eChapters

Disease is one of those terms that are very difficult to define. It is realized that disease (literally dis-ease) implies lack of ‘comfort’and therefore, involves deviation from normal functioning. From time to time several definitions which have been proposed, in fact descriptive but not simultaneously exclusive. The definitions for the term disease are.

Prologue: The Issues

Farmers lose a significant portion of their income when their crops and products become infested with various insects, diseases and weeds, resulting in much lower crop productivity and lower actual yields than the attainable yield of crops. Yield losses due to pests, pathogens and weeds are responsible for 20-40% losses in global agricultural productivity. India reports crop losses of 20-25% annually due to pest infestations. Without the use of crop protection solutions, there could be a 78% loss in fruit production, 54% loss in vegetable production and 32% loss in cereal production. According to the Ministry of Agriculture, India loses INR 1.48 billion worth of agricultural production annually due to pests, weeds and plant diseases.

26.1 Introduction

In a single equation model, the dependent variable Y is expressed as a linear function of one or more explanatory variables (say X1 , X2 , ... XK ). In such models, an implicate assumption is that the cause and effect relationship between (Y, Xs) is unidirectional. Here explanatory variables are the cause and the dependent variable Y is the effect.

However, there are some situations where two way flow of influence among economic variables exists. Thus one economic variable affects other economic variables and in turn is affected by them. Thus, in the regression of money M on the rate of interest r, the single-equation method assumes implicitly that the rate of interest r is fixed and it is tried to find out the response of money demanded when the level of interest rate is changed.

25.1 Introduction

Farmers must be able to take appropriate decisions at appropriate time. Incorrect judgement and decisions will return in failure of execution of farm plan and in turn economic loss. The farm management decisions can be broadly categorised into two ways.

24.1 Introduction

Linear programming is a budgeting technique which is more refined and systematic than conventional budgeting in determining the optimum combination of enterprises or inputs so as to maximise the income or combination of enterprises or the income or minimise costs within the limits of available resources. It may be defined as “The analysis of the problem in which a linear function of a number of variables is to be maximised or minimised when these variables are subject to a number of restraints in the form of linear inequalities”, In linear programming models, the objective of the typical farm i.e maximisation of net profit or cost minimisation is achieved through an optimal plan generated from its solution.

23.1 Introduction

The following Frank Kright, the knowledge situation can be classified into the following logical possibilities:

23.2 Perfect Knowledge

There would be no need for farm management experts if knowledge was perfect. If there were so technology, prices and institutional behaviour would be known with certainty for any period of time in the nature. But the concept of perfect knowledge is a fallacious one and does not represent the real world situation.

22.1 Farm Planning

It refers to setting the objectives and actions to be taken in directing or controlling the organisation of farm business and it precedes all other managerial functions on the farm to achive the desired results. It is deciding in advance to the production management problems viz. what to produce, how to produce, when to produce, financial management problems viz how to borrow, how much to borrow, when to borrow, from where to borrow and marketing management problems viz, where to buy, and sell, when to buy and sell, how to buy and sell ete. Farm planning governs the survival progress and prosperity of farm organisation in a competitive and dynamic environment. It is a continuous and unending process. Farm planning is as old as farming itself but mainly it uses the farmal planning.

21.1 Cost Principle

 We know that

 TC = VC + FC

 and Net Revenue = TR-TC.

In the short run, gross revenue (G.R.) must cover the V.C. The maximum net revenue is obtained when MC = M.R. If GRs VC, the guiding principle should be to keep increasing production as long as MR > M.C. In the short run, MC = MR point may be at a level of input use that may involve a loss instead of profit. Yet at this point, the loss will be minimised.This situation of operating the farm when MR > AVC but

 

 

20.1 Introduction

The farm management is the science which concerns with making decisions and choices about combining different enterprises and the optimal utilisation of resources available. It is necessary to understand the typical farming decisions. Decisions can be classified into agricultural management decisions, administrative management decisions and marketing management decisions which are discussed below:

20.2 Organisational Management Decisions

These are further sub-divided into operational management decisions and strategic management decisions.

19.1 Introduction

The farm management comprises of two words: ‘farm’ and ‘management’. Literally ‘farm’ means a piece of land where crops and livestock enterprises are taken up under a common management and has a specific boundaries. ‘Management’ means the act or art of managing, the agricultural production or enterprises etc.

18.1 Introduction

The farmers have limited resources and a number of enterprises/or enterprise combinations of crops and livestock to choose from. So, the question is how much of what to produce and with what technology. In other words, what combination of enterprises should be produced is expressed as.

17.1 Introduction

Factor-factor relationship is concerned with the possibility of substituting one input factor (X1 ) for another input/factor (X2 ) for producing a given level of output. It answers the crucial question of finding out the optimum or least cost combination of two or more resources in producing the given amount of output. The two fold objective of factor-factor relationship is:

 

In production one or a combination of the following relationship are commonly observed:

1. The law of constant marginal returns (productivity)

 2. The law of increasing marginal returns (productivity)

 3. The law of decreasing marginal returns (productivity)

15.1 Agricultural Economics and Definition

As a separate subject, agricultural economics emerged in the beginning of 20th century when the economic issues related to agriculture aroused interest at various educational centres. The depression of 1890s which wrecked have in agriculture at many places and it forced organised farmers groups to take keen interest in farm management problems. The study and teaching of agricultural economics was started at Harvard University (U.S.A.) in 1903 by Professor Thomas Nixon Carver. Agricultural economics may be defined as the “Application of Principles & Methods of economics to study the problems of agriculture to get maximum output and profits from the use of minimum in but for the wellness of society in general as well as the farming industry in Particular.

14.1 Introduction

In this chapter, we have to present the review matters related to the theory of the “Classical Linear Regression Model (C.L.R.M.) and Testing of Significance of Statistical Hypothesis”. Here, I have to provide the references about the topics and the names of the books from where the readers can refer about the availability of the subject matters (preliminaries, procedures and interpretations) of numerical results obtained through the statistical analysis carried out for the empirical studies considered there in.

13.1 Meaning of Dummy Variables

In econometrics, particularly in regression analysis, a dummy variable is also known as “Indicator variable or Binary variable or qualitative variable”. It is one which takes the value (0 or 1) to indicate the absence or presence of some categorical effect that may be expressed to shift the outcome, e.g.

i) Literate (1) and Illiterate (0)

 ii) Male (1) and female (0)

iii) Farmers in a cross sectional data in terms of year with normal weather condition (1) and year with abnormal weather condition (0).

12.1 Introduction

There is no other pair of words except the pair “Multi-Collinearity” which is more misused both in “Econometric Texts” and in “Applied Literature”. In many practical problems, many of our explanatory variables are found to be highly correlated among themselves.

One of the assumptions of the “classical linear regression model (CLRM) is that there is no “Multicolinearity” among the regressor variables included in the regression model.

 

11.1 Introduction

The term “regression” literally means moving back towards the average. It was first introduced by the British biometrician Sir Francis Galton (1822-1911). in connection with the inheritance with the stature.

a) Definition

Regression analysis is a mathematical measure of the average relationship between two or more variables in terms of the original units of data.

In regression analysis, there are two types of variables. The variable whose value is influenced and is to be predicted, is known as the dependent (or predicted/ response explained) variable and the variable that influences the values of the dependent variable or is used for prediction purposes, is known as the independent (predictor/explanatory/ auxiliary/ regressor) variable.

10.1 Introduction

Least square theory is a statistical technique used to estimate the parameters involved in the regression model in such a way that the sum of squares of errors (residuals) is minimum (least). We have generally two methods of estimation of population parameters. These are (i) Ordinary least square (O.L.S.) method and (ii) Maximum likelihood (M.L.) method. The method of ordinary least square (O.L.S.) is used extensively in regression analysis primarily because it is intutively appealing and mathematically much simpler than the method of maximum likelihood estimation (M.L.E.). In the context of lineaer regression analysis, the two methods generally give similar results.

9.1 Introduction and Definition

Literally, econometrics means “Economic measurements”. Although measurement is an important part of econometrics, the scope of econometrics is much broader. Econometrics is an amalgam of economic theory, mathematical economics, economic statistics and mathematical statistics. It can also be stated that “Econometrics consists of the application of mathematical statistics to economic data to provide empirical support to the model constituted by mathematical economics and to obtain numerical results from such data.

8.1 Matrix

An arrangement of m×n elements into m rows and n columns is called a matrix. A matrix is a rectangular array of numbers usually represented by enclosing the array in brackets.

Order of a Matrix : The number of rows and columns is called the ‘dimension’ or ‘order’ of the matrix.

 

7.1 Introduction

The integral calculus is concerned with the opeartion of “integration” which is the reverse process of differentiation. If f '(x) represents the differential coefficient of f '(x), then the problem of integration is to find f(x) from f '(x).

7.2 Integration of a Function Containing a Constant

If we integrate a function containing a constant factor, this factor must also be a factor of final integral.

6.1 Introduction

Let

v : Represents the volume of a gas.

p : Represents the pressure of a gas.

t : Represents the absolute temperature.

The law is represented by the relation writen as t v k. p ? where k is a constant.

1. Suppose the temperature varies and pressure remains constant then

2. Suppose the pressure varies and temperature remains constant then

5.1 Introduction

In many problems of economics, we may want to know how small or how large a certain quantity may become. In other words, we may want to know the minimum and maximum values of some functions of variables.

The term ‘optimisation’ may be used in general, both for maximisation and minimisation. The term ‘optimal position’ is often applied to the ‘equilibrium position’ resulting from the balancing of the forces.

4.1 Introduction

There are some mathematical tools that are applicable in solving the mathematical problems related to the subject matter on “Economic Theory”. Differential calculus is one of those mathematical tools. Hence the useful theory of differential calculus will be discussed in this chapter.

4.2 Differentiation

The mathematical term “Differentiation” is involved in finding the rate at which a variable quantity changes.

In the theory of “Differential Calculus” we are concerned fundamentally with the “Rate of Variation” in a function y = f(x) with respect to the change in other variable (Independent Variable X) on which the dependent variable ‘Y’ depends through a relation Y = f(x).

3.1 Definition

 Let f (x) be the function of a random variable ‘x’. If there exists a number ' ' ?

 such that f(x) may be made as close to ' ' ? as we proceed to choose x close to

 a given number ‘k’, then we say that the limit of f(x) as x approaches to k, is ' ' ?

 and we write it symbolically as

 x k

 limf(x)

 ?

 ??

 Example 3.1 : We are giving some examples as below:

 Example 3.1.1 : A function f (x) may become infinite as x tends to a value ‘c’

 and we write that

 x c

 limf(x)

 ?

 ??

 Example 3.1.2 : Consider the function 1 f(x) x ? . Then we say that as x ??,

 f(x) tends to zero and write it as :

 x

 1 lim 0

2.1 Function

A variable ‘Y’ is said to be the function of an other variable ‘X’ if for every value of ‘X’ there exists a corresponding value of ‘Y’. It is denoted as Y = f (X). The function f (X) is a relationship between two variables (Y, X) which associates any given number x with another number y.

A function is a mapping or transformation of x into y and is denoted by y = f(x). The variable X represents the elements of the domain ‘D’ and is called the “independent variable”. The variable ‘Y’ represents the elements of the range ‘R’ and is known as the “dependent variable”.

1.1 Common Logarithm

Logarithms to the base 10 are called common logarithm. This system was first introduced by Briggs in 1615. The mathematician Napier was the inventor of logarithms and Briggs was a contemporary of Napier. From the equation 10x = N, it is evident that the common logarithm will not always be integral and that they will not always be positive.

We have

 3154 > 103 and 3154 < 104

 Hence, log10

 3154 = 3 + a fraction

 Again we have

0.067 > 10–2 and 0.067 < 10–1

 Hence, log10

 0.06 = –2 + a fraction

 = 2+ a fraction

4.1. Physical characteristics

4.1.1. Colour, number of bands and hair profile

The physical characteristics of hair like colour, number of bands and hair profile showed huge variations in the same individual from region to region particularly in the domestic animal species. So, these features of hair cannot be considered as an important tool for species identification from hair. These findings are in accor dance with the observations of Sarkar et al. (2011). Who mentioned that the coat of mammalian species varies with season, habitat and sex of the individuals.

The present study on trichology of domestic and wild animals was conducted in the Postgraduate laboratory of the Department of Veterinary Anatomy and Histol ogy, Nagpur Veterinary College, Nagpur. The study was undertaken with an aim of species differentiation from the guard hair of domestic as well as wild animals. The hair samples were collected from a total of eight domestic animal species and six wild animal species. Six animals from each species were studied and only three animals studied from the Sambar species as only three animals from this species was reported for post-mortem to the Nagpur Veterinary College, Nagpur within the period of research.

Hausman (1920a) worked on the microscopic structure of hair from the commercial fur. The hair samples of 27 different species of animals were used for the study. He described in detail the structural features of guard hair. He classified medulla of hair into 4 different types as discontinuous, continuous, fragmental and interrupted on the basis of composition of medullar cells. He also classified the cuticular scale pattern into two types as imbricate interrupted and imbricate coronal. He mentioned in detail the methods for the preparation of slides for the study of microscopic structures of hair. He also studied the cortex and pigment granules.

India is well known for its rich flora and fauna and is referred as one of the richest biodiversity nations of the world. The mammalian population of India is a combination of Palaearctic, Oriental and Afro-tropical fauna (Sahajpal et al. 2009). It is the home of 400 different mammalian species, 129 of these species are protected under Wildlife (Protection) Act 1972 (India) and an arbitrator to Convention on International Trade in Endangered Species (CITES) (Nameer, 2015). Illegal trade of the wildlife for preparation of various products is the common issue in the conservation and is also responsible for regional extinction of the species.

Startup India, the initiative of Government of India, was first announced by Honourable Prime Minister Mr Narendra Modi during his Independence Day speech on 15 August, 2015 and discussed elaborately again on 27 December 2015 in his radio address ‘Maan ki baat’ mentioning startup as new opportunities for the youth who want to set up new business or innovative projects. Indian Government lunched this ‘Startup India – Standup India’ campaign on 16 January 2016 with an intention to build a strong startup ecosystem for nurturing innovation and encouraging private investment.

Solid waste disposal has become Nation’s great concern since after spending more than 50 percent of their budget by Municipalities, they could collect and dispose about 70% of MSW leaving many parts of the municipality unclean every day and residents are not at all satisfied (Sannigrahi, 2016). The Central Pollution Control Board (CPCB) collected data from 299 cities of India on the mode of collection of MSW and found that manual collection comprised 50% while collection using trucks comprised only 49% (CPCB Report, 2000). It is very interesting to note that majority (more than 90%) of MSW are disposed by dumping in unscientific open land filling on outskirts of towns and cities while 10% of collected and 2% of uncollected MSW are burnt in open condition.

The harmful impact of chemical pesticides and fertilizers like gradual low productivity of land, growing nutrient imbalance in cultivated soils, accumulation of high pesticide residue in food materials, increasing resistance of harmful pests towards chemical pesticides and continuous increase in environmental pollution are forcing farmers to adopt organic or sustainable farming by considering vermicompost as possible substitute to the costly chemical fertilizers during crop cultivation. Gradual awareness among common people on organic farming, large availability of organic wastes in both rural as well as urban areas, more avenues of vermicomposting training, global market for organically produced foods and ever increasing unemployment problem have opened up greater prospects of commercial vermicomposting (Sannigrahi, 2012).

Vermicompost is the result of the biooxidation and stabilization process of organic wastes by joint action of earthworms and microbial decomposers. In this process all nutrients present in organic wastes are transformed to plant available forms. Earthworms also secret various plant growth hormones along with polysaccharides, proteins and other nitrogenous compounds. Vermicompost, therefore, improves aeration, soil structure, nutrient availability, water holding capacity, ground biodiversity and nutrient efficiency, enhancing germination, growth and yield of crops. As compaired to farm yard manure, vermicompost contains 40 to 60% higher levels of humic substances and is superior in quality than conventional composts. The effect of humic substances is more prominent in stimulating root respiration, formation and growth, which in turn improves upper growth including the shoots, leaves, flowers and fruits (Theunissen et al., 2010).

Municipal solid wastes (MSW), the wastes generated in municipality area, are complex heterogenous in nature due to its collection from different places like residence, markets, institutes, hotels, etc., together before disposal. As per Hazardous waste (Management & Handling) Rules, 1989 and Bio medical wastes (Management & Handling) Rules, 1998, the industrial wastes generated in various factories and biomedical wastes generated in hospitals and nursing homes should not be dumped in MSW collection site as disposal process for those wastes are different as directed by Government of India in those rules. But those wastes produced by smaller units are discarded in street dustbin, which make disposal problematic.

Vermicomposting is the rapid aerobic non-thermophilic composting technique for decomposition of various biodegradable wastes using epigeic earthworms in comparison to other conventional pit or heap composting techniques. Earthworms fragment the half decomposed organic material, mix and promote microbial activity. Worm utilizes 5-10% of food for its body growth and excretes remaining portion as vermicompost. The action of earthworm is both mechanical and biochemical. Mechanical fragmentation of the half decomposed organic material to finer particles by earthworm in its gizzard helps to increase surface area of action by microbes and aeration inside bed. Biochemical action improves the enzymatic digestion, nutrient enrichment and change in organic and inorganic contents.

Composting means decomposing organic wastes. It is a safe, non-polluting and microbiological method for disposal and recycle of organic wastes by converting those to balanced plant food materials, commonly known as compost, the organic fertilizer. In other words, the mineralization and partial humifi cation of organic materials by the action of microorganisms under suitable condition is called composting (Figure 6.1). The organic wastes undergo different physical and chemical changes with the help of microbes like bacteria, fungi, actinomycetes, etc. During composting the population of pathogenic microorganism reduces while that of benefi cial microorganism increases.

Production of any selected species of earthworm in a particular place adopting semi-natural condition is called vermiculturing. As discussed earlier in chapter 2 and 4, commercial production of certain earthworm species is essential to meet up the huge demand of earthworms for vermicomposting of organic wastes, for production of earthworm meal for pet animals, poultry and fish farming, for preparation of medicine and for their use in reducing toxic chemicals from soil and water, etc. Since during vermicomposting, earthworm multiplies in vermicompost beds, many people confuse between this two terms – vermiculturing and vermicomposing.

Even though the great Indian author Surpala mentioned in his epic ‘Vriksha ayurveda’ (Science of Tree growing) about the value of incorporation of earthworms in soil for better propagation of pomegranate plants in 10th century AD, but Sir Charles Darwin’s recognition to earthworms as ‘Farmer’s friends’ in 1837 in fact, inspired researchers throughout the world to study the role of earthworms in soil ecosystem.

Earthworms are defined as soft, bilaterally symmetrical, tubular segmented worms which contain clitella gland, prostomium lobe in front of mouth and anus at the posterior end. The entire body is divided externally into a series of distinct segments. Scientifically these terrestrial worms are classified under phylum ‘Annelida’ due to presence of annuli or ring segments and class ‘Oligochaeta’ due to presence of few setae or hair like structure on all segments except the first and last ones.

Solid wastes, the unavoidable consequences of civilization, are the useless and unwanted heterogeneous solid materials discarded by human being. Human greed is the major factor in creation of unwanted solid wastes. With increase in human population and its demands, there is an increase in production of various types of wastes. When human being did not come to the earth there was very little wastes like tree leaves, animal excreta or dead parts which nature used to digest and produces something beautiful every time. Still there are certain remote areas free from wastes where human being could not reach due to inaccessible condition of terrain, forests and islands. Now–a-days wastes are found even in the top of Mt. Everest or in the interior of Antarctica.

The importance of earthworms in agriculture and human health has been realized since prehistoric times. The famous Greek philosopher, Aristotle (384-322 B.C.) first described the importance of earthworm by calling them as “The intestines of the Earth”. The question, ‘How lime and charcoal from soil surface gets into lower layers?’ in the mind of Sir Charles Darwin (1809-1882 A.D.) ended up with the findings in 1837 that earthworms took those materials to lower layers and it played a significant role in formation of humified soil layer. He wrote in his book, “The formation of vegetable mould through the actions of worms” in 1881 that ‘The plough is one of the most ancient and most valuable of man’s inventions; but long before he existed the land was in fact regularly ploughed, and still continues to be thus ploughed by earthworms.

India, the second most populous country in the world after China, is trying hard to provide basic needs like food, shelter, clothes, electricity and education facility to its 1,316 million people and to upgrade itself from the stage of ‘Developing economy’ to ‘Developed economy’. Table 1.1 depicts the trend of population increase from 1154 million to 1316 million during 2009 to 2018 with diminishing growth rate from 1.42% to 1.12%. Growing demand of ever increasing population has been met so far by over exploiting natural resources like land, water, fossil fuels, forests and mineral resources which resulted rapid unplanned urbanization, quick depletion of fossil fuels, more and more waste generation, alarming increase in environmental pollution, deforestation with loss of plant and animal species, desertification of cultivable land due to soil erosion, soil contamination & soil salinity and increase in health diseases due to malnutrition, starvation and environmental pollution.

Introduction

The impacts on the various facets of life – agriculture and food processing – need no longer be addressed in a way that is well established. Nearly every aspect of the planet has shown its effect at different rates, both positively and negatively. As a subtropical region, India is also witnessing different variations in weather and an increase in temperature that affect farming. Only in recent years has the potential to reduce transpiration from plants by the use of chemicals been further explored. These antitranspirants can either control perspiration by filming the leaf surface or by manipulating the aperture of the stomach. Antitranspirants are the materials or chemicals that reduce the water loss from plant leaves by reducing stomata size and number. During transpiration, almost 99 per cent of the water consumed by the plant is lost.

Introduction

The state of Odisha highly depends on rainfall for the agricultural production. But rainfall distribution is very erratic and uneven which result heavy floods and droughts in different pockets of the state. Thus, the agricultural production is very unstable. It is present in the eastern region of India which is again located in the subtropical belt of medium pressure. Here hot and dry summer welcomes wet humid monsoon which last about few months. Charming autumn and with short and mild winter entertain the human life. But here climate is characterized by high temperature and medium rainfall. Topography however modifies the local climate greatly. The four meteorological seasons prevailing in the state which are: winter (January to February), pre-monsoon season (March to May), south-west monsoon season (June to September) and north east monsoon season (October-December).

Introduction

Seasonal or annual fluctuation in weather patterns is termed as climate variability. However, climate change is a change in the mean state of weather statistic over three decades of time period. Climate change is exacerbating the challenges faced by the agriculture as well as horticulture sector. For last 10 years, Asia is facing the serious threats from climate change and variability such as tsunami, f loods and droughts. Extreme events are expected to have large negative impacts on crop productivity. The rise in temperature and reduction in rainfall under semi-arid environments are likely to reduce production of fruits, vegetables and flowers in the coming 20 years. The production and quality of fresh fruit and vegetable crops can be directly and indirectly affected by exposure to high temperatures and elevated levels of carbon dioxide and ozone. The rise in atmospheric CO2 levels due to global climate change and horticultural practices has both direct and indirect effects on secondary metabolite synthesis in plants.

Introduction Soil ecosystems are the foundation of human life support systems. Soil erosion, loss of soil organic matter and nutrient depletion are among the leading contributors to impaired soil health, reduced crop yields and poverty. Realizing the significant role that soils play in food and environmental security and in abating climate change, the United Nations declared 2015 as the Year of Soils. The International Union of Soil Sciences (IUSS), in 2002, proposed to observe the 5th December as “World Soil Day” [WSD] to create awareness among all stakeholders on the importance of soil as a critical component of the natural system and as a vital contributor to human commonwealth through its contribution to food, water and energy security and as a mitigation of biodiversity loss and climate change. These occasions remind all stakeholders associated with agriculture all over the world to put in all efforts to promote scientific management of soil resources for soil protection, conservation and sustainable productivity.

Agricultural production system has gone a long way in supporting the world’s food requirement. The projected estimates revealed that to meet the global population of about 11.3 billion in 2050, the global demand for cereal will increase by 60% (Rosegrant and Cline, 2003, Bengtsson et al., 2006). Agriculture is considered as the chief agent of environmental transformation. The unrestrained attitude of Homo sapiens towards the use of natural resource catalyzing the causes leading to global warming, has increased the challenges manifold to provide food security in a sustainable manner. Increased concentration of CO2 and other green house gases have resulted in an increase of 0.760 C in surface temperature globally since nineteenth century and the mean global surface temperature is predicted to increase by an additional 1.30C to 1.80C by 2050( IPCC, 2007). Sinha and Swaminathan (1991) reported that an increase of 20C in temperature could decrease the rice yield by about 0.75 t/ha in the high yield areas and a 0.5oC increase in winter temperature would reduce wheat yield 0.45 t/ha.

Introduction

Agriculture and allied sectors have always been the backbone of the Indian economy and despite concerted industrialization in the last six decades agriculture still occupies a place of pride. The significance of agriculture in the national economy arises from the role it plays in India’s national income, employment generation and export earnings; this can be seen from the provisional estimate on contribution of various sectors to the GDP in the f irst quarter of 2020-21, particularly during COVID-19 pandemic, positive percentage change (+3.4) over previous year when all other sectors have negative change.