eChapters

The classification of crop diseases is a fundamental aspect of plant pathology, as it provides a framework for understanding the causes, symptoms, and management of diseases that affect crops. Classification is the process of grouping organisms or diseases into categories based on their shared characteristics, and it is essential for developing effective disease management strategies. Crop diseases can be classified in various ways, including by their causes, symptoms, hosts, and environmental factors. Understanding the classification of crop diseases is crucial for farmers, agricultural professionals, and researchers, as it enables them to identify diseases accurately, select appropriate management strategies, and develop new control methods. One of the primary ways to classify crop diseases is by their causes, which can be broadly categorized into infectious and non-infectious diseases. Infectious diseases are caused by living organisms, such as fungi, bacteria, viruses, and nematodes, while non-infectious diseases are caused by environmental factors, such as temperature, moisture, nutrient deficiencies and some substances toxic to plants. Another way to classify crop diseases is by their symptoms, which can include visible changes in plant growth, color, or texture, as well as reductions in yield or quality. Symptoms can be categorized into different types, such as leaf spots, blights, wilts, and tumors, each of which is associated with specific diseasecausing agents. Classification of crop diseases can also be based on the host plant, with diseases being grouped according to the specific crop or plant species they affect. This type of classification is useful for developing crop-specific disease management strategies. In this chapter, we will explore the different classification systems used for crop diseases, including their causes, symptoms, hosts, and environmental factors. We will also discuss the importance of accurate disease classification for effective disease management and the development of new control methods. The broad classification of crop diseases followed uniformly throughout the world is based on the nature of the causal agent, and it categorizes diseases into two main groups: infectious diseases and non-infectious diseases.
5.1 Infectious diseases
These are caused by living organisms, such as fungi, bacteria, viruses, and nematodes, which can spread from plant to plant. These diseases can be further subdivided into several categories, including:

Droughts are intricate and multifaceted phenomena that can have far-reaching impacts on the environment, economy, and society. The complexity of droughts arises from the interplay of various factors, including climate variability, water availability, land use, and human activities. Given the varying characteristics and consequences of droughts, classification becomes a crucial step in understanding and managing these events. By categorizing droughts based on their severity, duration, and impact, researchers and policymakers can better grasp the intricacies of drought dynamics and develop targeted strategies for mitigation and adaptation. The classification of droughts is necessary for several reasons

Extensive studies have shown that much of the humified material in soil is finely bound to colloidal clay. However, it is uncertain to what proportion of the clay surface in any given soil is coated by organic substances as this will depend on the organic matter content and the type and amount of clay.

The ways in which organic substances are retained in soil are as follows:

1. As insoluble polymeric complexes of humic and fulvic acids.
2. As polymeric complexes of humic and fulvic acids bound together by di- and trivalent cations such as Ca²+, Fe³+ and Al³+.

Organic matter is of immense importance in forming good aggregates in a wide range of soil types, particularly those representing Mollisols, Alfisols, Ultisols and Inceptisols. Organic matter is somewhat less important in the Oxisols where hydrous oxides may play apredominant role. These relationships are depicted in Fig. 13.

Fig. 13.1: Relationship between OM and the formation of soil aggregates

Aggregates do not directly influence plant growth, but they alter the physical and chemical environments in which plant roots grow through their effects on porosity, aeration, moisture retention, etc., when well-irrigated, even fine- textured soils permit adequate exchange of gases with the atmosphere. The polysaccharides of soil have received the greatest attention in producing stable aggregates, but other organic substances bonded to clay through association with Fe or Al may also be involved.

ABSTRACT

Sedimentological studies such as textural, heavy mineral and clay mineralogy have been carried out for Warkalli Formations at Varkala, situated in the southern part of Kerala, India. The X-ray diffraction study reveals that kaolinite is the only clay mineral present in all the samples with trace amounts of gibbsite and goethite. The higher amount of kaolinite and gibbsite indicates warm and humid paleoclimatic conditions. The textural analysis shows that the sediments are moderate to poorly sorted, nearly symmetrical to fine skewed and lepto to mesokurtic in nature. A plot of skewness against sorting shows fluvial trend. The major heavy minerals present in the samples are magnetite, ilmenite, rutile, sillimanite, anatase and zircon. It can be inferred from these studies that these sediments would have been deposited in a lagoon by fluvial action. During that time, the source region has experienced tropical humid climate with mean annual precipitation (MAP) above 200 cm and intensive chemical weathering. Heavy mineral assemblage indicates medium to high grade metamorphic source rocks.

Indian Government has several developmental programmes to promote agriculture and rural sector. It includes Drought Prone Area Program, Antodaya Programme, Integrated Rural Development Programme, Hill Area Development Programme, Desert Development Programme, Intensive Jawahar Rojgar Yojna and Employment Assurance Scheme, Indira AwaasYojna, Integrated Waste Land Development Programme, National Food Security Mission, National Horticulture Mission, etc. Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS) has the main focus to provide guaranteed employment for 100 days in a year to every rural household. Since 2014, the Swachh Bharat Abhiyan has been a major initiative by the Government of India.

One ofthe biggest issues the world is facing today is the lack of clean and pure water. Due to rising water demands, rigid health regulations, and xenobiotic pollutants, traditional wastewater treatment technologies cannot provide safe water. The present era necessitates innovative approaches to wastewater treatment technologies and improved water resource conservation and management materials. By utilizing innovative nanomaterial, nanotechnology guarantees a continuous provision of potable water and contributes to the preservation of water sources. Nanomaterials expedite rapid processes for the purification, conservation, and reuse of wastewater, complementing other enduring industrial methods. 

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

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

We have now started to feel the impacts of climate change, as a threat to our health, directly as heat stress on our bodies, and indirectly as it damages crops, and causes storms, floods and wildfires (IPCC, 2022). People working in fields or factories, or in the open, suffer the most. Buildings are our first defense as we learn to adapt to these changes. Resilient buildings that provide passive cooling can protect us better from heat waves, buildings designed to withstand storms and f loods can provide better shelter, and net-zero buildings that produce and store their own energy can enable critical operations when the electric grid is down.

Introduction

Drylands account for over 40% of the global land surface, or approximately 5.2 billion hectares (de Sherbinin, 2002). They provide home for more than 2 billion people or nearly 40% of the population of the world (White and Nackoney, 2003). Asia alone accounts for about 32% of the World’s drylands. Broadly defined by their modest water supply drylands have many regional names, such as semideserts, grasslands, savannas, steppes, and pampas. Dryland ecosystems are a vital part of the earth’s human and physical environments and play a major role in global biophysical processes. They provide much of the world’s grain and livestock, forming the habitat that supports many vegetable species, fruit trees and micro-organisms. With an exception of Australia and the United States, almost all drylands are situated in developing countries with populations living in extreme poverty. Populations of drylands are frequently some of the poorest in the world. Food security and water availability of these areas has always been unstable due to high variability in both rainfall amounts and intensities and the occurrence of prolonged periods of drought. The increasing pressures caused by the global climate change and massive land-use changes further increase human vulnerability in dry regions. The impacts of climate change in drylands are likely to lead to still larger populations being affected by water scarcity and the risk of declining food security and increase the risk of environmental migrations and violent conflicts caused by the decline of resources, which are important to sustain livelihoods (Barnett and Adger, 2007).

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.

Key facts
        
Agriculture and livestock
    
·    The Intergovernmental Panel on Climate Change (IPCC) defines adaptation as ‘adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities’. The adaptation can be considered as tackling the effects of climate change, whereas mitigation is tackling the cause of climate change such as reducing the sources or enhancing the sinks of greenhouse gases. There could be different types of adaptation such as autonomous (spontaneous) and planned adaptation (policy decision).
    
·    Autonomous adaptation includes altering varieties and/or species those are more appropriate to the altered thermal regime or with increased resistance to heat shock and drought; altering the timing or location of cropping activities; altering fertilizer rates to maintain grain or fruit quality consistent with the climate and altering amounts and timing of irrigation and other water management practices; diversifying income by integrating other farming activities such as livestock raising, integrated agriculture and aquaculture/fish farming; development and use of varieties and species resistant to pests and diseases, wider use of technologies to ‘harvest’ water, conserve soil moisture (e.g. crop residue retention) and to use water more effectively in areas where rainfall is projected to decrease and using seasonal climate forecasting to reduce production risk.

1. Introduction

Agriculture has always been greatly dependent on climate patterns and variations, and is considered to be particularly at risk to the influences of climate change (James et al., 2014). Climate change is manifest in the form of reduction in rainfall and drought experienced in the last decade, pushing the agrarian community into real distress (MSSRF, 2020). To reduce the adverse impact of climate change on agriculture, adaptation is considered a crucial component of any policy response related with agriculture and climate change (Deressa et al., 2009). Adaptation to climate change involves changes in agricultural management practices in response to changes in climate conditions (Akinnagbe and Irohibe, 2014). Having knowledge about climatic adaptation practices by the farming communities would make them better equipped to deal with climate change related challenges (Mwazi&Ndokosho, 2011). Though smallholder cultivators are one of the most vulnerable groups to climate change, efforts to support their adaptation strategies are hindered by the lack of information on how they are experiencing and responding to climate change (Harvey et al., 2018). Senapati (2019) argues that farm households with access to weather-related information and extension agency contact have lesser level of vulnerability to climate change and enhanced adaptive capacity. Kavi Kumar (2009) contends the need to have region specific adaptation measures in farming as the key to address challenges of climate change.

Summary

Water security can be defined as reliable availability of water in sufficient quantity and quality to sustain human health, livelihoods, food (agriculture, fisheries and aquaculture) and the environment (biodiversity and ecosystems). Discharge of chemical and biological pollutants (from agriculture, industry and domestic uses) into rivers and development of engineering infrastructure such as dams and weirs over rivers have modified river ecosystems threatening the global water security, water quality and water dependent biodiversity. Climate change (increase in the intensity and frequency of floods, droughts, bushfire and sea-level rise, ocean acidification, etc.) is an additional stress on water security. There is a need to reduce climate change impacts on water security which can be done via adaptations to climate change. Adaptation is adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. In other words, the adaptation can be considered as, tackling the effects of climate change. Adaptation to climate change in terms of sustainable use of water may include increasing water availability by developing hydro-basins and transferring water from areas in which it is abundant to areas in which there is scarcity, the reduction of water losses, increasing storage capacity by building reservoirs and dams, rainwater harvesting, improvement of water use efficiency, desalination of seawater, water savings (leakage management, metering, retrofitting existing homes with water efficient products in toilets, showers, baths, using energy efficient dishwashers and washing machines), mandatory rainwater tanks in new and old buildings (for toilet flushing, washing clothes, gardens, car washing), use of recycled or reclaimed water for landscape irrigation or to recharge groundwater aquifers, and to meet commercial and industrial water needs.

The State of Kerala under the Humid Tropics is one of the wettest places in the Humid Tropics where annual rainfall is of the order of 3000 mm, ranging from less than 1000 mm to greater than 5000 mm. About 68 per cent of the rainfall is obtained during southwest monsoon while 16 per cent in post monsoon and the rest from summer (14 per cent) and winter rainfall (2 per cent). Bi-model rainfall pattern is noticed towards southern districts due to influence of both southwest and northeast monsoons while uni-model rainfall pattern towards northern districts of Kerala. Coconut productivity is better towards south despite dreaded disease of root-wilt when compared to that of northern districts due to less dryspells during summer. Floods during monsoon adversely affect paddy production in the State while prolonged droughts during summer in the absence of post monsoon rainfall adversely affect plantation crops’ production to a considerable extent. The wetlands in Kerala are rich sources of water during summer and act as sink during monsoon season. Such wetlands are fast declining in Kerala and converted as garden lands. Decreasing wetlands might be one of the reasons for frequent floods and droughts in Kerala in recent years. The forest cover of Kerala also declined from 70 per cent to 24 per cent over a period of one- hundred- and - fifty years due to deforestation and forest fires.

Introduction

We are faced with the dual challenges of Climate change and food insecurity irrespective of the countries and regions across the globe. Asia Pacific region is one of the most climate change vulnerable regions in the world (Prabhakar & Matsumoto, 2010) on account of its relatively higher & dense population depending on climate related sectors and living in climate change vulnerable locations. In particular, the agriculture production system is facing serious repercussions due to increasing weather vagaries since past few decades. Agriculture being highly dependent on climatic condition is like gambling at the hands of erratic rainfall or droughts leading to crop loss on a regular basis in terms of reduced yield, increased pest resurgence and lack of safety net in case of weather based disasters all of which prominently affects the small holder farm families. Indian subcontinent has been facing extreme climatic events since the past decades in form of floods, erratic rainfall, high temperature, shrinking water sources, etc. which have caused deprivation in agriculture in economic and non-economic terms. In a series of researches and studies conducted over the years; the need for enhanced adaptation research and policymaking capacity in developing Asia has been reflected. Hence, adaptation research has to take an important place at global, national and local level.

Climate change and variability are concerns of humankind. The recurrent drought and desertification threaten seriously the livelihood of over 1.2 billion people who depend on land for most of their needs. The global economy has adversely been influenced due to droughts and floods, cold and heat waves, forest fires, landslips and mudslips, icestorms, duststorms, hailstorms, thunder clouds associated with lightning and the sea level rise (Fig. 1). The year 1998 was the warmest and declared as the weather related disaster year, which caused hurricane havoc in Central America and floods in China, India and Bangladesh. Canada and New England in the U.S suffered heavily due to icestorm in January while Turkey, Argentina and Paraguay with floods in June 1998. In contrast, huge crop losses were noticed in Maharashtra (India) due to unseasonal and poor distribution of rainfall during 1997-98. The 1997/1998 El Nino event, the strongest of the last century affected 110 million people and costed the global economy nearly US$ 100 billion. A string of 16 consecutive months saw record high global mean temperature in 1997-98.

Agriculture, the cultivation of plants and rearing of animals for food, fiber, and other products, is intrinsically linked to the Earth’s climate. Temperature, rainfall patterns, and atmospheric composition profoundly influence agricultural productivity and distribution. However, the stability of these climatic conditions is increasingly threatened by climate change, driven primarily by the escalating concentration of greenhouse gases in the atmosphere. This chapter delves into the multifaceted relationship between climate change and agriculture, exploring the ways in which altered climatic conditions affect agricultural practices, productivity, and sustainability. We will examine the impact of rising temperatures, shifting precipitation patterns, and increased frequency of extreme weather events on crop yields, livestock health, and overall agricultural output. Furthermore, the chapter will discuss the implications of these changes for global food security, economic stability, and the livelihoods of millions of people who depend on agriculture. Finally, we will explore strategies for mitigating the adverse effects of climate change on agriculture and enhancing the resilience of agricultural systems in the face of this unprecedented challenge.