eChapters

A watershed is an area that provides pathway to the surface or sub surface water flow to a given drainage system. The watershed is a hydrological unit. The area of watershed may vary from few hectares to thousands of square kilometres. The watershed development involves effective management of land and vegetation in order to conserve and improve the quantity of water. The watershed development is a comprehensive and sustainable solution to water conservation (Fig.13.1).
The watershed development has several advantages. It helps in
• Conservation, upgradation and utilization of natural resources particularly land, water and vegetation
• Minimise the inequalities between rainfed and irrigated areas
• Promoting cost effective adoptable simple technologies
• Supply water for domestic ,agricultural and industrial use
• Poverty alleviation and employment generation
• Reducing chemical pollution
• Adopting flood control measures by constructing water storage or impounding structures

Agriculture is world’s single largest employer and probably the most weather dependent of all human activities.  Climate and its variability have been and continue to be, the principal source of fluctuations in global food production. Throughout history, extreames of heat and cold, droughts and floods, and various form of violent weather have wretched havoc on the global agricultural production. With the unprecedented increase in population over past few decades, clearly the mankind faces undertaking task to ensure food and nutritional security for all, considering reduced per capita land, reduced availability of water, depleting biodiversity and need to preserve ecology and environment. In India, of the total geographical area of 328 m ha, about 175 m ha (53 % of total) are categorized as degraded land, of which 150 m ha are subjected to serious water and wind erosion (Singh et al. 1981). Crops are sown in about 180 m ha annually. Since it seems very much impossible to bring more area under cultivation we need to achieve greater efficiency in the natural resources use while conserving the environment by placing greater emphasis on understanding and exploiting climatic resources for the benefits of agriculture.

As we conclude this comprehensive review of the complex relationships between weather, crop diseases, and disease management, it is essential to reflect on the current state of knowledge and identify areas that require further research and attention. The preceding chapters have highlighted the significant impacts of weather factors on crop diseases, emphasizing the need for a deeper understanding of these relationships to develop effective disease management strategies. Significant work particularly on effects of different weather combinations on pathogen population and disease severity needs to be addressed well in time. Despite significant advances in our understanding of the weather-crop disease nexus, there remain substantial knowledge gaps that hinder our ability to predict and manage disease outbreaks effectively. For instance, the complex interactions between weather factors, crop physiology, and disease development are not yet fully understood, making it challenging to develop accurate predictive models. Furthermore, the impacts of climate change on weather patterns and crop diseases are still being researched, and more work is needed to understand these relationships fully. To address these knowledge gaps and improve our understanding of the weather-crop disease nexus, several action plans are required. Firstly, continued research is needed to elucidate the complex relationships between weather factors, crop physiology, and disease development. This research should focus on developing a deeper understanding of the underlying mechanisms driving these relationships, as well as identifying key weather thresholds that trigger disease outbreaks. Secondly, the development of accurate predictive models that can forecast disease outbreaks based on weather data is critical. These models should be able to account for the complex interactions between weather factors, crop physiology, and disease development, as well as incorporate data from multiple sources, including weather stations, satellite imagery, and field observations. Thirdly, there is a need for more effective communication and collaboration between researchers, policymakers, and farmers to ensure that research findings are translated into practical disease management strategies. This will require the development of user-friendly decision support tools that can provide farmers with timely and accurate advice on disease management, based on weather forecasts and other relevant data. Finally, addressing the impacts of climate change on weather patterns and crop diseases will require a coordinated effort from researchers, policymakers, and

The march of weather factors during crop period is never smooth and regular. Agriculture, because of its dependance on climate is inevitably subjected to unpredictable long and short term fluctuation characteristic of atmosphere conditions. Climate introduces an element of risk in farming which makes it particularly hazardous occupation.

A Weather hazard in this context can be defined as any type of extreme weather condition that can damage the crops and animals leading to abnormal decrease in production and income. The extent to which these hazards create risk depends on the time of occurrence, intensity and duration of the hazard besides the age, stage of development and inherent resistance of the crop or livestock involved. Major abnormalities affecting the crop production are:

Agriculture, the cultivation of life that sustains human civilization, is profoundly intertwined with the rhythms of the natural world. Of all the environmental factors that influence farming, weather reigns supreme, orchestrating a complex symphony of elements that dictate the success or failure of crops. This chapter delves into the intricate relationship between weather and agriculture, exploring how temperature, precipitation, sunlight, and other atmospheric conditions shape every facet of agricultural production.
Weather’s influence begins with the very first stage of a plant’s life. Temperature governs seed germination and seedling development, while sunlight provides the energy for photosynthesis, the process by which plants convert light energy into chemical energy. The availability of water, dictated by rainfall patterns, is crucial for plant growth and nutrient absorption. Wind patterns can aid in pollination but also cause damage to crops.
Throughout the growing season, weather continues to play a critical role. Optimal temperatures are essential for each stage of plant development, from flowering to fruit production. Adequate rainfall, or irrigation to supplement it, ensures healthy growth and abundant yields.
Extreme weather events, such as droughts, floods, heatwaves, and frosts, can have devastating consequences for agriculture. These events can destroy crops, reduce yields, and disrupt food production, leading to economic losses and food insecurity (Fig. 18.1).

Weather and climate have great influence on farm animal production. The environment in which an animal lives is referred to as its habitat. A habitat includes both biotic (living) and abiotic (nonliving) components of the animals’ environment. Abiotic components of an animal’s environment include temperature, humidity, oxygen, wind, soil composition, day length and elevation. Knowledge of how potential environmental stressors (ambient temperature, humidity, thermal radiation, air speed, etc.) can directly and adversely affect animal performance, health and wellbeing is also required for a successful animal farming. The indirect consequences of weather include their impact on feed quality and availability.

Birds and mammals are warmblooded (endotherms or homeotherms), possessing a thermoregulatory system that maintains a stable body temperature and uniform internal environment (homeostasis) by converting food energy into heat. All metabolic processes generate substantial heat and much of this is retained within the body of homeotherms by insulating layers of fat, feathers or fur. Dairy cattle, like other warmblooded animals, function most efficiently in environments where they can maintain their body temperature at around 38° C. Tissue and cellular metabolism and the underlying biochemical reactions that sustain life and productive functions need body temperature to be maintained within very narrow limits. Relatively small increases in body temperature result in the breakdown of body protein and a significant depression in production.

Climate change, particularly global warming has complex impacts on domestic animal production system affecting feed supply, challenging thermoregulatory mechanism resulting thermal stress, emerging new diseases due to change in epidemiology of diseases and causing many other indirect impacts. So, climate change will have farreaching consequences for dairy and meat production, especially in vulnerable parts of the world where it is vital for nutrition and livelihoods. Due to poor availability of good quality feed and fodders in India, animals are generally maintained on poor quality grasses available in the pastures or are stallfed, mainly on crop residues. India is already deficit in feed and fodder. These shortages would be further aggravated by the adverse effects of global warming on fodder crop production.

Bacterial diseases are a significant threat to human health, agriculture, and the environment. These diseases are caused by pathogenic bacteria that can infect various hosts, including humans, animals, and plants. The severity and spread of bacterial diseases are influenced by various factors, including weather parameters. Weather conditions, such as temperature, humidity, wind, and precipitation, play a crucial role in the development, dissemination, and survival of bacterial pathogens (Fig. 8.1). Fig. 8.1. Bacterial infection on soybean leaves Temperature, for instance, affects the growth and reproduction of bacteria, with optimal temperatures varying among different species. High temperatures can accelerate the growth of some bacteria, while low temperatures can slow it down or even kill them, however every pathogenic bacterium have its own weather window. For example, a daytime temperature of 35°C and nighttime temperatures of 27°C are most favorable for Xanthomonas oryzae infecting rice. Similarly, humidity influences the survival and dissemination of bacteria, with high humidity favoring the growth and spread of many bacterial pathogens. For example, lower soil moisture decreases the chances of infection of Ralstonia solanacearum in tomato plants. Wind and precipitation also impact the spread of bacterial diseases. Wind can disperse bacterial spores and cells, allowing them to reach new areas and infect new hosts. Precipitation, on the other hand, can influence the availability of moisture, which is essential for the growth and survival of many bacterial

Agriculture is the backbone of human civilization, providing food, fiber, and livelihoods for billions of people around the world. Crop yields, which are a critical component of agricultural productivity, are influenced by a complex array of factors, including genetics, soil quality, water availability, and management practices. However, among these factors, weather and climate stand out as two of the most significant drivers of crop yields.
Weather and climate are intimately linked, with weather referring to short-term atmospheric conditions, such as temperature, precipitation, and wind, and climate describing the long-term average atmospheric conditions in a particular region. Together, they form a dynamic duo that shapes the fate of crops, influencing their growth, development, and productivity.
The impact of weather and climate on crop yields is multifaceted. Weather events, such as droughts, floods, and heat waves, can have devastating effects on crops, leading to reduced yields, lower quality produce, and even complete crop failures. Climate, on the other hand, influences the overall growing conditions, determining the suitability of a region for specific crops and the timing of planting, growth, and harvest.
Understanding the complex interplay between weather, climate, and crop yields is crucial for ensuring food security, improving agricultural productivity, and promoting sustainable farming practices. This chapter aims to explore the intricate relationships between weather, climate, and crop yields, examining the ways in which these factors interact and influence each other. By delving into the latest research and findings, this chapter will provide insights into the following key topics:
The impact of weather events, such as extreme temperatures, precipitation, and wind, on crop yields
• The influence of climate on crop growth, development, and productivity
• The role of climate change in altering weather patterns and crop yields
• Strategies for mitigating the negative impacts of weather and climate on crop yields, such as climate-smart agriculture and weather-based crop insurance

In climatology, terms “Weather” and “Climate” have different connotations. Weather refers to the state of atmosphere at any given time denoting the short- term variations of atmosphere in terms of temperature, pressure, wind, moisture, cloudiness, precipitation and visibility. Weather is highly variable. It is constantly changing, sometimes from hour to hour and at other times from day to day. The aforementioned properties of the atmosphere are subject to constant change and their state at any time determines the state of the weather. However, weather elements are not separate rather they are closely related with each other.

David I. Blumenstock, an eminent climatologist has defined the weather in more restrictive sense. According to him, weather is the behaviour of the lower atmosphere with particular emphasis on the atmospheric behaviour which affect the lands and oceans and have a marked influence on the organisms that live upon the lands, within the waters of the earth or in the lower air. For the geographer, this definition of weather is more satisfactory. Since, he is interested more in the working of the lower atmosphere which affects the life of man as well as natural environment directly. Thus, we come across a great many varieties of weather covering a wide range of conditions.

INTRODUCTION

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

Many diseases, nematodes, insects and weeds affect crop production, causing severe yield loss. Weather is the most important factor that determines the geographical distribution of these crop pests. The local weather patterns have a significant impact on the abundance of diseases and insect pests in the crops. The severity of disease and pest development depends on the combination of weather conditions during the growing season and is variable from season to season. The weather conditions include temperature (both the maximum and the minimum), light, rain, humidity, dew, cloudiness, sunshine, wind, air currents, evaporation, snow and atmospheric pressure. However, among these weather parameters, temperature and humidity play the major roles in infection of crops due to insect pests and diseases.

Fungal diseases are a significant threat to crop health and productivity worldwide, causing substantial economic losses and compromising food security. The development and spread of fungal diseases are influenced by a complex array of factors, including crop susceptibility, pathogen virulence, and environmental conditions. Among these environmental factors, weather plays a critical role in determining the severity and impact of fungal diseases on crops. Weather conditions, such as temperature, humidity, precipitation, and wind, can significantly affect the life cycle of fungal pathogens, including spore production, dispersal, and infection. For example, high temperatures and dry conditions can inhibit the growth and development of some fungal pathogens, while cool and wet conditions can favor their development and spread. Similarly, wind and precipitation can facilitate the dispersal of fungal spores, leading to the rapid spread of disease (Fig. 7.1). Understanding the impact of weather on fungal diseases is essential for developing effective disease management strategies. By recognizing the weather conditions that favor or inhibit the development of fungal diseases, farmers and crop managers can take proactive measures to prevent or mitigate disease outbreaks. This may involve adjusting planting dates, irrigation schedules, and fungicide applications to minimize the risk of disease. Furthermore, knowledge of the weather effects on fungal diseases can also inform the development of more accurate and reliable disease forecasting systems.

Coffee is grown at higher elevation across the Western Ghats between 750 and 1200 m amsl. It requires a certain degree of shade for its better performance.  The annual rainfall over the coffee growing tracts varies between 1400 and 2600mm, having uni/bi-model rainfall with prolonged dryspell from November to May. It is more so over North of the Western Ghats. The mean annual maximum temperature varies between 24 and 300C while the minimum between 15 and 180C. The difference between maximum and minimum temperatures (temperature range) varies between 5 and 160C across the coffee tract. The ‘Monsooned Malabar Coffee’ is a specialty coffee produced from the erstwhile ‘Malabar Region’. It undergoes certain changes in physical and biochemical characters when the coffee beans are processed during the summer monsoon (June to September). It is processed at Mangalore, located in Coastal Karnataka. The processing location experiences heavy rainfall of more than 1000 mm in July, followed by 950 mm in June and 600 mm in August. Out of 3264 mm of annual rainfall, 2852 mm is received during the monsoon period. It accounts more than 80 per cent of annual rainfall. The maximum temperature during the coffee monsooning period varies between 28 and 30°C while night temperature revolves between 22 and 24°C. Being located in the tropics along the West Coast, the crop processing environment in terms of surface air temperature is relatively uniform and moderate with a characteristic feature of heavy clouds and continuous rainfall during the monsoon period. These monsoon features are more predominant from the middle of June to August during which the coffee beans are subjected to monsooning. The coffee beans
bulge in the process of monsooning and the volume increases significantly due to absorption of atmospheric moisture. It is directly related to the monsoonal wind during which coffee beans are processed. The bulging was less in all the samples processed during monsoon 2003, which varied from 2.1 to 2.7 ml/100 number, while it ranged between 2.7 and 5.8 ml/100 number in the samples processed during monsoon 2004.

Weather parameters, such as temperature, humidity, rainfall, and wind, play a significant role in the epidemiology of viral diseases in crops. Viral diseases, caused by viruses that infect plants, can have devastating effects on crop yields and quality, leading to significant economic losses for farmers and the agricultural industry. The impact of weather parameters on viral diseases is complex and multifaceted. Weather conditions can influence the spread of viruses, the survival and multiplication of virus vectors, and the susceptibility of plants to virus infection (Fig. 9.1). Understanding the relationships between weather parameters and viral diseases is essential for developing effective disease management strategies and mitigating the impacts of viral diseases on crop productivity. Fig. 9.1. Yellow Leaf Curl Viral disease of Tomato Temperature, for example, can affect the replication and transmission of viruses, with optimal temperatures varying depending on the specific virus, its vector and host plant. Humidity and rainfall can influence the spread of viruses by affecting the movement and behavior of virus vectors, such as insects and nematodes. Wind can also play a role in the spread of viruses by dispersing virusinfected pollen and insects. This chapter will explore the effects of weather parameters on viral diseases in crops, with a focus on the relationships between temperature, humidity, rainfall, wind, and viral disease epidemiology. By examining the complex interactions between weather parameters and viral diseases, we can gain a deeper understanding of the factors that contribute to the spread and impact of viral diseases in crops, and develop more effective strategies for managing these diseases.

Abstract

Under Ministry of Earth Sciences, India Meteorological Department has launched District level Agro-meteorological Advisory Services in June 2008. The agro-advisory bulletins containing the forecast on rainfall cloud cover, wind direction and speed aid minimum and maximum temperature with their likely impact on crops are in use twice in a week.

Under normal weather situation, agriculture depends on timely occurrence of rainfall for crop management activities irrespective of different farming situations namely, irrigated and unirrigated agriculture. Changes in temperature and rainfall pattern together with frequent occurrence of extreme weather events are major anticipated threats from the climate change that occurs now around the world. This threat in long run, if not addressed properly, would affect food security of a country. Pratap Narain et al., (2000) observed an increase in moderate and severe drought occurrence numbers in the arid zone of India during last decade (1991-2000) as compared to the earlier decades of the last century. Similarly, Pasupalak (2008) reported daily maximum rainfall of 400.3 mm in the last decade against earlier record of 256.4 mm (1969–78) in a location at Odisha State. Further the inter- annual variation within the decade did increase and also the number of rainy days with very heavy rainfall > 125 mm also found increased in the location against the daily mean rainfall of 20 mm/day in India.

A day may be with heavy rainfall or with bright sunshine or windy or in combination of these. When heavy rainfall continues for more than a week with some system like cyclone, floods may be the result. Similarly, if dry spell continues during a cropping season for more than 15 days, drought would initiate in that region. This is again depending upon the nature of the soil water holding capacity and nature of soils, topography and green cover of that region. In between these two extremes, we have normal season, where we get normal seasonal rainfall during a cropping season. Hence like dress code, in agro-climatology, there are three weather codes, namely floods code, drought code and normal code. The jargon weather code was developed by Dr.M. S Swaminathan in India. Across the countries of the World, if these weather codes occur, the impact would be universal. The strength of adaptation capacity to maneuver these extreme events by the farming community rests with their past experience made for similar situations, financial support and also the technology options that are available from the scientific institutions.

In the preceding chapters, we embarked on a comprehensive journey through the realm of vegetables, covering a wide range of species that belong to different botanical and culinary groups. These chapters provided an indepth exploration of the characteristics, growth habits, and environmental requirements of various vegetables, as well as the effects of weather conditions on their productivity.
However, the diversity of vegetables is vast, and there are several other important species that were not covered in the earlier chapters. These vegetables may be regionally specific, possess unique characteristics, or have distinct environmental requirements. Despite their importance, they have remained outside the scope of our previous discussions.
This chapter aims to fill this knowledge gap by providing an overview of these additional vegetables, with a focus on understanding the impact of weather conditions on their growth, development, and productivity. By examining the effects of temperature, moisture, light, and other environmental factors on these vegetables, we can gain valuable insights into their cultivation requirements and optimize their production.
Through this chapter, we hope to provide a more comprehensive understanding of the vegetable kingdom, highlighting the diversity of species, their environmental requirements, and the strategies for maximizing their yields. By expanding our knowledge of these lesser-covered vegetables, we can promote their cultivation, conservation, and sustainable use, ultimately contributing to global food security and nutrition.

Weather forecasting is the application of science and technology to predict the state of the atmosphere for a given location. Forecasts based on temperature and precipitation is important to agriculture. Agricultural production is highly dependent on weather, climate and water availability, and is adversely affected by weather and climate related disasters. In many developing countries where rainfed agriculture is the norm, a good rainy season means good crop production, enhanced food security and a healthy economy. Farming in many parts of the world, especially in the arid and semiarid regions is risky, because climate is highly variable. A timely seasonal forecast of favourable conditions could permit farmers to adjust cropping patterns and input use in order to benefit fully from these conditions. Under rainfed conditions, even a less reliable, but earlier forecast may be more valuable than an accurate but late forecast.

In about 340 B.C., Aristotle described weather patterns in Meteorologica. Later, Theophrastus compiled a book on weather forecasting, called the Book of Signs. Ancient weather forecasting methods usually relied on observed patterns of events. This experience was accumulated over the generations to produce weather knowledge. However, not all of these predictions prove reliable, and many of them have since been found not to stand up to rigorous statistical testing. Two officers from of British Royal Navy, Francis Beaufort and Robert FitzRoy formed the basis for all of today’s weather forecasting knowledge by middle of 19th century. A terrible storm in 1859 inspired FitzRoy to develop charts to allow predictions to be made, which he called ‘forecasting the weather’, thus coining the term ‘weather forecast’. The ‘Weather Book’ which FitzRoy published in 1863 was far in advance of the scientific opinion of the time. By the early 20th century, scientists had begun to believe that weather forecasting could be predicted based on mathematical methods. Computers were first used to create surface analyses in 1992 and by 1998 digital imagery were used for satellite, radar and surface observations, encompassing nearly every factor of weather interpretation. Modern technology, particularly computers and weather satellites, and the availability of data provided by coordinated meteorological observing networks, has resulted in enormous improvements in the accuracy of weather forecasting.