eChapters

1.1 Forest Resources

Forest resources usually provide the raw materials for homes, workplaces, the books and newspapers, and the packaging that contains food and other products of our labor. Forest ecosystems supply our water, maintain our climate, and help purify the air, protect soils, and provide for wilderness experiences. Forests provide habitat for wildlife, and serve as preserves of biological diversity. Forests are sources of food, fuel and medicine for people all over the world. Forests shape the recreational landscape, help stabilize our farms, and enhance our cities.

About 30 per cent of the world’s total land areas are covered by forest with the area of 3.9 billion hectares. Nearly 47 percent of the world’s forests are in the tropics, 33 percent in the boreal zone, 11 percent in the temperate zones, and 9 percent in sub-tropical areas. The 94 million hectares of forest lost over the ten-year period, represented about 2 per cent of the world’s total forest cover, or an area larger than Venezuela. Two thirds of the world’s forests are located in ten countries: the Russian Federation, Brazil, Canada, the United States, China, Australia, the Democratic Republic of the Congo, Indonesia, Angola and Peru. Most of the deforestation work was performed in natural tropical forests, which lost 14.2 million hectares a year over the last decade. Africa and South America have suffered the most deforestation.

Africa was the region with the highest deforestation in the world, which lost 5.3 million hectares of forest per year in the 1990s. Forests are a major factor in the climate change issue. Forest ecosystems contain more than half of all terrestrial carbon, and account for about 80 per cent of the exchange of carbon between terrestrial ecosystems and the atmosphere. Deforestation in the 1980s may have accounted for a quarter of all human-induced carbon emissions, the second greatest emitter after fossil fuels. Forest plantations comprise 5 percent of the world’s forests. Asia has the largest area of plantations, accounting for 62 per cent of the world total. China accounts for 24 percent of that total and India, 18 per cent. Plantations supply about 35 percent of the world’s round wood. The area of forest plantations increased by an average of 3 to 4 million hectares per year during the 1990s. Half of this increase was the result of afforestation on land previously under non-forest land use, whereas the other half resulted from conversion of natural forest. There are reports that 12 percent of the world’s forests, or about 480 million hectares, are in protected areas.

2.1 Ecosystem

An ecosystem can be defined as a dynamic entity composed of a biological community and its associated abiotic environment. Often the dynamic interactions that occur within an ecosystem are numerous and complex. Ecosystems are also always undergoing changes or alterations to their biotic and abiotic components. Some of these alterations begin first with a change in the state of one component of the ecosystem which then cascades and sometimes amplifies into other components because of relationships.

The human activities of various kinds have resulted in caused a number of dramatic changes to a variety of ecosystems found on the Earth. Humans use and modify natural ecosystems through agriculture, forestry, recreation, urbanization, and industry. The most obvious impact of humans on ecosystems is the loss of biodiversity. The number of extinctions caused by human domination of ecosystems has been steadily increasing since the start of the Industrial revolution. The frequency of species extinctions is correlated to the size of human population on the Earth which is directly related to resource consumption, land-use change, and environmental degradation. Other human impacts to ecosystems include species invasions to new habitats, changes to the abundance and dominance of species in communities, modification of biogeochemical, and modification of hydrologic cycling, pollution, and climatic change.

3.1 Air Pollution

Air pollution is a phenomenon by which particles either a solid or liquid and gases contaminate the environment. Such contamination can result in health effects on the population, which might be either chronic arising especially from long-term exposure or acute due to accidents. Other effects of pollution may be damage to materials, agricultural damage namely reduced crop yields and tree growth, impairment of visibility namely tiny particles scatter light very efficiently, and even climate change global warming.

3.1.1 Classification of Air Pollutants

Air Pollutants are classified as Natural as well as Anthropogenic. Natural pollutants are those that are found in nature or are emitted from natural sources. For example, volcanic activity produces sulfur dioxide, and particulate pollution may derive from forest fires or windblown dust. Anthropogenic pollutants are those that are produced by humans or controlled processes. For example, sulfur dioxide is produced by fossil fuel combustion and particulate matter comes from diesel engines.

Air pollutants are further classified as primary or secondary. Primary pollutants are those that are emitted directly into the atmosphere from an identifiable source. Examples include carbon monoxide and sulfur dioxide. Secondary pollutants are those that are produced in the atmosphere by chemical and physical processes from primary pollutants and natural constituents. For example, ozone is produced by hydrocarbons and oxides of nitrogen (both of which may be produced by car emissions) and sunlight.

4.1 Urban Issues

(i) Water Problem

The world’s population is increasingly found in the cities. Now a days, throughout the developing world, urbanization trends are gaining speed and are irreversible. From a technical standpoint, it is easier to provide water and sanitation services to people living closer together in urban settings than in dispersed rural communities. However, the costs of meeting the needs are much higher per capita, and are growing. The health risks posed by the lack of sanitation increase exponentially as densities increase and as people share drinking water and sanitation resources.

The urban environmental sanitation crisis in developing countries is taking a large health, economic, and environmental toll on all city residents. Willingness to pay for basic water and sanitation services is often high in peri- urban neighbourhoods, provided that services are appropriate, effective, and affordable. The use of a strategic sanitation approach should helps to build capacity within implementing agencies and enhances the ability of communities to make sustainable sanitation improvements.

(ii) Energy Problem

Energy is basic to development. Modern energy services are powerful engine of economic and social opportunity: no country has managed to develop much beyond a subsistence economy without ensuring at least minimum access to energy services for a broad section of its population. It is not surprising to find, therefore, that the billion who live in developing countries attach a high priority to energy services. On average, these people spend nearly 12% of their income on energy. At the same time, the provision of energy services especially through the combustion of fossil fuels and biomass can create adverse environmental effects. In rich countries, much attention is directed to the regional and global consequences of fuel combustion, because many of the local effects have been controlled at considerable expense over the past half- century. In developing countries, the local environmental problems associated with energy use remain matters of concern that are as, or even more, urgent than they were in industrialized countries 50 or 100 years ago. Further, it is the poor who suffer most severely from such problems, because it is they who are forced to rely upon the most inefficient and polluting sources of energy services for lack of access to better alternatives.

5.1 Population Growth

In 2000, the world had 6.1 billion human inhabitants. This figure may rise to more than 9 billion in the next 50 years. For the last 50 years, world population multiplied more rapidly than ever before, and more rapidly than it will ever grow in the future. Anthropologists believe the human species dates back at least 3 million years. For most of our history, these distant ancestors lived a precarious existence as hunters and gatherers. This way of life kept their total numbers small, probably less than 10 million. However, as agriculture was introduced, communities evolved that could support more people.

World population expanded to about 300 million by A.D. 1 and continued to grow at a moderate rate. But after the start of the Industrial Revolution in the 18th century, living standards rose and widespread famines and epidemics diminished in some regions. Population growth accelerated. The population climbed to about 760 million in 1750 and reached 1 billion around 1800.

In 1800, the vast majority of the world’s population (86 percent) resided in Asia and Europe, with 65 percent in Asia alone. By 1900, Europe’s share of world population had risen to 25 percent, fueled by the population increase that accompanied the Industrial Revolution. Some of this growth spilled over to the Americas, increasing their share of the world total. The 2000 growth rate of 1.4 percent, when applied to the world’s 6.1 billion population, yields an annual increase of about 85 million people. Because of the large and increasing population size, the number of people added to the global population will remain high for several decades, even as growth rates continue to decline.

Between 2000 and 2030, nearly 100 percent of this annual growth will occur in the less developed countries in Africa, Asia, and Latin America, whose population growth rates are much higher than those in more developed countries.

In today’s times, a lot of innovation has come into agriculture. This very hard occupation requires an amalgation of farmers with the scientists. From the rural areas after education the technocrats are moving to the cities and this is creating a great loss to the agriculturists. As the population is growing so is the demand for food. Due to shortage in the storage systems the amount of wastage has increased a lot. It is an important aspect to be looked into. A lot of waste material is seen in the vegetable markets, city markets and near the slums. This causes a lot of pollution and spoils the environment. It is important to know why is it increasing and why the facilities for wastes do not exist.

After the agricultural activities a number of by-products are obtained and these are known as agricultural waste. These include residues of different crops like stalks, straws, leaves, roots, husks and shells. The animal waste is in the form of manure. All these agricultural wastes are free of cost however; they can be utilized as an important resource (Lionel and Arnold, 1931). Agrawal (1998) has mentioned India as the final dumpyard. The wastes obtained from various resources can be converted into heat, steam, charcoal, methanol, ethanol, biofuel, compost, energy, biogas, construction and high valued chemical compounds. Many times these agri-industrial wastes are not completely utilized and either they rot in open areas or are burned in the fields.

3a. Sources and problems of agricultural wastes
3b. Waste Reduction
3c. Waste Treatment
3d. Waste Disposal
3e. Clean Technology

Different Kinds of Agricultural Wastes
Table 1: Common Hazardous Wastes: Community Source

All these methods of utilization and the conversion to useful energies depend on the climate, population density of the area and the basic infrastructure. It is important to work out the market for the products which are produced.
 
Bio-waste management: It needs to take from small actions to the ambitious ones. European Commission proposes to use wastes which could make up to 25% of total energy consumption by 2020. They propose to have directives for the promotion of renewable electricity (Directive 2001/77/EC) and biofuels (Directive 2003/30/EC). The waste production in Europe has gone upto 2 kg per capita per day. Recycling rates are also rising (European Commission, 2017). The Member states must develop a national action plan and outline the national policies to develop existing biomass resources and mobilise new biomass resources for different uses. A European project has studied the amount of renewable energy to be used in 2020. According to them it will be around 195 million tons of oil equivalents (Mton) of biomass which is biodegradable part of MSW. This will be 20% of renewable energy target. It has also been estimated that the amount of bio-energy from the MSW will be 20 Mton, which would account for around 7% of all renewable energy in 2020. This may be available after composting and anaerobic digestion (Atanasiu, 2010).

The possibility of making genetic changes in the laboratory in plants, animals and microbes used in food started almost 10,000 years ago. Along with natural changes taken place during the evolution totally different species have come into existence. This has helped in increased food production with better taste and nutrition. The losses caused by biotic and abiotic stresses from fungi and bacterial pathogens have reduced.

In the Asian and Pacific ‘region, it is China alone which produces the largest quantities of agricultural waste and also crop residues. This is followed by India. From the production of rice, corn and wheat alone 587 million tons of residues are generated per year in China. Maheshwari (2014) has surveyed the proportions of waste that Malaysia generates from the production of rice, palm oil, rubber, coconut and forest products. In Myanmar the crop waste and residues constitute about 4 million tons per year out of which more than half constitutes rice husk.

There is no cereal in the world which has no immense patentability as in maize and that’s why it is called the “Queen of cereals”. It is the world’s leading cereals crop after rice and wheat. It is one of most important cereals of Nepal. At national level, it stands second position after rice in term of area and fourth in term of production after rice, potato and sugarcane. Maize is the most important cereals crop of hill and mid hills of Nepal. It is grown single as well as mixed cropping with millets or legumes or potato. Maize crop in hill is grown as rainfed farming. Generally, farmer of such region does not apply chemical fertilizer but they fertilize the land with organic manures in three seasons viz., rainy, winter and spring season. In rainy season it grown in upland while in spring season in low land. The winter maize is grown in Terai and inner Terai in low land as well as upland.

1.    Kernel type: Dent, Flint, Floury, Waxy, Sweet and Pop corn 
        •    Dent corn (Zea mays indentata Staurt.)
        •    Flint corn (Zea mays indurate Staurt.)
        •    Pop corn (Zea mays everta Staurt.)
        •    Sweet corn (Zea mays saccharata Staurt.)
        •    Flour/soft corn (Zea mays amylacea Staurt.)
        •    Waxy corn (Zea mays ceatina Kulesh)

Maize is a tall, determinate annual C₄ plant varying in height from (1-4) meters producing large, narrow, opposing leaves (about a tenth as wide as they are long), borne alternately along the length of a solid stem. The botanical features of various plant parts are as follows: 

Root

Root system of maize consists of seminal roots, crown or coronal or adventitious or fibrous roots and brace, pop or aerial roots. Seminal roots - which develop from radical and persist for long period. Crown roots developing from the lower nodes of stem below ground level which are the effective and active roots of plant and.  Brace or prop roots, produced by lower two nodes. The roots grow very rapidly and almost equally outwards and downwards. Favorable soils may allow corn root growth up to 60 cm laterally and in depth.

•    A corn plant requires a certain number of growing degree units (GDUs) to reach maturity, regardless of the number of calendar days it takes to accumulate.
•    The relationship of GDU accumulation and corn development, along with utilizing the estimated number of days to reach a certain growth stage, can help predict when important growth stages will occur.
•    Growth stages can be used to help growers make timely applications of herbicides and fungicides. The following information is on corn growth and development from emergence to R6 growth stage.
•    Corn growth stage development can vary according to corn maturity. An early maturing product may produce fewer leaves or develop through growth stages faster than a slower paced late maturing product. This is important to remember when staging corn in relation to accumulated GDUs.

Basic principles of breeding hybrid maize
1. Inbreeding
•    Produce a plant which breeds true
•    Produce uniform plants
•    Increase the homozygosity at all or specific loci in the plant genome
•    We know what inbreeding does and I do not propose to spend people’s money to learn how to reduce corn yield-Hopkins

Germplasm
 
Germplasm of crop may be defined as sum total of hereditary materials, i.e. all alleles of various genes present in a crop species and its wild relatives. The germplasm can be utilized in a breeding programme in following ways:
•    Direct release as a variety
•    It may be subjected to selection for developing a variety
•    It may be used as one of parents in hybridization programmes

Terminology of experiments
    
Evaluation trials are important in plant breeding where the selected lines are compared with standard varieties. In most cases, it will be necessary to make comparable yield trials under field conditions. In such case, the field becomes the experimental unit. In these cases, the field becomes the experimental unit. It requires the use of small plots and adequately replicated.

Progeny test

Progeny trials involve large numbers of progenies of a family type, such as full-sib, half-sib, or S1 lines. The progenies are evaluated to identify those that may be used to generate synthetic or experimental varieties, or recombined to form an improved population in a recurrent selection program. Progenies in the trials are normally a random sample from the particular population under study. Therefore, data obtained from progeny trials may be used to estimate genetic variances and covariances from which heritability estimates, predicted responses to selection, genetic correlation coefficients, and correlated responses to selection may be obtained. Progeny trials are normally researcher-managed. Progeny trials involve complex field designs, such as balanced incomplete block, lattice, and alpha-lattice. Some examples of lattice are 11 × 11 for 121 progenies, 14 ×14, 16 × 16, etc. Because of the large number of entries, single-row plots with only 2–3 replications in a few environments are used in progeny trials.

Formation of a Rectangle

Experiments are usually laid out in square or rectangular plots for data and yield estimation, even though the field may be irregular. The plot is usually placed on the contour, parallel with a road, or in a north-and-south alignment. To mark a plot, construct a right angle and then form a rectangle or square.

Characteristics of a well-planned experiment
 
•    The treatments, design, management, and data collected should be consistent with the objectives.
•    The experiment should be planned and conducted so that there will be a high probability of measuring differences between treatments with an acceptable degree of precision. 
•    The experiment must be planned and executed to ensure that treatment effects are estimated in an unbiased way.

Introduction
Project title:
Objective (S):

Plant diseases are of paramount importance to humans because they damage plants and plant products on which humans depends for food, clothing, furniture, the environment and in many cases the housing. The kinds and amounts of losses caused by plant diseases vary with the plant or plant products, the pathogen, the locality, the environment, the control measures practiced and combination of these factors (Agrios, 2005). Disease is one of the major biotic constraints to reduce crop yield and also deteriorate the quality of product that ultimately reduce the market price.

Biometric observations

The phenological stages i.e. germination, tasseling, silking, and physiological maturity were recorded from fixed mid three rows of each plot. A particular stage was supposed to be completed while 90% of the observed plant showed the characteristics of that phase and number of days was counted from date of sowing.

Days to emergence (DOE)
 
When the plant shoot pokes through the soil surface. Count the 75% seedlings emerged from at least 50% of the total rows starting from the centre. If 75% of the total expected seedlings emerged, then can be considered as 75% emergence. How the growth stages of maize are distinguished can be observed from the chart below.

Hypothesis: A statement about the value of a population parameter developed for the purpose of testing.

Type I and Type II Errors

•    Type I Error: Rejecting the null hypothesis when it should not be rejected.
    •    Therefore accepting the alternative hypothesis (your theory) when you should not.
    •    Probability of a Type I error is called a.
•    Type II Error: Failing to reject the null hypothesis when it should be rejected.
    •    Therefore not accepting the alternative hypothesis (your theory). Opportunity loss.
    •    Probability of a Type I error is called b.
•    Minimizing Type I errors is the main concern of hypothesis testing