eChapters

FOR GROUPED DATA

Objective: The following data shows the marks of students and their frequencies find the standard deviation and its coefficient.

STANDARD DEVIATION AND THEIR COEFFICIENT

The standard deviation is a measure of the spread of scores within a set of data. Usually, we are interested in the standard deviation of a population. However, as we are often presented with data from a sample only, we can estimate the population standard deviation from a sample standard deviation. These two standard deviations - sample and population standard deviations - are calculat- ed differently. In statistics, we are usually presented with having to calculate sample standard deviations.

STANDARD NORMAL DISTRIBUTION

If μ = 0 and σ = 1, the distribution is called the standard normal distribution or the unit normal distribution, and a random variable with that distribution is a standard normal deviate. The approximate test is given by

t TEST FOR PAIRED OBSERVATION

This test is used for testing whether two series of paired observations are gen- erated from the same population on the basis of the difference in their sample means.

t TEST FOR SINGLE MEAN

A t-test is any statistical hypothesis test in which the test statistic follows a Student’s t distribution if the null hypothesis is supported. It can be used to determine if two sets of data are significantly different from each other, and is most commonly applied when the test statistic would follow a normal distribution if the value of a scaling term in the test statistic were known. When the scaling term is unknown and is replaced by an estimate based on the data, the test statistic (under certain conditions) follows a Student’s t distribution.

t TEST FOR TWO SAMPLE MEAN:

Comparison of two sample means  and assumed to have been obtained on the basis of random samples of sizes n₁ and n₂ from the same population which is assumed to be normal.

ABSTRACT

Trace Elements were analysed from water samples collected from bore wells from block 2, 5, 14, 26 and 29 at Neyveli Township. Lead Concentration has crossed the limit of ISI standard prescribed for drinking which is 0.100 ppm. Lead concentration in the order of 0.082 ppm at block 5 and 0.11 ppm in block 29 were observed. Cadmium concentration has also crossed the limit of ISI (0.010 ppm) for drinking purpose, which is 0.02 ppm in block 26. Chromium concentration has also crossed the permissible limit of ISI standards (0.05 ppm) for drinking, which is 0.098 ppm in Block 14.

The above elements when compared with ISI standards for drinking water have shown a slight increase in concentration of lead, cadmium & chromium. Concentration of lead in Neyveli basin may be attributed to basement geochemical sources influenced by physical and chemical weathering. High concentration of chromium and cadmium in the aquifer may be due to anthropogenic activity probably from effluents of closed briqueting & carbonization plant, which is due south of block 14.

INTRODUCTION
The engine of a tractor is often referred to as its heart, as it drives the machine’s ability to carry out essential heavy-duty tasks in farming. As technology progresses and environmental sustainability becomes a key focus, it is increasingly important for Indian farmers in 2025 to understand the workings of tractor engines. This article aims to simplify the intricacies of tractor engines by covering their types, key specifications, performance features, maintenance, and recent innovations.
Tractors typically use diesel engines, which generate mechanical power through the compression and combustion of fuel. These engines are designed with a complex structure that ensures high power output and durability, which are vital qualities for the demanding work tractors are used for. To effectively meet these needs, tractor engines must be both powerful and built to last. These engines function based on the principles of compression and combustion of fuel. Here is a comprehensive analysis of their attributes and significance:
• High force: Tractor engines must produce significant mechanical force to execute diverse agricultural chores such as plowing, tilling, transporting, and other heavy-duty operations. Diesel engines are especially appropriate for this application due to their capacity to generate greater torque at reduced speeds, which is crucial for managing substantial loads.
• Durability: Tractors are frequently employed in severe locations, operating for extended periods under challenging conditions. Diesel engines are designed to endure the demands of continuous operation, making them preferred for agricultural machines. Their durable construction guarantees enduring reliability and longevity.
• Compression and Combustion: Diesel engines operate by compressing air within the engine cylinder. Upon the injection of fuel into this highly

The two-way ANOVA compares the mean differences between groups that have been split on two independent variables (called factors). The primary purpose of a two-way ANOVA is to understand if there is an interaction be- tween the two independent variables on the dependent variable. For example, you could use a two-way ANOVA to understand whether there is an interac- tion between gender and educational level on test anxiety amongst university students, where gender (males/females) and education level (undergraduate/ postgraduate) are your independent variables, and test anxiety is your depen- dent variable. Alternately, you may want to determine whether there is an in- teraction between physical activity level and gender on blood cholesterol con- centration in children, where physical activity (low/moderate/high) and gender (male/female) are your independent variables, and cholesterol concentration is your dependent variable.

The interaction term in a two-way ANOVA informs you whether the effect of one of your independent variables on the dependent variable is the same for all values of your other independent variable (and vice versa). For example, is the effect of gender (male/female) on test anxiety influenced by educational level (undergraduate/postgraduate)? Additionally, if a statistically significant interaction is found, you need to determine whether there are any “simple main effects”, and if there are, what these effects are (we discuss this later in our guide).

Bunding is a traditional yet effective soil conservation method that involves constructing embankments or barriers along land contours to manage water flow and reduce soil erosion. These embankments, known as bunds, are particularly beneficial in semi-arid and erosion-prone areas, where water conservation and soil stability are essential for sustainable agriculture.
Bunds slow down surface runoff, allowing water to infiltrate the soil rather than washing away valuable topsoil. This not only reduces erosion but also improves soil moisture retention and supports crop growth. Bunds can be made from local materials such as soil, stones, or a combination of both.
TYPES OF BUNDING
There are several types of bunding, each with its unique features and benefits. Let’s explore the most common ones:
Contour Bunding
Contour bunding is a well-established soil conservation technique that involves constructing embankments along lines of equal elevation across sloping terrain. These structures, often equated with level terraces, are designed to intercept surface runoff, thereby reducing soil erosion and improving moisture retention in cultivated lands. Originating as a famine relief initiative in Maharashtra, India, contour bunding has since proven to be an effective and sustainable method for preserving agricultural productivity in hilly and semi-arid regions.
This practice is particularly suited to a wide range of permeable soils, including alluvial, red lateritic, shallow and medium black soils, as well as deep black cotton soils. However, challenges such as soil cracking in black cotton soils may compromise bund integrity, necessitating periodic repair and upkeep.

Terrace farming is a widely practiced agricultural method in India, particularly suited for hilly and mountainous areas. It involves shaping the landscape by carving out flat sections—known as terraces—into the slopes of hills or mountains. These levelled surfaces make it easier to cultivate otherwise steep and challenging terrain. This age-old technique, also known as step farming, creates a series of stepped platforms that resemble a staircase along the hillside. The approach is both practical and resourceful, allowing farmers to use sloped land efficiently for crop cultivation.
The primary motivation behind transforming large hill surfaces into terraces— despite the considerable labor it demands—is to control the rapid downhill flow of water that typically occurs in such regions. However, terrace farming comes with its own set of challenges. The soil on terraces often has limited water retentioncapability, and erosion can become more severe. Nutrients and soil particles tend to be washed away into rivers. In addition, if trees are cleared for farming, the land becomes vulnerable to landslides and mudslides during periods of heavy rainfall. Terrace farming is a prevalent agricultural practice in India, especially in regions characterized by hilly or mountainous topography. This method involves the creation of flat, horizontal plots—referred to as terraces—along the natural contours of slopes. These terraces transform steep, uneven land into cultivable platforms, making farming on such terrain more manageable and productive. Also known as step farming due to its resemblance to staircases carved into hillsides, this traditional technique is both efficient and adaptive. It enables the utilization of sloped land that would otherwise be unsuitable for agriculture. The primary reason for undertaking this labor-intensive process is to manage the rapid runoff of water common in elevated terrains. By interrupting the slope, terraces help slow water flow and reduce surface erosion. Nevertheless, terrace farming poses several challenges. The soil tends to have limited capacity to retain moisture, and erosion can still displace vital topsoil and nutrients. Furthermore, deforestation to create terraces can heighten the risk of landslides and mudflows during intense rainfall.

The chi square is a continuous distribution based on the assumption that the ul- timate class frequency is not less than 5 otherwise the value of χ₂ will be over- estimated and may cause too many rejections of null hypothesis. Therefore, to maintain the continuity of χ₂ and to draw the correct inference in 2×2 we apply a correction which is known as Yates’s correction for continuity.

Abstract

Data pertaining to 1761 records on daily milk yield and 1416 milk samples for estimation of fat and SNF percent in Banni buffalo during the year 2008-10 were collected from the breeding tract under In-situ conservation project on Banni buffalo and utilized for present study. The overall means ± SE for daily milk yield was 09.86 ± 0.07 lit. The month-wise daily milk yield was observed highest in second month, followed by 1st (12.96 ± 0.19 lit), 3rd (12.73 ± 0.19 lit), 4th (11.66 ± 0.20 lit), 5th (10.81 ± 0.25 lit), 6th (09.77 ± 0.23 lit), 7th (08.58 ± 0.18 lit), 8th (07.26 ± 0.17 lit), 9th (06.15 ± 0.11 lit), 11th  (05.70 ± 0.10 lit), 10th (05.41 ± 0.09 lit), 12th (05.78 ± 0.08 lit) and 13th  (05.48 ± 0.63 lit) months of lactation. The data on milk constituents’ viz. fat and SNF percent was grouped according to the seasons of the year and morning – evening milking.

Abstract

Conventional wisdom holds that variability in rainfall represents a significant variability of agriculture production. But urbanization of the cities on one hand and climate change on theother hand areaffecting the agriculture. Surprisingly, there have been very few analyses exploring the link between rainfall variability and urbanization on agriculture production. Therefore an attempt is made in this paper to know the affect of rainfall variability and urbanisation on the cropping area. For this purposeNDVI analysis is carried out in the catchments of Osmansagar and Himayathsagar Reservoirs by using the medium to high spatial resolution multi spectral data provided by remote sensing satellites, such as Landsat TM, IRS-1C/1D LISS-III and IRS-P6 LISS-III has been used for the years1989, 1994, 1998, 2002 and 2008 for Kharif season, 1975, 1990, 1994, 1998, 2003 and 2008 for rabi season which is collected from NRSC (National Remote Sensing Centre). From this analysis it is found that the increment is more in rabi season compared to kharif season due to the increment of non-monsoon rainfall intensities and ground water withdrawal structures. The increased utilization of the groundwater is causing the reduction of inflows to the reservoirs in the recent years because whatever the rainfall that occurs in the catchment, first utilised for meeting the depleted soil moisture and ground water consequently reducing the surface runoff.

Keywords : Climate change, Urbanisation, Inflows, Cropping area, NDVI

ABSTRACT

In vitro culture and cryopreservation techniques are complementary to ex situ conservation of plant genetic resources that are vegetatively propagated or having recalcitrant seeds. An in vitro germplasm conservation study has been conducted on Banana passionfruit (Passiflora mollissima), a plant used in rural medicine. Micropropagated plants survived up to 12 weeks in Murashige and Skoog medium supplemented with 0.5% sucrose. Cryopreservation experiments were carried out on the explants (apical and/or axillary buds), pre-treated with vitrification solutions, dimethyl sulphoxide (DMSO) and PVS2 (Plant vitrification solution-2) with or without desiccation treatment and frozen in liquid nitrogen (LN). The survival and regeneration of apical buds were higher than axillary buds when pre-treated with 15% DMSO. Treatment with 20 % PVS2 for 1 h followed by 100 % PVS2 for 20 min gave maximum shoot recovery (40%) from cryopreserved apical buds. Desiccation alone was not successful but combination of pre-treatment of PVS2 (20% for 1h and 100% for 20min) with 3 h desiccation gave 30% plant survival from frozen apical buds. Regenerated shoots were rooted on MS medium with 1.0 mgl-1 naphthalene acetic acid (NAA) and 0.2 % activated charcoal.

Introduction

Cotton is a fiber crop of Malvaceous family. There are four cultivated species of cotton viz. Gossypium arboreum, G. herbaceum, G. hirsutum and G. barbadense out of which G. hirsutum is the predominant species contributing about 90% to the global production. In India all the above four cultivated species are grown on commercial scale as a kharif crop. India is the largest producer as well as consumer of cotton in the world. The major cotton growing states of India are Maharashtra, Punjab, Haryana, Rajasthan, Uttar Pradesh, Madhya Pradesh, Gujarat and parts of Andhra Pradesh & Karnataka. In Odisha cotton cultivation is an up-coming activity. Many of the western belt farmers, mainly from Rayagada, Bolangir, Kalahandi, Nabarangpur, and Nuapara districts have been taking cultivation of this cash crop. According to the report of Odisha economic survey, 2018-19 a total of 1.45 lakh ha area was cultivated in 2017-18 producing 3.65lakh bales of cotton. In Rayagada district cotton is cultivated in 9 blocks out of 11 blocks comprising an area of 35170 ha. For the year 2018-19 yield was 12.37 q/ha with production of 25.6 MT of cotton according to the data given by District agriculture office, Rayagada.

1. Introduction

Milk is the principal source of protein and lactose in the diet. Dairy farming is viewed as a whole ecosystem of reciprocal relationships and reliance, as well as there production and safe guarding of societal values. Dairy farms are primarily made up of high-yielding dairy cows. Goats, sheep, and camels are some of the other animals employed in commercial dairy production. Milk has always been regarded as a healthy food. Milk includes more than9 other essential elements, including protein, carbs,vitamins, minerals, and lipids, in addition to calcium, which makes it critical for your bones.

Every year, about 600 million tonnes of milk are produced by over 264million dairy cows across the world. The global average for milk output per cow is around 2,200 litres. India is the world’s top milk producer followed by the United States, China,Pakistan, and Brazil. The economy of India is mostly dependent on agriculture and animal husbandry, with milk production playing a significant role. It is also the world’s largest producer of buffalo milk (FAO, 2019).

Co-operative dairy sector proved to be resilient as it continued to procuremilk from farmers and supply it to the consumers despite several logistical and other challenges. Milk production in India did not show any sign of slowdown. Milk productionis anticipated to be around 209.96 million tonnes in 2020-21, an increase of about 6.3 percent over the previous year. The estimated per capita availability of milk is expected to increase to about 425 gms /day which is more than the world average of around 315gms/day(NDDB,2020).The dairy co-operatives had a difficult year due to an influx of more milk production, a reduction in milk sales, and the building of inventories of preserved goods. Throughout the year, milk procurement by dairy co-operatives increased as it accepted diverted extra milk from farmers that would otherwise be sold to private and unorganized businesses. During the 2020-21 budget year, milk procurement by dairy co-operativesincreased by 7.9 per cent. Indian dairy co operatives have installed milk processing capacity of 66.3million litters per day,73.3million liters/day in private sector enterprises, and 2.5 million litres per day in producer companies.

Aim

To study the working principle and cleaning efficiency of air-screen seed cleaner cum grader

Apparatus required

Lab model air-screen seed cleaner cum grader

Seed sample

Weighing balance

Introduction
Any species that has been accidentally or purposely brought outside of its current range by humans is considered an introduced (or exotic) species (Kottelat and Whitten, 1996). According to the International Union for Conservation of Nature and Natural Resources (IUCN), an alien species is considered invasive when it establishes itself in natural or semi-natural ecosystems or habitat, causes change, and endangers the biological diversity of the host species. These invasives encompass all classes of living things and are widely dispersed throughout the world's ecosystems (Raghubanshi et al., 2005). Numerous reasons led to the introduction of exotic fish species in various parts of the world: (a) increasing the potential for local fisheries and diversifying species in aquatic systems; (b) promoting sport fishing; (c) maintaining aquariums; and (d) managing undesired organisms like mosquitoes, etc. (Biju Kumar, 2000). Furthermore, floods and a variety of other factors may allow exotic fish imported into one nation to spread to its neighbors. According to Welcome (1988), 168 fish species from 37 families have been introduced worldwide outside of their native area. At least 67 of these species have established themselves in various bodies of water, with 27 of them turning out to be serious pests. Approximately 20 percent of freshwater fish species worldwide are either extinct or in danger of going extinct (Moyle and Leidy, 1992). Over time, the introduction of new species might prove to be a very harmful issue. Nyman (1991) stated that the introduction of alien species may cause the aquatic environment to undergo permanent alterations and perhaps cause the extinction of some species.
As a result, the careless introduction and movement of aquatic species, especially fish, caused much worry across the world since it led to several issues, including the extinction of native species. Fish native to the area compete with exotics for food and habitat. They might kill local fish, bring in new illnesses and parasites, create hybrids, pollute the genetic pool, and lower the standard of the aquatic ecosystems. The loss of priceless biodiversity will result from all of these (Nyman, 1991). Potential hazards include those that might affect not just biodiversity quality or quantity but also the socioeconomic facets of the human society that depend on aquatic environments for survival (Philipp et al., 1995). Introductions are a legitimate way to increase aquaculture and fisheries productivity and economic advantage. Indeed, the primary driving force behind the migration of fish and shellfish across continents and even geographic regions has been aquaculture. To address the growing need for food and nutritional security, exotic species have been used to diversify fisheries and aquaculture. Species introductions and transfers from one hydrographic

This practical assignment is designed in a way that students will acquire knowledge on various development departments in the district, especially on organizational structure, functioning and activities of any agency like District Rural Development Agency (DRDA).

PURPOSE

To get the students acquainted with the organization and functioning of DRDA.

To give the students a brief idea about the organizational structure and functions of other development departments at district level.