Factors affecting Plant Health – Edaphic factors and Biotic Factors

Factors affecting Plant Health – Edaphic factors and Biotic Factors

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  FACTORS AFFECTING PLANTHEALTH – EDAPHIC FACTORS AND BIOTIC FACTORS Dr. Nandadulal Sannigrahi, Associate Professor, Department of Botany, Nistarini college, Purulia D.B. Road, Purulia, INDIA (W.B)
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  PLANT HEALTH  Healthyplants are able to grow and produce in the face of environmental stress, pests, and competition. The nation’s food supply relies upon sufficient sources of healthy plants. A range of variables affect plant health, including the surrounding environment and the extent to which they are protected from pests and disease.  Healthy plants are vital to sustainable and profitable crop production and to the quality and cost of the nation’s supply of food, fuel, and fiber. Health is also critical to plants used for ornamentals, natural resources, and animal feed.  Scientists are using innovative methods to breed more productive and nutritious crops. Advances in breeding and genetics are allowing farmers to grow plant varieties that are healthier and more resilient to drought and losses from pests and diseases.  Research and innovation on plant health are key to keeping crops healthy in a challenging environment while aiming for a sustainable, climate-neutral and biodiversity-friendly farming system.
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  PLANT HEALTH  Moreover,climate change is altering pests’ behavior and geographical distribution, which may further increase the risk of introducing pests to new areas and the severity of the impact.  These factors can cause significant damage to crops, native plants and the environment. Risks to plant health are on the rise, threatening agricultural sustainability, biodiversity and food security.  The introduction and spread of plant pests are serious threats with far- reaching economic, social and environmental consequences.  Tackling numerous and highly dynamic biotic and abiotic changes requires integrated approaches and the development of a wide range of solutions for the prevention, early detection, monitoring, control and management of pests and diseases, along with risk management strategies.  Reducing pesticides in the management of plant pests protects the environment, pollinators, natural pest enemies, beneficial organisms, animals and people.
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  EDAPHIC FACTORS  Theedaphic factor includes the physical, chemical, and biological properties of soil that result from biologic and geologic phenomena or anthropogenic activities.  Discontinuities in the edaphic factor contribute to the intriguing patterns of diversity we see in the biotic world. Chemical and physical features of soil greatly influence the ecology and evolution of plants and their associated biota.  Extreme soil conditions, such as those found on serpentine outcrops, limestone and gypsum deposits, and even mine tailings, have led to the formation of unique plant communities characterized by both rarity and endemism.  Such sites have also provided model organisms to examine the process of divergence due to adaptation and reproductive isolation and subsequent genetic differentiation, in some cases even resulting in speciation.  Ever-expanding agriculture and forestry, mining activity, and urbanization cause severe threats to the world’s unusual edaphic habitats and their biota.
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  PLANT HEALTH
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  EDAPHIC FACTORS  Whilesome areas have been preserved for their unique biota associated with unusual edaphic conditions, there are many more that are rapidly being impacted by human activities.  Without strict conservation measures, many species, including metal- hyper accumulating plants that are useful for innovative, green technologies such as phytoremediation, may soon be extirpated.  For every type of organism, there is only limited range of conditions in which growth and multiplication of pathogen can be proceed,  There are optimal conditions in which the growth is most rapid and there are extremes- maximum or minimum above or below which growth ceases,  Temperature, humidity, light and nutritional conditions are the chief factors which affect the pathogen and the plant diseases,  All these factors indirectly help to regulate the health conditions of the plants,  So, the regulation of the edaphic factors play a very critical role in this regard for doing the same.
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  BIOTIC FACTORS  Theecosystem is made up of biotic and abiotic factors.  Abiotic factor comprises non-living components like sunlight, temperature, water, soil, wind, humidity and radiations. These are the physical and chemical agents that ultimately affects the biotic factors.  Biotic factor or components means the living things of an eco-system. It is also responsible for the different outbreaks of diseases. Both abiotic and biotic factors work together. It determines what the ecosystem will look like and the availability of the ecological niches.  The biotic factors mostly include the living organisms of diverse forms- bacteria, fungi, nematodes, insects along with the different types of other Protista,  All these living organisms either directly associated with the disease development or plant health through competition, predation and diseases,  All the above factors-biotic and abiotic play a very crucial health for plant health.
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  ABIOTIC FACTORS  Ifno pathogen can be found, cultured from, or transmitted from a diseased plant, it must be assumed that the disease is caused by an environmental (physiological) factor. The specific factor might be determined by observing a change of the environment, i.e. flooding, unseasonable frost, etc. Some environmental factors cause specific symptoms, while others cause general symptoms. Unless the history of the environmental conditions is known, these diseases are often difficult to diagnose.  Non-infectious (non-transmissible, physiological) diseases are usually caused by a surplus or deficiency of some or other factor which supports the life of the plant. These diseases are non-transmissible and no pathogens are present. The symptoms caused by these diseases differ in degree of severity, depending on the degree of deviation from the normal range of the factor.  The four important zones of the plants that are highly affected by the different factors- Anthospheres, Phyllospheres, Spermosphere and Rhizosphere
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  IMPACT OF ABIOTICFACTORS
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  DIFFERENT LAYERS OFEARTH ND PLANT HEALTH  Abiotic factors mainly distributed in the four layers-  Rhizospheres-  The conceptual term ‘rhizosphere’ is commonly used to describe the volume of soil influenced by roots but may also be extended to describe root–soil interfaces that can be separated into ecto -rhizosphere (rhizosphere soil), rhizoplane (root surface), and endo-rhizosphere (inner root).  Rhizospheres are complex and highly-dynamic environments where an immense number of interactions between roots, minerals, organic compounds, solutes, gases, and (micro)organisms drive the biogeochemical cycling of elements. The dynamics of this layer is very important for plant health due to highly dynamic environments reared by multiple factors.  Spermospheres-  The spermosphere represents a short-lived, rapidly changing, and microbiologically dynamic zone of soil surrounding a germinating seed. It is analogous to the rhizosphere, being established largely by the carbon compounds released into the soil once the seed begins to hydrate.  These seed exudations drive the microbial activities that take place in the spermosphere, many of which can have long-lasting impacts on plant growth and development as well as on plant health.
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  DIFFERENT LAYERS OFEARTH ND PLANT HEALTH  Anthospheres-  The anthroposphere encompasses the total human presence throughout the Earth system including our culture, technology, built environment, and associated activities. When compared with most natural changes in other spheres, change in the anthroposphere is happening rapidly.  This is partly due to the rapid increase in population over the past several centuries but also as a result of the strides in technology and energy that have empowered humans to directly and indirectly affect environmental change. The plant health is effected by the change of the layer by the different activities of the counterparts.  Phyllospheres -  The term phyllosphere refers to “the parts of a plant above the ground, usually surface of leaves, regarded as a habitat for microorganisms.” This is a place where ordinarily a variety of microorganisms (bacteria and fungi) colonize.  The phyllosphere is the environment in which bacteria invade and form associations with plants, most prominently epiphytes. The phyllosphere’s microbial communities are extraordinarily complex, containing both uncultured and cultured bacteria.
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  DIFFERENT LAYERS OFEARTH ND PLANT HEALTH  There are external factors that affect the diversity of microbes thriving in the phyllosphere like light, temperature, nutrient availability, water, and UV light.  The phyllosphere has specific microenvironments that are according to the leaf physiology and arrangement of leaf epidermal cells and these highly affect the abundance of microorganisms on the surface. The cuticle layer outside has aliphatic compounds in it and it allows permeability and moisture, which provide better attachment of microorganisms.  Thus, all the aforesaid layers play a very crucial role for the plant health by drawing the desired nutrients as far as the requirements for the best of productivity .  It also enables the plants to grow and adapt in the changing dynamics by the different man made constraints,  These layers provide the key roles to eliminate the pathogens and welcome the good microbes for achieving sound health by their special adaptive mechanisms to maintain system dynamic in nature.
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  PLANT HEALTH FACTORS
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  ABIOTIC FACTORS  Extremesof Temperature  For each kind of plant there exists a minimum-, optimum- and maximum temperature for growth. When the prevailing temperature falls outside this range, the plant will be damaged.  Low temperature: Cold and frost damage will depend on the time and degree of deviation from the minimum temperature for growth. Cold damage is caused by:  1) the ice crystals formed by the freezing of the water vapor in the air spaces between plant cells, physically damaging the cells;  2) ice crystals form in the cell sap and cytoplasm, thus disrupting the membranes of the cell;  3) the freezing of water vapor in the spaces between plant cells causes more water vapor to diffuse out of the cells, leading to increased concentration of solutes in the cell which may damage the cell.  High temperature:  Plant parts, especially leaves, become singed (burned) mostly on hot windless days. Tree branches are sometimes scorched by the sun leading to the formation of cankers.
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  ABIOTIC FACTORS  Thetemperature of the both the high and the low affects the plant health by providing the predisposing factors of disease development.  The incubation period of wheat rusts has been frequently affected by alteration of temperature. The uredospores of Puccinia striformis are formed at 15-17℃, P. graminis tritici , low temperature as 10 ℃ and 0℃, favor abundant uredosori formation in some forms and stimulate teliospore development,  Extremes of Moisture  Too little soil moisture causes water stress in the above ground parts of the plants leading to temporary wilting which may become permanent if the moisture content of the soil decreases further. Too much soil moisture leads to decreased aeration of the soil which may cause anaerobic (i.e. oxygen deprived) soil conditions under which root respiration is impeded, causing decreased water uptake by the roots.  The humidity affects the production of spores of fungi in many cases. It is not always that the high humidity favors spore formation. Peronospora destructor on onions and Bremia lactcae on Lactuca require 100% relative humidity (R.H) for the formation of conidiophores and conidia, minimum being 90%% and 96% respectively.
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  ABIOTIC FACTORS  Onthe other hand, conidia formation of Sphaerotheca humuli is reduced at 100% R.H but abundant at 93% and 96% R.H . In certain cases, the production of spores is favored more by alternating periods of wet and dry conditions,  The time of production of spores also seems to be important. It becomes necessary for the optimum conditions for spore formation to occur at right moment and is also necessary for them to remain so for as long as possible. Extremes of Light  Too much light on shade-loving plants may cause the loss of the normal green coloration (chlorosis) of the leaves, while too little light on sun-loving plants give rise to a sub-normal green color, development of long internodes and lack of mechanical tissue in the stems called etiolation. Intense light may cause heating and the inhibition of spores. Germination of the different types of spores like uredospors of Puccinia is inhibited by day light and germinate at night frequently.  Oxygen deficiency  Lack of oxygen in roots growing in poorly aerated soil result in reduced
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  ABIOTIC FACTORS  wateruptake and wilting. When potato tubers are stored in big piles under condition of high temperature, the tubers in the centre of the pile are subject to a state of oxygen deficiency because of the high respiration rate. of the tubers at elevated temperatures. The characteristic ‘black heart’ symptom then develops.  Electrical Conductivity (EC)  Electrical Conductivity is another critical factor to monitor. EC measures the concentration of nutrients in your water solution. Maintaining the correct EC levels ensures that your plants receive the right amount of nutrients.  High EC levels can indicate an excess of nutrients, while low EC levels can suggest a deficiency. Regular monitoring helps you adjust nutrient levels accordingly.  Air Pollution  Crops grown in the proximity of industries sometimes develop chlorosis and/or necrosis of the leaves due to the presence of gases such as chlorine, sulphur dioxide, nitrogen dioxide, hydrogen fluoride and ozone.
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  ABIOTIC FACTORS  toxicitiesor interference with the uptake of other elements.  Soil pH  Soil pH has an important effect on the solubility and thus the availability of  plant nutrient elements. Nutrient elements may be changed to insoluble forms when the soil pH falls outside the range of about 4.5 to 8. Very acidic or alkaline soils may lead to toxicities as mentioned.  Most of the fungal spores germinate well under slightly acidic conditions , may at a range of pH 3.0-8.0 but some prefers alkali pH but it is not limiting factors of spore germination,  The growth and productivity of soil is favored by the soil pH depending upon the availability of the issue.  Toxic agricultural remedies  The extensive use of herbicides leads to a lot of damage to crops. Most herbicides are safe to use for the purpose they were manufactured for, especially when it is used as indicated. Other agricultural remedies may also be harmful when used at too high concentrations or under the wrong conditions. It is mandatory to follow the instructions on the label closely.
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  ABIOTIC FACTORS  Toxicminerals  Soils may contain excessive amounts of macro- as well as micro elements. Both may harm plants if they occur in high concentrations. Excessive macro elements are less harmful than excessive micro elements. Too much sodium induces a calcium deficiency. Excessive sodium salts increase the pH of the soil leading to alkali injury of plants. A low soil pH causes increased solubility of especially metal elements. This may lead to  Nitrogen Deficiency  Nitrogen is responsible for promoting healthy leaf and stem growth. A nitrogen deficiency can cause yellowing of leaves and stunted growth. Ensuring your plants receive adequate nitrogen is vital for their development.  Phosphorus Deficiency  Phosphorus is essential for energy transfer and photosynthesis. A deficiency in phosphorus can result in dark green or purplish leaves and poor root development. Regularly checking phosphorus levels helps prevent this issue.
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  ABIOTIC FACTORS  PotassiumDeficiency  Potassium is crucial for overall plant health, including disease resistance and water regulation. A potassium deficiency can cause yellowing of leaf edges and weak stems. Monitoring potassium levels ensures your plants remain strong and healthy.  Calcium Deficiency  Calcium is important for cell wall structure and growth. A deficiency in calcium can lead to distorted or stunted growth and blossom end rot in fruits. Maintaining proper calcium levels is key to preventing these problems.  Iron Deficiency  Iron deficiencies become more prominent over time, making it difficult to distinguish from other forms of nutrient deficiency in the early stages. Iron is essential for chlorophyll production, and a deficiency can cause yellowing between leaf veins. Regular monitoring helps catch and correct iron deficiencies early.
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  ABIOTIC FACTORS  NutrientAvailability  Nutrient availability is the concept of how readily a plant can access nutrients from the nutrient solution. At different pH levels, the percentage of each nutrient that can be absorbed can go up or down.  For instance, the nutrient availability of iron decreases at higher pH levels, while phosphorus availability decreases at lower pH levels. Maintaining the optimal pH range ensures that your plants can absorb the nutrients they need effectively.  Thus, the abiotic factors play crucial role by extending four important biological principles though soil composition, climatic factors, water availability and exposure to toxic elements through  Antibiosis- by antibiotics, Polyketides, HCN  Stress response-Acc deaminase, ISR, SAR, IST  Nutrient acquisition- N fixation, P solubilization, siderophores  Plant hormone response-IAA, ABA, Cytokinines, Gibberellins
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  BIOTIC FACTORS ANDPLANT HEALTH  Biotic factors—living organisms such as bacteria, fungi, viruses, nematodes, insects, and weeds—significantly impact plant health.  The biotic factors of diverse types affect the plant health by causing diseases, nutrient depletion, and physical damage. These factors induce biotic stress, leading to symptoms like necrosis, wilting, reduced growth, and potentially plant death, accounting for approximately 40% of global crop yield losses.  The different biotic factors ranges from virus to protists play a very significant role in this regard by causing a number of irreparable damages of the different parts of the plants by reflecting the quantitative and qualitative decrease of the plants growth and productivity by a number of biochemical process pathways alteration and modulation,  Emerging data indicate global agricultural losses, flustered plant-population ecology, and wavering conservational status due to overexploitation of plant life by other living organisms, specifically viruses, bacteria, fungi, nematodes, herbivores, and weeds.
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  BIOTIC FACTORS ANDPLANT HEALTH  Plants under biotic stress elusively undergo various biochemical, physiological, and ecological changes for their survival. Plants employ sophisticated mechanisms at different levels with variable adeptness to minimize metabolic constraints and compensate for multidimensional effects of biotic stress.  Pathogens (Bacteria, Fungi, Viruses): These microorganisms cause diseases such as bacterial wilt, powdery mildew, and mosaic viruses, which directly impair plant tissues and reduce vitality. Plant pathogenic bacteria (PPB) have been classified into three families: Xantomonadaceae, Pseudomonaceae, and Enterobacteriaceae. Most of them belong to the following genera: Erwinia, Pectobacterium, Pantoea, Agrobacterium, Pseudomonas, Ralstonia, Burkholderia  Herbivores and Pests: Insects and animals consume plant parts (leaves, seeds, stems), causing direct physical damage and, in some cases, transmitting diseases.  Nematodes: Microscopic worms often attack the root system, causing root knots and hindering nutrient uptake.  Competing Vegetation (Weeds): Competing plants (weeds) compete for resources like light, water, and nutrients, causing stress.  Microorganisms (Rhizosphere): Not all biotic factors are harmful; some soil microbes, such as fungi and bacteria, can enhance plant resilience and nutrient availability, despite others acting as pathogens.
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  BIOTIC FACTORS &PLANT HEALTH  Energy flow- The green plants harvest solar energy and by the dint of photon, they produce the biomass reflected in the form of net productivity; the primary consumers uses the biomass and transfers into the secondary consumers, followed by the tertiary consumers and the decomposers following the 10% law of energy transfer. Thus, by means of energy flow, the transfers from energy from the abiotic systems take place and this process enables the growth and development of the plants along with the pride and promise to contribute in the plant health of the standing crops.  Nutrient recycling- Decomposers in general and bacteria along with fungi in particular recycles the nutrients by means of the different biogeochemical cycles. These cycle enable the replenishable nutrients supply into the ecosystem to offer sustainable supply of the nutrients in the large scale.  Population Control- Predation, competition and other biological process enable to maintain the population dynamics in a sustainable ways to maintain the optimum supply of the different life supporting factors into the ecosystem.  Maintaining biodiversity- Each species from microbes to large animals are the vital component in any ecosystem and this intangible biodiversity is the paradise beauty of the living species.
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  CONCLUSION  In conclusion,plant health monitoring in a hydroponic system is essential for achieving optimal growth and yield. By keeping a close eye on factors such as pH balance, electrical conductivity, water temperature, and environmental humidity, you can ensure your plants receive the right conditions to thrive.  Additionally, understanding and addressing common nutrient deficiencies, while being mindful of nutrient availability and balance, will help you maintain a healthy and productive hydroponic garden.  With the right tools and knowledge, you can create an environment where your plants can flourish and reach their full potential.  Thus, the understanding of the plant health is a very important issues nowadays in the quest of sustainable productivity to feed the millions of starved people in general and the third world countries in particular.  Not only the biotic and abiotic factors, the global climate changes ar also to be addressed properly and periodically because any of the factor change can bring a disaster.
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  THANKS FOR YOURVISIT  ACKNOWLEDGEMENTS: a. Google for images, b. Different websites for enriching the course content, c. Science Direct pages, d. Plant Pathology- Dr. B. P. Pandey, e. Plant diseases, insects and pests- NCBI-NH, f. Topics in Mycology and Pathology-L.N. Nair g. www.nature.com h. www.spruce.com i. www.aphis.usda.gov j. Puregreensaz.com k. www.fao.org l. Many more websites for references.  This presentation has been designed to address the academic fraternity without any financial interest. This is absolutely free to use . The author does not claim any kind of financial benefits from this content
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  HEALTHY PLANTS, SUSTAINABLEEMNVRONMENT