europe
6. Aporocactus, Rhipsalis and Schlumbergera are native of Mexico
7. Dischidia and Hoya are native of South-East Asia

I. General information

1. Japanese flower arrangement is called as Ikebana
2. Meaning for Ikebana is flowers kept alive
3. Western style of flower arrangement involves symmetrical arrangement of flowering plants in a vase
4. Ikebana style possess asymmetric flower arrangement
5. Tatebana is a type of flower arrangement in which flowers are placed in standing arrangement and are of tall nature
6. Basic lines of Japanese flower arrangement are heaven, man and earth
7. ‘Shin’ in Japanese flower arrangement represents Heaven
8. ‘Soe’ in Japanese flower arrangement represents Man

I. General information

1. Bonsai is defined as Japanese art of growing trees & shrubs by extreme dwarfing in a shallow container
2. Bonsai, the name is derived from two words, Bon & Sai
3. The meaning for the word ‘Bon’ is tray or shallow container
4. The meaning for the ‘Sai’ is to grow
5. Origin of Bonsai is china
6. In Mamie bonsai, plant height is 2-6 inches
7. In small bonsai, plant height is 6-12 inches
8. In medium bonsai, plant height is 12-24 inches

I. General information

1. Cool season turf grasses are Perennial rye grass, Creeping bent grass, Colonial bent grass, Kentucky blue grass, Canada blue grass, Poa spp, Festuca spp, Agrostis spp, Lolium spp
2. Warm season turf grasses (25-35^oC) are Cynodon sp, Zoysia sp, Stenotaphrum secundatum, Paspalum notatum, Eremochloa ophiuroides, Axonopus sp, Pennisetum clandestinum, Buchloe dactyloides
3. Broad leafed turf grasses are Arachis pintoi, Dichondra repens
4. Based on mowing height, turf grasses are classified into tall, medium & dwarf
5. Turf grasses which needs high mowing height of>3.5 cm are Tall fescue, sheep fescue, Canada blue grass, fine fescue, wheat grass, orchard grass
6. Turf grasses which requires medium mowing height of d” 3.5 to 1.0 cm are perennial rye grass, Kentucky blue grass, Buffalo grass, etc.,
7. Turf grasses which requires low mowing height of d” 1.0 cm are colonial bent grass, creeping bent grass, Annual blue grass
8. Turf grasses are classified based on their recuperative capacity into fast, medium & slow

1. Ornamental ferns

Adiantum capillus – Maiden hair fern

Asplenium nidus – Bird’s nest fern

Cheilanthes argentea – Silver fern

Davallia bullata – Squirrels foot fern

Nephrolepsis aureum - Boston fern

Polypodium aureum – Hare’s foot fern

Pteris cretica – Brake/ Ribbon fern

Drynaria quercifolia -Oak-leaf fern / basket fern

I. General information

1. Cacti plants suitable for rock garden are Opuntia, Cereus and Mamillaria
2. Succulents suitable for rock garden are Agave, Aloe, Euphorbia splendens, Sedum, Sempervivum, Stapelia, Yucca, Furcraea
3. Ferns suitable for rock garden are Drynaria, Nephrodium, Nephrolepis, Polypodium
4. Famous rock garden of India is located at Chandigarh
5. The founder of Rock garden in Chandigarh is Nek Chand
6. Annuals suitable for rock garden are

I. General information

1. Lotus stem is referred as naval cord of Lord Vishnu
2. Lotus flower is described as the throne of Brahma
3. Vishnu, Brahma and Laxshmi are associated with lotus
4. Poet Asvaghosa reported that Lord Buddha saw lotuses and flowering trees in Nandavana
5. Surface flowering plants of water garden are

I. General information

I. General Information

Use of computers into the design process has benefited landscaping industry in several ways. There are several advantages in using computers for design. The most important factor is that the computer can store and handle large amount of engineering data, which can be used in various stages of design, development and manufacturer, like conceptual design, analysis, component design, documentation, process planning and manufacturing. The product development approach using the computer aided design and computer aided manufacturing (CAD/CAM) results in better and consistently good quality products invariably at a lower cost, with the attendant benefits of faster development of different variants of the product or model. The following table highlights the relative advantage of human designers and computers.

Importance of Rainfed Farming

In India, rain dependent areas are vast and they have a great contribution to make in agricultural production, with just 1/40th of the world land. Of the 141 M ha of net sown area in the country, 80 M ha is rainfed. Rainfed agriculture contributes 40% of food grain production and supports 2/3rds of the livestock population. Despite considerable progress in irrigation development over the five year plans, 85% of coarse cereals, 83% in pulses, 42% in rice, 70% in oilseeds and 65% in cotton are still cultivated as rainfed. A large portion of industrially important crops such as cotton, groundnut and castor are cultivated under dry land conditions and has a great contribution to make to the production of food, fibre, fuel and furniture timber etc. Though, impressive gains were noted in some of the rainfed crops in recent times, the gap between attainable and farmers’ yields still remain high which is a major cause of concern. Small and marginal farmers who are the backbone of rainfed farming are resource poor and risk averse. Moreover, both public and private investments in technology adoption and infrastructure have been quite low in rainfed agriculture resulting in a vicious circle of low yields-low net returns-low investments in improved technologies.

With several resource management problems emerging in irrigated regions, rainfed agriculture offers scope to contribute to the growing food needs of future particularly of pulses and edible oils. The high yield gaps between attainable yields realized by progressive farmers using improved technologies and those actually realized by the farmers at large in any given region offer scope for enhancing overall productivity of rainfed crops anywhere between 50 to 70% in the near term with the adoption of the available technologies, provided resource and institutional constraints in delivering the technology and inputs are addressed timely and adequately. With the promised break-through in yields through genetic manipulation and large scale adoption of water saving technologies through conservation agriculture, the yield gains can be further enhanced in the medium to long term.

The 80 million hectares of rainfed farming area is not uniform for resource base, opportunities and constraints. There are areas receiving high rainfall and fertile deep soils where crop yields can be enhanced significantly by double cropping combined with supplemental irrigation with water harvesting. For the relatively lower rainfall regions, the overall system productivity needs to be enhanced by integrating crops, trees and livestock. This agro-eco region based differential approach is the key for realizing the full potential of rainfed agriculture besides addressing the dimension of regional equity.

Rainfed Agriculture - A historic view

Historically, famines and scarcities have been recorded from the earliest times in India. They were mentioned in the epic Mahabharata, and there is Jain legend of a 12-year famine in the fourth century A.D. During the reign of the Moghul Emperor Shah Jehan in 1630-32, The official historian recorded in ‘Badsha Namah’ that soup Kitchens were opened, a lakh and half coins were given in charity and one eleventh of land revenue was remitted in the drought effected area.

In the remote past, these famines were tided over by saving grains and fodder from years of bumper harvest and by migration of people and cattle to greener pastures. With the rise of population pressure on arable land, the effects of scarcity and famine became progressively severe because the traditional methods of tiding over were no longer adequate. The successive famines in the closing decades of the 19th century closing decades of the 19th century led to the setting up of three Famine commissions.

The Commissions made several suggestions which formed the basis of the Famine Code promulgated in 1883 onwards and adopted by the then provincial governments. Apart from the relief works to be taken up during famine, the Commission recommended protective irrigation projects in dry and scarcity area and establishment of department of agriculture at the center and in the province. Later, the Royal commission on Agriculture (1928) reiterated in its report the problem of dryland agriculture and recommended a close attention by departments of agriculture to these problems.

The first systematic approach was made in 1923 by setting up small plots at Manjri, near Poona. This was followed by a more comprehensive research scheme on dry farming sanctioned by the Imperial (then Indian) Council of Agricultural Research during 1933-35. Under the scheme, research was conducted in low rainfall areas at Rohtak, Solapur, Bijapur, Raichur and Agra. Based on the results of this scheme, a series of dry farming practices were evolved which were known as ‘ the Bombay Dry farming ‘, ‘ the Madras Dry farming ‘ and ‘ the Hyderabad Dry farming ‘ practices. These practices emphasized soil and water conservation as basic to dryland production programs. The Scheme was terminated in 1943, since it was felt that the immediate objectives had been achieved.

Problems Associated with Rainfed Farming Agriculture

It is a dream desire to eliminate drought from this region. There are many problems that are associated with rainfed farming systems. The problems may be grouped into four major factors: climatic, edaphic, technological and socio- economic.

Climatic

1.Scarcity of rain-water which is low and unpredictable with respect to intensity and distribution;

2.High ET (nearly 3650 mm annually compared to total annual precipitation ranging from 350 to 1400 mm);

3.Extreme thermic values (upto 490C with the mean annual temperature exceeding 180C at some places);

4.High solar incidence (450 to 500 Cal cm² day^-1);

5.High wind velocity with desiccating winds causing a high rate of ET and wind erosion;

6.Low relative humidity;

7.Extensive climatic hazards such as weather aberrations, drought, flood, frost, gale, cyclones and burning winds due to dry, deserted and denuded situations.

Climatic conditions prevalent in rainfed areas

Weather, which is part of climate, plays an important role in crop planning in dry farming area. Out of the several elements of weather, rainfall has key position in success of dry farming. In dryland areas, South West Monsoon brings the bulk of rainfall. The South West Monsoon is followed by North East Monsoon which supplements to South West Monsoon are the main source of rainfall. There are four types of rainfall characterized by the nature in different parts of India. Generally, the rainfall is scanty, erratic and ill distributed.

1. Rainfall

The monsoon period is not one of continuous rains in any part of the country. Meghalaya that is uncommon in the behavior of monsoon in the country. There are at least four variations in rainfall.

1.The commencement of rains may be quite early or considerable delayed according to the dates of monsoon for central Maharashtra zone is 10th June but is started as early as 28th May 1925 and its onset was delayed upto 26th June 1954 according with the date of onset of monsoon in Rajasthan is between June 21 to 30 but is started as late as up to end of July 1987 to 1992.

2.There may be prolonged breaks in rainfall. These breaks in monsoon rains can be different duration. The breaks of 5-7 days may not be all serious concern but breaks of longer duration of 2-3 weeks created the situation of plant water stress leading to reduction in agricultural production. Another important point is the physiological properties of soil and available water holding capacity in the relation to the breaks and drought, some of the soils e.g. deep black soils have capacity to store more than 300 mm of water per meter depth where as the desert soil can ensure only 100 mm. The impact of drought is felt more quickly in the soil having less water holding capacity but in sols with high storage capacity 15 days dry break may not affect the crop where as the soils of less storage capacity show wilting symptoms in and dry break such breaks cannot be predicted for a given season in advance. The drought caused due to this break is therefore of different magnitude and severity.

Drought

There is no universally accepted definition of drought. Early workers defined drought as prolonged period without rainfall. Drought is a situation when the actual seasonal rainfall is deficient by more than twice the mean deviation. American Meteorological Society defined drought as a period of abnormally dry weather, sufficiently prolonged for lack of water to cause a severe hydrological imbalance in the area affected.

Prolonged deficiency of soil moisture adversely affected crop growth indicating incidence of agriculture drought. It is the result of imbalance between soil moisture and evapotranspiration needs of an area over a fairly long period as to cause damage to standing crops and to reduce the yields.

Natural resources conservation and their management hold key to sustainable agriculture and livestock production. It is all the more crucial for countries with predominant agrarian economies where development of sustainable agriculture is essential for overall growth, redressal of poverty and security. Conservation of both soil and rain water as very crucial and basic resources have been practiced since ancient times in India. However, there has been renewed emphasis on conservation and efficient utilization of these resources in the recent past. The fact that 70% of the arable area of India is rainfed with precarious supply of water and that rainfed agriculture supports 44% of India’ s human population and contributes 90 per cent of coarse cereals and pulses, 80 per cent of oilseeds and 65 per cent of cotton and growing realization that further gains i n productivity of crops and livestock will emanate from rainfed regions, leave no room for complacency in this regard.

Year after year, the fate of a vast ‘majority of Indian farmers hangs in balance, as success with rainfed agriculture continues to be a gamble. It is evident that crop yields in semi-arid areas depended more on rainfall distribution than on total rainfall and lack of serious efforts to create d water supply for crops through scientific management of rainwater is a factor favouring this avoidable uncertainty. In rainfed agriculture no other input can perhaps enhance the yield without effectively tackling of the rainfall aberration related sub-optimal moisture availability. Therefore a prerequisite for substantial improvement in the agriculture production in the semi-arid region is to manage runoff water and to use it either at the time of moisture stress even during the monsoon or in next season. It has been reported that only one supplementary irrigation at proper stage can double of Rabi crops. But supplemental water is a developed resource and is more expensive than the natural resources. Hence, it is all the more necessary to use this water judiciously and efficiently. Standardization of techniques by which as much of precipitation as possible can be conserved for crop use, either directly in the soil profile through infiltration or through runoff collection and recycling is an area of priority in research.