eChapters

Introduction: N metabolism

Nitrogen is one of the three essential macronutrients for plant growth and yield (Su et al., 2005) and most crucial elements for root growth also (Fageria, 2014). Most macromolecules and a variety of secondary and signalling substances, such as proteins, nucleic acids, cell wall components, hormones, and vitamins, contain nitrogen (N), an important element. In order to assimilate nitrogen, nitrate must be reduced to ammonium, and then ammonium must be converted into amino acids. Perez et al. (1973) pointed out that the rice genotype with high protein yield translocated N from leaf blade to the developing grains more efficiently than the low protein genotype. This was reported due to a high concentration of free amino acids in the sap translocated to the developing grains rather than to differences in translocation rates. Therefore, proper understanding of N metabolism and amino acid translocation are prerequisite to comprehend higher grain protein in high yielding rice genotypes. Use of N by plants involves several steps including uptake, assimilation, translocation and remobilization; and recycling and remobilization when the plant is ageing (Fig. 1). The enzyme nitrate reductase (NR) assimilates nitrate, the main form of nitrogen available to agricultural plants in the field. This enzyme and the nitrogen status of various higher plant systems have a strong positive link, and growth, yield, or protein content can occasionally be connected to this enzyme’s level in seeds or leaves. Nitrate intake occurs at the root level, and it has been demonstrated that plants have two nitrate transport systems that work together to cohabit, absorb, and distribute nitrate from the soil solution throughout the entire plant. (Srivastava 1980) Following NO3- uptake by NO3- transporters and reduction of NO3- to NO2- by nitrate reductase (NR) in the cytoplasm, the process of NO3- assimilation commences (Lea and Miflin, 1974).

Aim

Phytosynthesis of silver (Ag) nanoparticles using Cassia roxburghii aqueous leaf extract.

Introduction

The Ag nanoparticles constantly exhibit adverse effects on microbes such as inhibition and inactivation (Nasrollahi et al., 2011). The Ag nanoparticles synthesized by using various biological sources such as herbs, plants and biological organisms display excellent properties in various fields i.e., non-linear optics and intercalation materials for electrical batteries as optical receptors, catalysts in chemical reactions biolabelling and as antibacterials (Sanghi and Verma, 2009).

Plant diseases caused by variety of pathogens pose a serious challenge and economic threats to various agricultural crops all around the world. It has been evidenced that despite wide use of chemical pesticides in crop production, the losses due to pests and diseases are significant. Phytonematodes are one of the major groups of organisms that live in diverse habitat and continue to challenge variety of agricultural crops all around the world. Since early times the major agricultural crops have been plagued by these noxious nematodes that feed on various plant parts viz. roots, rhizome, sucker, tubers, seedlings, stem, leaves, buds, crowns and cause damage worth more than 100 billion dollars annually. The major crops severely affected by these pests are, vegetables, fruits, sugarcane, sugar beet, cotton, oil seed, pulses, tobacco, tea, coffee, cereals, spices, medicinal and aromatic plants.

Introduction

India has the distinction of being the largest producer of pulses in the world. Among the important pulse crops cultivated in the country are: chickpea, pigeonpea, lentil, mungbean, urdbean, fieldpea, rajmash and lathyrus. The pulse crops occupied an area of 22.85 million ha with a total production of 13.07 million tones and average productivity of 572 kg/ha. Being a high protein grain, pulses have special status in the diet, particularly for vegetarian population. Apart from being a good source of protein, they are also good source of energy, essential amino acids and vitamins in the daily diets of the people, especially of low-income group. Pulses have importance in sustainable agriculture by way of fixing atmospheric nitrogen in the soil.But with intensification of agriculture and introduction of irrigation and other facilities the area and production under pulses is declining so much so that per caput availability of pulses has declined from 69 g day-1 to about  36 g day^-1.

Introduction

Rice (Oryza sativa L.), one of the most important cereal crops of India, occupies 23.3 per cent of total cropped area of the country. Rice contributes 43 per cent of total food grain production and 46 per cent of total cereal production. It continues to play a vital role in the nation’s food grain supply. It is also a staple food of nearly half of the world population. Rice is primarily a high caloric food having protein content (6-17%) with high biological value and a low amount of fat (2-2.5%). B-group vitamins content in rice grains are at par with wheat, however, calcium content in rice is generally low. It ranks third after wheat and maize in terms of worldwide production. Asia accounts for 90 and 92% of the world’s rice area and production, respectively. Thus, rice production, consumption and trade are concentrated in Asia. Among the rice growing countries in the world, India has the largest areas under rice crop and ranks second in production next to China.

Introduction

Banana is the forth ranked agricultural crop in the world and first among fruits. A large number of pests and diseases threaten banana production. The major constraints in production are diseases and pests transmitted through the conventional planting materials. Although the average yield for bananas worldwide is over 40 t per hectare, production in India averages only 20 t per hectare. The nematode parasites are among the most important pests on commercial and subsistence banana production and their control remains difficult, as the nematodes are involved in the destruction of primary roots that disrupt the anchorage system resulting in toppling or uprooting of plants. The most widespread and important are burrowing nematode, Radopholus similes, some species of root lesion nematode, Pratylenchus coffeae and P. goodeyi, species of root knot nematode, Meloidogyne incognita and M. javanica; the spiral nematode, Helicotylenchus multicinctus, H. mucronatus and semi endo-parasitic nematode Rotytlenchus reniformis.

Pulses are seeds of leguminous plants used as food. They produce dal rich in protein. The important pulse crops are greengram, blackgram, redgram, bengal gram, soybean, cowpea, peas, lentil and lathyrus. The total area under pulses in India is 29.81 m ha with a production of 25.42 m t and the productivity is 853 kg / ha. Pulses can grow both in rainfed and irrigated conditions.

Of the total global pigeonpea production, over 90 percent of this is grown in India. The major pigeonpea growing states are Karnataka, Andhra Pradesh, Tamil Nadu, Maharashtra, Bihar, and Uttar Pradesh, contributing to 88.2% of the total pigeonpea basket and the same holds goodover the years. Over the decades, whatever little increase in production level was observed i.e. from 1.75 mt (19701975) to 2.75 mt (20052009), it is neither uniform nor steady. It is mainly through the expansion of area from 2.52 mha to a level of 3.58 mha ( 20052009 ) without significant change in productivity which ( 1970 1975) has remained almost stagnant around 700 kg/ha (Table 1) and is a matter of real concern (Srivastava, 1993).The gross geographical shifting of area ( 467 th. ha) took place mainly from traditional areas (Uttar Pradesh and Bihar) to new and less productive areas (Maharashtra, Karnataka, Gujarat, Andhra Pradesh, Orissa) with a netgainof area 837 th. ha in Central zoneandSouthzone includingexpandedadditional area (Table 23).

Laboratory pipettes are classified by their method of liquid transfer. There are two types of pipette one is plastic which is made up of polystyrene and are essentially disposable and second one is glass pipettes are very resistant to chemicals. Glass pipette can be used frequently by washing, sterilising and dry heat sterilisation is also available. Some of the common types of pipettes are using in laboratory such as serological, volumetric, micropipettes, multichannel, and Pasteur pipettes. Serological and graduated pipettes are used for transferring various volumes, while micropipettes and volumetric types of pipettes are only considered for precise measurement and transfer. Multichannel pipettes are used for dispensing into multiple wells, and Pasteur pipettes are simple for transferring small amounts.
1. Serological Pipettes
• Also known as graduated pipettes, made of glass or transparent polystyrene they are calibrated with markings to measure and dispense varying volumes.
• Appropriate for cell culture applications, transferring liquids and mixing.
2. Multichannel Pipettes
• It is design to transfer multiple samples at once, often used for 96 well plates or pcr tubes.
• It can be manual or automated, with multiple heads for faster dispensing.
3. Volumetric Pipettes
• It is designed to supply for single and particular volume of liquid.
• Marked by single graduation for an exact volume, such as 1, 5, 10, 25, and 50 mL.
• Used in chemical reactions and analysis where accuracy is crucial.

Today the world is facing a variety of interrelated problems such as food production, energy use, pollution, unemployment and urbanization, mainly because the developmental strategies contravene the basic philosophy of ecology. The world ecosystem is becoming increasingly more unstable through an ever growing dependence on finite resources of fossil fuels. Food production system in developed countries, both terrestrial agriculture and fisheries are energy intensive and are thus, not entirely suitable for developing countries. An alternative strategy to an increasing reliance on fossil for agriculture development should depend on locally available sources of renewable energy and resources. A significant effect could be made through recycling organic wastes into fish. Organic wastes can be recycled in ecologically sound pond based systems fueled by solar energy. The reuse of wastes would safeguard the environment from pollution and lead to a reduction in diseases of insanitation. Recycling of animal wastes is the cheapest way of protein production by reducing cost of production. Fish farming in Europe, Israel and USA is energy intensive, since more farmers use commercially prepared feed formulations which resulted in cost to feed often exceeding 50% of the total operating costs.

In recycling of waste through fish culture, fish is considered to have a great potential to change raw protein into high energetic edible protein. The rationale behind raising fish on organic manure is that about 72.98% of the nitrogen, 62.87% of phosphorus and 82.92% of potassium in the feed rations fed to animals are recovered in their excreta. In most of the world, cereals and legumes account for most of the proteins and calories consumed, but fish produced cheaply by recycling wastes would provide a low energy way to produce an animal product and diversify the diet. Fish, being the cheap source of animal protein is now widely accepted to meet the persistent and widespread malnutrition in developing countries.

Aquaculture is the fastest growing food production sector in the world with annual growth in excess of 10% over the last two decades. Much of this development has occurred in Asia, which also has the greatest variety of cultured species and systems. Asia is also perceived as the ‘home’ of aquaculture, as aquaculture has a long history in several regions and knowledge of traditional systems and is most widespread.

Introduction

A planer machine is a commercial machine tool hired for transforming the metal blocks or metal workpiece into the desired calculated shapes by generating the flat surfaces on a workpiece. Similar to a shaper machine, a planer machine is used for forming flat surfaces on the work piece using the single-point cutting tool.Planer machines are generally hired for operation on the larger workpiece or metal structure (blocks) that cannot be achieved by the shaper machine. They generally have larger beds and larger reciprocating movements covering a greater working length and surface area as compared to shaper machines.

The growth and productivity of crops depend on various factors, with the nutrient content of plant parts like leaves and stems playing a crucial role. These parts are often used as indicators to assess the nutrient status of plants. Each crop requires essential elements at specific concentrations during different growth stages, known as ‘critical levels’. When the nutrient content falls below these critical levels, plants may display symptoms of deficiency.

Nutrient requirements and availability can be evaluated through: i) plant diagnosis, ii) soil analysis, and iii) plant analysis using qualitative or quantitative methods. By conducting these tests, necessary nutrients can be identified and applied to crops to sustain growth and correct deficiencies. While rapid tissue tests offer quick solutions for nutritional problems, quantitative estimation of both plant and soil nutrient concentrations is more economical and provides a long-term strategy for managing nutritional issues. Implementing quantitative estimation allows for informed application of fertilizers, whether as basal or foliar, thus addressing deficiencies effectively and ensuring sustainable crop growth.

Different diagnostic tools are designed to avert nutrient deficiency or sufficiency and if properly used both loss of yield and quality of crop can be minimized. Among several diagnostic tools, nutrient analysis of standing crop seems to be an efficient method in arriving at the need-based fertilizer scheduling for various crops.

Nutrient uptake by plants indicates the actual accessibility of nutrients in soil to the plants. Also, concentration of certain heavy metals in plant indicates their solubility in soil which leads to poor crop quality.Although, different plant species and even different varieties of same species may differ in their nutrient requirements, the concentration of nutrient element in plant can act as guide to support the soil test result in assessing nutrient supplying capacity of a soil and as a tool for correcting any deficiency if carried out early enough to prevent yield loss. However, analysis of harvested or mature crop is like a post mortem as this information only can help in nutrient management planning in subsequent years.

Like soil testingplant analysis also suffers from some limitations. Amongthem, the most important are the risk of sampling error as well as the chances of incorrect interpretation of test report in recommending fertilizers. Selection of right plant part and right stage of crop growth are very crucial for successful plant analysis.

4.1 Sampling and Preparation for Analysis

The determination of nutritional need of crops is an important aspect of nutrient management of any plant analysis programme. The need of fruit plants for mineral nutrients differ from those of annual crop species in a number of ways, many of which are related to the perennial nature of tree crops. In perennial tree crops, there is a need to supply nutrients both for ultimate fruit production, the fruits and the vegetative organs, which persist from year to year. The need for leaf analysis in perennial horticultural crops and forest trees has proved its superiority over soil diagnostic methods. This is essentially because of their deeper root system and the fact that nutrients supplied in one year may have its effect on both the nutrition and crop production in following years. However, it is largely being used not as an alternative method to soil testing, but as a supplement to soil testing. Results of foliar analysis are usually interpreted using the critical nutrient level (CNL) approach. Accurate interpretation of foliar analysis using the CNL approach is possible only when sampling is restricted to the same growth stage at which standard reference values have been established (Beaufils, 1971, 1973). The general purposes of plant analyses are:

Accumulation of nutrient elements in plant tissues indicates the accessibility of the concerned elements from the soil to the plant. Although different plant species and even different varieties of the same species may vary in their nutrient requirements, composition of a part or of the whole plant may well be adopted as a guideline to support the soil-test results for factual assessment of soil’s nutrient supplying power.

This chapter introduces plant analysis as a means of determining crop nutrient status and diagnosing nutritional deficiencies. It explains the selection of representative plant tissues at suitable stages of growth, followed by washing, drying, grinding, digestion and elemental estimation. Recommended tissues and sampling stages are provided for cereals, pulses, oilseeds, fibre crops, vegetables, ornamentals and fruit crops. Procedures are included for estimating nitrogen, phosphorus, potassium, sulphur, boron, zinc, iron, copper and manganese in plant samples. The chapter stresses that reliable interpretation depends on correct tissue selection, careful sampling and freedom from contamination. It thereby connects laboratory measurements with crop nutrition and fertilizer management.

Methods for plant diseases control were first classified by Whetzel (1929) into exclusion, eradication, protection and immunization.

Two more principles - avoidance and therapy were created (NAS, 1968).

4.1. Physical methods

Employed for reduction or elimination of primary inoculums that may be present in seed, soil or planting material.

Introduction

In Organic farming; agricultural management system uses eco-friendly management practices and biological fertilizers derived largely from plant residue, animal excreta and nitrogen-fixing cover crops. It favorably affects the quality and yield attributes of crops. In modern agriculture system, development of organic farming in relation with the environmental hazard triggered by the huge application of inorganic pesticides and synthetic fertilizers in conventional agriculture, and it has abundant ecological aids. Spent mushroom substrate (SMS) can be used as such fertilizer. It is an organic mass that can be converted into humus in the soil.

Mushrooms are a fleshy, macroscopic, saprophytic, spore-bearing fruiting structure of a fungus (edible fungus) belonging to class Basidiomycetes except few which belong to Ascomycetes. It grows on dead and decaying organic materials derived from the agriculture, horticulture, poultry, brewery waste materials for its cultivation. Mushrooms are delicate, nutritional and medicinal fruit bodies of fungus which are used as an important ingredient of human dishes. It contains protein, minerals, vitamins and essential amino acid. Mushroom industries does not only produce edible mushroom but also produces virtually in-exhaustible supply of a co-product called spent mushroom substrate (SMS). Mushroom industry is flourishing day by day and not just mushroom as a whole is being used but many of its other uses are also studied and performed like using mushroom production for bioremediation or using mushroom waste which is known as SMS for different purposes. Therefore, growing mushrooms just for consumption is not true but its growth has many underlying purposes through which not just humans but the entire ecosystem is benefitted (Staments, 2005; Phan and Sabaratnam, 2012).

6.1. Fungicides

Fungicide originated from two latin words viz., fungus and caedo.

Word caedo means to kill.

Fungicide is a chemical agent which has the ability to reduce or prevent the damage caused to plants and their products.

Physical agents like ultra violet light and heat should also be considered as fungicides.

Antisporulant and fungistatic compounds do not kill the fungi, they are included under the broad term fungicide

5.1. Cultural methods

5.1.1. Eradication

Elimination of pathogen after it has become established in the area where host is growing.

Introduction

Indigenous Technological Knowledge (ITKs) refers to the knowledge that acceptable to all as absolute hearing and developed about the meticulous altitude by the people irrespective of gender that is women and men ancient to an a specific geographical area. This ancient technological knowledge that humans in an accustomed association accept developed over time and abide to advance it, is predicated on animal kingdom adventures on accumulation scale, activating and changing, activated throughout a lot of cases over centuries of use. Highest accessible knowledge to bounded knowledge and ambiance and put greater weightage on abbreviate risks instead of maximizing profit. The traditional technological knowledge (ITKs) covers a complicated sphere of subjects, viz. crop production, livestock rearing, accustomed knowledge management, ailment preparation, healthcare, insect administration, and others. The utilization of non-chemical methods for protecting lives and crop aegis is already accepting in several countries including India. The administration strategies developed and answer by the Governments is now supported the utilization of plant extracts. If an accomplishment is fabricated arise the cultivation of Indigenous Technological Knowledge (ITK) based articles on the small scale, it is often an economically applicable advantage for the appropriate development of eco-friendly chemicals.

Indian agriculture has been started over 10,000 years old, over millennia, farmers developed innumerable practices to auspiciously abound crops and accession animals within the awful adapted agro ecological regions of the Indian subcontinent. About 170 years of acceptance brought in new techniques, some advantageous in addition to a few harmful event of ancient Technological knowledge (ITK) systems, including administration of accustomed environment, has been a bulk of adaptation to the humans who generated these systems continued aback. Million of ITKs were supported to avail knowledge of actual and living assets to construct sure basal livelihoods for bounded people.

2. 1. Plant domestication

Process of bringing wild species under human management.

2.1.1. Changes in plant species under domestication

Elimination or reduction in shattering of pods, spikes, etc.

Elimination of dormancy

Decrease in toxins of other undesirable substances. Eg. Bitter principle of cucurbits.

Cultivated plants show altered tillering, branching, leaf characters.

Decrease in plant height. Eg. Cereals and millets.

13.1. Germplasm

Also known as genetic resources or gene pool or genetic stock.

Sum total of hereditary material i.e. all the allele of various genes, present in a crop species and its wild relatives

Abstract

The concern of global food security is growing day by day as the agriculturally available land is reducing each day with the expansion of industrialization and urbanization. During the course of urban and industrial development, crop production is greatly affected by global warming, contamination of hazardous materials, salinity and drought. To combat against such adversities, scientists have taken several additives measurement like development of transgenic crops, application of indigenous plant growth promoting microbes etc. for sustainable agriculture. Use of plant growth promoting microbes is getting popular day-by-day as they occupy a privilege niche with the autochthonous flora of specific environment. For the expanse of food and shelter, the microbes supply a wide range of plant regulators (e.g. auxins, cytokinins, gibberellins, ABA, phenols, NH₃ etc.), antibiotics, alkaloids, steroids, terpenoids, diterpenes, enzymes (e.g. cellulases, lipases, proteinase, esterases etc.) etc. for overall development of the plant. Apart from growth promotion, it also protects the plants against pathogenic invasion creating a competition with pathogens for nutrition and habitat. In near future, formulation of different plant growth promoting bacteria (like alpha- Azorhizobium, Azospirillum, Ancylobacter, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium sp., beta- Burkholderia sp., gamma- Acinetobacter, Aeromonas, Azotobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Stenotrophomonas sp. Proteobacteria, Bacillus sp., Paenibacillus sp. and Actinobacteria- Microbacterium sp. etc.) and fungus (Aspergillus, Trichoderma, Penicillium etc.) may reduce the use of pesticides and chemical fertilizer to promote greener ways of crop production.

Abstract

Microbes are endowed with a high and exploitable potential of being useful associates with their surrounding environment and host in case of symbiotic relationship. Most of the microbes live alone but many of them require association of other living system for its survival. Hence, the beneficial role of microbes is always correlated with growth promotion and survivability of other associated living system. Now it is established that microbes play an important and key role in plant growth and development, even its survivability in case of symbiotic mycorrhizal association with orchids. They are nothing but potential tool protecting plants from different adverse conditions like diseased state, environmental stress like cold temperature, drought, metal contamination, salt and acidic or alkaline stress.

Introduction

Plant growth in agricultural soils is inf luenced by a myriad of abiotic and biotic factors. As a routine practice growers normally use physical and chemical approaches to manage the soil environment to improve crop yields while the application of microbial products for this purpose is less common. An exception to this is the use of rhizobial inoculants for legumes to ensure efficient nitrogen fixation; a practice that has been occurring in North America for over 100 years (Smith, 1997). The region around the root, the rhizosphere, is relatively rich in nutrients, in expense of as much as 40% of plant photosynthates from the roots (Lynch and Whipps, 1991). Consequently, the rhizosphere supports large and active microbial populations capable of exerting beneficial, neutral, or detrimental effects on plant growth. The importance of rhizosphere microbial populations for maintenance of root health, nutrient uptake, and tolerance of environmental stress is now recognized (Bowen and Rovira, 1999; Cook, 2002). These beneficial microorganisms can be a significant component of management practices to achieve the attainable yield for in other words a crop yield limited only by the natural physical environment of the crop and its innate genetic potential (Cook, 2002).

The prospect of manipulating crop rhizosphere microbial populations by inoculation of beneficial bacteria to increase plant growth has shown considerable promise in laboratory and greenhouse studies however, responses have been variable in the field (Bowen and Rovira, 1999). The potential environmental benefits of this approach, leading to a reduction in the use of agricultural chemicals are fitting the sustainable management practices. Realizing the biological interactions occurring in the rhizosphere, recent progress are in need to fulfill the practical requirements of inoculant formulation and timely delivery which would increase the technology’s reliability in the field and facilitate its commercial development.

Plant Growth Promoting Rhizobacteria (PGPR) are root-colonizing bacteria that form symbiotic relationships with many plants. The name comes from the Greek rhiza, meaning root. Though parasitic varieties of rhizobacteria exist, the term usually refers to bacteria that form a relationship beneficial for both parties (mutualism). They are an important group of microorganisms used in biofertilizer. Biofertilization accounts for about 65% of the nitrogen supply to crops worldwide. The term PGPRs was first used by W. Kloepper in the late 1970s and has become commonly used in scientific literatures. PGPRs have different relationships with different species of host plants. The two major classes of relationships are rhizospheric and endophytic. Rhizospheric relationships consist of the PGPRs that colonize the surface of the root, or superficial intercellular spaces of the host plant, often forming root nodules. Endophytic relationships involve the PGPRs residing and growing within the host plant in the apoplastic space.Some common examples of PGPR genera exhibiting plant growth promoting activity are: Pseudomonas, Azospirillum, Azotobacter, Bacillus, Burkholdaria, Enterobacter, Rhizobium, Erwinia, Mycobacterium, Mesorhizobium, Flavobacterium, etc.An ideal PGPR should possess high rhizosphere competence, enhance plant growth capabilities, have a broad spectrum of action, be safe for the environment, be compatible with other rhizobacteria, and be tolerant to heat, UV radiation, and oxidizing agent.

Introduction

Lithosphere, including the earth’s crust, is helpful in providing the base or medium for sustenance of most life processes and forms, interwoven in fine network interdependencies within themselves and the environment surrounding them i.e. ecosystems. Terrestrial ecosystem contains an important dynamic living matrix termed soil, which is critical for agricultural production and food security. Soil forms the medium for growth and maintenance of a variety of plant species while the plant roots in the soil represent a four dimensional region in space and time of profuse activity relative to the bulk soil, revolving around pH, nutrient, redox potential, and exudate gradients changing as distance from the root increases (Marschner, 1995). The soil region adhering the plant roots is being strongly influenced by the presence of these roots and is characterized by high rates of microbial population and activity and referred as rhizosphere (the soil adhering to plant roots).

Unlike root-free soil, the rhizosphere around growing plants is a very dynamic environment that hosts a much higher number of microbes, in particular bacteria. Microbes interact with each other and with plants in symbiotic, associative, neutral or antagonistic ways. A plant colonized or penetrated by a microorganism can either result in asymptomatic or disease or form an association or symbiosis, depending on the cells’ perception of each other and how the environment affects that interaction. Microbes that penetrate and colonize plants have developed elaborate strategies to subvert plant defenses.

The rhizosphere is the narrow zone of soil surrounding the root that is under the immediate influence of the root system. This zone is rich in nutrients when compared with the bulk soil, due to the accumulation of a variety of organic compounds released from roots by exudation, secretion and deposition. Organic compounds released by plant roots include amino acids, fatty acids, nucleotides, organic acids, phenolics, plant growth regulators, putrescine, sterols, sugars and vitamins. Because these organic compounds can be used as carbon and energy source by microorganisms, microbial growth and activity is particularly intense in the rhizosphere.

Abstract

Rhizobia are soil bacteria that fix atmospheric dinitrogen after establishing symbiotic relationship inside the root nodules of legumes (Fabaceae). Plant Growth Promoting Rhizobacteria are the group of bacteria which thrive in the rhizosphere region and enhance the plant growth through direct & indirect mechanisms. Pulses are being inoculated with specific rhizobial strains to have better nodulation in India. The native rhizobial strains from the root nodules of legumes from different agroclimatic zones of Odisha was isolated, characterised and screened for PGP activities. Out of all eleven isolates showed similar characteristics with the family Rhizobiacae. Among them six isolates contained nif-gene and PGPR activity (B2, B4, B5, B6, B7 and B8) were applied to seeds, that helped in faster germination and better elongation of root and shoot. The observations were statistically significant.

1. Introduction

In the field of sustainable agriculture our main aim to produce high quality, safe and affordable food for ever-increasing worldwide population. Today, global agriculture is at crossroads and this is the consequence of climatic change, increased population pressure and detrimental environmental impacts. Furthermore, agricultural growers and producers have the additional constraints of economic profitability and sustainability. During the last couple of decades excessive amounts of chemicals are used to improve plant health, productivity and for management of plant pathogens, which has disturbed the ecological balance of soil and has led to the depletion of nutrients. Therefore, there has been ever-increasing interest to develop new mechanisms to ensure food security through sustainable crop production system that will supply adequate nutrition without harming the agroecosystem. Plant growth in agricultural soil is influenced by many abiotic and biotic factors. There is a thin layer of soil immediately surrounding plant roots that is an extremely important and active area for root activity and metabolism which is known as rhizosphere.

When crops are grown in either intercropping or sequential cropping interaction between different component crops occurs which is essentially a response of one species to the environment as modified by the presence of another species is commonly referred to as interference or interaction.

The interaction are classified into three groups

1. Competitive interaction: One species may have greater ability to use the limiting factor and will gain at the expense of the other and this is called competitive interaction or when one or more growth factors are limiting, the species that is better equipped to use the limiting factor(s) will gain at the expense of the other and this is called competitive interaction.
2. Non competitive: If the crops are grown in association and the growth of either of the concerned species is not affected, such type of interaction is called non competitive interaction or if resources (growth factors) are present in adequate quantities, as a result of which, the growth of either of the concerned species is not affected, then it is non-competitive interaction or interference.
3. Complementary: If one species is able to help the other, it is known as complementary interaction or if the component species are able to exploit growth factors in different ways (temporal or spatial) or if one species is able to help the other in supply of factor (like legumes supplying part of N fixed by symbiosis to non-legumes), it is complementary interaction or interference and also referred to as Annidation.

Plant mineral nutrition is a sub branch of plant physiology which addresses issues on uptake of elements that plant needs to absorb from air or water or soil to grow and to live. Besides function of nutrient elements in plants, it also includes deficiency symptoms and how to address deficiency symptoms in a plant. Plant mineral nutrition and mechanism of uptake has two major aspects:

7.1. Introduction

Like all other living organisms such as humans, animals, and microorganisms, plants also need elemental nutrients for their growth and development. They assemble the nutrients from soil, water and air. However, to obtain economical crop yield, nutrients are also supplied to the crops from external sources such as chemical fertilizers and manures and using biofertilizers. It is the present-day need to handle the soil fertility status in a more realistic and careful way to obtain maximum crop harvest. Under poor management practices, soil may become infertile and loose its importance in agricultural use. In modern days, huge food demand for the burgeoning human population does not permit to show luxury to use only fertile soil. Moderately fertile soil or even degraded soil should also be managed properly so that they may be used to grow crops. For this, plant nutrients status of the soil plays a significant role along with other soil properties. For sustainable soil fertility management, parameters such as crop to be raised, its nutrient demand at various growth stages, current nutrient status of the soil, amount of nutrient application based on the soil testing results etc are important to be considered. Balanced nutrition to the plants is the prerequisite to obtain maximum benefit. If nutrients supplied to the plants are low in quantity than their requirement, crop production is lowered down. Similarly, if the nutrients are provided in more amount in the soil or unbalanced way through fertilizer or manure applications, total crop yield is suffered. It is a very common example that excess of phosphorus leads to zinc deficiency in most crop plants and it has been observed that excess N is responsible for potassium starvation in potato. Again, excess of iron, manganese, zinc, copper shows plant toxicity. Addition of nutrients to soils in excess also causes environmental pollution when the excess nutrients are lost from soil by leaching, surface run-off and volatilization. Unscientific way of soil fertilization leads to increasing cost of cultivation and imparts adverse effect to the environment instead of doing any good. Therefore, one should have a clear knowledge on soil fertility to obtain a sustainable productivity.

Involved in plant metabolic functions and the plant cannot complete its life cycle without the element.

7.1. Plant nutrient concentration and plant growth

1. Deficient

Lowest concentration of an essential element that limit yield severely and cause distinct deficiency symptoms.

In the realm of natural elements, there exist approximately one hundred and three distinct elements. Among them, nearly ninety elements are absorbed by plants. To differentiate essential elements from those that plants can assimilate but are not vital, Arnon (1954) established the following criteria:

1. The plant must be incapable of normal growth or completing its life cycle in the absence of the element

2. The element is specific and irreplaceable by another

3. The element directly participates in plant metabolism

By applying these criteria, molybdenum and chlorine are not deemed essential, even though they serve a functional role in plant metabolism. This is because they can be substituted by vanadium and halides, respectively. Subsequently, D. J. Nicholas refined the definition of essential elements, replacing the term “functional or metabolic nutrient” to encompass any mineral element that contributes to plant metabolism, regardless of whether its action is specific.

Crop Stand Establishment

Good crop establishment is one of the most important features in better crop production. The better crop establishment is in turn expressed as optimum plant population in fields.

Plant population is the number of plants per unit area in a cropped field. It indicates the size of the area available for individual plant.

Optimum Plant Population

It is the number of plants required to produce maximum output or biomass per unit area. Any increase beyond this stage results in either no increase or reduction in biomass.

Crop geometry is the pattern of distribution of plant over the ground or the shape of the area available to the individual plant, in a crop field.

Plant propagation refers to the process of increasing number of plants of a cultivar. Plant propagation is of two types viz. sexual and asexual. Sexual propagation is done by seeds, whereas asexual plant propagation is done by vegetative means such as stem/root cuttings, slips, corm, bulbs, rhizomes, grafting, budding, layering, etc. Good quality seed or planting material of established crop varieties should be procured from authentic source to get desired result. The seed should be uniform in size, free from disease infestation, possess good vigour and having good viability. The quality of the seed is decided based on germination percentage. Seeds can be directly sown to raise a crop or seedlings are raised in nursery beds, which are transplanted later to main plot.

Seedlings can be raised in nursery beds, poly bags or pro-trays. The nursery beds are usually kept one meter wide, convenient length and of 15 cm height. The soil of the bed is prepared by addition of well decomposed bulky organic manure, sand and garden soil in equal proportion. The beds have to be disinfected by exposing the soil to sun (solarisation) and addition of neem or karanj oil cake. After sowing the seeds in the bed, those are covered with straw, leaves or compost to protect the seeds from birds and to conserve moisture in the soil. It also helps to maintain the temperature for quick germination. The seeds are sown in lines on the bed.

The application of agricultural chemicals for control of insects, pests, fungi, weeds and plant diseases plays an important role in crop production. Before 1980 few chemicals were known for control of plant pests.  The chemical pesticides have played an important role in the rapid advancement of agricultural production. Chemical pesticides are getting popular due to non availability of labours especially for weeding operation during kharif season. The chemical pesticides and herbicides are applied with the help of different types of sprayers and dusters.

12.1. Sprayers

Atomizes spray fluid into a small droplets and eject it with little force for distributing it properly.

Regulates amount of pesticide to avoid excessive application that is wasteful or harmful.

9.1. Plant quarantine

Legal restriction of movement of plant materials between countries and between states within the country to prevent or limit introduction and spread of pests and diseases in areas where they do not exist.

Plant quarantine regulatory measures are operative through the Destructive Insects & Pests Act, 1914 (Act 2 of 1914) in the country.

Introduction

Plant analysis can be defined as the quantitative determination of the concentration of an element or extractable fraction of an element in a sample from a particular part or portion of a crop. From the nutritional standpoint, plant analysis is based on the principle that the concentration of a nutrient within the plant is an integral value of all the factors that have interacted to it. Plant analysis is used as an index of available nutrient element supply. Plant growth or yield are compared with the elemental concentrations contained in the dry matter of the entire plant or plant structures such as leaves, petioles, fruit or grain sampled at different times during their development. Plant analysis gives the overall picture of the nutrient levels within the plant at the time the nutrient was taken. The use of plant analysis is based on the principle that the nutrient level present is as a result of all factors affecting the growth of the plant.

Plant analysis involves the determination of nutrient concentration in diagnostic plant part(s) sampled at recommended growth stage(s) of the crop. In a way plant analysis complements soil analysis. There are reliable sampling criteria and procedures for most of the world’s commercial crops.

Importance

Plant analysis assesses nutrient uptake while soil testing predicts nutrient availability. The two tests are complementary to each other as crop management tools. Plant analysis will detect unseen hidden hunger and confirm visual deficiency symptoms. Toxic levels may also be detected. If it is done early, plant analysis will allow a corrective fertilizer application in the same season.

5.1 Plant Breeder’s Rights (PBR) and Protection of Plant Varieties and Farmers’ Rights (PPV&FR) Act
5.1.1 Introduction
In the context of biotechnology and agricultural innovation, Plant Breeder’s Rights (PBRs) offer exclusive intellectual property protection to individuals or organizations that breed, develop, or discover new plant varieties. These rights ensure economic incentives for plant breeders while promoting innovation in seed development and agricultural productivity. In India, the unique and inclusive Protection of Plant Varieties and Farmers’ Rights Act (PPV&FR), 2001, balances breeders’ rights with recognition of farmers’ contributions, making it one of the most progressive legislations in the world.
5.1.2 Concept of Plant Breeder’s Rights (PBR)
Plant Breeder’s Rights refer to the exclusive rights granted to plant breeders to produce, sell, market, distribute, import or export their registered plant varieties. These rights are sui generis, meaning they are a special form of IP distinct from patents, developed to cater specifically to plant varieties.
Key Objectives of PBR
• Encourage investment in plant breeding and biotechnology.
• Ensure access to improved crop varieties.
• Prevent unauthorized commercial exploitation of novel varieties.
• Facilitate biodiversity conservation through formal registration systems.