PREFACE Climate of a particular place is dynamic in nature. Climatic changes which have recently been occurring are causing a great concern. Over the years, the anthropogenic activities have resulted in an increasing emission of greenhouse gases and the global mean annual temperature has been increased by 0. 4 to 0. 7oC above that recorded at the end of the 19th Century. Due to sudden spurts in temperature before ripening of wheat, India has already witnessed a damage to this crop. Perennial rivers are gradually drying up and aberrations in rainfall are being noticed at regional levels. A shift in monsoon rainfall patterns has occurred since the last 3 years with heavy rainfall in drought prone areas and scanty rain in flood prone areas. The farm productivity, as it is predicted by US- based Centre for Global Development and Peterson Institute for International Economics, would decline in the range of 3 to 16% by 2080 in India. Considering the issue of climate change and its impact on food supply, a National Symposium on Agrometeorological Advisory Service to Ensure Food Security in North East India was held on the 7th February 2006. The symposium was inaugurated by his Excellency, the Governor of Tripura Shri D. N. Sahay and was attended by many experts in the discipline of Agrometeorology. We do express our heartful thanks for the logistic support provided by the National Centre for Medium Range Weather Forecast (NCMRWF), National Horticultural Board (NHB), National Bank for Agriculture and Rural Development (NABARD), State Bank of India (SBI), Tripura, Pelican Equipments, Chennai, Metos Instrument (India) Pvt. Ltd, Delhi in organizing the symposium.

INTRODUCTION The debate on climate change is going on. From the report of the Inter Governmental Panel on climate change (IPCC), a premier organization set up in 1998 by the World Meteorological Organisation and United Nations Environment Programme, it is known that the average surface temperature has increased over the 20th century by about 0. 6ºC. The number may seem insignificant but it is an unprecedented rise. In the past 150 years, the 11 hottest years were witnessed. It says that 1990s was the warmest decade and 1998 the warmest year since 1861. Worse, the Artic is warming twice as rapidly as the rest of the world and there is a distinct possibility of the Greenland Ice Sheet collapsing altogether and pushing up sea levels by several metres. It is predicted that 2035 is the year when Himalayan glaciers may totally disappear causing catastrophic disruptions. Unfortunately, India is among the countries that will suffer the most serious consequences as a result of global warming. Following is the probable effect of global warming.

INTRODUCTION Research in agriculture and allied activities and the subsequent technological innovations are important requisites for enhanced productivity and generating income for the farmers. In India, farming is a way of livelihood to 65 per cent of nearly 1. 1 billion population. Our farm population is increasing annually by 1. 84 per cent. The average farm size is becoming smaller each year and the cost-riskreturn structure of farming is becoming adverse with the result that farmers are getting increasingly indebted. There is no option except to produce more food and other commodities under conditions of diminishing per capita arable land and irrigation water resource. Hence, we must harness the best in frontier technologies, thus integrate them with traditional wisdom and thereby launch an eco-technology movement. The productivity in agricultural sectors is dependent on several bio physical and socio-economic factors. The significant biophysical factors are weather parameters, soil health, water resources, crops/ varieties and pest environments. In order to monitor the impact of weather parameters, we need to have weather forecasts and the accuracy of which to harvest the economic benefits should be given top priority. Only fifty years ago, weather forecasting was an art which was derived after interpretation of data received from land based observing stations, balloons and aircraft etc. Now, modern technology particularly computers / weather satellites / radars has resulted in enormous improvements in the accuracy of weather forecasting with the help of various coordinated meteorological observing networks.

INTRODUCTION Inspite of recent technological developments which have helped to increase agricultural production in many countries, growth of plants and animals continue to depend to a large extent on the weather conditions. Each plant has its own climatic requirements for growth and development and any large scale deviation from it exert negative influence. Growth of plants is most sensitive to temperature just above a threshold value and near the maximum value, where growth normally stops. Therefore, periods of extreme temperature i. e. low temperatures below the threshold value and high temperatures above the maxima are hazardous to plant development and growth. Extreme temperature conditions during cold spells cause stress and frost; high temperatures lead to heat stress, and both affect agricultural production. Snow and ice storms in late spring or early autumn are very hazardous to many temperate crops. Similarly extremes of moisture conditions namely dry desiccating winds, drought episodes and low moisture conditions as well as very humid atmospheric conditions including wet spells tend to affect agriculture. High soil moisture situations of water logging and flooding associated with heavy rainfall and tropical storms have adverse effect on plant growth and development since they influence the rate of transpiration, leaf area expansion and ultimately plant productivity. Drastic changes in rainfall variability can have very significant impact, particularly in climatically marginal zones such as arid, semi-arid and sub-humid areas where incidence of widespread drought is frequent. Dry desiccating and strong winds reduce agricultural production as a result of very high evapotranspiration rates. It also causes mechanical damage to plant with weak stems by lodging such as the sugarcane and the banana.

INTRODUCTION In spite of technological developments for the last few decades, Indian agriculture is still rain dependent. Extreme weather events such as drought in 2002, cold wave during 2002-03, heat wave in the year 2003, increased temperatures during rabi 2003-04 and 2004-05, deficit rainfall in many parts of the country during 2004 and excess rains in 2005 (100cm in Mumbai, floods in MP, Gujarat, Orissa, AP, Tamilnadu and Karnataka) could affect the food grain production considerably. The spatial and temporal changes in important weather parameters such as rainfall, temperature, wind, cloud cover, humidity, etc. would influence crop yields by affecting farmers’ decision in selection of cultivar, use of inputs, crop management practices, etc. These decisions significantly influence the aggregate agricultural output, which , in succession has an impact on the economy of the country as a whole. Thus, the timely and accurate weather based agro -advisories is the need of the hour for sustainable agricultural production. Further, the quality of utility of agro-advisories can be improved through value addition to the agromet information including forecast and demonstration of economic benefits accrued due to the following of the advisories. Thus making farmers to adapt weather-based advisories for (i) Increasing the quality and quantity of produce, (ii) Efficient utilization of resources, (iii) Minimizing losses due to adverse weather, (iv) Effective utilization of favourable weather events, and (v) Reducing cost of cultivation to enhance profits.

INTRODUCTION The discipline of Agrometeorology, an applied science is less than fifty years old. Its services are operationally used by individual farmers in developed countries, and by agricultural or development services in more than half of the countries of the world. Its contribution to agricultural production by examining forecast is sought in virtually all countries. In many countries, the respective governments have expressed the desire to use meteorological information to a much larger extent in day-to-day farm planning and operations. The climate database is used for the development of practical criteria in planning and management of irrigated and rainfed crop production system (Martin Smith, 2000). Though a huge set of Agromet data exists in India, its utility has not been effective due to the scattered location of these data sources and the impediments for free flow of data to the users to analyze and interpret for real-time decision making in agriculture. There is also a considerable time lag between the actual observation and data availability. In view of the importance and the immediate exigency to centralize the database system for helping the researchers and planners, a central agrometeorological databank facility funded by DST from 1998 to 2003 and later by ICAR with the following objectives was established at Central Research Institute for Dryland Agriculture (ICAR), Hyderabad.

INTRODUCTION India is endowed with a vast and rich diversity of natural resources particularly soil, water, climate and agro-biodiversity. To realize the optimum potential of the agricultural production system on a sustainable basis, there is a need to bestow a paramount importance in the arena of efficient management of natural resources. India with a geographical area of 329 M ha presently supports 17% of the world’s population on merely 2. 5% of world’s land area and 4% of world’s freshwater resources. India’s economy is predominantly agrarian in nature with about 72. 2% of its 1028 million population (census 2001) living in villages and about 54. 4% people (cultivators) directly depending on agriculture.

INTRODUCTION Any crop has its own optimal requirements or selective response to the environmental factors such as rainfall/ soil moisture supply, day/night air temperature, soil temperature, duration of sunshine and its intensity. The growth and development of a plant which ultimately governs the agricultural productivity of a region, is closely related with climatic factors. Weather phenomenon has a profound influence on crop growth stage. A moderate wind or a light rain, when the crop growth is near to harvest, may do more damage than even heavy rain and high wind in the vegetative phase. So land use planning by matching crop growth with weather parameters forms a basis for successful agriculture (Samra, 2003) in a particular region. In order to achieve sustainable agricultural productivity in the 21st century, the climate and weather systems are being recognized as critical agenda and input.

INTRODUCTION The agriculture in north eastern hill region of India is mainly rainfed in nature and shifting cultivation, known as jhuming, is the dominant farming system. The shifting cultivation is detrimental to both soil and vegetation as it is connected to heavy soil and nutrient losses when practised in steep slopes. The burning and slashing operations are responsible for reduced floral and faunal diversity in the region. It is a well known fact that climate is the main driving factor that governs the sustainability of other natural resources such as land, water and vegetation. So far the NE region gets abundant rainfall for survival of the crops at least during the kharif season. The rainfall starts early March and continues up to the late October. The jhum cultivators follow the rainfall trend and get their field ready for sowing of seeds by early March itself so that vegetative stage of crops gets plenty of rainwater for growth and development. Due to increased population pressure, the hills of NE region are over exploited and the jhum cycle has been reduced from 10-12 years to 4-5 years now-adays. Hence the soils do not get sufficient time to revitalize it and are subjected to more and more exploitation and get degraded permanently.

INTRODUCTION Of an estimated 142 mha of net cultivated areas in India, about 67 % is rainfed and only 45 mha is irrigated. The NCA (1976) predicted that even when the full irrigation potential of the country is exploited by 2013 AD, over 50% of arable land would continue to remain rainfed in future. It is the rainfed belt where cultivation of 91 % coarse cereals (Sorghum, Pearl millet and Finger millet), 91% pulses (Chickpea and Pigeon pea), 80% oilseeds (Groundnut, Rapeseed, Mustard and Soybean) and 65% cotton have predominated. Even the crop that formed the backbone of green revolution such as rice and wheat, still have 50% and 19% area under rainfed condition, thus emphasing the importance of rainfed agriculture in India. Inadequate resource (soil and rain water) management coupled with traditional farming practices are responsible for subsistence farming. Monocropping, traditional crops and their varieties, low and imbalance nutrients and inadequate crop establishment, in past, had been the major cause for poor development of dryland agriculture in the eastern region.

INTRODUCTION Rubber cultivation in regions extending from 10°N to 10°S latitude is known as the traditional region and the areas other than its natural climatic origin is termed as the non-traditional region. Northeast India comprises majority of the non-traditional areas in India with major climatic constraints like high seasonal rainfall, excessive precipitation and to some extent dry conditions. These areas extending from 22 to 29°N latitude, holds promise in extending rubber cultivation because of its exceptional climatic make-up and abundant amount of annual precipitation (2000 mm) distributed over a fair period of time. This perennial crop generally yields latex rubber at the 7th year after planting (with an economic life span of 20 years), although the period (immaturity period) it requires, is higher in the non-traditional region (Rubber Growers Companion, 2006). This immaturity period has also been shown to reduce with water availability in sub-humid climates (Vijayakumar et al. , 1998). Harvest of this crop is by tapping. Tapping is a process of controlled wounding during which thin shavings of bark are removed, thus opening the latex vessels which exude latex. Dry rubber yield is obtained after the latex is coagulated and rolled into sheets (about 500gm) which is then smoked and dried.

INTRODUCTION The weather conditions during the growing season of crops influences the onset and development of disease. The relationship between weather and plant disease development is the basis for meteopathological forecasting. On the basis of observed or forecast weather conditions, the incidence of plant disease is likely to be predicted. Such predictions are designed to warn growers of expected significant developments in the manifestation of a particular plant disease. Such disease forecasts, if sufficiently accurate, permit efficient and competent counter measures to be adopted. A short range or medium range of disease forecast, issued at short intervals during the growing of crops, can give guidance to the farmers on the best remedial measures. Growers can decide whether a chemical control measure is needed or not, and if needed then optimum date on which to be applied and similar day to day decisions to fight against disease to minimize the losses to be caused. The result, of adopting such a plan of weather based control measures, is to reduce the number of chemical sprays to a well timed few, thus giving an equal or even better protection at a lower cost in chemical and labour, and simultaneously reduces losses caused by phytotoxic and mechanical damage to the crop. The reduction in the use of potentially toxic chemical is a matter to be welcomed in the present world, considering the consequences of the widespread use of toxic chemicals.

INTRODUCTION Integrated Pest Management (IPM) has been defined as a “system that, in the context of the environment and the population dynamics of the pest species, utilizes all suitable techniques and methods in as compatible manner as possible that maintain the pest populations at levels below those causing economic injury” (Glass 1975). The Inter society Consortium for Plant Protection (ICPP) has defined integrated pest management as “the use of multiple tactics in a compatible manner to maintain pest population at levels below those causing economic injury while providing protection against hazards to humans, domestic animals, plants and the environment”. The term ’integrated’ means it is a broad interdisciplinary approach taken using scientific principles of plant protection of variety of management strategies and tactics to fuse into a single system. The terms ‘pest’ means all biotic agents which adversely affect plant production. This includes insects, mites, nematodes, weeds, bacteria, fungi, viruses, parasitic seed plants and vertebrates. The term ‘management’ indicates to keep the pest population below some level based on economic criteria. It does not mean complete eradication of entire pest population.

INTRODUCTION Mizoram is a hilly terrain lying in the north eastern part of the country. The total geographical area of the state is 21, 087 sq. km and lies between 92º 15/ to 93º 29/ E longitude and 21º 58/ to 24º 35/ N latitude. Out of six agro climatic zones of the NEH region, Mizoram comes under sub tropical hill zone and posses a sub tropical and humid climate due to high rainfall (Fig. 1). These climatic conditions are very conducive for the cultivation of a large number of agri-horticultural crops. The physiography of the state is divided into hills and valley lands. About 90 % area of the state comes under hills and only 10 % area is under valley. The valley lands are sporadically distributed in small patches except in Champhai district. The slope of the hills in Mizoram is much steep as compared to the other states in the North Eastern region. The land use statistics of the state is presented in Table1.

INTRODUCTION Several biophysical factors govern the agricultural productivity of a region. Among the key biophysical factors, weather and more particularly rainfall has the over riding impact on agricultural productivity since rainfall is a primary source of water and the first requirement for raising any crop. This element influences various dynamics of crop growth and development and accounts from nearly two thirds of variation in agricultural productivity. The amount of rainfall at a particular place is important; an equal important factor is its temporal distribution, which is uneven, uncertain and erratic in most part of the country. Breaks in monsoon are common phenomenon during the monsoon period. The analysis of rainfall characteristics such as occurrence and distribution of dry or wet spell is essentially required for successful crop planning, development of befitting agro techniques, recommendation of suitable crop variety, designing of water harvesting ponds, earthen dams and other soil conservation structures. It is also an established fact that the crop development will be affected if the dry spell coincides with sensitive phonological stage of the crop and sometimes beneficial if it coincides with the ripening stage. Hence for the purpose of crop planning and to carry out the agricultural practices, it is important to know the sequence of dry and wet periods. An attempt has been made in this paper to analyse the rainfall in standard meteorological week as well as monthly basis at different probability levels for Lembucherra by using computer based forecasting technique.

INTRODUCTION The state of Manipur is located at the easternmost border of India and is characterized by flat valleys comprising of four valley districts (Bishnupur, Imphal East, Imphal West and Thoubal) surrounded by five mild to steep slope hill districts (Chandel, Churachanpur, Senapati, Tamenglong, and Ukhrul). The state is geographically bordered by Nagaland in the north, Burma in the east, Mizoram in the south and Assam in the west. The total geographical area of the state is 22, 327sq. km divided into 20, 089sq. km in the hills and 2, 238sq. km. in the valley. More than 98% of the population in the hill is in rural areas whereas around 60% of the population in the valley is in rural and around 40% are in the urban areas. The AAS Unit, Imphal is located at 24045' N latitude, 93054' E longitude at an altitude of 774m above msl. The agro-climatic zone of the state covers sub tropical plain zone, sub tropical hill zone, temperate hill zone and sub temperate zone.

INTRODUCTION It is well accepted that the climatic changes also influence the geomorphic process efficiency and landform development (Ahamad, 1985). Glaciation, sea level changes, flooding and many other geo- environmental events are related with global and regional climatic changes along with tectonic and other non-tectonic factors like natural vegetation, soil, organic development etc. Considering the role of climate on landform development and dynamics of the Late Quaternary climate, a climato-geomorphic study was conducted on the coastal and paleo-coastal areas of the Bengal Basin namely-lower Western (West Bengal coast) and Eastern (Tripura Paleo-coastal Fold Belt Province) Geo-provences. The main objectives of the study were to investigate (i) Development of the landforms during Late Quaternary period with sea level changes and (ii) Climatological influences on the landform modifications.

INTRODUCTION India has varied agroclimatic conditions, which favour the cultivation of various horticultural crops. Based on the adaptability and system of cultivation, the horticulture can be grouped into four major class such as Temperate, Sub-tropical, Tropical and Arid. India has become the second largest producer of both fruits and vegetables with a total production of 46. 75 million tonnes of fruits from an area of 4. 56 million ha and 93. 16 million tonnes of vegetables from 6. 30 million ha (2003-2004). Besides, there is a tremendous scope for increasing the production of flowers, spices and condiments, plantation crops and medicinal and aromatic plants. Floriculture has emerged as a viable agribusiness. The commercial cultivation of flowers in open field conditions was much popular than protected cultivation in India. But, now- a-days, the protected cultivation has brought a great revolution in Indian floriculture and it helps for the quality production and export to earn sizeable amount of foreign exchange. India has approximately 350 ha under green house cultivation with export value of approximately Rs. 330 crores during 2003-04(APEDA). On the other hand, the prevailing climatic conditions in India are highly suitable for cultivation of the almost all spices from tropical black pepper to temperate saffron. The major spices are mainly grown in humid tropics like Western Ghats and NE States. Out of 21 agro-ecological sub regions in India, spices are grown in 14 different agro ecological sub regions. Fruits, vegetables, flowers spices and condiments, plantation crops and medicinal plants are widely distributed across the country, while plantation crops are restricted to a few regions.

INTRODUCTION Edible mushrooms are higher fungi occurring seasonally all over the world in various habitats varying from sandy plains to thick forests. About 2000 fungal species in the world have been identified as edible, of which, only a few (20) are cultivated commercially (Chang and Miles, 1991). These mushrooms are generally considered as the good source of protein, vitamins and minerals in addition to their flavour and condiment value. About 3.

INTRODUCTION Livestock plays a very important role in the mixed farming system of the country contributing about 25 per cent of Gross Domestic Products (GDP) from agricultural sector. India has the largest population of cattle and buffaloes and the highest producer of milk in the world. India has also the second largest population of goats and one of the leading countries in poultry sector. There has been a tremendous increase in milk, meat and egg production since independence. However, owing to various reasons viz. , low genetic potential, scarcity of feeds and fodders, diseases, poor management practices etc. , the productivity is quite low. Climatic conditions of a place have also an important bearing on livestock production and productivity. Climatic factors like ambient temperature, humidity, solar radiation and wind velocity are the important ones which make up the physical environment of the animal having direct and indirect influences on animal’s responses towards climate. Temperature and humidity are the most crucial with the former being the most researched one. Extremes of hot and cold weather are creating stress to any animal and the effects are more severe under hot and humid climate. The varied effects of undesirable climate on animals are pertaining to feed and water intake, physiological, biochemical and endocrinological aspects, reproduction, health and productivity etc. Thus, the positive and negative effects of the environment on the livestock have been discussed in a way to undertake some protective measures.

INTRODUCTION Prediction of helminthic infections is impractical. The aim of any control programme must therefore, ensure that parasite populations do not exceed levels compatible with economic production. The parasitological monitoring (e. g. faecal egg counts or pasture sampling) at intervals, forecasting on the basis of meteorological data and computer simulation may provide an alternate approach to control parasitic infection (Brunsdon, R. V. , 1980) in a given geographical area. The most common gastrointestinal parasite prevalent throughout the year in Meghalaya, India is Strongyle infection. This is because of the high rainfall and humidity prevalent in the North-Eastern region. As the prevalence of this infection is mainly dependent on rainfall and humidity, study was being initiated to identify the relationship between rainfall/temperature and strongyle infection. The study would be also helpful in predicting/ forecasting the disease occurrence based on the prevailing pattern of rainfall in a particular location.

INTRODUCTION One of the most important changes in the global environment which affects the existence of all living things , is the climate change. The climate change globally and locally also changes the aquatic habitat which, in turn directly and indirectly affects the environment. Anyway, the changes in climate are certain to occur and may be inevitable. The only possible way is to analyze the situation and find out the reasons for such changes and take immediate steps to minimize the impact of these climate changes. Global warming has eventually become synonymous with climate change because almost all the variables of the ecosystem are influenced directly or indirectly at different levels. Aquatic environment is extremely diverse and influenced by the climate changes to a large extent both locally and globally. The changes in the ocean and its life are well studied at different levels with all possible details compared to the freshwater habitats. Unlike agriculture and animal husbandry, the vast majority of the fish production still comes from the natural habitat or the wild collections. Agriculture and animal husbandry usually focus on few important species but for fisheries, all the species of fishes including most of the aquatic living organisms are commercially important. The media (water) in which the aquatic organisms dwell, is much more important to all living organisms of the earth and so the influence by climate changes on water becomes very much relevant in the present situation. Freshwater habitats are limited and are much more complex to investigate in respect of climate changes due to the variability and diverse micro and macro level interactions. A holistic approach to deal with all these problems has not got much attention both globally and locally even though , it is the need of the hour to address the issues of impact of climate changes in the aquatic environment.

INTRODUCTION Aquaculture had undergone rapid expansion and intensification in the recent past and has taken the shape of a full-fledged diversified industry. But the risk involved in aquaculture activity has also increased significantly due to the outbreak of diseases which has a devastating effect on the aquaculture crops. Fish are aquatic and poikilothermic, their existence and performance are dominated by the quality of their environment . The aquatic environment is a complex system subject to constant physical and chemical changes brought about by natural and manmade processes. Therefore, choosing the proper site to develop aquaculture facility is paramount to its success. A disease is an abnormal condition of an organism caused by infection, inherent weakness or environmental stress; it prevents the organism from functioning normally which ultimately leads to death (Avault, 1998). In an aquatic environment, there is a profound balancing of relationship between host (fish), pathogen and the environment existing and this is the fundamental concept to disease susceptibility of fish (Snieszko, 1973). A disease organism may be present in the environment or host, but will not cause disease as long as the host has high natural resistant or the physical condition of the host is strong. Once the imbalance is created to any of the component, opportunistic pathogen invades the host resulting to the outbreak of disease.

Index A Abiotic factors 192 Acclimation 283 Accumulation 201, 202, 208, 210, 211, 259, 271, 320 Acid lime 247 Adequate rains 133 Adreno corticotrophin hormone 280 Adult emergence 177 African marigold 263 Age at puberty 280 Agri export zones 264 Agricultural 21, 22, 24, 25, 27, 28, 35,