eChapters

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.