eChapters

Large quantities of crop residues are produced and if properly used, they can provide cost effective means for supplying organic matter, plant nutrients and improved soil health. The highly lignocellulosic nature of crop residues indicate their potential role in maintaining soil organic matter and enriching the soils with N-rich microbial biomass resulting from decompositions. However, their indiscriminate handling often burning leads to decline in soil health, air pollution and overall loss. Since most crop residues find use as feed and fuel, efficient recycling of the remaining amount can have very significant
and positive effect.
The data regarding five major crops are shown. Even after use of some of them as animal feed they offer a great opportunity of using them back in to the soils which are hungry for organic carbon and other matters. Practice of Crop Residue Burning
The problem of collection and transport of crop residue and the short timebetween harvesting of one crop and making the farm free for the second crop has led to the harmful practices of crop residue burning. If instead of burning it, the residues can be incorporated into soils, a host of heterotrophic microorganisms bring about minor discharge of carbon and other elements contained in plant residues. A large increases in beneficial soil microbial populations and organic carbon can be achieved

Rice-wheat (RW) is the major cropping system occupying about 10.5 mha in the IGP of India. It contributes more than 60% of the foodgrains to the central pool. With shrinking land resources and burgeoning population, the RW system will be under pressure to produce more grain output per unit area in the coming decades. Meeting this challenging task requires sustainable management of soil, water and plant nutrient resources. High yields of the irrigated RW system result in production of huge quantities of crop residues. Total production of crop residues in Punjab is about 47.2 mt which includes paddy straw, wheat straw, cotton sticks, sugarcane leaves, maize stalk, and other oilseeds and pulse residues (Beri and Gupta, 2003). Wheat and rice straw constitutes more than 70% ofthe crop residues produced in the country. Paddy straw alone constitutes more than 50%. Cotton and sunflower residues are generally used as fuel. Sugarcane trash (leaves) is generally burnt in-situ or used as fuel after collection from the field. Increasing constraints of labour and time have led to the adoption ofmechanized farming in the highly intensive RW cropping system. Approximately 91% ofthe total rice area is mechanically harvested, while 82% of the total wheat area is mechanically harvested. Traditionally, wheat and paddy straws have been removed from the fields for use as cattle feed and for several other purposes such as livestock bedding, thatching material , for houses, and fuel. While more than 80% ofwheat residue is collected by the farmers after combine harvesting and often fed to animals, paddy straw is considered poor feed for animals due to its high silica content.

Substantial loss ofplant nutrients (especially N and S) and organic carbon occurs during burning of crop residues, with important implications to soil health. About 40% of the N, 60-85% of the K, 30-35% of the P, and 40-50% of the S absorbed by rice remains in the vegetative parts at maturity. One tonne of paddy straw contains approximately 6-7 kg of N, 1.0-1.7 kg of P₂O₅ and 14-25 kg K₂O. Apart from huge loss of precious plant nutrients, burning of crop residues depletes soil health. Air pollution from stubble burning also impacts human and animal health both medically, and by traumatic road accidents due to restricted visibility. In view ofthe serious problems associated with the residue burning, new ways are being sought to efficiently utilize the huge amount of surplus residues produced in the country.

11.1 Biomass

Globally, all agricultural countries have promoted the use of biomass sources for many household applications and biomass energy generation. Biomass is defined as the bio residue available from the sum of crop production, agricultural waste, vegetation, forestry waste and organic waste. Biomass is a renewable source of energy and contains a complex mixture of carbon, nitrogen, hydrogen, and oxygen. Various biomass resources are available in different parts of countries and are classified based on their availability. The broad classification of biomass energy is in three formats; residue of agricultural crops, energy plantations, and municipal and industrial waste. Agriculture residues are organic materials produced as the byproduct from processing and harvesting of agriculture crops. 

Indian crop production system excels in front of several biophysical adversities commonly known as biotic and abiotic stress.  Water is the principal factor limiting crop yield and about 2/3 of total cultivated landing India comprise of Dry land agriculture primarily under rainfed conditions with no or limited water supply system.  The Indian production systems are dominated by cereals, primarily rice maize, sorghum, pearl millet other coerces and fine cereals leguminous (urd bean, mung bean, peanut) and oil yielding crops during kharif and  wheat barley chickpea, lentil and forage legumes in rabi  season.  The production systems are generally characterized by cereal/legume mixed-cropping dominated by maize, millet, sorghum and wheat. The major constraints in both regions to crop production are low soil fertility, insecure rainfall, low-productive genotypes, low adoption of improved soil and crop management practices, and lack of appropriate institutional support. choice of crop  is important but selection of right varieties is utmost  important because  varieties which have proven excellent in irrigated or high rainfall areas are generally not suited for limited irrigated conditions.

Introduction

Through the use of both art and science, crop breeding is the process of enhancing significant agricultural plants for the benefit of humanity. Crop breeders attempt to improve the productivity and nutritional value of our food, f iber, pasture, and industrial crops via their efforts. In order to meet the needs of a growing global population with rising dietary demands, crops are essential. Additionally, the activity of crop breeders contributes to the improvement of environmental protection.

Since the beginning of agriculture, farmers have been selecting plants for desirable characteristics such as bigger seeds, more flavourful fruits, and other desirable characteristics. This method is known as plant breeding. In today’s world, the breeding of plants is a collaborative effort between scientists and farmers.

Different techniques are used by plant breeders, depending on the manner of reproduction of crops. This process is known as self-fertilization, and it occurs when pollen from one plant fertilizes the reproductive cells or ovules of another plant. There is a phenomenon known as cross-pollination, in which pollen from one plant can only fertilize another plant. For example, runners from strawberry plants are an example of asexual propagation, in which the new plant is genetically identical to its parent plant. Apomixis, also known as self-cloning, is a process in which seeds are created asexually and their offspring are genetically identical to their parents. When it comes to developing appropriate breeding and selection strategies, the mode of reproduction of a crop is the decisive element. This is because the genetic makeup of the crop is determined by the mode of reproduction. Additionally, it is necessary to have knowledge of the way of reproduction in order to artificially manipulate it in order to produce enhanced varieties. The only breeding and selection strategies that are appropriate for a crop are those that do not disrupt the crop’s natural condition or guarantee that it will remain in that form. The imposition of self fertilization on cross-pollinating crops results in a significant decrease in the performance of such crops for several reasons, including those listed above.

Introduction

The crops, its significance along with its classification has got paramount importance in agricultural heritage. A crop is a plant or animal product that can be grown and harvested in an area with a target to earn profit or achieve subsistence. Crop may refer either to the harvested parts or to the harvest in a more refined state (husked, shelled, etc.). Most crops are cultivated in agriculture or aquaculture.

A crop is usually expanded to include macroscopic fungus (e.g. mushrooms), or alga (alga-culture) at the point of origination. Most crops are harvested as food for humans or livestock (fodder crops) or to get raw materials for agro-based industry. Some crops are gathered from the wild collection (including intensive gathering). The important non-food crops include horticulture, floriculture and industrial crops. Horticulture crops include plants used for other crops (e.g. fruit trees, grown single or in orchard). Floriculture crops include blanket plants, houseplants, flowering garden and pot plants, cut cultivated greens, and cut flowers. Industrial crops are produced for clothing (fiber crops), bio-fuel (energy crops, algae fuel), or medicine (medicinal plants).

Microbes (fungi, bacteria or viruses) are rarely referred to as crops. Animals raised for human or animal consumption are referred to as livestock and microbes as microbiological cultures. Microbes are not typically grown for food itself, but are rather used to alter food (e.g., for production of citric acid, fermenting yogurt, soya sauce and so on). The importance of a crop varies greatly by region. Crop production depends on the availability of arable land and is affected in particular by yields, macroeconomic uncertainty, as well as consumption patterns; it also has a great incidence on agricultural commodities’ prices. The importance of crop production is related to harvested areas, returns per hectare (yields) and quantities produced. Crop yields stands for harvested production per unit of harvested area for the particular crop i.e. products. In most of the cases yield data are not recorded, but are obtained by dividing the production data by the data on area harvested. The actual yield that is captured on farm depends on several factors such as the crop’s genetic potential, the amount of sunlight, water and nutrients absorbed by the crop, the presence of weeds and pests infestation. These indicators are presented for wheat, maize, rice and soybean. Crop production is measured in tons per hectare, in thousand hectares and thousand tons.

Agricultural systems are complex, and understanding this complexity requires systematic research under shrinking agricultural research resources. Field experimentation can only be used to investigate a very limited number of variables under a few site-specific conditions. The crop growth simulation models simulate crop growth, development and yield taking into account the effects of weather, genetics, soil water, carbon and nitrogen, planting, irrigation and fertilizer (e.g. Nitrogen, Phosphorus) management. Ofthe many factors that potentially affect the growth of plants, the two that are most responsive to management are water and nitrogen. It is therefore not surprising that most crop models include routines to handle responses to water and nitrogen. Less frequently do models attempt to describe limitations due to other soil constraints (Probert and Keating, 2000). In the context of integrated nutrient management, the performance of a crop model depends mainly on its ability to adequately describe the release of nutrients from diverse inputs and their uptake by the crop.

Origins and genesis of a crop simulation model

Crop simulation model approach was started near about 50 years ago, in early 1960s when early simple crop models were developed for estimation of transpiration and photosynthesis. The first step towards crop modeling was the development of simple models to estimate light interception and photosynthesis (Loomis and williams, 1963; De wit, 1965 and Duncan et al., 1967). There are many crop growth simulation models. Some are more generic in nature while others are built for specific purposes. Most of these models simulate crop growth and soil processes using daily time steps. All models are developed with some assumptions and hypotheses, and all have strengths, weaknesses and limitations for appropriate application. Well-known crop modelling groups across the world include IBSNAT/IFDC (International Benchmark Sites Network for Agro technology Transfer/International Fertilizer Development Centre) in USA, WAU/AB-DLO (Wageningen Agriculture University/Centre for Agro-biological Research) in the Netherlands, and APSRU (Agriculture Production Systems Research Unit) in Australia. The IBSNAT project was initiated in 1982, and over the past 20 years it has developed more than 15 models, including CERES (Crop Estimation through Resource and Environment Synthesis) Rice and CERES Wheat, which are available either as stand-alone models or within the DSSAT (Decision Support System for Agrotechnology Transfer) shell (Uehara and Tsuji, 1993).

5.1 Introduction

A Crop Simulation Model is a mathematical model which describes crop growth and development processes as a function of environment, soil conditions, and crop management. Simulation model is a schematic representation which works on set of underlying assumptions, equations and algorithms, closely replicating the behaviour of the agricultural systems. A crop growth simulation model predicts the harvestable yield. Apart from this final state of crop production, the model also provides a host of quantitative information about major processes involved in the various stages of crop development. The information covers each component of the crop such as leaves, stems, roots and harvestable products as they change over time, including the changes in soil moisture and nutrient status.

An increase in the population, demands an increase in agricultural production with available resources. Efficient management of available resources under varying weather conditions is important for increasing agricultural productivity. Besides that, the emphasis of agricultural production changes from quantity to quality and sustainability (Aggarwal et al., 2000). Solution of these new challenges lies in understanding the interaction of the numerous elements affecting the plant growth and generating a crop growth model. This extremely complicated information needs to be processed and interpreted on a spatial scale. Information technology which has unleashed new frontiers in data analysis and automation is the driving force behind this model generation. These powerful computer programmes simulate the crop growth or yield of crops under various management regimes and provide near real time information to help farmers to make strategic decision in the management of their crops.

The susceptibility and vulnerability of crops to diseases are critical factors that determine the impact of disease outbreaks on agricultural productivity and food security. Crop diseases can have devastating effects on crop yields, quality, and marketability, resulting in significant economic losses for farmers and the agricultural industry as a whole. The susceptibility of crops to diseases refers to the inherent characteristics of the crop that make it more or less prone to infection by a particular diseasecausing agent. This can include factors such as the crop’s genetic makeup, its physiological state, and its environmental conditions. For example, some crop varieties may have a natural resistance to certain diseases, while others may be more susceptible due to their genetic characteristics. Vulnerability, on the other hand, refers to the degree to which a crop is exposed to disease-causing agents and is unable to withstand or recover from disease outbreaks. This can include factors such as the crop’s location, climate, soil type, and farming practices. For example, crops grown in areas with high disease pressure, inadequate soil moisture, or poor farming practices may be more vulnerable to disease outbreaks. Understanding the susceptibility and vulnerability of crops to diseases is essential for developing effective disease management strategies. By identifying the factors that contribute to a crop’s susceptibility and vulnerability, farmers and agricultural experts can take proactive measures to prevent or mitigate disease outbreaks. This can include using disease-resistant crop varieties, implementing integrated pest management practices, and adopting sustainable agricultural practices that promote soil health and biodiversity. In this chapter, we will explore the concept of susceptibility and vulnerability of crops to diseases in more detail, including the factors that contribute to these phenomena and the strategies that can be used to manage and mitigate disease outbreaks. By understanding the complex interplay between crops, diseases, and environmental factors, we can develop more effective and sustainable approaches to disease management that promote agricultural productivity and food security.
4.1 Factors Determining Susceptibility
The susceptibility of crops to diseases is determined by a complex interplay of factors, including genetic, physiological, and environmental factors. Genetic factors play a crucial role in determining the susceptibility of crops to diseases. Some crop varieties may have a natural resistance to certain diseases, while others

Introduction

The literary meaning of voyage is a long journey by water or air to a distance place. The crop voyage means the introduction of different crops from outside and movement of the crops originated in India to abroad. India is one of the mega agro-biodiversity countries of the world. Many plant species have been domesticated here. The agro-biodiversity of the indigenously domesticated higher plant species was further enriched with introduction of exotic crops since ancient times, as reflected by the presence of American cereals such as maize and amaranths, African cereals such as pear millet and sorghum, West Asian legumes such as field pea, grass pea and chickpea, and Chinese proso millet and buckwheat in the archeological remains and/or in ancient Indian agriculture writings. Most of these crops have acclimatized and adapted to diverse ecological conditions offered by the Indian Sub-continent to such an extent that many appear natural to the land, and have thrown enormous genetic diversity, making India either a secondary center of diversity for crops such as pearl millet, sorghum, maize, amaranths, cowpea, niger, safflower, muskmelon, pumpkin, chilies and others or regional center of diversity for crops such as barley, grain amaranth, buckwheat, pearl millet, foxtail millet, chickpea, bottle gourd and others. All details of crop voyage has already been discussed in the relevant topic of discussion (Chapter 8) on “Journey of agriculture and its development from past to modern era.”

Crop water requirement is the water required by the plants for its survival, growth, development and to produce economic parts. This requirement is applied either naturally by precipitation or artificially by irrigation. Hence the crop water requirement includes all losses like:

• Transpiration loss through leaves (T)

• Evaporation loss through soil surface in cropped area (E)

• Amount of weather used by plants (WP) for its metabolic activities which is estimated as less than 1% of the total water absorption. These three components cannot be separated so easily. Hence the ET loss is taken as crop water use or crop water consumptive use.

• Other application losses are conveyance loss, percolation loss, runoff loss, etc., (WL).

• The water required for special purposes (WSP) like puddling operation, ploughing operation, land preparation, leaching, requirement, for the purpose of weeding, for dissolving fertilizer and chemical, etc.

• Hence the water requirement is symbolically represented as:

The Crop Weather Calendar (CWC) is arguably one of the most practical and indispensable tools developed within agricultural meteorology. It transcends simple weather data by synthesizing comprehensive information about a specific crop’s entire life cycle with the historical climate patterns and recommended agricultural practices for a particular geographical area, typically an agro-climatic zone or even a district. More than just a timetable, it serves as a strategic blueprint that guides farmers and agricultural professionals toward optimized, resilient, and sustainable farming (Fig. 4.1).Imagine it as a detailed annual planner for a specific crop, where every entry is backed by decades of climate data and agronomic research. 4.2 Crop Weather Calendar: A Deeper Dive

Introduction 
Building upon our foundational understanding of how weather intrinsically shapes crop development, from the micro-scale physiological responses to the broader patterns revealed by Indigenous Technical Knowledge, we now transition to a chapter dedicated to a highly practical and actionable synthesis of this critical interrelationship: Crop Weather Calendars. These calendars are far more than mere chronological charts; they represent systematically organized and dynamic compilations of meteorological information meticulously integrated with precise crop-specific data, designed to serve as an indispensable guide for optimizing agricultural practices. In this chapter, we will embark on a comprehensive exploration of Crop Weather Calendars, moving beyond the often informal or culturally embedded ecological calendars previously discussed. We will delve into how these powerful tools systematically integrate historical weather patterns, which involves analyzing longterm meteorological data to establish reliable averages and identify probabilities of specific weather events, such as the typical onset of monsoons, average frost dates, or periods of peak solar radiation. They also incorporate real-time meteorological data, bringing in current weather observations to track actual conditions against historical norms and initial forecasts. Furthermore, Crop Weather Calendars utilize future weather forecasts, drawing on short-, medium-, and long-range meteorological predictions to anticipate upcoming conditions (Fig.12.1). This integrated weather information is then critically aligned with the precise phenological stages of a given crop cultivar, recognizing that a crop’s sensitivity and requirements vary significantly throughout its life cycle. Our exploration will detail the essential components that constitute a robust crop weather calendar, including the identification of crucial growth periods, pinpointing the most sensitive and influential developmental stages of the crop like germination, tillering, flowering, and grain filling, where weather impacts are most pronounced. It also involves the establishment of weather thresholds, which means defining the optimal, critical, and damaging ranges of key weather

Variation in field crops between years is associated with many factors. This is mainly due to weather, soil and management factors. There is complex reaction of weather variables among themselves as well as with other factors. Therefore, many attempts were made to study the effect of weather variable on crop yield through simulation modeling.

Climate, soil, input and management factors influence the crop yield. Weather is the most important natural input that affects the agricultural production and productivity. The agricultural activities starting from the land preparation to harvest and post-harvest storage are greatly influenced by the weather. The effects of weather on crops may be direct such as those of precipitation, solar radiation, humidity, temperature, etc., or indirect such as those of pest, diseases, weed competition, etc. Thus, the success or failure of a crop is determined by the prevailing weather conditions. Although influence of weather conditions on yield is well established, the quantitative assessment is not always straight forward and simple. The quantitative assessment of the effect of weather on crops is an important application of agrometeorology. The relationship between weather and crop production has been understood through crop weather modelling and study on this aspect through a systematic approach started a century ago. The aim of developing crop weather models is to ensure better utilisation of resources and hence a more environmental friendly and sustainable agriculture.

A model is a schematic representation of the conception of a system or an act of mimicry or a set of equations, which represents the behaviour of a system. Its purpose is usually to aid in explaining, understanding or improving performance of a system. Agricultural models are mathematical equations that represent the reactions occurring within the plant and the interactions between the plant and its environment. However, it is a difficult task to represent any system completely in mathematical terms because of the complexity of the system. Universal models do not exist for the agricultural systems and agricultural models are built for specific purposes and the level of complexity is accordingly adopted. Different models are developed for different subsystems and several models may be built to simulate a particular crop or a particular aspect of the production system. Crop weather models may be defined as a simplified representation of the complex relationships between weather or climate on one hand and crop performance such as growth, yield or yield components, on the other hand by using mathematical and/or statistical techniques

Plant competition is a powerful force for the elimination of some weaker plants. Plants require nutrients, water, light, Oxygen and Carbondioxide for their growth and development. Weeds compete with the crop for growth factors and the competition is maximum at the early growth stages of the crop. But the competiting ability of the weeds becomes practically nil as soon as the crops attain maturity. Weeds need more nutrients and water than the crop plants. The weeds in general grow faster and shade the crop plant if they are not controlled at proper time and afterwards interfere in the growth of crop plant. Weeds have allelopathic effect on crop growth. Some weeds excrete certain chemicals into the soil which inhibit the germination and growth of other plants in their vicinity and the phenomenon is called allelopathy. Allelopathy is defined as the direct or indirect harmful effects of one plant on another plant through the production of chemical compounds that escape in the environment.

1.1 Weather Parameters

The atmosphere is a gaseous component surrounding the earth as an integral part and its interaction with ocean (water bodies), other planets of the solar system and land (Earth) generates one physical product namely weather elements (temperature, pressure, wind, humidity, precipitation, etc.,) and these form the weather and climate of the Earth. The process of generation of weather and climate of the region is purely natural and cannot be modified by the human being. But they can do adaptation to the existing climate and weather for their sustainable life. The weather can be defined as day to day change in the atmosphere in terms of heat and moisture exchange, while the climate is average of long period weather covering larger area or a region.

The particular climate of a region dictates/permits the genesis of a particular bio-organism in that domain and this selected organism’s growth and multiplication are triggered by the prevailing weather of that particular climate. Hence weather parameters of the atmosphere are very important to human being and other organisms of the Earth. The details on weather elements are given in question and answer section of this book (Annexure-I)

ABSTRACT

Echinacea purpurea (L.) Moench. is a medicinal and nutraceutically important herb of American origin, extended its distribution to other parts of the globe in subtropical and temperate environment. This species is known for various biological properties such as antimicrobial, immuno-stimulatory and anti-inflammatory properties due to the presence to several bioactive compounds loaded in the form of phenylpropanoids, flavonoids, terpenoids, lipids, nitrogenous compounds, carbohydrates and others such as ascorbic acid, sitosterol, linoleic acid, cyanidin glycosides and sesquiterpene esters in different quantities. Published data reveals that its major chemical constituents possess anti-anxiety, anti-depression, cytotoxicity, anti-infective and anti-mutagenicity properties. Besides, plants respond to abiotic and climatic signals that are responsible for various adaptive responses at the cellular level and vary with ecosystem in which the species grows. It may behave differently in different ecological climates, thereby, modifying their gene expressions, and this reveals that the plant growth and the adaptability are mainly affected by microclimatic factors. Experimental trials conducted to collect data on growth phenology in relation to crop-weather interaction and investigated result is presented in this research. Studies on chemical evaluation of E. purpurea under two constrasting environment, subtropical and temperate climate, with reference to cichoric acid and chlorogenic acid undertaken for this plant is also presented. Future studies in relation to the application of biotechnological interventions and chemical evaluation at different time scale would be a great contribution to the science for this species as it has the tremendous potentials which may lead to development of various nutraceuticals and value added products in future for human health and medicines.

There are some weeds which prefer to in crop field and some of them have a distinct association with some crops.

Crop: Plants grown in association, sown (or planted) and also harvested by human being, are collectively known as crop.
Crop plants have some economic values and there is an interaction or competition among the plants.

Comparison of different cropping systems with reference to land use and yield advantages is possible through various efficiency indices. The various cropping and farming systems practiced in an area have to be properly evaluated to decide their suitability and relative advantages. The comparisons can be made with reference to many factors viz., yield, monetary, water use efficiency, nutrient use efficiency, total dry matter production, intensity of land use etc., The cropping as well as farming systems research are being perused at national level with major focus for identification of location specific efficient systems since 1990. However, on perusal of research publications we find that the data of cropping systems are interpreted in different ways with major focus only on production and net return on hectare basis. In fact, these two aspects are not the indicator of the efficiency of a particular system. Many advances have been made in recent years to identify the efficient system for a particular location. Some of the methodologies, which are of concern to crop scientists in general and agronomists in particular, are highlighted here for ready reference to the researchers, agronomists and crop planners. Different indicators of system efficiency are as follows (Gangwar et al., 2003).

What is Crop?
Crop refers to plants sown and harvested by man for economic purposes. 
Cropping Seasons: There are three main seasons and two sub seasons.
1. Rainy or Kharif Season – Main characteristics of the Kharif season are 
    ·    It starts from June and spreads to September.
    ·    There is high temperature and high humidity.
    ·    More than 2/3^rd of annual rainfall is received in a year.
    ·    In the beginning, days are longer than nights while days and nights are equal when season ends. 
    ·    Important crops grown are maize, rice, sorghum, Moong, Urd, groundnut, cowpea, soybean etc. 

1.1. Cropping pattern

Yearly sequence and spatial arrangement of crops or crops and fallow on a given area.

1.2. Cropping seasons in India

1.2.1. Kharif season: Southwest monsoon

Crops - Rice, cotton, jute, jowar (sorghum), bajra (pearl millet) and redgram (Pigeon pea).

Terms associated with cropping and farming systems are:

1. Cropping system: is an important component of a farming system. It represents cropping pattern used on a farm and their interaction with farm resources, other farm enterprises and available technology which determine their makeup.
2. Cropping pattern: means the proportion of area under various crops at a point of time in a unit area. It indicates the yearly sequence and spatial arrangement of crops and fallow in an area.
3. Cropping scheme is a plan according to which crops are grown on individual plot of a farm during a given period of time with the object of obtaining maximum return from each crop without impairing soil fertility. Thus a cropping scheme is related to the most profitable use of resources, land, labour, capital, and management.
4. Multiple cropping: Growing two or more crops on the same piece of land in one calendar year is known as multiple cropping. It is intensification of cropping in space and time dimensions. It includes intercropping, mixed cropping and sequence cropping.
5. Quadruple cropping: Growing of four crops in a year in sequence.
6. Competition effect: Competition of intercropped spp. For light, nutrients, water, carbon dioxide, and other growth factors.
7. Complementary effect: Effect of one component on another which enhances growth and productivity.

In agriculture, the ideal management practices were developed for individual crops through regular research and feedback received from the farmers. However, farmers are growing various crops in different seasons based on their adaptability to a particular season.

System is a set of principles or procedures according to which management is done; it is an organized scheme or method. A system is a group of interrelated or interacting elements (crops or livestock) that act according to a set of rules to form a unified whole.

5.1 Introduction

Rainfed agriculture accounts for about 60-95% of farmed land in major areas of the world covering Saharan Africa, Latin America, North Africa and East Asia and South Asia. Agriculture in about 60 percent of 142 m ha of net cultivated area in India is rainfed without access to any source of irrigation. Rainfed agriculture is mostly practiced in arid, semi-arid and sub-humid regions where the rainfall is low in quantity, erratic in distribution and is also characterized by high inter-year variability. Together with poor and degraded soils, this limits the length of growing season as well as the choice of crops that can be grown sustainably. Coarse cereals, pulses, oilseeds and cotton dominate the cropping pattern in the regions where rainfed agriculture is concentrated. More importantly, these rainfed regions provide a livelihood to a majority of the rural poor, and as a result they are often described as concentrations of mass poverty and hotspots for civic strife. The productivity of crops grown in rainfed areas is considerably lower than its potential and much lower than that of irrigated crops. Enhancing the productivity of rainfed crops is therefore important from the viewpoints of growth, equity and sustainability.

Cropping systems are designed to mimic nature and bring diversity into our farming system. The cropping system should provide enough food for the family, fodder for cattle and generate sufficient cash income for domestic and cultivation expenses.

The objective of any cropping system is efficient utilization of all resources viz., land, water and solar radiation, maintaining stability in production and obtaining higher net returns. The efficiency is measured by the quantity of produce obtained per unit resource used in a given time. The objective of traditional agriculture was to increase the production by two means:

a) By increasing area under cultivation.

b) By increasing the productivity per unit area of the crop.

The types of crops and the practices used to grow them and the sequence in which they are grown altogether refers to cropping system. It comprises of all components required for the crop production and their relationships with the environment. Traditionally the cropping systems aim at maximizing the per unit area productivity, which can be done by growing improved high yielding varieties, by adequate and scientific crop management practices and by increasing cropping intensities with the help of different cropping patterns.

In today’s world cropping system should produce more, at the same time the practices should be ecologically and environmentally sustainable. There should be efficient utilization of land and water. It should be designed to conserve soil, soil moisture and improve soil resilience.

A cropping system refers to the type and sequence of crops grown and practices used for growing them. It is based on the available technologies of crop production. Cropping systems have been traditionally structured to maximize crop yields. Now, there is a strong need to design cropping systems, which take into consideration the emerging social, economic and ecological or environmental concerns for each ecosystem. The goal of a cropping system must be to conserve natural resources i.e. soil, water and sustain crop production. Conserving soil and water and maintaining longterm soil productivity depend largely on the management of cropping systems, which influence the magnitude of soil erosion and soil organic matter dynamics. Crop diversification is an important option in sustainable agricultural systems. Management of cropping systems implies management of tillage, crop residue, nutrients, pests, and practices for soil conservation. Difference between dry land and rainfed farming is as follows.

Growing more than one crop in sequence or simultaneously as a mixed crop is an ancient practice. In Indian Vedas, there is a mention about double cropping. In early periods, the objective to adopt sequential cropping practices was to reduce the risk of total crop failure due to uncertain monsoon and to have a variety of produce to meet food requirement of farmer’s family, fodder to animals and to meet his cash requirements. Other benefits of yield increase was due to complementary effects of the component crops in improving the soil fertility, spreading the labour requirement throughout over a period of time and to reduce damage caused by weeds, pests and diseases were only incidental.

Multiple cropping in simple terms refers to the practices that increase production in a unit area of land through two or more growing crops simultaneously. The importance of intensive cropping in sustainable agriculture has been well understood by the agricultural scientists of late and there has been surge of interest in the research community to explore these complex systems in detail and to see what can be learnt from the farmers in our quest to make cropping system more sustainable progress made in the past through intensive research carried by the various agricultural universities, ICAR, research institutes/ coordinated research projects and international research institutes such as IRRI, ICRISAT, IITA and CIMMYT, it has shown that and more efficient utilization of the natural resources is possible by suitably modifying the present cropping systems in the various regions of the world.

The present cropping intensity in India is 136 per cent. There is a great prospect for increasing the cropping intensity both in irrigated and rainfed areas. In many irrigated areas, cropping intensity can be increased to 200-300 per cent. There is good scope to increase cropping intensity to 180-200 per cent with proper policies and technology options in rainfed conditions also.

A system is a set of components that are interrelated and interact among themselves. A system may be natural, social or artificial. Natural systems consist
of all the materials both physical and biological and are independent of human beings. Our role in relation to natural systems is to try to understand these
systems and make use of them as per our needs. 

15.1 INTRODUCTION

Cropping system is defined as a cropping pattern followed on a farm and its interaction with farm resources, other farm enterprises and production technology. In other words, cropping system refers to a combination of crops in time and space. When annual crops are considered, a cropping system usually means the combination of crops within a given year (Willey et al., 1989). This cropping system might provide insurance against crop failure by reducing disease (Fininsa and Yuen, 2002) and insect incidence (Gahukar, 1989) or against unstable market prices by planting two or more crops under intercropping and thus, reducing the risk of unexpected changeable prices. Intercropping in scientific way should be viewed from a theme of competition to one of collaboration with mutually beneficial relation with proper planning to get more return from limited natural resources. Legumes have been the common intercrops in any intercropping system owing to their short duration, N-fixing ability etc. Even though non-leguminous vegetables require longer duration than legumes and are non-N-fixers, they can also be suitable as intercrops because of their high profitability and higher yields.

In general crop is an organism grown or harvested for obtaining yield. Agronomically crop is a plants cultivated for economic purpose.

Classification of Crops

Classification is done to generalize similar crop plants as a class for attaining better understanding of them. Field crops are classified in the following ways.

1. According to range of cultivation
2. According to the place of origin
3. Botanical classification
4. Commercial classification
5. Economic / Agricultural / Agrarian classification
6. Seasonal classification
7. Classification based on ontogeny

The occurrence of periods of water deficit for crop production, referred to as climatic drought, is commonly observed and leads to low water availability for crops. Besides climatic drought, crop water stress may also result from low levels of plant available water in the soil profile due either to the existence of physical barriers to water infiltration (e.g., surface sealing) or to soil chemical or physical limitations to plant root growth and root water uptake. Drought resulting from such factors will be referred to as edaphic drought since it is caused by soil specific conditions rather than by limited rainwater supply, and can occur even under conditions of sufficient and well-distributed rainfall. Finally, even where water is very scarce, particularly in the driest areas, a surprisingly small proportion of the available water is actually transpired by the crop. Non-productive losses include surface runoff, deep drainage, evaporation from the soil surface and deep cracks, and transpiration by weeds. Dry land farming is a system of crop cultivation depending on rainfall as the only source of moisture and the technologies refers to the cropping pattern/ rotation and agronomic practices adjusted and adopted in accordance with the moisture regime. The crops selected should have short duration, deep root system, erect leaves, moderate tillering and photosynthetically efficient.

Rainfed farming has a distinct place in the Indian agriculture, occupying 67 % of cultivated area contributing 44 % of food grains to our national food basket, supporting 40% of human and 65% of livestock population. The system is characterized by resource poor farmers, poor infrastructure and low investment in technology inputs. Even when full irrigation potential of the country is realized, 50% of the net sown area is continued to be rainfed. The important problems encountered in rainfed areas are unfavorable weather, limited choice of crops and varieties, low cropping intensity and unstable productivity. The research work done by the net work of AICRPDA (All India Co-ordinate Research Project for Dryland areas) centres and SAUs (State Agricultutal Universities) indicated that the production in rainfed environment could be enhanced by 200 % compared to the productivity of farmers’ field by adopting improved cropping systems and agro techniques.

Climate change presents a formidable challenge for agriculture, particularly in regions like South Asia and parts of the Pacific. Severe flooding in Bangladesh, droughts in Afghanistan, and rising sea levels in Fiji exemplify how erratic weather patterns disrupt food production. In Pakistan, erratic monsoons damage crop cycles, while in Nepal and Bhutan, glacial melt threatens downstream water availability. Vietnam and Thailand are increasingly vulnerable to salinity intrusion in the Mekong Delta, jeopardizing rice productivity. According to FAO estimates, post- harvest losses in South and Southeast Asia exceed 15% due to inadequate storage and handling (FAO, 2022). Investment in improved storage facilities, resilient farming systems, better transportation infrastructure, and post-harvest technologies is crucial to mitigating such losses. 4.2 Infrastructure Deficits Infrastructure gaps are a major bottleneck for efficient agri-food supply chains. The Regional Logistics Performance Index (LPI) average for South Asia is 2.6, compared to 3.5

Spikeborer : Helicoverpa armigera : Noctuidae

Larvae of this polyphagous moth feed on the spikelets, flowers and developing seeds. The young larvae bite holes into the spikelets and the grown up ones attack the mature spikes

Crossandra belongs to family Acanthaceae. It is also known as Kanakambaram in Tamil or Kanakambara in Kannada and Fire cracker in English because of cracking sound during opening of seed pod. Crossandra is derived from Greek word “krossoi” meaning fringe and “aner” meaning male i.e. fringed anthers. Crossandra is an evergreen shrub and one of the important loose flower used for adornment. The flowers are commonly grown for flower adornment in the form of garlands, venis and gajras. Though it is not fragrant, flowers are very popular because of its attractive bright colour, light weight and good keeping quality. These are used for making garland, either alone or in combination with jasmine flowers. Using crossandra flowers in combination with jasmine is becoming increasingly popular in India, particularly in southern parts, because the jasmine flowers provide colour contrast and the desired fragrance. Crossandra varieties show a remarkable range of colours, varying from orange, pink, red, yellow and double coloured blue-type with white throat.

Crossandra belongs to family Acanthaceae. It is also known as Kanakambaram in Tamil or Kanakambara in Kannada and Fire cracker in English because of cracking sound during opening of seed pod. Crossandra is derived from Greek word “krossoi” meaning fringe and “aner” meaning male i.e. fringed anthers. Crossandra is an evergreen shrub and one of the important loose flower used for adornment. The flowers are commonly grown for flower adornment in the form of garlands, venis and gajras. Though it is not fragrant, flowers are very popular because of its attractive bright colour, light weight and good keeping quality. These are used for making garland, either alone or in combination with jasmine flowers. Using crossandra flowers in combination with jasmine is becoming increasingly popular in India, particularly in southern parts, because the jasmine flowers provide colour contrast and the desired fragrance. Crossandra varieties show a remarkable range of colours, varying from orange, pink, red, yellow and double coloured blue-type with white throat.

ORIGIN AND DISTRIBUTION

Crossandra is native to Indo-malaya region. They are all native to sub-tropoical regions including India, Southeast Asia, Africa, and Madagascar.

Crossandra Salisb is a genus of about 50 species which are shrubs or herbs from Tropical Africa, Madagascar and Arabia, where it is grown as a perennial shrub. Crossandra undulaefolia Salisb. (Syn C. infundibuliformis Nees) is a native of East Indies. However, it is sometimes considered to be native of south India and Ceylon. C. guinensis is native of east Africa while C. nilotica has its origin in east Africa and Mozambigue. C. flava is a native of tropical west Africa.

The crossandra plants are distributed in tropical as well as subtropical regions of the world such as south Asia, South America, South Africa and Madagascar. In India, it is commercially cultivated in southern states of Karnataka, Tamil Nadu and Andhra Pradesh (Singh, 2006).

INTRODUCTION

Crossandra is an important traditional flower crop of south India. It is small evergreen shrub that is quite hardy and has the ability to produce beautiful flowers with a remarkable range of colours almost all the year. This has made it extremely popular in southern states of India where the flowers are widely used in temple offering and for making gajras and venis to use as hair adornments.

Owing to their attractive colours, light weight and good keeping quality, crossandra flowers are ideal for garland making. Even though the flowers lack fragrance, they are widely used in garlands either alone or along with jasmine to produce charming colour contrasts. Steady market demand and assured and regular income have made crossandra a profitable venture for south Indian farmers.

Abstract: Crossandra, traditional flower crop of India, produce beautiful flowers in remarkable range of colours of almost all the year. Flowers are ideal for garland making and hair adornments. Only few species are cultivated across the world. Improvement is focused on drought tolerant ornamental types for landscape/ container use, better keeping quality, heavy yield and vivid range of flower colours, long spikes, earliness and big flower size. Breeders have created mutant cultivars and F₁ hybrids having valuable traits. Lack of fragrance and meager seed set require biotechnological interventions.

Introduction

Crossandra is an important traditional flower crop of South India. The word crossandra is derived from Greek words ‘krossoi’ meaning fringe and ‘aner’ meaning male, thus word crossandra means fringed stamens. It is grown for loose flower production and commonly used in temple offering and for making Gajras and Venis to use as hair adornments. Owing to their attractive colours, light weight and good keeping quality, crossandra flowers are ideal for garland making. Steady market demand and assured and regular income have made crossandra a profitable venture for South Indian farmers.

Genetics

The genus Crossandra belongs to family Acanthaceae. The diploid chromosome number of crossandra is 2n=40. This genus consists of around 50 species of tropical plants with only a few cultivated species such as Crossandra undulaefolia, C. mucronata, C. guineensis and C. sebacaulis. Crossandra undulaefolia is an important species which is grown for commercial value across the world.

Crossandra is an important tropical flowering crop valued for its attractive flowers and continuous production of loose blooms. It has particular importance in southern India, where flowers are widely used for garlands, hair decoration and religious purposes. This chapter covers the crop’s botanical characteristics, origin, distribution, genetics and commercially important varieties. It explains propagation, nursery management, climate and soil requirements, land preparation, planting, irrigation and nutrient management. Important cultural practices and plant growth management are discussed for obtaining regular flowering and good-quality blooms. The chapter also addresses insect pests, diseases, harvesting and postharvest management, including the correct method of flower collection. It provides a comprehensive production package for growers and students.

11.1 Introduction

The crossopterygians, primitive, lobe-finned, bony fishes, represent a very interesting group of fish showing many features of amphibians and other tetrapods. They possess paired fins with a large median lobe, fins covered by scales, a cosmine layer, swim bladder as lungs, nostrils that open into the mouth cavity and autostylic jaw suspension.

11.2 Taxonomic position