eChapters

In India marigold is one of the most commonly grown flowers and used extensively on religious and social functions in different forms. Because of their ease in cultivation, wide adaptability to varying soil and climatic conditions, long duration of flowering and attractively coloured flowers of excellent keeping quality, the marigolds have become one of the most popular flowers in our country. Flowers are sold in the market as loose or as garlands. Due to its variable height and colour marigold is especially use for decoration and included in landscape plans.

Botany :Annual Chrysanthemum is a winter annual that can be grown either as pot plants or in groups as bed plants for various ornamental purposes. There are two types of annual Chyrsanthemums: Chrysanthemum Segetum and C.coronarium. Major varieties of Chrysanthemum segetum L. are Morning Star, Evening Star, Eastern Star, Blanca, Eldorado, Gloria, Isabel, Romeo, and yellow Stone while popular cultivars of C. coronarium L. include Nivea, Oreon, Albo, Golden Crown, Luteum, Tom Thumb Golden Gem, Tom Thumb-Primrose Gem and Tetra Comet. In addition to this, there is another type of annual Chrysanthemum, i.e. C. carinatum. Popular varieties of C. carinatum S. are Merry, Atrococcineum, Burridgeanum, Eclipse, Flammenspiel, John Bright and Northern Star.

Propagation

Annual Chrysanthemums can be propagated by seeds. Their sowing time depends upon climate. It varies in different parts of India. In the Northern plains, winter season annual Chrysanthemums are sown during September–October. The seeds are sown in nursery beds, earthen pots, seed pans or wooden seed trays. The seed compost should consist of one part each of garden soil, coarse sand, farmyard manure and leaf-mould. For preparing the nursery beds, the soil should be dug up thoroughly and sufficient farmyard manure, should be mixed in soil. Raised nursery beds of convenient size (normally 60cm wide and 15cm high) should be prepared. If soil is heavy, some quantity of sand may be added. It is better if the soil of nursery bed or earthen pots is sterilized with 2% formalin. For this, soil is drenched with formalin solution and is covered with polythene sheet for 45hr. Afterwards, the polythene is removed and soil is dried before sowing the seeds.

Pre sowing seed treatment: Fortification with GA3 100 ppm (or) moringa leaf extract 2% for 16 h (or)KH₂PO4 2% for 16 hours

Age of the seedling for transplanting: The seeds are first sown in primary nursery (pot) and after 16 day the seedlings are transplanted to raised nursery and after 24 days transplanted to main field.

Varieties: No named variety

Soil: Red sandy soil and sandy loam soil are highly suitable. Soil drainage is essential and hard pan and water logged soils should be avoided.

Climate: Suitable for plain and lower hills. Requires 70 cm annual rain fall

Propagation: Terminal three to four nodal cuttings measuring 10 cm length is used

Land Preparation: Apply 15 t FYM/ha. Ridges are formed at a spacing of 60 cm. Cuttings have to be planted at a spacing of 45 cm.

Nutrient management: Nutrients Quantity (kg / ha) N 30 P 60 K 50 The above nutrients can be applied in two split doses viz., 30 and 45 days after planting. In micronutrient deficient soils, ZnSO4 can be applied as basal fertilizer.

Botany

Ashwagandha (Withania somnifera), also known as Indian ginseng belonging to the family Solanaceae, is an important ancient plant, the roots of which have been employed in Indian traditional systems of medicine, Ayurveda and Unani to cure asthma, fever, chest complaints. It is an erect branching undershrub reaching about 1.50 m in height. It grows in dry and sub-tropical regions. Being hardy and drought tolerant species with its enormous biocompounds, its usage is forever regarded and continuous to enjoy the monopoly in many parts of India, particularly in Madhya Pradesh. It grows in dry parts in sub-tropical regions. Rajasthan, Punjab, Haryana, Uttar Pradesh, Gujarat, Maharashtra and Madhya Pradesh are the major Ashwagandha producing states of the country. Roots are fleshy, tapering, whitish brown. Leaves are ovate and flowers are greenish. The mature fruits are orange-red berries.

Varieties:Poshita and Rakshita are high yielding varieties released by CSIRCIMAP, Lucknow. Jawahar 20 is cultivated in Madhya Pradesh. WSR is another variety released by CSIR-Regional Research Laboratory, Jammu. Nagori is a local variety with starchy roots

Botany: Periwinkles (Catharanthus roseus) belonging to the family Apocynaceae are evergreen perennials that produce bright blue flowers. They grow best in well-draining, moist soil and partial sun to full shade. They work well as sprawling groundcover or border plants and bloom from early spring to early fall. Periwinkles are often grown as transplants, but they can be started from seed about 10 weeks before the last frost with the proper care.

Varieties: Nirmal, Dhawal and Prabal

Soil and climate: It is suited to all types of soil and tropical climatic conditions. Well distributed annual rainfall of 100 cm or more is ideal for raising as a rainfed crop.

Seeds and planting: Propagated through seeds either by direct sowing or throughtransplanting.

Seed rate: 2.5 kg/ha : Direct sowing

0.5 kg/ha : Through seedlings

45 - 60 days old seedlings are transplanted at a spacing of 45 x 20 cm during June - July or September - October.

Botany: Senna, Cassia angustifola belonging to the family Leguminosae is a perennial 1-2 m height undershrub. The stem is erect, smooth, and pale green to light brown with long spreading ascending branches. Leaves are compound with four to eight pairs of leaflets. The full grown leaflets are bluish-green to palegreen in colour and emit a characteristic fetid smell when crushed. The flowers are small and yellow and axillary arranged racemes. The pods are broadly oblong about 5-8 cm long and 2-3 cm broad, green in beginning and change to greenish-brown to dark brown on maturity. Each pod has 5 to 7 ovate, compressed, smooth, dark-brown seeds.

Varieties : KKM - 1, Anand Late Selection, ALFT-2 and Sona

Soil and climate: In Tamil Nadu, it is grown in sandy or sandy loam or laterite soils. It is a hardy warm weather crop grown under rainfed and irrigated conditions. Senna is also cultivated successfully on black cotton soils. It has a great tolerance to high soil salinity, however, shedding of some lower leaves often occurs. The soil pH suited for cultivation is 7.0-8.5. But, the most suitable to sandy loam to loam soils which are more friable and well drained.

Botany

Phyllanthus is an herb common to Central and Southern India. It can grow to 30–60 centimeters in height and blooms with many yellow flowers. All parts of the plant are employed therapeutically. It is a small erect annual herb 10-60 cm tall widespread in tropical areas. Leaves are small elliptical - oblong and flowers are whitish green & minute. It bears ascending herbaceous branches. The bark is smooth and light green. The fruits are tiny, smooth capsules containing seeds.Kizhanelli is a circum-tropical weed, thriving well under tropical conditions. In India, it grows abundantly up to 700m altitude in Punjab, Haryana, Uttar Pradesh, Bihar, West Bengal, Orissa, Madhya Pradesh, Maharashtra, Andhra Pradesh, Karnataka, Tamil Nadu and Kerala.

Major constituents – Phyllanthin (0.4-0.5%) and Hypophyllanthin

Uses- Hepatitis B and Jaundice

Botany:Coriandrum sativum belonging to the family Umbelliferae. It is an annual soft shrub that attains a height of 1 to 3 feet. Leaves are in basal cluster varies from 3 to 15 cm in length and are oblong to ovate in shape. Leaflets are 1 to 2 centimeter in length and are ovate to round. Flower is of white color which can vary from light purple to creamish in color. These appear in umbles. Fruit is roundish in shape bearing color that varies from yellow to brown. It is tripped and gets divided in to two then crushed with fingers. The plant flowers and fruits in late winters.

Land Requirement: Land to be used for seed production of coriander should be free from volunteer plants

Varieties: CO 1, CO 2, CO 3, CO (CR) 4, GAU 1, UD 1, UD 2, UD 20 and UD 21

Soil: Well drained black cotton soil and red loamy soil. For rainfed cultivation soil should be clay in nature and the pH should be 6 – 8.Coriander performs well at a temperature range of 20 – 25 °C.

Climate: Cool and comparatively dry, frost free climate

Botany:Fenugreek is a leguminous plant, belonging to the Papilionaceae family. Fenugreek is an annual herbaceous plant between 20 and 50cm high. (sometimes up to 100cm.). Its stem is erect, branched, grooved and with little pubescence. The leaves are compound, petiolate, oblong leaflets formed by three kills reminding those of alfalfa. White or yellow flowers , isolated or arranged in pairs. Fenugreek fruits are narrow and elongated pods. They contain 10 to 20 seeds, tiny yellow, quadrangular, with a groove in the central part dividing them into two unequal lobes.

Land Requirements: Land to be used for seed production of Kasuri methi and methi shall be free from volunteer plants.

Varieties: Co 1, Pusa Early Bunching, Lam selection 1, Rajendra Kranti, Kissar Sonali, RMT1and CO 2.

Soil: A rich well drained loamy soil is best suited.

Climate: Cool and comparatively dry, frost free climate. It requires a warm climate with mild temperatures for a good seed production (between 8 and 27°C).It grows well in full sun. Sow it in places sheltered from the wind. Resistant to frost and temperatures down to -5°C. However, low temperatures during planting causes not all seeds to germinate.

Season: June - July and October - November.

Botany: The Cocoa (Theobroma cocoa) belonging to the family Sterculiaceae. Cocoa tree is a shade tolerant, moisture loving, understory rainforest tree. The trees live for up to 100 years, but cultivated trees are considered economically productive for only about 60 years. Naturally Cocao grows to a height of 15 meters, but cultivated trees are trimmed shorter to make harvesting easier. The leaves of Cocoa are smooth bright green, oblong, about 15cm by 8cm. The seeds are encased in a large colourful pod which grows close to tree after a flower. The large pod is green while maturing and turns yellow, orange, red or purple when ripe. They range from about 10 cm to greater than 40 cm in length.

Soil and climate: Potash rich alluvial soils friable in nature with high humus and moisture retentivity with a pH of 6.6-7.0 are suitable. Cocoa is normally cultivated at altitudes upto 1200 m above MSL with an annual rainfall of 150 cm and a relative humidity of 80 % and annual mean temperature of 24^oC to 25^oC. Cocoa can be grown as intercrop in coconut and arecanut gardens.

Botany: Cashew belongs to the Family Aricardiaceae. A small evergreen tree native of tropical America from Mexico to Peru and Brazil but now cultivated largely in Malabar, Kerala, Karnataka, Tamil Nadu and Andhra Pradesh and to some extend in Maharashtra, Goa, Odisha and West Bengal

The commercial production is mainly confined to India, Mozambique, Tanzania, Kenya; Brazil, Philippines, Malaysia and Sri Lanka.Cashew is an important foreign earning crop of India, remarking second (29%) in the international trade of the nuts. It is a crop of marginal lands and can be grown under rainfed conditions.

Soil and climate: It grows up well in all soils. Red sandy loam is best suited. Plains as well as hill slopes upto 600 - 700 feet elevation are suitable for cultivation. Season: June - December. Propagation: Soft wood grafting, air layer and epicotyl grafting. Requirement of plants: 200 plants/ha. Preparation of field: Pits of 45 cm3 size are dug and filled up with a mixture of soil + 10 kg FYM + one kg neem cake and 100 g Methyl parathion 1.3 %.

Botany: Coffee trees are evergreen shrubs of the rubiaceae family. Coffee of commerce consists of seeds of coffee which when roasted, ground and soaked in hot water yields a fragrant stimulating infusion used for preparing the beverage called Coffee. It is native of America and introduced in India in 1936 near Chickmanglur in Karnataka.

Coffee plants have bright green opposite leaves with smooth margins. Its flowers, white, grow in clusters in the axils of the leaves and are aromatic. From them, fruits are born.They are red drupes with the size of a cherry The outside of the fruit is fleshy and inside it there are two seeds or coffee beans, surrounded by a membranous layer of leathery texture, hence this layer is commonly known as the “parchment”. Some species of trees only produce one seed per fruit are known as “pearl coffee”. In double seed varieties, the two seeds that grow inside each fruit press each other, so they stop the growth in the part which is in contact, so this becomes flat.

Soil and Climate: Coffee arbica comes up well in high altitude from 800 to 1650 meters but -C. canephora Pierre ex A.Froehner adopts well to lower elevations. At high altitude the crop is often late and susceptiable to frost and high winds.Evenly distributed rainfall of 2250 mm is essential. Heavy rainfall is not counducive as it encourages rotting of leaves and plants are easily susceptible to fungal diseases.

Botany: Coconut palm (Cocos nucifera) belonging to the family Palmae is a slender palm tree widely distributed throughout the tropical regions,with a size that can vary between 12 to 30 meters high. Each inflorescence is a branched flower cluster (panicle), located at the base of the leaves. Its flowers, male and female (monoecious), can be white to pale yellow. Fruiting occurs throughout the year, and the fruit is a drupe with a dry fibrous mesocarp popularly known as coconut.

Coconut fruit has an ovoid shape, constituted by 3 angles and 3 germination holes at the end, with a size between 20 and 30 centimeters in diameter. Coconut fruit consists of a brown fibrous bark and a hard shell, booking a seed inside. The central cavity of the fruit has an aqueous or milky liquid called coconut water that is a nutritional mixture aimed for coconut to grow. When the fruit ripens , this fluid accumulates fat and it is called coconut juice or milk. The seed of the coconut palm is the second largest known , after the coco-de-mer (Lodoicea maldivica ), that can reach 40–50 cm in diameter and weigh from 15 to 30 kg. The seed of coconut is hollow inside and it is covered with a white pulp, oily and edible.

Medicinal uses:It is said to have analgesic, antirheumatic, antibacterial , anticancer, antioxidant, hypoglycemic, hypotensive and immune stimulating properties. Its oil also has numerous cosmetic applications

Botany: Emblica officinalis belonging to the family Euphorbiaceae commonly known as Amla or Indian Gooseberry or Nelli is an important crop with high medicinal value. The fruits have the richest source of vitamin-C (700 mg per 100 g of fruits) and is considered to be good liver tonic. The various preparations using Amla include Chyavanprash, Triphala churna, Brahma Rasayana and Madumegha churna. The fruit is valued as an antiscorbutic, diuretic, laxative, antibiotic and anti-dysentric. Phyllemblin, obtainedfrom fruit pulp has been found to have mild depressent action on central nervous system. It has good demand from the industries for the preparation of various health care products also like hair oil, dye, shampoo, face creams and tooth powder.

Soil: Light as well as medium heavy soils except purely sandy soil is ideal for amla cultivation. The tree is well adopted to dry regions and can also be grown in moderate alkaline soils.

Climate: It is a tropical plant. Annual rainfall of 630-800 mm is ideal for its growth. The young plant upto the age of 3 years should be protected from hot wind during May-June and from frost during winter months. The mature plants can tolerate freezing temperature as well as a high temperature upto 46^OC.

Varieties: The varieties recommended for cultivation are Banarasi, Chakaiya, Francis, NA-4 (Krishna) NA 5 (Kanchan), NA-6, NA-7, NA-10 and BSR-1 (Bhavanisagar).

Introduction:Jamun (Syzygium cumini) belonging to the family Myrtaceae is a popular indigenous fruits Of India. It is also known as black plum, Indian black cherry, Ram jamun etc. in different parts of India. The tree is tall and handsome, evergreen, generally grown for shade and windbreak on roads and avenues. In India, the maximum number of jamun trees are found scattered throughout the tropical and subtropical regions. It also occurs in the lower range of the Himalayas up to an elevation of 1,300 meters and in the Kumaon hills up to 1,600 meters. It is widely grown in the larger parts of India from the IndoGangetic plains in the North to Tamil Nadu in the South.

Soil:The jamun tree can be grown on a wide range of soils. However, for high yield potential and good plant growth, deep loam and a welldrainedsoil are needed. Jamun can grow well under salinity and waterlogged conditions too.

Climate: Jamun prefers to grow under tropical and subtropical climate. It is also found growing in lower ranges of the Himalayas up to an altitude of 1300 meters. The jamun requires dry weather at the time off towering and fruit setting.

Varieties: The common variety grown under North Indian conditions is “Ram Jarnun”. It produces big sized, oblong fruits, deep purple or bluish-black in color at full ripe stage. The pulp of the ripe fruit is purple pink and the fruit is juicy and sweet. The stone is small in size. The variety ripens in the month of June- July and it is very common both in rural as well as in urban markets.

Abstract

The tectonics of the geological past from Archaeozoic to early part of Cenozoic era has been studied due to their penetrative documentation in the form of folds and faults. But the tectonic history of the latter part of the Cenozoic era (i.e Pleistocene period) has remained a matter of conjecture owing to the poor response of the rocks to Pleistocene movements. In the present study the authors presented a model for the Pleistocene earth movements of South India through the study of river migration, coast line changes and lineament fabric derived from the space borne photographs.

In the area of study, the northerly migration of Paleru and Pennar and southerly shift of Palar, Ponnaiyar and Cauvery rivers, marine regressions restricted within this segment and the closely spaced crest line fractures suggest a lineament controlled E-W trending Quaternary upwarping along Mangalore-Madras alignment. Similar E-W cymatogeny is inferred in the southern tip of the Peninsular India on the basis of once again such observations. Such E-W trending Pleistocene arching phenomenon suggests a N-S oriented regional compression which could be related to the collision of Indian plate with Tibetan plate.

Abstract

The southern part of the Indian Peninsula has long been regarded as a stable area free from Pleistocene tectonics as it represents the Precambrian shield region. But the frequent earth tremors even up to a magnitude of 6.5 (Richter scale) which occurred in Tamil Nadu have started encouraging the geologists to think that it could possibly be a seismic prone zone. In addition, images acquired by the polar orbiting satellites offered valuable information on the fracture systems and fluvial anomalies suggesting possible Pleistocene tectonism in South India. Hence, a study has been undertaken to evaluate the signatures of Pleistocene tectonism in South India using IRS-lA, LISS-1 FCC imagery (Indian Remote Sensing Satellite lA, Linear Imaging Self Scanning 1, False Colour Composite) involving band 2, 3 and 4 under blue, green and red bands respectively.

The study has brought out a series of E-W trending cymatogenic arches and N-S trending extension, NE-SW trending sinistral, NW-SE trending dextral and E-W trending release fractures with characteristic signatures supporting Pleistocene tectonism in Tamil Nadu and Kerala.

On the basis of such morphotectonic features, a Pleistocene tectonic model has been presented with a N-S trending greatest principal stress and an E-W oriented least principal stress related to the movement of the Indian plate towards the Tibetan plate. Based on the model developed for Tamil Nadu and Kerala, a series of E-W trending cymatogenic arches and deeps have been proposed for Cochin- Rameswaram in the south to the Himalayas in the north. Further studies for seismotectonics, geothermal resources and hydrocarbon search have also been suggested along such arches and deeps.

The geologists of the Indian subcontinent have all along been of the opinion, that, the southern part of the Indian Peninsula is a stable shield area. But, the recently acquired IRS-1A image of June, 1988 vividly displays spectacular geomorphic anomalies suggesting that this part of the Indian subcontinent is prone to earth movements. In order to unearth more evidences on such earth movements / neotectonism in Tamil Nadu, the IRS-1A image of Coromandel coast of Tamil Nadu was analysed ( Fig. 1).

OBSERVATIONS

• The IRS-1A image conspicuously displays three contrasting morphotectonic domains in the study area marked by the western undissected Tertiary upland (Vallam upland), central highly dissected Tertiary upland (Pattukottai -Mannargudi upland) and the eastern Cauvery delta (Fig 1 and 2). These three domains are separated by two conspicuous N-S trending lineaments (E and F, Fig.1 and 2) namely the Tanjavur - Avadaiyarkovil lineament in the west and Kumbakonam -Muttupet lineament in the east.
• In addition, two more E-W trending lineaments (G and H, Fig.1 and 2) are also observed trifurcating the undissected Vallam upland into three blocks.
• Along these lineaments, especially the Tanjavur -Avadaiyarkovil and Kumbakonam -Muttupet lineaments, the rivers show conspicuous drainage anomalies in the form of drainage deflection, drainage compression etc., wherever they transect the lineaments.

Abstract

The recent earth movements and the related seismicities in the Southern part of the Indian Peninsula has been a matter of enigma for a century and more. While one school was strongly holding the opinion that the southern Indian Peninsula is free from recent earth movements as it is a shield area, the other school has narrated the possibilities for the ongoing earth movements. Under these circumstances, the various anomalies observed from satellite data and ground based information on geomorphology, subsurface lithology, geophysics, hydrogeology, geochemistry etc. have suggested a possible Pleistocene / Holocene graben along Pondicherry in the northeast and Cumbum Valley in the southwest in the southern tip of the Indian Peninsula.

Abstract

Satellite imagery interpretation has shown the existence of a major Palaeochannel system in the Great Indian desert. These palaeochannels belong to the mythological Sarasvati river, which seems to have flowed southwesterly close to the Aravalli hill ranges and joined the sea in the Great Rann of Kutch. Subsequently it seems to have shifted northwesterly, and more precisely in an anti-clockwise direction and got buried in the desert in Anupgarh plains. While its oldest course is the now misfit Luni river, its final trace is now represented by Ghaggar river. Whereas its overall northwesterly migration is attributed to NE-SW trending cymatogenic arching along the Great Rann of Kutch in the southwest to the Siwalik hills in the northeast, its multivariate palaeodrainage is attributed to block faulting and land subsidence in the Bikaner sector.

Abstract

It has been established beyond doubt that the drainage architecture and the fluvial histories of river systems give excellent indications not only on the surficial lithology but also on the ongoing morphotectonic processes of the planet earth. Among the various drainage patterns, the ‘eyed drainage’ pattern is considered to be one of the most significant anomalies and such ‘mega eyed’ drainages interpreted from IRS-IA imagery in some of the major river systems in Tamil Nadu, Indian Peninsula, are found to signify ongoing tectonic movements in an otherwise seismically inert shield area.

Abstract

The anomalies observed in the reverine systems have been demonstrated to be the potential tool in deciphering the tectonically active zones. Such various drainage anomalies viz: radial drainages, anomalous compressed meanders, eyed drainage and the youthful floodplains observed in Annamali – Palani - Varushanad hill ranges of the Western Ghats of Tamil Nadu show that the N-S and NE-SW trending faults are tectonically active in the recent years.

Abstract

The art of remote sensing has opened up many vistas in the study of river migration as satellite photographs, both in their normal and digitally enhanced modes, vividly show the rivers and their migratory signatures. The rivers migrate for various reasons amongst which tectonic movement is one of the main causes. In the present study an attempt has been made to exhibit the palaeochannel network of the rivers of Western India and integrate them with lineament fabric, so as to understand the Quaternary tectonics of the region. The study has shown that Western India shows considerable signs of Quaternary tectonics.

Much has been talked about the mighty river systems and their migratory histories, since Purana and Vedic times. In Mahabharata the places where the Lord Krishna is said to have played with Gopis in the banks of River Yamuna are now forming flat lands many kilometers away from the present day Yamuna. In the same way, there is a mention in ancient literature about the ‘Indo-Brahm’ river which was originated from the Himalayas and flown through Brahmaputra valley, Indo-Gangetic plains, Rajasthan desert and met the Arabian Sea in Rann of Kutch. Such a mighty river is said to have fragmented into Brahmaputra, Ganges and the Indus rivers due to Tectonic activity in Himalayan regions. Similarly there are many evidences in the Tamil literature. For example in ‘Kalingathuparani’ it is mentioned that the river ‘Palar’ was flowing north of Kanchipuram but the same river is now flowing south of it.

All these facts show that the rivers have the tendency to frequently change their courses. The advent of modern Remote Sensing Technology has opened up new vistas in studying such migratory rhythms of the rivers, as such old and buried rivers exhibit spectacular ribbon like, linear, curvilinear and contorted features with typical darker tone in black and white images and reddish tone in false color composites (FCC) and other color coded images.

Abstract

Satellite photographs depict exciting evidence on the migratory melodrama of river systems. A study has been conduced in parts of Tamil Nadu using IRS-IA Satellite pictures, archaeology and Tamil literature, which reveals that from Pleistocene to 2700 years B.P.(Before Present) the river Cauvery flowed in a northeasterly direction from the Stanley reservoir via Chinnar, Palakkodu, Mattur, Tiruppathur (Tiruppattur), Gudiyatham (Gudiyattam), Vellore and Walajapet to meet the sea at Madras. From 2700 to 2300 years B.P., it flowed via Uttangarai and Tirukkovilur to meet the bay of Bengal near Pondicherry, over which the present-day Ponnaiyar is a misfit stream . From 2300 to 1300 year B.P. it has flowed via Erode, Tirukkampuliyur, Alagarai , Tiruchy, Kiranur and Pudukkottai meeting the sea in the region where the present-day Agniar and Ambuliar meet the sea. Subsequently, between 1600 and 1300 years B.P., the Cauvery flowed along the present-day tracts of the Vennar and Vettar, after which it seems to have flowed as the Kodamurutti, Arasalar and PalanCauvery from 1300 to 1000 years B.P. From about 900 years B.P. it flowed via Tirupurampayam (Tirupurambiyam), Achalpuram till around 750 years B.P. and then it is stabilised as the Colleroon (Kollidam). Such periods and phases of river migration as well as their implications in the search for archaeological remains are discussed in this paper.

Abstract

The East Coast of Tamil Nadu exhibits a spectacular network of deltas formed by the easterly flowing river systems. The study of raw and digitally enhanced Landsat TM and IRS data shows, that these deltas were formed due to multivariate dynamic processes of fluvial, marine and aeolian actions. The wide fan shaped delta observed northwest and north of Madras city spanning out over an area of 700 sq.km is a feature, standing testimony to the PaleoCauvery river systems.

The regional slope and the overall arcuate arrangement of the crescent shaped lakes in the area and the tentacles of paleochannels show, that it is overall a fan shaped delta and its successive growth towards the sea might have been due to the constant progradation of lobes by continuous reworking of preceding lobes. The depressions in between successive concentric lobes have become the lakes. The absence of any beach ridges in such palaeo deltaic regime suggests that, it would be a sub aerial delta only. The overall arcuate shape of the shoreline in between Madras city in the south and Pulicat lake in the north is due to this fan delta. This feature once again symbolises the active river dominated delta. The Palar delta is a ‘cuspate’ one. The Ponnaiyar river has developed a linear delta, along a narrow depression found in between Tertiary uplands. While the avulsion phenomenon indicates the ancient shoreline near Villupuram, the east-west trending micro sandy uplands within the delta suggest, that it is a tide dominated delta.

Remote sensing has proved its credibility beyond doubt in natural resources survey and environmental monitoring owing to its synoptivity, multispectral photographic capability and repetitive coverage. While its synoptivity gives unbiased information on the regional panorama of the earth surface, its multispectral possibility aids precise interpretation of various objects, as different terrestrial objects exhibit various spectral responses in different bands of the electromagnetic spectrum. Amongst various terrestrial objects, water has a characteristic spectral response of its own, i.e. it permits the blue / red part of EMR (electromagnetic radiation, 0.4-0.8 µm) to penetrate inside. On the contrary, it totally absorbs the infrared part of EMR (0.8-1.5 µm). As such blue/red part of EMR penetrates the water bodies, the impurities and suspended sediments are seen very clearly in various shades of gray as and when the water bodies are shallow. Many workers, therefore, have used blue / red band of the satellite data in such water-quality studies^l-3. Hardy⁴ has observed that the infrared light in the spectral regions of 0.6-1.4 µm has the potential to map the turbidity in the ocean water, whereas Kritakos et al ⁵ have used the rationed data of visible and near infrared bands (0.4-1.1 µm) and obtained better results for water quality monitoring. Keeping such facts in mind, the blue/red band (band 2) of the IRS 1A satellite data was used to configurate the bathymetry along Madras coast in Bay of Bengal (Figure 1 a).

In the present study, the IRS lA band 2 data (0.52-0.59 µm) of March 1991 was used and subjected to edge enhancement studies for the coastal zone of Madras (Figure 1 a). Such edge enhancement normally sharpens the edges of two contrasting objects or sharpens the edges of objects of contrasting relief. In such edge enhanced data, few

Abstract

There is a consensus amongst the geoscientists that overall there has been progradation along the east and west coasts of peninsular India. However, the present day configuration of the coasts and some of the geomorphologic features such as absence of spit and delta along west coast and absence of major estuaries and petroliferous structures along east coast still remain controversial. The present study, based on the appreciation of certain geomorphological and tectonic features on Landsat imagery and aerial photographs of southern part of Indian Peninsula, suggests that the evolution of the coastline has been mainly controlled by tectonism.

The tapering nature of the coastline is attributed to the Precambrian orographic axis. The serrated nature of the post Precambrian coast line is due to the Precambrian transverse faults, whereas the serrated margin of the post Gondwana, Post cretaceous and post Tertiary coast lines are attributed once again to the Precambrian faults reactivated time and again. During the Quaternary period the coast line has undergone many modifications. The coast line attained sinuosity due to Pleistocene folding which is well manifested by river migration. The coast line was subsequently faulted and shifted with en echelon pattern due to N-S regional compression which is referable to the collision of Indian Plate with Tibetan plate.

Abstract

The tectonic and the geomorphic features observed along the west coast of the area between Mangalore and Cape Comorin show that the NNW-SSE trending west coast has been carved out by the Western Ghats orogeny and the related NNW-SSE trending release fractures. The sinuosity of the otherwise straight coast line is due to Quaternary cymatogenic arching caused by the thrust related to the northerly movement of the Indian plate. The coast line has further attained peaks, projections and serrations due to the ENE-WSW trending series of Precambrian extension fractures which were reactivated gaining the northeasterly directed forces from the rising Carlsberg ridge. Overall, the west coast is being tectonically evolved even today due to the rise of Carlsberg ridge and the Indian plate movement.

Abstract

The Remote Sensing and the followed up field based investigations show that the Tamil Nadu coast, India, is facing series of geoenvironmental problems due to tectonic movements and morphodynamic processes. Such problems pose a challenge to the engineering geologists. The paper discusses such challenging engineering geological problems and plausible remedial measures.

The great Indian epic ‘Ramayana’ says that ‘Lord Rama’ has tried to cross over the Bay of Bengal so as to reach Sri Lanka from India from three points along the southeastern fringe of the Indian coast. Firstly, he is said to have tried to cross from Vedaranniyam which is mythologically called as ‘Kodiyakkarai’ Secondly from Manamelkudi and finally crossed over to Sri Lanka from Rameswaram Island (Fig.1), as the former two coastal locations were widely separated from Sri Lanka by Bay of Bengal and the Rameswaram Island was nearer to Sri Lanka during that period. But, the recently acquired satellite data shows the huge accretion of sediments and rapid land building activity off Vedaranniyam coast (Fig. 2 and 3). The geomorphic interpretations carried out using IRS 1A imagery and 14^C archaeological dating of such geomorphic features have shown that such ongoing sediment accretion phenomena off vedaranniyam nose might in future connect the Vedaranniyam part of Indian Peninsula with Jaffna Peninsula of Sri Lanka if the sediment accumulation continues unabated. The sediment accretion in this area, therefore, requires detailed studies particularly in the context of the coastal ecosystem (Fig. 1).

Abstract

The art of remote sensing has opened up many vistas in the study of river migration as satellite photographs, both in their normal and digitally enhanced modes, vividly show the rivers and their migratory signatures. The rivers migrate for various reasons amongst which tectonic movement is one of the main causes. In the present study an attempt has been made to exhibit the palaeochannel network of the rivers of Western India and integrate them with lineament fabric, so as to understand the Quaternary tectonics of the region. The study has shown that Western India shows considerable signs of Quaternary tectonics.

Abstract

The present study has revealed that the NE-SW and WNW-ESE trending sinistral faults are very active along the Tamil Nadu coast and the same have caused considerable slope modifications along the Coleroon and Karungalar rivers which are well-manifested in the land, water and mudflat distribution pattern. Similarly, the progradation of the land in Vedaranniam nose is due to the rise of Pattukottai-Mannargudi area and the time transgressive modifications of the Vedaranniam backwater indicates the opening up of the N-S trending Pleistocene-Holocene faults.

The resources on the land have started showing sign of faster depletion owing to the population explosion, over exploitation of mineral and water resources and also the improper exploitation and the related wasting of the natural resources. Hence a time has come to search for more and more newer natural resources amongst which the ocean resources gain supreme importance as this treasure is yet to be hunted due to the non - availability of suitable technology for the same.

Such ocean resources mainly include the mineralogical and biological resources. The ocean biological resources, their birth, growth, population and migration greatly depend as chlorophyll content, total dissolved oxygen, total suspended solids, salinity etc. These parameters which constitute the marine environment drastically change in a quick span of time owing to the dynamically changing marine forces.

OBSERVATION

The examination of the IRS - 1A imagery under raw and the digitally enhanced modes vividly display heavy concentration of suspended sediments in certain sectors along the east coast of Tamil Nadu. Such pockets of suspended sediments are seen as long and linear bodies trending parallel to the coast to the strike length of 20 - 30 km and width of 5 - 10 km. Such Phenomenon of suspended sediments concentration are strikingly observed in two sectors. One in between Tuticorin harbour and Vaippar river mouth and the other just at the mouth of Ponnaiyar river along Cuddalore-Pondicherry coast. Both of them are observed along conspicuous (Fig.1& 2) concave coasts.

INTRODUCTION

Coastal zones are always dynamic and active, because of the multivariate morpho tectonic and morpho dynamic processes, viz: tectonic, fluvial, marine and aeolian which act in varying degrees and duration along the coasts. As these geomorphic / morpho dynamic processes act in varying permutations and combinations in different segments of the coasts, the land - ocean interactive phenomenon vary greatly in time and space, which in turn frequently and dynamically alter the coastal environment, and cause fragility to the coastal ecosystems. Further, as the coastal zones act as the junction between the Continents and the oceans, even mild earth movements exhibit exemplified expressions in land - water distribution pattern along the coasts. The green house effect and the much apprehended sea level rise and the disasters like cyclones also contribute in their own way in accelerating such land - water distribution / land - ocean interactive phenomenon.

Abstract

The analysis of IRS - 1A satellite imagery has indicated the existence of two NE - SW trending sub parallel faults along which the coast is undergoing land subsidence as revealed by the concavity in the shore line, preferential migration of the river systems and the drainage congestion, absence of beach ridges, occurrence of off shore shoal etc. The study has further indicated chains of tectonically induced environmental problems such as ground water logging, coastal zone flooding, storm surges, harbour sedimentation etc.

Abstract

The landslides of the hill ecosystems are either due to the natural morphotectonic and morphodynamics processes of the planet earth or due to the anthropogenic effects or due to the combinations of the both. In the Indian subcontinent, the landslides are reported from three major provinces viz: Himalayas, Westernghats and The Nilgiris. While the landslides of the Himalayas are demonstrated to be predominantly due to active tectonics, the landslides of the Westernghats are attributed to excessive weathering and rock fall. On the contrary the landslides of the Nilgiris have been thought to be due to extensive deforestation and the related increase in the pore pressure during rainy seasons. But the studies carried out in the recent years show that not only in the Nilgiris but also in other hill systems of Tamil Nadu, the landslides seem to be related to the recent earth movements. This is very significant in the context of fastly recurring seismicities in South India and hence this aspect warrants detailed studies for landslide mitigation.

ABSTRACT

Bats: A colony of 500 insectivorous bats of Hipposideros speoris inhabited a natural cave in Madurai (9^O58’ N. lat; 78^O10’ E long). At a depth of 40 m, the cave experiences a constant temperature of 27 + 0.1^OC, 95 % relative humidity and absolute and perpetual darkness. Therefore there were no day/night cues. Yet all the members of the bat colony flew out 10 to 15 min. after sunset as though they knew the time of sunset. Recorded flight and rest experiments in flight activity cages and a hand-wound Thermohygrograph drum 40 m from the cave mouth over periods of 50 days revealed that the free-flying conspecific bats were socially synchronizing the activity patterns of the three captive bats. Bats were telling other bats time.

Mice : In the field mouse, Mus booduga the mother conveys information of day and night to her pups by means of her presence and absence (PA) cycles. Her presence meant day and absence denoted night. We named this phenomenon maternal entrainment. Such entrainment of the time sense of the pups was possible if in every cycle the mother was presented for a minimum of 8 hr but not exceeding 16 hr. Therefore 8 hr and 16 hr describe the limits of maternal entrainment.

ABSTRACT

Education begins at home, then in community and finally in the educational institutes. At present 90% of the children in the age group of 6-14 years are receiving free primary education. Education policy of the 11^th plan states that there should be free and compulsory secondary education for all. To meet this goal, additional schools have to be set up to cater to the 30 million students. To teach the 30 million students atleast one million teachers would have to be trained to ensure the 1:30 teacher– student ratio. How do we plan to meet this target?

The projected target has to be met by developing innovative teaching methods in the institutes of higher learning. These methods have to be technology based, as well as community based regional approach. Emphasis has to be given to Liberal Education where there has to be a close interaction between the teacher and learner. The Open and Distance Learning isone such System which can be compared to Liberal Education– where there is flexibility in time and pace of learning for the learners. Reforms and innovations have to be brought in this system of education with utmost caution so that there is no compromise on quality and ethics, since every age has its own ethical environment.

Ethics in this context means traditions and culture of the small communities. This is more so in the North Eastern Region where there is an intimate connection between large and small communities. This region is rich in its community based values, bioresources and cultures. Need based Vocational and Professional courses have to be designed for enriching the region with human resources infused with sophisticated skills, resulting in the economic growth for the region. This method is envisaged to take care of the social challenges, traditions and cultural ethos.

Distance Education coupled with Information Communication Technology plays a pivotal role in meeting the requirements of today’s knowledge society by cutting across the barriers of time and geographic isolation.

ABSTRACT

Studies on the behaviour of animals are of utmost importance in the conservation of species. Ecology of the communities and individual species has to be examined in terms of different activities to understand the requirements of the species. Foraging and breeding are the major activities while resting and flight maintenance are also essential, although the time spent might vary in different species or situations.

Bird community studies conducted along with my students in different habitats in the Western Ghats since 1995 showed how the species are associated with each other and the impact of habitat changes on them. Endemic and threatened birds of the Western Ghats were specific about selection of habitat and food in different seasons. Identification of such critical habitats is crucial for conservation and management.

The studies on the bird community and drongos at Thekkady, Periyar Tiger Reserve conducted by me during 1979 to 1982, examined the association of drongos with other species in the area, especially while foraging. They fed mostly in mixed foraging flocks which is beneficial to all the participants. The strategy adopted by them for ecological isolation to reduce competition was by selecting different strata and substrate of the vegetation, varying sizes of insects, and methods of feeding.

In the case of wetland birds also habitat selection is a major behaviour limiting their numbers. For the threatened birds such as the Siberian Crane and the Andaman Teal, habitat quality and food availability were critical. Habitat degradation with over abundance of grass and reduction in sedges resulted in spending long duration for feeding and less returns.

Breeding behaviour of birds is interesting because of their strategies such as when to nest and where to nest. Studies on the seasonality have shown the importance of climatic factors. Many of our land birds nest during summer. Nest-site is also crucial as selection of the site with suitable macro and micro-habitats determine the success of the brood. The habitat patches for the individual pairs or groups of breeding birds which are defended against intruders are termed as territories which play a vital role in the distribution and density of birds. Thus the strategies adopted by species are dependent on the environment and species specific constraints affecting the survival of the species.

ABSTRACT

Insect societies such as those of ants, bees, wasps and termites are characterized by reproductive division of labour and cooperative brood care. Thus these societies consist of one or a smallnumber of reproductives (usually only queens but also kings in the case of termites) and a large number of sterile or nearly sterile workers

ABSTRACT

Malabar Spiny Dormouse (Platacanthomys lasiurus), the endemic rodent found in the Western Ghats of South India was studied in the Peppara Wildlife Sanctuary, Thiruvananthapuram District, Kerala, to determine the status, distribution, food and feeding of the species.

ABSTRACT

Science essentially involves confronting our ‘models’ of nature, against data from the real world, in a continuous effort to refine our knowledge of the system under study. Scientific monitoring of animal populations is therefore best viewed in the context of questions such as why monitor, what to monitor and how to monitor.

ABSTRACT

Social primates appear to be knowledgeable about one another’s behaviour to different extents. But do they know as much about one another’s beliefs and intentions? Are they adept at recognizing the similarities and differences between their own and others’ states of mind?

ABSTRACT

Male crickets use acoustic signals for long-distance mate attraction. Each cricket species has a unique calling song, used by females to recognize and localize conspecific males. Field cricket songs have wavelengths of several centimeters, which pose a difficult problem for these small animals in terms of localizing males, particularly in choruses. The chorus structure in terms of spacing, call intensity and timing, are important determinants both of the ability of males to synchronise their calls and of female mate-finding strategies.

ABSTRACT

Ethology, the biology of behaviour has been a fascinating area of biological investigations during past few decades. In recent past the information gathered by reputed ethologists on social behaviour of insects, fishes, birds and human beings are very helpful in the application of these principles for the welfare of the humanity as well as for the environmental sustainability. Ethology differs from the study of Animal Behavior, in that animal behaviorists generally are interested in learned behaviors while ethologists concentrate on innate behaviors.

ABSTRACT

Insects are considered the most successful in the animal kingdom. Many factors contribute to their success. One major factor that operates strikingly is the economy and optimal use of energy. One can give several examples taking the life of a single insect

ABSTRACT

The Indian false vampire bat, Megaderma lyra detects and captures prey (e.g. frogs) mainly by listening to the rustling sounds that are created when the prey is on ground. In addition, echolocation and vision are also involved. Mothers of M. lyra take meticulous care of their young. At the age of about seven weeks, juveniles exhibit gleaning flights. Among eight mother-young pairs, four young (group A) began to capture frogs at the age of 62 days