Heart rot is a fungal disease that causes decay of the heartwood in tree trunks and branches. Fungi enter through wounds in the bark and slowly decay the inner wood, weakening the structural integrity of the tree. This can cause branches and trunks to break. Heart rot has major economic and environmental impacts. It causes significant losses to the logging industry by damaging timber. In forests, trees weakened by heart rot are more susceptible to disturbances and allow new growth, changing the forest environment over time. Heart rot is diagnosed through visual examination of symptoms and signs like mushrooms or decayed wood.
The document discusses various diseases and disorders that affect plantation crops and forest species. It describes diseases caused by bacteria, fungi, insects and other living organisms as biotic stresses, and diseases caused by non-living factors like water, nutrients, chemicals, heat or cold as abiotic stresses. It then provides details on specific diseases affecting leaves, stems, roots and needles of trees. These include bacterial blight of eucalyptus leaves, pink disease affecting stems, Phytophthora root rot of acacia, and Dothistroma needle blight of pine. It describes the symptoms, causal organisms, species affected and management strategies for each disease.
This presentation summarizes several diseases that affect the sissoo tree species (Dalbergia sissoo), including leaf spot caused by various fungi which produce yellowish or grayish lesions on leaves, leaf blight caused by Rhizoctonia solani which causes stomata-infected blotches on leaves, powdery mildew caused by Phyllactinia dalbergiae which produces a dense white mycelium on leaves, and rust disease caused by Maravalia achroa which infects seedlings. It also discusses wilt symptoms of flagging leaves and die-back symptoms of thinning foliage and drying branches. Control methods include fungicide applications and sanitation practices.
This document provides lecture notes on tree improvement and silviculture. It begins with definitions of key terms used in tree improvement like additive genes, allele, backward selection, breeding orchard, breeding population, and breeding value. It then discusses the objectives and importance of tree improvement, noting that it aims to increase tree value through selection, breeding, and testing of desirable trees over multiple generations. The document emphasizes that tree improvement relies on understanding and utilizing natural genetic variation in tree populations.
This document provides an introduction to forest classification. It discusses that forests can be classified based on criteria such as composition, age, climate, structure and habitat. The objectives of forest classification are to study and characterize different forest types, develop suitable management techniques, and avoid waste and costs. Forests are commonly classified based on age (even-aged vs. uneven-aged), regeneration method (high forest vs. coppice forest), species composition (pure vs. mixed), ownership (state, private, community, panchayat), management objective (production, protection, fuel, farm, recreation), growing stock (normal vs. abnormal), and legal status (reserve, protected, village).
This document discusses different silvicultural systems used in forest management. It defines a silvicultural system as a set of operations used to tend, harvest, and regenerate a forest crop. Several specific systems are described in detail, including the selection system, clearcutting system, shelterwood system, and periodic block system. For each system, the document outlines the procedure, results or effects on forest structure, applicability to different forest types, as well as benefits and disadvantages.
Tectona grandis, commonly known as teak, is a large deciduous tree found in a variety of habitats with annual rainfall between 1,250-1,650 mm and a 3-5 month dry season. It is a light demander that is drought and frost tender, but highly resistant to fire, and regenerates well from coppicing and pollarding with a rounded crown. Teak grows best in deep, well-drained loamy to sandy loamy soil and is commonly associated with Acacia catechu and Adina cordifolia. Due to its high oil content, tensile strength and tight grain, teak is suitable for outdoor uses where weather resistance is required, such as
Important fire wood and timber yielding plant 1. dalbergia sissoo 2. a...gohil sanjay bhagvanji
This document summarizes three important firewood and timber yielding plants: Dalbergia sissoo, Terminalia arjuna, and Mangifera indica. It provides details on the classification, habitat, morphology, wood properties, and uses of each plant. Dalbergia sissoo is used widely for furniture and construction in North India. Terminalia arjuna has medicinal properties and is used to treat heart and lung conditions. Mangifera indica wood is used for rotary veneer, plywood, furniture, and other wood products in India.
Forestry involves the cultivation, management, and conservation of forests. It is important for economic, environmental, and social reasons. Forestry provides timber, fuelwood, and helps improve water quality and the environment. It also generates employment. The major branches of forestry include forest management, forest utilization, agroforestry, social forestry, and silviculture. Forestry uses scientific principles and involves measuring forests, understanding tree diseases, and sustainably managing both natural and urban forests.
The document discusses various diseases and disorders that affect plantation crops and forest species. It describes diseases caused by bacteria, fungi, insects and other living organisms as biotic stresses, and diseases caused by non-living factors like water, nutrients, chemicals, heat or cold as abiotic stresses. It then provides details on specific diseases affecting leaves, stems, roots and needles of trees. These include bacterial blight of eucalyptus leaves, pink disease affecting stems, Phytophthora root rot of acacia, and Dothistroma needle blight of pine. It describes the symptoms, causal organisms, species affected and management strategies for each disease.
This presentation summarizes several diseases that affect the sissoo tree species (Dalbergia sissoo), including leaf spot caused by various fungi which produce yellowish or grayish lesions on leaves, leaf blight caused by Rhizoctonia solani which causes stomata-infected blotches on leaves, powdery mildew caused by Phyllactinia dalbergiae which produces a dense white mycelium on leaves, and rust disease caused by Maravalia achroa which infects seedlings. It also discusses wilt symptoms of flagging leaves and die-back symptoms of thinning foliage and drying branches. Control methods include fungicide applications and sanitation practices.
This document provides lecture notes on tree improvement and silviculture. It begins with definitions of key terms used in tree improvement like additive genes, allele, backward selection, breeding orchard, breeding population, and breeding value. It then discusses the objectives and importance of tree improvement, noting that it aims to increase tree value through selection, breeding, and testing of desirable trees over multiple generations. The document emphasizes that tree improvement relies on understanding and utilizing natural genetic variation in tree populations.
This document provides an introduction to forest classification. It discusses that forests can be classified based on criteria such as composition, age, climate, structure and habitat. The objectives of forest classification are to study and characterize different forest types, develop suitable management techniques, and avoid waste and costs. Forests are commonly classified based on age (even-aged vs. uneven-aged), regeneration method (high forest vs. coppice forest), species composition (pure vs. mixed), ownership (state, private, community, panchayat), management objective (production, protection, fuel, farm, recreation), growing stock (normal vs. abnormal), and legal status (reserve, protected, village).
This document discusses different silvicultural systems used in forest management. It defines a silvicultural system as a set of operations used to tend, harvest, and regenerate a forest crop. Several specific systems are described in detail, including the selection system, clearcutting system, shelterwood system, and periodic block system. For each system, the document outlines the procedure, results or effects on forest structure, applicability to different forest types, as well as benefits and disadvantages.
Tectona grandis, commonly known as teak, is a large deciduous tree found in a variety of habitats with annual rainfall between 1,250-1,650 mm and a 3-5 month dry season. It is a light demander that is drought and frost tender, but highly resistant to fire, and regenerates well from coppicing and pollarding with a rounded crown. Teak grows best in deep, well-drained loamy to sandy loamy soil and is commonly associated with Acacia catechu and Adina cordifolia. Due to its high oil content, tensile strength and tight grain, teak is suitable for outdoor uses where weather resistance is required, such as
Important fire wood and timber yielding plant 1. dalbergia sissoo 2. a...gohil sanjay bhagvanji
This document summarizes three important firewood and timber yielding plants: Dalbergia sissoo, Terminalia arjuna, and Mangifera indica. It provides details on the classification, habitat, morphology, wood properties, and uses of each plant. Dalbergia sissoo is used widely for furniture and construction in North India. Terminalia arjuna has medicinal properties and is used to treat heart and lung conditions. Mangifera indica wood is used for rotary veneer, plywood, furniture, and other wood products in India.
Forestry involves the cultivation, management, and conservation of forests. It is important for economic, environmental, and social reasons. Forestry provides timber, fuelwood, and helps improve water quality and the environment. It also generates employment. The major branches of forestry include forest management, forest utilization, agroforestry, social forestry, and silviculture. Forestry uses scientific principles and involves measuring forests, understanding tree diseases, and sustainably managing both natural and urban forests.
Bamboo is a perennial grass native to warm tropical and temperate climates that grows from rhizomes. It has many uses including construction, textiles, medicine, culinary purposes and musical instruments. Silviculturally, bamboo is a strong light demander that is moderately sensitive to drought and highly sensitive to frost, fire and browsing. It occurs on various soil types from sandy loams to clayey soils and has a rhizome root system. Associates include Shorea robusta, Tectona grandis and various shrub species.
The document discusses natural and artificial regeneration of forests. Natural regeneration refers to the natural process by which plants replace or re-establish themselves through seed dispersal or vegetative reproduction like coppicing. It depends on several factors like seed production, germination conditions, seedling establishment and survival. Artificial regeneration involves human intervention through methods like sowing, planting or other means to renew forest crops. The choice of species, site selection, nursery practices and planting methods are important considerations for artificial regeneration.
Tree breeding is the application of genetic principles to improve the traits of forest trees. It involves selecting superior trees, known as plus trees, for traits like growth, form, and disease resistance. Progeny of plus trees are tested in progeny tests and seed orchards established to produce improved seed for planting. Tree breeding techniques include selection, hybridization, progeny testing, and use of seed orchards. The long generation times of trees require accelerated breeding approaches like vegetative propagation to shorten breeding cycles. Modern techniques also include use of micropropagation and genetic engineering. Tree breeding aims to develop trees with improved traits for yield, quality and stress resistance to enhance forest productivity.
A silvicultural system is the process used to tend, harvest, and regenerate a forest over time. There are two main groups of silvicultural systems: high forest systems and coppice systems. Systems are generally classified based on the pattern of regeneration and how the tree canopy is removed, and can result in even-aged or uneven-aged forest structures. Common systems include clearcutting, shelterwood systems, selection systems, and coppice systems.
This document discusses the collection, evaluation, and documentation of plant genetic resources or germplasm. It provides details on the importance of biodiversity in India and outlines the primary and secondary centers of diversity for various fruit crops. It then describes the process of germplasm collection, including planning exploration missions, areas to survey, sampling techniques, and collection methods for different plant types. The document also covers evaluation of germplasm for traits and stresses, as well as the documentation process which records information about accessions, collection, characterization and more.
Wood anatomy and structure , wood and its products DeepakYadav843
This document provides an overview of wood structure and anatomy at different structural levels from gross to microscopic. It discusses the gross structure of wood including heartwood, sapwood, growth rings, and defects. It then covers the microstructure of wood including different cell types in softwoods and hardwoods such as tracheids, fibres, vessels, and parenchyma. Specific features of softwood and hardwood microstructure are described along with cell wall features, extractives in heartwood, and reaction wood.
This document discusses tree crop interactions in agroforestry systems. It defines agroforestry as the deliberate combination of woody perennials and agricultural crops on the same land. Positive interactions include microclimate amelioration and soil improvement, while negative interactions are mainly competition for light, water and nutrients. The balance between positive and negative interactions determines the overall effect. Management techniques to reduce negative interactions and maximize yields include pruning trees, adjusting densities, mulching, and selecting complementary species mixtures.
Importance of non wood forest based industry in indianParvati Tamrakar
non- wood forest products, economic importance, socioeconomic benefits, tribal community, production and trade of nwfp- national and international, recent economic patterns of nwfp, india's noteworthy produce
This document describes the comparison-tree method for selecting superior trees for breeding programs. The method involves comparing candidate trees to nearby comparison trees of similar age and site conditions to account for environmental influences. If the candidate tree is superior to the comparison trees for traits of interest like growth, form, or disease resistance, it is designated as a plus tree suitable for the breeding program. Guidelines are provided for selecting stands and individual trees to identify the most genetically superior specimens while maintaining genetic diversity.
Abiotic and biotic factors can cause plant diseases. Abiotic factors include nutrient abnormalities, pesticide exposure, environmental pollution, temperature extremes, moisture issues, and light levels. Biotic factors are living organisms like fungi, bacteria, nematodes, viruses, and parasitic plants. Common symptoms of diseases caused by these factors include chlorosis, leaf curling, root knots, and mosaic patterns. Nutrient deficiencies or toxicities can result in yellowing. Pesticide drift may cause leaf cupping. Fungi, bacteria, nematodes, viruses, and parasitic plants can infect and damage various plant parts through their different life cycles and modes of transmission.
This document discusses principles of disease control in agricultural microbiology. It outlines four main principles: 1) Avoidance/Exclusion to prevent import and spread of pathogens, 2) Eradiation to reduce pathogen amounts, 3) Protection to directly protect plants from infection, and 4) Resistant varieties that hinder pathogen development. Specific control methods are described under each principle, including quarantine, sanitation, crop rotation, biological and chemical controls, and genetic engineering to develop resistant varieties.
Silvicultural characteristics of three tree species on subtropical region y...sahl_2fast
Mr. Yam Bahadur Rumba presented on the silvicultural characteristics of three tree species - Pinus roxburghii, Alnus nepalensis, and Schima wallichii - that are common in Nepal's subtropical regions. Pinus roxburghii is an evergreen pine species that tolerates poor soils and is important for its timber and resin. Alnus nepalensis is a deciduous broadleaf species that grows well in moist soils and is used for paper, plywood, and agroforestry. Schima wallichii is an evergreen broadleaf used locally for construction that grows across a wide range of soil types.
Silvicultural systems are methods of harvesting, regenerating, and tending forests. The two main types are high forest systems and coppice systems. High forest systems regenerate from seedlings and have long rotations, while coppice systems regenerate from stumps and have short rotations. Some common high forest systems include clearfelling, seed tree, shelterwood, and selection systems. Clearfelling removes the entire mature crop at once, while shelterwood and seed tree methods remove trees gradually to allow for natural regeneration under shelter. Selection systems involve uneven-aged management with continuous regeneration throughout the forest area.
Forest mensuration involves measuring various characteristics of trees and forests, including diameter, height, age, and volume. It provides important information for tasks like estimating timber quantity, evaluating forest growth and condition, and sustainable forest management. Key concepts include measuring trees at breast height for standardization, and ensuring accurate measurements through proper use of instruments and accounting for errors. Forest mensuration underpins many aspects of forestry.
1) The gene for gene hypothesis states that for each resistance gene in the host plant, there is a corresponding avirulence gene in the pathogen. When the two match, the plant is resistant and disease does not occur.
2) When a new resistant variety is developed and widely grown, it creates a "boom and bust cycle" - as the variety booms in popularity, it puts selection pressure on the pathogen population that favors strains that can overcome its resistance, leading to an epidemic that causes the variety's popularity to bust.
3) The "Vertifolia effect" occurs when a variety's resistance is overcome by new pathogen strains, as happened with the potato variety Vertifolia - its resistance
Forests play important productive, protective, and regulatory roles. They provide food, fodder, fuel, renewable energy, clothing, and other products for human use. Forests also protect against soil erosion, regulate climate and rainfall, maintain biodiversity, and purify the air. Forests ameliorate climate by intercepting sunlight, reducing temperature and wind speeds, and increasing precipitation. They are crucial ecosystems that sustain human and environmental well-being.
The document discusses the oak wilt fungus, one of the most destructive tree diseases in the United States. It kills oak trees in central Texas in epidemic proportions. It is caused by the fungus Bretziella fagacearum and is present in over 20 eastern and midwestern states. In Texas it is found in 76 central and west Texas counties and was first identified in Dallas in 1961. It impacts both rural and urban areas by reducing property values and destroying thousands of acres of live oaks. The document provides information on the fungus, how it spreads, symptoms, identification, and management strategies like prevention, trenching, and injection.
Fungi are categorized as saprophytic, parasitic, or symbiotic based on their relationship with other organisms. They require water, favorable temperature, oxygen, food sources, and other conditions to grow. Fungi can spread through spores and survive between crops. Common plant diseases caused by fungi include foliage diseases, bark diseases, and root diseases. Managing fungal diseases is important for crop protection and individual farmers' profits. Fungal diseases can compromise trees' photosynthetic ability and physiological processes, sometimes causing death.
Bamboo is a perennial grass native to warm tropical and temperate climates that grows from rhizomes. It has many uses including construction, textiles, medicine, culinary purposes and musical instruments. Silviculturally, bamboo is a strong light demander that is moderately sensitive to drought and highly sensitive to frost, fire and browsing. It occurs on various soil types from sandy loams to clayey soils and has a rhizome root system. Associates include Shorea robusta, Tectona grandis and various shrub species.
The document discusses natural and artificial regeneration of forests. Natural regeneration refers to the natural process by which plants replace or re-establish themselves through seed dispersal or vegetative reproduction like coppicing. It depends on several factors like seed production, germination conditions, seedling establishment and survival. Artificial regeneration involves human intervention through methods like sowing, planting or other means to renew forest crops. The choice of species, site selection, nursery practices and planting methods are important considerations for artificial regeneration.
Tree breeding is the application of genetic principles to improve the traits of forest trees. It involves selecting superior trees, known as plus trees, for traits like growth, form, and disease resistance. Progeny of plus trees are tested in progeny tests and seed orchards established to produce improved seed for planting. Tree breeding techniques include selection, hybridization, progeny testing, and use of seed orchards. The long generation times of trees require accelerated breeding approaches like vegetative propagation to shorten breeding cycles. Modern techniques also include use of micropropagation and genetic engineering. Tree breeding aims to develop trees with improved traits for yield, quality and stress resistance to enhance forest productivity.
A silvicultural system is the process used to tend, harvest, and regenerate a forest over time. There are two main groups of silvicultural systems: high forest systems and coppice systems. Systems are generally classified based on the pattern of regeneration and how the tree canopy is removed, and can result in even-aged or uneven-aged forest structures. Common systems include clearcutting, shelterwood systems, selection systems, and coppice systems.
This document discusses the collection, evaluation, and documentation of plant genetic resources or germplasm. It provides details on the importance of biodiversity in India and outlines the primary and secondary centers of diversity for various fruit crops. It then describes the process of germplasm collection, including planning exploration missions, areas to survey, sampling techniques, and collection methods for different plant types. The document also covers evaluation of germplasm for traits and stresses, as well as the documentation process which records information about accessions, collection, characterization and more.
Wood anatomy and structure , wood and its products DeepakYadav843
This document provides an overview of wood structure and anatomy at different structural levels from gross to microscopic. It discusses the gross structure of wood including heartwood, sapwood, growth rings, and defects. It then covers the microstructure of wood including different cell types in softwoods and hardwoods such as tracheids, fibres, vessels, and parenchyma. Specific features of softwood and hardwood microstructure are described along with cell wall features, extractives in heartwood, and reaction wood.
This document discusses tree crop interactions in agroforestry systems. It defines agroforestry as the deliberate combination of woody perennials and agricultural crops on the same land. Positive interactions include microclimate amelioration and soil improvement, while negative interactions are mainly competition for light, water and nutrients. The balance between positive and negative interactions determines the overall effect. Management techniques to reduce negative interactions and maximize yields include pruning trees, adjusting densities, mulching, and selecting complementary species mixtures.
Importance of non wood forest based industry in indianParvati Tamrakar
non- wood forest products, economic importance, socioeconomic benefits, tribal community, production and trade of nwfp- national and international, recent economic patterns of nwfp, india's noteworthy produce
This document describes the comparison-tree method for selecting superior trees for breeding programs. The method involves comparing candidate trees to nearby comparison trees of similar age and site conditions to account for environmental influences. If the candidate tree is superior to the comparison trees for traits of interest like growth, form, or disease resistance, it is designated as a plus tree suitable for the breeding program. Guidelines are provided for selecting stands and individual trees to identify the most genetically superior specimens while maintaining genetic diversity.
Abiotic and biotic factors can cause plant diseases. Abiotic factors include nutrient abnormalities, pesticide exposure, environmental pollution, temperature extremes, moisture issues, and light levels. Biotic factors are living organisms like fungi, bacteria, nematodes, viruses, and parasitic plants. Common symptoms of diseases caused by these factors include chlorosis, leaf curling, root knots, and mosaic patterns. Nutrient deficiencies or toxicities can result in yellowing. Pesticide drift may cause leaf cupping. Fungi, bacteria, nematodes, viruses, and parasitic plants can infect and damage various plant parts through their different life cycles and modes of transmission.
This document discusses principles of disease control in agricultural microbiology. It outlines four main principles: 1) Avoidance/Exclusion to prevent import and spread of pathogens, 2) Eradiation to reduce pathogen amounts, 3) Protection to directly protect plants from infection, and 4) Resistant varieties that hinder pathogen development. Specific control methods are described under each principle, including quarantine, sanitation, crop rotation, biological and chemical controls, and genetic engineering to develop resistant varieties.
Silvicultural characteristics of three tree species on subtropical region y...sahl_2fast
Mr. Yam Bahadur Rumba presented on the silvicultural characteristics of three tree species - Pinus roxburghii, Alnus nepalensis, and Schima wallichii - that are common in Nepal's subtropical regions. Pinus roxburghii is an evergreen pine species that tolerates poor soils and is important for its timber and resin. Alnus nepalensis is a deciduous broadleaf species that grows well in moist soils and is used for paper, plywood, and agroforestry. Schima wallichii is an evergreen broadleaf used locally for construction that grows across a wide range of soil types.
Silvicultural systems are methods of harvesting, regenerating, and tending forests. The two main types are high forest systems and coppice systems. High forest systems regenerate from seedlings and have long rotations, while coppice systems regenerate from stumps and have short rotations. Some common high forest systems include clearfelling, seed tree, shelterwood, and selection systems. Clearfelling removes the entire mature crop at once, while shelterwood and seed tree methods remove trees gradually to allow for natural regeneration under shelter. Selection systems involve uneven-aged management with continuous regeneration throughout the forest area.
Forest mensuration involves measuring various characteristics of trees and forests, including diameter, height, age, and volume. It provides important information for tasks like estimating timber quantity, evaluating forest growth and condition, and sustainable forest management. Key concepts include measuring trees at breast height for standardization, and ensuring accurate measurements through proper use of instruments and accounting for errors. Forest mensuration underpins many aspects of forestry.
1) The gene for gene hypothesis states that for each resistance gene in the host plant, there is a corresponding avirulence gene in the pathogen. When the two match, the plant is resistant and disease does not occur.
2) When a new resistant variety is developed and widely grown, it creates a "boom and bust cycle" - as the variety booms in popularity, it puts selection pressure on the pathogen population that favors strains that can overcome its resistance, leading to an epidemic that causes the variety's popularity to bust.
3) The "Vertifolia effect" occurs when a variety's resistance is overcome by new pathogen strains, as happened with the potato variety Vertifolia - its resistance
Forests play important productive, protective, and regulatory roles. They provide food, fodder, fuel, renewable energy, clothing, and other products for human use. Forests also protect against soil erosion, regulate climate and rainfall, maintain biodiversity, and purify the air. Forests ameliorate climate by intercepting sunlight, reducing temperature and wind speeds, and increasing precipitation. They are crucial ecosystems that sustain human and environmental well-being.
The document discusses the oak wilt fungus, one of the most destructive tree diseases in the United States. It kills oak trees in central Texas in epidemic proportions. It is caused by the fungus Bretziella fagacearum and is present in over 20 eastern and midwestern states. In Texas it is found in 76 central and west Texas counties and was first identified in Dallas in 1961. It impacts both rural and urban areas by reducing property values and destroying thousands of acres of live oaks. The document provides information on the fungus, how it spreads, symptoms, identification, and management strategies like prevention, trenching, and injection.
Fungi are categorized as saprophytic, parasitic, or symbiotic based on their relationship with other organisms. They require water, favorable temperature, oxygen, food sources, and other conditions to grow. Fungi can spread through spores and survive between crops. Common plant diseases caused by fungi include foliage diseases, bark diseases, and root diseases. Managing fungal diseases is important for crop protection and individual farmers' profits. Fungal diseases can compromise trees' photosynthetic ability and physiological processes, sometimes causing death.
Effective Prevention Tips for Sudden Oak Death.pdfTree Doctor USA
Discover effective prevention tips and treatment options for Sudden Oak Death with Tree Doctor USA. Learn to identify symptoms, implement prevention measures, and promote tree health.
This document discusses common tree diseases and disorders caused by biotic and abiotic agents. It describes symptoms of diseases like powdery mildew, anthracnose, bacterial leaf scorch, and various tree cankers. Signs and conditions favorable for disease development are explained. The role of stress factors in predisposing trees to disease is also covered. The document provides guidance on diagnosing tree problems and submitting samples for analysis. Common urban tree insects like bark beetles, borers, caterpillars, and sucking insects are also outlined.
This document provides an introduction to plant diseases and disorders. It describes several common fungal diseases that affect plants, including grey mould, strawberry powdery mildew, damping off, honey fungus, rose black spot, potato blight, clubroot and hollyhock rust. For each disease, it outlines the symptoms, life cycle, and methods of spread. It also lists two methods for minimizing the effects of each disease, such as removing infected plants, improving cultural practices like hygiene and rotation, and in some cases chemical controls. The learning objectives cover explaining why diseases must be controlled, defining plant disease, describing several diseases and their impacts, comparing life cycles and spread, and outlining prevention and control strategies by understanding
This document provides an overview of plant disease diagnosis and tree disorders. It discusses the importance of distinguishing between biotic and abiotic disorders, outlines the systematic diagnostic process, and describes common symptoms and signs. Key terms are defined throughout. Abiotic disorders can include improper planting sites, weather damage, and other environmental stresses. Biotic disorders involve living organisms like insects, diseases, and pathogens. Correct diagnosis requires examining multiple aspects of the plant and site conditions.
Decoding The Seasons: Why Trees Shed Their Leaves NaturallyTree Doctor USA
Discover the ultimate Tree Healthcare Solutions at Tree Doctor USA. Our expert team offers personalized care, diagnostics, and eco-friendly treatments to ensure the vitality and beauty of your trees. Experience a revitalized landscape with our cutting-edge techniques. Trust us to nurture your trees and enhance the health of your outdoor environment.
This document discusses several bacterial diseases that affect important pome and stone fruits grown in Pakistan. It describes the causal organisms, symptoms, and management strategies for blister spot, crown gall, fire blight, and bacterial spot/canker diseases of apple, pear, peach, and other fruits. The diseases are caused by bacteria such as Pseudomonas, Erwinia, Agrobacterium, and Xanthomonas species. Symptoms vary by disease but include leaf spots, cankers, shoot blights, and galls or tumors on roots and stems. Management involves practices like sanitation, resistant varieties, and antibiotic sprays to control the spread and reduce impacts of these bacterial diseases.
Loquat diseases By Allah Dad Khan Provincial Coordinator IPM KPK MINFALMr.Allah Dad Khan
This document summarizes four diseases that affect loquat trees: canker, Phytophthora root rot, fire blight, and Verticillium wilt. Canker causes circular brown spots and sunken areas on the bark, which is controlled by removing infected bark and spraying Bordeaux mixture. Phytophthora root rot is a soil-borne disease that causes wilting, yellowing foliage, and death over several years, controlled through water management and pruning. Fire blight causes dripping and staining on branches from cankers. Verticillium wilt infects through roots and causes foliage yellowing, stunting, and dieback, with no cure other than removing infected trees.
This document provides an overview of plant disorders and their diagnosis for urban foresters. It distinguishes between biotic disorders caused by living organisms and abiotic disorders caused by non-living factors. A systematic six-step process for diagnosis is outlined involving identifying the plant, examining patterns of abnormality, carefully examining the site, noting foliage characteristics, checking trunks and branches, and examining roots. Common signs and symptoms of disorders are defined, as well as types of stresses, abiotic disorders, biotic disorders, and how to seek additional information on diagnosis.
This document provides information on diagnosing tree problems and what causes trees to die. It discusses that tree death is usually caused by a complex interaction of biotic and abiotic factors combined with some bad luck. It outlines various insects, diseases, and environmental factors that can separately or combined kill trees, including root rots, stem/branch cankers, needle casts, bark beetles, borers, and more. It emphasizes that the underlying environmental situation should be examined before determining the primary cause of death, as many insects/diseases only impact declining trees.
This document provides information on nematodes that damage home gardens and landscapes. It summarizes that nematodes are microscopic roundworms that can infect and feed on plant roots. The most damaging nematode in gardens is the root knot nematode, which attacks many common vegetables, fruits, and ornamentals. It also lists other nematode species that can damage plants. The document describes the lifecycle of plant-feeding nematodes and the types of damage they cause, such as galls on roots or stunted aboveground growth. It provides recommendations for managing nematodes through sanitation, using resistant varieties, crop rotation, fallowing, soil solarization, and adjusting planting dates.
The document discusses the benefits of exercise for mental health. Regular physical activity can help reduce anxiety and depression and improve mood and cognitive functioning. Exercise causes chemical changes in the brain that may help boost feelings of calmness, happiness and focus.
Diseases of Bombax ceiba by sagar chaudhary.pptxSagar Chaudhary
Bombax ceiba grows to an average of 20 meters, with old trees up to 60 meters in wet tropical regions. The trunk and limb bear numerous conical spines particularly when young, but get eroded when older. The leaves are palmate with about 6 leaflets radiating from a central point (tip of petiole), an average of 7–10 centimetres (2+5⁄6–4 in) wide, 13–15 centimetres (5+1⁄6–5+5⁄6 in) in length. The leaf's long flexible petiole is up to 20 centimetres (8 in) long.
Huge Red Cotton Tree at Kodungallur, India
Cup-shaped flowers solitary or clustered, axillary or sub-terminal, fascicles at or near the ends of the branches, when the tree is bare of leaves, an average of 7–11 centimetres (2+5⁄6–4+1⁄3 in) wide, 14 centimetres (5+1⁄2 in) in width, petals up to 12 centimetres (4+2⁄3 in) in length, calyx is cup-shaped usually 3 lobed, an average of 3–5 centimetres (1+1⁄6–2 in) in diameter. Staminal tube is short, more than 60 in 5 bundles. The stigma is light red, up to 9 centimetres (3+1⁄2 in) in length, ovary is pink, 1.5–2 centimetres (2⁄3–5⁄6 in) in length, with the skin of the ovary covered in white silky hair at 1mm long. Seeds are numerous, long, ovoid, black or gray in colour and packed in white cotton.
Huge trunk of Red Cotton Tree
Immature fruits of Bombax ceiba in Hong Kong.
The fruit, which reaches an average of 13 centimetres (5 in) in length, is light-green in color in immature fruits, brown in mature fruits.
The document summarizes how Bordeaux Mix, the first liquid fungicide, was discovered in 1882 in Bordeaux, France. Grape growers noticed that grapevines along roads that had been sprayed with a blue substance to deter thieves were not affected by downy mildew, unlike other vines. When a local professor observed this, he discovered Bordeaux Mix, made of copper sulfate, lime, and water, which controls many plant pathogens and is still used today.
Healthy trees provide many benefits to communities by cooling streets and providing shade, habitat for wildlife, and safety and well-being for families. Unhealthy trees, on the other hand, pose risks and should be inspected. Signs of an unhealthy tree include the presence of mushrooms, dead or dying limbs, cracks in the bark, weak branch unions, and decay. Anyone noticing these signs in a tree should immediately consult an arborist to assess the tree's condition and address any health issues or risks.
This document provides an outline and overview of the causes of plant diseases. It discusses both abiotic factors such as nutrient deficiencies or toxicities, pesticide exposure, environmental pollutants, and extreme weather conditions. It also examines biotic factors including fungi, bacteria, viruses, nematodes, and phytoplasmas. Specific examples are given for each type of pathogen and the symptoms they cause in plants.
2 Plant Health Care Fungal Pathogens Lecturesherylwil
The document discusses several fungal pathogens that affect plants. It describes the structures and life cycles of fungi, including hyphae, mycelium, and fruiting bodies. Several fungal diseases are then summarized, including powdery mildew, rust, early blight, fusarium wilt, and verticillium wilt. The diseases are grouped based on whether they primarily affect leaves, stems, or roots. Specific symptoms and management strategies are provided for selected fungal pathogens.
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
The simplified electron and muon model, Oscillating Spacetime: The Foundation...RitikBhardwaj56
Discover the Simplified Electron and Muon Model: A New Wave-Based Approach to Understanding Particles delves into a groundbreaking theory that presents electrons and muons as rotating soliton waves within oscillating spacetime. Geared towards students, researchers, and science buffs, this book breaks down complex ideas into simple explanations. It covers topics such as electron waves, temporal dynamics, and the implications of this model on particle physics. With clear illustrations and easy-to-follow explanations, readers will gain a new outlook on the universe's fundamental nature.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
2. Heart rot
Introduction:-
In trees, heart rot is a fungal disease that causes the
decay of wood at the center of the trunk and branches. Fungi
enter the tree through wounds in the bark and decay the
heartwood. The diseased heartwood softens resulting in trees
being structurally weaker and prone to breakage. Heart rot is a
major factor in the economics of logging and the natural
growth dynamic of many older forests. Heart rot is prevalent
throughout the world affecting all hardwood trees and can be
very difficult to prevent. A good indication of heart rot is the
presence of mushrooms or fungus conks on the tree.
3. In living trees, most of the decay is confined to the
older, central wood (heartwood) of roots, trunks, or branches.
Once the tree is cut, however, the outer wood or sapwood is
also colonized by the wood-decay fungi, as are the wood
products made from the tree, if moisture and temperature
conditions are favorable for growth of the fungi. When deep
wounds or cuts are present, discoloration and decay often
spread into the outer wood, and the entire tree, especially if it
is a hardwood, loses its economic value.
4. Biological cause
Heart rot is caused by fungi entering the trunk of the
tree through wounds in the bark. These wounds are areas of
the tree where bare wood is exposed and usually, a result of
improper pruning, fire damage, dead branches, insects, or even
animal damage. The fungal spores enter the exposed wounds,
germinate within the wood tissues, and slowly ingest the
heartwood.
The infection is a very slow process and can take from
months to years, depending on conditions and tree health. An
average fungus will advance in the heartwood by 6–8
centimeters per year, and extensive development in the wood
tissue is needed before mushrooms or conks are produced.
5. Impact
Heart rot fungi have both a huge economic and
environmental impact. The fungi only target the nonliving wood
tissue of the heartwood and do not affect the living sapwood.
Initially, infected heartwood is discolored but not structurally
compromised. As the fungi grow they decay more wood and the
tissue becomes increasingly soft and weak. The tree can still grow
around the decayed heartwood because the live wood tissue is not
affected. The growth around decayed areas of heartwood creates
structural weaknesses in the tree. Trees with extensive decay are
more susceptible to broken branches and trunks.
7. Logging
Heart rot causes huge profit loss in the logging industry every
year due to damaged and decayed timber. It is estimated that
about one third of annual timber (20 billion board feet) harvest
is lost due to some form of rot. Trees wounded from
machinery or other falling trees are more susceptible to heart
rot. It results in trees that cannot be sold due to substantial
decay and introducing ideal rot conditions into younger forests
that would normally not be as susceptible
8. Environmental
Heart rot and other tree disease serve as factors of environmental
change. This is magnified in areas that are not prone to large-scale
dynamic disturbances like wildfires or are dominated by old-growth
timber. In older-growth forests, trees are unable to combat heart rot
effectively because they grow at a much slower pace. Extensive rot
causes these trees to be more susceptible to high winds and trunk
fracture. As the old growth dies out, it allows new growth to take its
place, altering the dynamic of the environment. Decaying trees also
provide shelter to animals as well as microorganisms. Through this
process of dynamic change, heart rot contributes to biologically diverse
habitats
9. Diagnosis of tree diseases- Symptomatology, signs,
Methods of identification of diseases:-
Diagnosis of tree Problems:-Several steps must be taken in order to effectively diagnose tree
problems. The following are general guidelines:
1. Properly identify the tree. It is important to know exactly
what species you are looking at.
2. It is also vital to know what the leaves, bark, trunk, and roots
should look like under “normal” conditions.
3. Check for host specificity.
4. Carefully examine the types of symptoms and the part of the
plant impacted.
10. a) Typical symptoms include:
underdevelopment of tissues or organs (stunting and malformed leaves);
overdevelopment of tissues or organs (galls, brooms, and stress cones); necrosis (death) of plant
parts (wilting, dieback, and leaf spots); and alteration of normal appearance (chlorosis).
b) Examine how the symptoms are distributed:
If the entire tree is infected, there islikely something wrong with the roots or stem, or
there may be an environmental cause. Single or randomly scattered affected branches are often
associated with insects or diseases.
c) Biotic agents tend to affect one species, are clumpy in distribution, show progressive
symptoms, and usually impact specific plant parts. Abiotic agents tend to affect many species
relatively uniformly.
11. 5. Determine the history of the tree and the site. Has the root system been disturbed? Have
chemicals been used? Has there been any harvesting? Other site factors, such as changing water
relations, extreme temperatures, or wind, fire etc.
6. Look for signs of biotic agents such as fungal fruiting bodies parasitic plants, larvae, or adult
insects.
a) Identify agents. Laboratory studies may be necessary in some circumstances.
12. Classification of forest tree diseases (root diseases, heart diseases,
wilt diseases):-
A. Root Rot Diseases:
1. The root rot diseases are caused by fungi and nematodes
2. Seedlings or tree wilt or decline or show deficiency symptoms
3. Discoloration and decay of the roots
4. Symptoms of root rot do not manifest till a large percentage of roots is attacked.
5. In natural forest resistant and susceptible species are mixed; the fungus remains in an
endemic stage.
6. Root rot fungi are considered to be specialized parasites, two groups may be
distinguished.
-The fungi cause typical root rot and don’t attacks the heart wood.
e.g. Ganoderma lucidum.
- The fungi not only attack the ling sapwood but also the heartwood and in case of
Fomes annosus, Armillaria mellea and Polyporus schweini zii.
13. Modes of infection of root rot fungi:
1. Fungi causing root rot are transmitted through root graft, by mycelium
growth through soil, or insects and nematodes
feeding on roots.
2. Fungi produces cellulose and lignose enzyme capable of breaking cellulose
and lignin.
3. This type of diseases problems is escalated (the act of getting up a wall) by
nutrient imbalance, poor soil aeration, water logging condition etc.
Control Measure:
Root diseases are generally difficult to control since the diseased parts are not
easily accessible. Some of the techniques used in root diseases control are as follows:
14. A). Silvicultural Control Measures;
1. Suitable site: Sisoo grows healthy free from root diseases on sandy loam
soils with good drainage but becomes diseases due to various root-infecting fungi
when raised in stiff soils of clay.
2. Control burning (Polyporus shoreae): It inhibits development of root
diseases. A root rot diseases caused by the Polyporus shoreae in sal at the wet forest is
controlled.
3. Site preparation: Removal of residual and tree stumps (Fomes annosus)
4. Resistant species and mixed species: If the threat due to root diseases is
suspected, planting resistant species in the first rotation is advisable. In case a species
susceptible to root rot is raised in the first rotation, it should be planted in intimate
mixture with resistant species which will serve as barriers to rapid spread of the
diseases.
5. Isolation trenches: Root rot diseases generally spread by the root to root by
contact or root graft resulting in diseases plants in groups. Isolation trenches results
effective in containing the disease in between the trenches thus preventing its spread
beyond the trenches.
15. B) Chemical Control Measures:
This is preventive type of control where Fomes annosus root rot is prevalent;
freshly cut stumps can be immediately spread with boric acid or sodium nitrate. The
chemical should be easily available, cheap, easy to apply and non-poisonous.
C)Biological Control:
Colonization of stumps by Fomes annosus can be prevented by inoculation fresh stumps
with another non pathogenic fungus, e.g. Peniophora gigantean. Inoculation pine stumps
with P. gigantea soon after felling by oidia of the fungus gives satisfactory protection
against F. annosus.
16. B )Heart Wood Diseases:
Decaying of living trees, heart rot accounts for more or less in sawn timber than
fire, insects, whether or any other diseases agents. About one third of all losses in sawn
timber are caused by heart rot.
I) Progress of decay in trees:
Decay is progressive nature in tree. The rate of spread of the decay depends on
the host and the fungus. It depends on the
following factors:
1. Age
2. Site
3. Soil moisture
4. Soil texture
5. Soil reactions
6. Stand vigor.
17. II) Detection of heat rots:
Heart rots in trees may be detected either from external symptoms manifested by
diseased trees or through direct probing into the
heartwood.
III) External indicators:
1. Sporophore:
2. Trunk knots: due to Fomes pini
3. Swollen knots
4. Swollen boles
5. External injuries.
IV) Direct Probing:
Heart rot may be detected by taking increment cores from tree suspected to
contain decay and isolate the fungus from the decayed wood.
18. V) Base on the type of rot the fungi are grouped as:
1. White Rot fungi (Polyporus versicolor)
2. Brown Rot Fungi (Porea monticola)
3. Simultaneous Rot fungi
4. Soft Rot fungi (phyco mycetes and fungi imperfectile)
VI) Mode of Infection:
1. The heart Rot fungi use:
a) wounds on stem or
b) dying or dead branches and twinges.
2. Spores in the infection court germinate, produce enzymes and digest cell wall
component.
19. VII) Control:
1. Control burning.
2. Sanitation cutting.
3. Thinning and improved felling.
4. Prune properly so that the wound heals quickly.
5. Slash should be burnt after clear cuttings.
6. Removal of diseases tree:
a. More and more timber becomes decayed with age
b. Decayed trees occupy space that may profitably be taken up by healthy trees
c. The sporophore developing on decayed trees release spores, which serve as
inoculums or new infection.
20. C. Wilt Diseases:
Wilt of plant diseases characterized by the loss of turgor, which results in
drooping of leaves, stems and flowers or whole trees.
I) Wilt is caused by:
1. Bacteria, fungal or nematode activities in the vessels and tracheid's often by
clogging.
2. Disruption of uptake of water by feeder roots
3. By canker fungi girdling trunk or branches.
II) Symptoms:
1. Drooping or limp of normal colored leaves followed by yellowing, browning,
dying and defoliation.
2. Discoloration of current year’s vessel when stems are spiltted.
21. III) Example:
1. Sissoo Wilt (Fusarium solani)
2. Oak wilt in southern USA (Ceratocystis fagacearum)
3. Verticillium wilt (verticilium spp.)
IV) Mode of action:
1. By plugging pits and pores.
2. By disturbing translocation by toxin.
3. By introduction of air bubbles into the vessel.
4. By death and decay of roots.
V) Control:
1. Use resistant varieties.
2. Avoid wounding.
3. Control nematode in soil.
4. maintain tree health.
5. Use sanitation program.
22. Concept on pythium, polyporous, fomes, ganoderma, poria, lenzites, fusarium, and
their control:-
1) Pythium:
1. Pythium belongs to the class Omycetes.
2. Hyphae are aseptate (no partition wall).
3. Root Rot and dumping off are extremely destructive diseases of many plants
especially in nursery seedlings.
4. Pythium artotrogus on deodar (Dumping –off).
5. P. spinosum on cashew (Root Rot).
6. P. vexans on rubber (Patch canker).
7. Pythium is capable of living saprophytically in soil.
23. Life cycle:
1. Asexual fruiting body is a sporangium, in which the zoospores are formed. When
zoospores are formed they number up to 125 per sporangium and germinate by a
germ tube.
2. Oospore is formed after fertilization of antheredium and oogonium is formed.
Control:
1. Sterilization of soil.
2. Seed treatment (Blitox, zinc oxide).
3. Maintain drainage and watering of seedlings.
24. 2) Fomes:
This belongs to basidio mycetes.
It is one of the most common and destructive heart rot diseases.
It is worldwide in distribution and occurs on many species including:
1. Fomes caryophylli (heart rot in sal).
2. Fomes badius (heart rot in khair).
3. Fomes annosus (root and butt rot in deodar).
4. Fomes pini (heart rot in pine).
Diseases cycle:
1. Mycelium usually branched and septae.
2. The basidio spores produced in the body are discharged forcibly and carried by air.
3. When spore germinate on the surface of tree, the mycelium invades through wounds.
Control:
1. Sterilization of soil.
2. Seed treatment (Blitox, zinc oxide).
3. Maintain drainage and watering of seedlings.
25. 4) Ganoderma:
1. This belongs to basidio mycetes.
2. It is one of the distractive root rot diseases
3. The pathogen possesses a wide host range among broad leaved species, which go into the
composition of natural forests.
4. Ganoderma lucidum (root rot on khair, sissoo, Eucalyptus, poplars, chir-pine)
Disease cycle:-
The fungus is normally endemic in natural forests. When forest is clear-felled, the hoist
resistance is lost and fungus quickly spread on residual roots and stumps to build high
inoculums. Sporophores commonly develop on attacked plants, usually at the base or apparently
on the ground. Sporophores are usually stalked, corky, and later woody.
Control Measures:
1. Planting resistance species
2. Isolation trenches
3. Mixed plantation
26. 5) Poria:
It is also belongs to basidio mycetes. Fungus causes root rot and heart rot diseases.
1. Poria hypobrunnea on rubber.
2. Poria epimiltina on eucalyptus.
3. Poria monticola on chir pine.
Disease cycle:- Fungus establish on stumps through wind-blown spores and then
attacks hoist through rhizomorph (In some fungi, the hyphae aggregate to produce
long, firm and branching stands with a hard rid).
Control: Same as root rot and heart rot diseases.
27. 6) Lenzites:
1. Lenzites belongs to class basidio mycetes and family agaricaceae.
2. Spores are lathery when fresh and brittle when dry.
3. They cause brown cubical rot on coniferous logs, e.g. Lenzites betuling.
7. Fusarium:
Fusarium belongs to the Deutero mycetes (fungi imperfecti).
Most of the species are soil inhabiting. They pose serious problems in nursery
seedlings diseases.
1. Fusarium solani (wilt diseases on Sissoo)
2. Fusarium oxysporum (wilt diseases on teak)
3. Fusarium fuliginosporum (root rot in deodar)
Disease cycle:-
Pathogen is mostly restricted to roots. Diseased roots are plugged with hyphae and
infiltrated with jelly like substances, which hinder sap, flow to the crown resulting
wilt symptoms.
28. 8. Armillarea:
1. This fungus belongs to agaricaceae family.
2. It is saprophytic fungus and widespread incident of root rot of forest.
3. Armillaria mellea causes root rot in chir pine, blue pine, Eucalyptus, deodar, teak.
4. The mycelium develops in white, fan shaped felts between bark and wood.
5. The fungus subsists on roots and stumps in the form of rhizomorph.
29. Symptoms, pathogenic organism, mode of
infection, life cycle and control measures:
1. Sal (Shorea robusta)
a. Sal is an important timber species distributed in tropical and subtropical climate.
Some of the important disease of Sal forest is as follows:
A) Root and Butt Rot diseases:
Causal organism: Polyporus shoreae
Occurrences:
Polyporus shoreae occurs on sal throughout its range of distribution. It is
sporadic in drier types of sal, becoming common in locations with higher rainfall.
30. Infection and damage:
a. The fungus is capable of infecting healthy and uninjured roots.
b. The roots are first attacked at the distal end.
c. The infection progress up to the collar region and does not usually progress up to stem.
d. The infections spread by the root.
Predisposing factors:
a. P. Shoreae root rot in sal is significant in areas of high rainfall.
b. This fungus attack on the high moisture areas.
c. Fire protection leads to high soil moisture and heavy weed growth under which conditions
the roots become susceptible to attack by P. Shoreae.
31. Symptoms:
1. Affected trees do not exhibit symptoms till some roots are attacked.
2. Tree shows top-dying and it gradually extends down ward till trees are dead.
3. Such trees become windblown because they loose foothold in soil due to decay of roots.
4. Drier locations, killing of trees is slow, while in moister types death is rapid.
5. Tree may put forth epicormic branches.
6. Presences of white pocket rot in the bark and sapwood.
7. Small. light yellow mycelia felts of the fungus develop on bark or roots.
8. The heart wood usually remains unaffected.
32. Life Cycle:
1. Sporophores produces basidiospores.
2. The sporophores of the fungus are usually formed on affected trees at the base or on exposed roots.
3. Spores are disseminated by wind or water.
4. Infection gradually spreads to other parts of the root.
5. Sporophores are sessile, funnel-shaped, and soft when fresh.
6. Becoming brittle when dries. Light in weight, single or imbricate; upper surface is brown to black, glabrous.
Control Measures;
1. Reduces soil moisture by control burning and thereby minimizing infection by the fungus.
2. Remove dead and dying trees.
3. Isolate infected root by trenches.
4. Burning also helps in checking weed growth which conserves and increases soil moisture favorable for
diseases development.
Other root rots diseases: caused by:
a. Ganoderma lucidum and
b. Fomes lamaoensis also cause root rot in Sal.
33. B) Heart Rot diseases:
Sal has the reputation of being one of the most naturally durable timbers. However the living
trees are liable to attacked by heart rot fungi.
Causal organism:
a. Hymenochaete rubiginosa
b. Fomes caryophylli:
c. Fomes fastuousus:
Mode of infection:
a. Heat rot fungal infection occurs through open wounds on trunks or branches cause by
lightening, branch breakage,
browsing by animals and during felling and logging operations.
b. Dead branches, branches stubs and knots constitute important infection courts.
c. Frost may also cause splitting of the bark through which F. caryophylli infect.
d. Coppicing results in wounds on the stool and Hymenochaete rubiginosa, Fomes caryophylli
and F. Fastuousus fungi infect the stools.
34. Indicators of decay (symptoms):
a. Presence of sporophores, punk knot, wounds, swollen bole, knots, branch stubs, dead
branches.
b. In advanced stages of decay, sporophores develop on the host.
c. Punk knots are characteristics symptoms of attack by Fomes caryophylli on sal.
d. Hollow sound.
I) Hymenochaete rubiginosa
Occurrence;
1. Occurs in tropical and temperate zones and attacks a wide range of hosts in broadleaved
species.
2. The fungus may remain active on logs and converted wood.
3. The fungus occurs on sal and its associates like; Terminliaalata, Terminalia vellerica,
Lagerstroemia parviflora etc.
35. Damage;
1. H. rubiginosa commonly enters through fire injuries and may account for nearly 50% of the
total decay due to all causes.
2. Heart wood of sal is dark brown and discolored.
3. Finally a white pocket rot develops.
Sporophores:
Sporophores sessile, upper surface dark brown zoned velvety, in young later becoming
smooth, corky and rigid on drying.
36. II) Fomes caryophylli:
1. Decay due to Fomes caryophylli is commonly known as gauj or ankhya-rot or eye.
2. Widely distributed in sal forest and also its associates; Aogeissus latifolia, Ougeinensis etc.
3. In sal forest Fomes caryphylli may account for over 25% of the total decay due to all causes.
4. At the initial stage of infection wood strains dark brown which changes to white pocket rot in
advance stage.
5. Sporophores are perennial, dark brown, woody, and small hairy when young.
6. Yellow mycelia may develop in decayed wood.
37. III) Fomes fastuousus:
1. It occurs in all sal forest and abundant in coppice forest.
2. Wound parasite, invades through wounds made by fire.
3. Generally causes butt rot and extend up to main root.
4. Early decay manifests dark brown discoloration and advance stages indicate by white pocket.
5. Sporophores are hard perennial, sessile, woody, large.
Control Measures:
1. Reduce through the management practices and silvicultural measures by minimizing development of
wounds and infection courts.
2. In heavy frost areas, the injury to young crop may be prevented by adjustment of the canopy
3. Canopy adjustment is important in preventing suppression because due to suppression under storey crops
may suffer from dead branches, branch stubs and knots, all which constitute infection courts for heart rot.
4. Controlled burning in early stage minimize the risk of severe fire injury resulting prevent from the heart rot.
5. During felling operations, falling trees may cause injury to residual trees and cause a wound which becomes
courts for decay fungi. Such injury is prevented by the lopping of thick branches before felling.
6. Pathological rotation period should be obtained.
38. 2) Dalbergia Sissoo and casuarina:-
It is a strong light demander tree growing in well-drained soil of the tropical and
subtropical climate of Nepal. The following are:
important diseases of sissoo.
a. Wilt diseases;
Occurrences;
1. Wilt diseases in sissoo is prevalent in nursery as well as plantations raises in heavy soils with
poor drainage.
2. Wilt diseases is rarely problem in the natural forest.
Predisposing factors;
1. Wild diseases is correlated with the soil texture and moisture
2. It is absent in high proportion of sand containing soil.
3. Wilt in sissoo is favored by high soil moisture in sites with poor drainage
Causal organism: Fusarium solani:
1. Fusarium infects dead and weakened roots and progresses into healthy tissues.
2. Pathogen is restricted to the root
39. Symptoms:
1. Outer sapwood of infected root exhibits a characteristic pink to reddish pink stain.
2. In diseased root, vessels are plugged with hyphae and jelly like substances, which hinders sap
flow to crown.
3. Symptoms of tree diseases include yellowing of leaves, defoliation and death with few
months.
4. It shows yellowing and death of leaves in acropetal succession up the tree
Control:
Sissoo should be raised on the light textured soil with adequate soil moisture and good
drainage systems.
40. 3) Acacia Catechu:
1. Khair is a middle-sized tree.
2. It grows in riversides along with sissoo.
The important diseases for khair are as follows:
1. Ganoderma root rot.
2. Heart rot diseases: Fomes badius.
1. Ganoderma root rot: caused by Ganoderma lucidum
Mode of infection:
1. Wound parasite, infects khair through mechanical wounds of wounds made by animal.
2. Sporophores perennial, hard, woody, sessile and easily detachable from the host.
3. Upper surface brown to black, cracking with age
4. G. lucidum may be traced back to residual stumps and roots of the previous forest cover.
5. The common genera including species attacked by G. lucidum are Acacia, Albizia, Cassia,
Casuarina, Dalbergia, Delonix, MangiferaTerminalia etc.
41. Damage:
1. Kills the bark and causes white spongy rot in the sapwood.
2. Khair is susceptible at all stage.
3. Affected plants exhibit pale foliage which eventually dries up.
4. Young plants are killed soon after infection.
5. The fungus produces thin white mycelia mat between the bark and the wood.
6. Mortality occurs from third year and increases with age of the plantation.
Host susceptibility:
1. In plantations where khair and other preferred species like sissoo. Semal, ailanthus, and teak
are raised on a reforested
stand not cleared of residual stumps and roots. The risk of G. lucidum root infections is high.
2. Khair and sissoo are the most susceptible hosts; Simal is attacked only when vigour is poor,
while others are resistant.
3. Pure culture inoculations on these confirm this observation.
42.
43. Sporophores:
1. Fruiting bodies of G. lucidum commonly develop on affected plants, usually at the base on
the ground but in the latter
case, the fruit bodies are invariably attached to decayed roots.
2. Due to presence of sporophores, it is easy to locate the infected minute.
3. Sporophores are usually stalked, rarely sessile, corky, and later woody.
Symptoms:
1. Presence of signs (sporophores) on different height of trees.
2. Yellow spongy, mottled decay due to formation of long black steak and zone lines.
Control:
1. Avoid injury.
2. Remove source of inoculums.
3. Conduct selected cutting.
Ganoderma lucidum may be minimized or kept under control by adopting one or more of the following
procedures;
1. Mechanizes plantations
2. Extraction of stumps
3. Isolation trenches.
44. 5. Mixed stands.
1. Mechanized plantations; this diseases risk is minimized through the mechanized plantations
as stumps and roots are removed during the plantations.
2. Extraction of stumps: If it is not possible to raise mechanized plantations, the incidence of the
disease can be minimized if the stumps and roots present in the lines are removed completely,
unlike the current practice where they are removed only up to the depth of the trench.
3. Isolation trenches; once the disease is attack in the line, its further spread are rapid from plant
to plant through root contact. This lateral spread can be checked by isolating trenches.
4. Planting resistant species: It is recommended that where the chance of G. lucidum root rot is
high than there is not to plant the susceptible speces like khiar and sissoo, in the first rotation
but to raise resistant species, like simal. Etc.
5. Mixed stands; If susceptible species like Khair and sissoo, are raised in a stand with high risk
of root disease, it may be necessary to raise then in intimate mixture with resistance species,
like simal and ailanthus, which will break the continuity of a pure line of khair and other
susceptible species and there by prevent rapid spread of the disease in the plantation.
45. 2. Heart rot diseases: Fomes badius causing heart rot in khair (Acacia catechu) and Australian
Babul (Acacia mangium) is distributed throughout the range of its distribution.
Occurrences:
1. This is common in natural and planted forests of khair.
2. The fungus is mostly restricted to khair and occasionally attacks babul.
Infection and damage:
1. Fomes badius is a wound parasite.
2. The fungus infects khair through injuries due to mechanical causes and damage caused by
animals.
3. Decay in the heartwood.
4. Sapwood remains healthy
5. Heartwood is decayed progressely and finally becomes useless for katha and cutch.
6. Heartwood becomes yellow, spongy and light and presents a mottled appearance due to
formation of long streak lines.
47. Sporophopre:
1. Sporophores develop freely on affected trees.
2. Sporophores are perennial, sessile, hard, woody and easily detachable from the host.
3. The upper surface is brown or black, cracking with age and the hymenial surface dull brown
with minute pores.
Control measures:
1. Control of tree injures
2. Infection through the basidiospores that develop in them, so it is necessary to remove and
destroyed the sporophores.
3. Remove the attacked tree from the stands so as to enable salvaging of greater volume of
sound wood.
4. During the cultural or other silvicultural operations, all trees which have sporophores are
marked and removed.
Other fungi causing heart rot in khair are;
1. Fomes fastuous
2. Fomes senex and
3. Ganoderma applanatum.
48. 4) Deodar (Cedrus deodara)
1. Deodar is gregarious in well-drained soils.
2. It is fire sensitive and is also sensitive to frost.
3. Important diseases of this species are:
1. Fomes annosus: Root and butt rot:
This fungal species attacks mostly conifers and few other broad-leaved species and is
distributed all over the world. It is severe in temperate climate and minor important in
subtropical climate.
Mode of infection;
1. Basidiospores produced in the sporophores are windblown; the spores fined freshly cut
stumps or wound at the tree base, and infect trees.
2. Fresh cut stumps are very susceptible to be colonizes by this fungus and becomes epidemic
after thinning.
49. Symptoms:
1. Death of young trees or old trees in groups, mostly centrifugal, dead trees in center and dying
trees in periphery
2. Crown decline, Chlorosis, and defoliation.
3. Presences of white pocket rot in root and butt region.
4. Presence of thin mycelia mats in between bark and wood.
50. Control Measures:
1. Removal of infected trees.
2. Thinning in hot summer.
3. Use of chemical seal 9boric acid) after fresh cut.
4. Spraying spore suspension of Peniophora gigantia, which checks the further
growth of Fomes annosus.
51. 5. Chir Pine (Pinus roxburghii)
Chir pine is distributed on the subtropical climate. It is fire resistant and heavily tapped
for resin.
Some important diseases of chir pine are;
1. Root Rot diseases:
Causal Organisms:
1. Armillaria mellea,
2. Fomes annosus.
3. Ganoderm lucidum.
(Note: It are described previous slides.)
52. 2. Stem rust diseases:
1. This is stem rust diseases caused by Cronarium himalyense.
2. This fungus produces five types of spores in four stages
3. Pycniospore and aeciospores are produced on pine stem
4. Uredinosphore and Teliospore
5. Aeciospores are windblown in May-June that infect the leaf of secondary host (Swertia
species) and swertia spp. Produce basidiospores, which are windblown, and infect to the chir
pine stem.
Symptoms:
1. Early symptoms are resin exudation from pine stem.
2. Canker develops in late stage by bark crack
3. Pycnial and aecial cups through ruptured bark.
53.
54. Control Measures;
Eradication of secondary host
3. Heart rots diseases:
In chir pine heart Rot diseases is caused by Fomes pini and Ganoderma applanatusm.
55. 6) Pink diseases of Eucalyptus:-
1. A pink disease in eucalyptus is caused by Corticium salmonicolor, and is distributed
indigenously in tropical and temperate region.
2. Pathogen also damages economically important plants such as coffee, cinchona, rubber,
poplar, casuarinas, teak etc.
3. Plants of all ages are susceptible to diseases.
Symptoms:
1. Branch girdling by cankers
2. Repeated killing of leader branches
3. Big trees develop cankers resulted by bark splitting.
Control:
No effective control measures are known for pink diseases.
58. BROWN ROTS:-
Quinine Fungus
Brown Trunk Rot Fomitopsis officinalis (Fomes officinalis)
Hosts:- Douglas fir pines western larch spruce and hemlock are
common hosts. The fungus seldom occurs on true firs.
Distribution and damage:- This fungus is an important trunk rot of old
growth conifers. It is found most commonly on Douglas fir and larch
but also attacks pines and some other species. The incidence of this
organism in second growth forests is not well known but appears to be
low. It is believed that wounds broken tops and branch stubs are
common entrance points for the fungus It may also occasionally enter
fire scars.
59. Identification:-
The brown trunk rot only occasionally
occurs in the butt and is found mainly in the
trunk and upper bole of the tree where it is often
very extensive. Another characteristic that
distinguishes F. officinalis from L. sulphureus is
the bitter taste of fresh mycelial felts present in
the decayed wood. Thus it has been called
quinine fungus.
Fruiting body :-Fruiting bodies do not commonly occur on trees attacked by the fungus.
When present they are pendant woody perennial often hoof shaped structures with a chalky
surface. They may range in size from several inches to more than 2 feet 0.6 m long. Their
presence indicates extensive decay The fruiting bodies are white and leathery when young
but chalky and crumbly when old. Like the mycelial felts they also have a bitter taste.
61. Red Belt Fungus/ Brown Crumbly Rot
Fomitopsis pinicola (Fomes pinicola).
Hosts:- Most western conifers including pines true firs Douglas fir
western hemlock western larch spruce and western red cedar are hosts for
this fungus.
Distribution and damage:- This fungus is one of the most common wood
rot organisms in coniferous forests of western North America. Although it
is mainly a decomposer of dead and down it has also been known to cause
heart rot in living trees. The mode of entrance for this fungus is mainly
wounds and broken or dead tops Decay in living true firs the red belt
fungus has also been found to be associated with large open bole
swellings caused by dwarf mistletoe.
62. Field identification
Rot -The rot caused by this fungus is somewhat
lighter in color than that caused by some of the other
crumbly brown rots. Rot develops in both sapwood
and heartwood, It may vary in color from a yellow
brown to slightly reddish Cubical cracking is
common and the shrinkage cracks are usually filled
with white fungus felts.
Fruiting body:- Fruiting bodies are commonly found associated with this rot. They are
leathery to woody perennial bracket type structures that when young appear as a round
white fungus mass. As they develop the upper surface turns dark gray to black while the
fresh lower pore surface remains white to creamy in color. A conspicuous reddish margin
develops between the two surfaces thus the name red belt fungus Fruiting bodies of this
organism are among the most common ones seen on dead and fallen coniferous trees
They generally range from about 4 to 18 inches 10 to 46 cm across.
64. Scaly Cap Fungus:- Lentinus lepideus
Hosts:- Common hosts include pine western red cedar incense cedar hemlock true
fir and Douglas fir.
Distribution and damage:- This fungus is of worldwide distribution. It also decays
dead and down wood As a heart rot organism it does not appear to be limited to any
particular part of the tree. It has been observed rotting roots as well as heartwood in
the upper portion of the bole It is common on pines in the high elevations.
Field identification:- Rot Incipient decay appears as a yellowish stain. Advanced
decay is dark brown cubically cracked almost black where exposed. Thin white
mycelial fans are in shrinkage cracks Rotten wood is said to have an anise or
turpentine Odor.
65. Fruiting body:- Of all the important brown heart rots. this is the only one caused by a
typical mushroom type fungus. The fruiting bodies are often large and range from 2 to
12 inches 5 to 30 cm in diameter are borne on a stalk are leathery and have a white
gilled lower surface. The top of the cap is composed of a whitish surface overlaid with
darker tan to brown scales thus the name scaly cap The dry fruiting bodies become
quite hard and brittle.
66. Pocket Dry Rot:- Oligoporus amarus (Polyporus amarus)
Hosts:- Incense Cedar is the only known host.
Distribution and damage:- Oligoporus amarus causes a Common heart rot of
incense Cedar throughout its natural range. More than a third of the volume or
about 5 billion board feet of the merchantable incense Cedar is culled because of
rot by this fungus.
Pocket dry rot is most common in trees on good growing sites and moist
microsites and less common in trees on marginal sites near the eastern limit of
incense Cedar Trees less than 150 years old are relatively free of rot, whereas in
trees 200 years or older the incidence of decay increases rapidly. Fire scars, large
open knots and branch stubs are the most common entry point for the fungus.
67. Field identification:-
Rot O. amarus produces a characteristic brown pocket rot not unlike the
brown cubical rot of redwood . The initial stage the rot appears as a brownish
discoloration of the heartwood elongated pockets usually several times longer
than wide develop. The wood within the pockets is broken down into a dry dark
brown crumbly residue separated by cross and longitudinal shrinkage cracks.
Although pockets may coalesce with one another the margin between rotten
wood and sound wood remains sharp. The pockets never become so numerous
that the entire Central cylinder of heartwood is decayed as happens when brown
cubical rot decays redwood.
68. Fruiting body:- The fruiting bodies furnish certain evidence of
extensive pocket dry rot. Usually one rarely two fruiting bodies are
produced and then only on trees with extensive rot. They have a smooth
margin and often appear somewhat hoof shaped Old fruiting bodies
darken in color and become dry and firm. They appear annually and only
in late summer and fall Eaten by insects they may be destroyed in a short
time As a result they are only occasionally seen on trees with pocket dry
rot Shot hole cups depressions in the bark caused by woodpeckers
searching for insects at the base of an old fruiting body are also common
indicators of decayed trees.
69. Velvet Top Fungus:-
Red Brown Butt Rot:-Phaeolus schweinitzii
Hosts Douglas – fir, pines, true firs, larch, spruce, incense cedar, western red cedar
and rarely hemlock are known hosts.
Distribution and damage:- The velvet top fungus occurs through out the world
where conifers are native or introduced. Hardwoods are seldom attacked. This
fungus is most common on Douglas fir .The fungus generally enters trees through
basal fire scars and is known mainly as a butt rot, Organism but is also a root
parasite. Although it has been reported as a trunk rot it almost always is confined to
the root system and lower 8 to 10 feet 2.4 to 3.0 m of the tree bole. Timber losses
are not precisely known but considered high both because the valuable butt logs are
badly decayed and because infected trees are predisposed to wind throw and
breakage Infected trees often exhibit a pronounced butt swell.
70. Field identification:- Rot Incipient decay from this fungus is not easy to recognize but
may appear as a yellow green to reddish discoloration of heart wood Advanced decay
is a typical brown rot limited to the heart wood. Rotted wood characteristically
appears reddish brown and tends to form large cubes and cracks across the grain. Thin
white resinous fungus mats may appear in the shrinkage cracks. Dry decayed wood
may be easily crumbled into a fine powder .
71. Fruiting body:- The fruiting bodies of this fungus may appear either on the soil around
the base of an infected tree or on the butt of the tree itself. Depending on the site of
development they may be either brackets or mushroom like in structure. Brackets tend
to form on exposed wood whereas the stalked mushroom type fruiting bodies usually
appear on the soil. The fruiting bodies have a soft velvety top that when fresh is
usually reddish brown in color and encircled by a yellowish margin. Concentric lines
are also present on the top surface. The lower spore producing pore surface varies
from dark green to light brown The fruiting bodies are produced annually in summer
and fall and when old dry up darken and closely resemble cow dung. Windborne
spores enter and infect the host through fire scars and wounded roots Infection can
also spread from tree to tree through root contact.
72. Sulfur Fungus :
Brown Cubical Rot:- Laetiporus sulphureus (Polyporus sulphureus)
Hosts:- The usual hosts of this fungus are Douglas fir, true firs, pines, hemlock
spruce, larch and western red cedar.
Distribution and damage :-The sulfur fungus is common on hardwoods and conifers.
it causes considerable rot in conifers particularly true firs. The organism generally
enters through basal fire scars and wounds on conifers and primarily causes a butt rot.
Although sulfur fungus is not considered a major slash decay organism it is often seen
on stumps logs and dead trees.
Field identification:-
Rot - Advanced decay is similar to that caused by red brown butt rot. Decayed wood
is dark to reddish brown cubically cracked and is easily crumbled. Usually white
mycelial felts are present in the shrinkage cracks. These may be very thin or range up
to 0.25 inch 0.6 cm thick a foot 0.3 m or so wide and several feet long.
73. Fruiting body:- Clustered annual shelf like fruiting bodies are typical of this
organism. When fresh they are soft and fleshy with a bright yellow orange upper
surface and a bright sulfur yellow lower pore surface. Old fruiting bodies are hard
brittle and chalky white.
74. Redwood Cubical Rot:- Oligoporus sequoiae (Poria sequoia)
Hosts:- Coast redwood is the only known host.
Distribution and damage:- This rot is distributed throughout the natural range of
redwood. As one of the two major rots in redwood it is the most common and causes
the most cull. About 10 billion board feet of cull in redwood is attributed to heart rots
of which more than 75 percent is caused by Oligoporus sequoia. Surveys have shown
that by far the greatest amount of rot occurs in old growth redwood particularly in
those with basal fire scars or broken tops. Second growth redwood may suffer some
loss from O. sequoiae but fortunately the rot is not transferred from stumps to stump
sprouts.
Field identification:-
Rot - Initial stages of rot range from a dark brown stain of the inner heartwood to
scattered pockets of brown charcoal like dry rot which shrinks and cracks into cubes.
In the advanced stages the pockets of rot are so numerous that nearly the entire central
and to some degree the outer cylinder of heartwood is rotted.
75. Fruiting body:- The spore producing structure is unlike the typical bracket or
mushroom shaped fruiting bodies produced by most of the rot fungi. Instead the
entire fruiting body develops as a thin white mantle or crust composed of fungus
strands and a spore producing pore surface. The fruiting bodies often are no more
than 2 inches 5 cm long and 1 inch 3 cm wide and most frequently are found in fire
scars dark crevices and on the ends of down logs.
76. • Integrated Pest Management Strategies
• 1. Proper planning. Appropriate species and cultivar selection to match the right tree for
the right site will make it easier to keep trees healthy for their entire life.
• 2. Proper tree maintenance. Subsequent good cultural practices (planting, fertilizing,
watering, pruning, etc.) will help to maintain the health and vigor of any tree.
• 3. Avoid damage to tree trunks and roots. Even small wounds from mowers and trimmers
can allow infection by decay fungi. Avoid damaging all deciduous trees, both young and
old.
• 4. As soon as possible, remove trees that exhibit conks on the lower trunk and exposed
root areas. Large trees with severe internal rot may fall with little warning, injuring people
and causing extensive property damage. Consult a certified arborist for removal of large
trees.
77. Forest disease control
One prime object of forestry is to grow crops free from diseases and obtain profitable
harvest.
Forest crops are:
1. Perennial,
2. Rotation age of many decades
3. Low value per unit area in compound to agro crops
4. Therefore the chemical control measure of diseases is limited only for nursery and plantation.
5. Silvicultural and management practices are broadly applied to control diseases in case of
natural forest.
6. More valuable species are likely to be more damage and require more effort to protect.
A. Direct Measures:
1. Sanitation,
2. Eradication,
3. Isolation Trenches,
4. Chemical Control.
78. 1. Sanitation:
a. It is the process that reduces or eliminates the initial inoculums from which the disease
develops.
b. Control by sanitation requires an early detection of the diseases in the forest and taking
suitable steps to remove the diseases inoculums before it can spread the diseases. Cuttings,
thinning, felling.
c. Sanitation may also be carried out by removal of fruiting bodies of fungi.
2. Eradication:
a. Heteroecious rust requires two hosts complete their life cycle; these diseased can be
controlled by eradication of one of the hosts (weeds or unevaluated spp.) by weedicides..
b. Control of root rot may be obtained by removal of residual stumps and roots prior to planting
either by raising mechanized plantations or through extraction by physical means.
79. 3. Isolation:
a. Generally root diseases are not spread through soil.
b. Diseases are mainly contaminated to adjacent healthy plants through root contact or root graft.
c. The spread of disease can be checked by isolating diseased plants by trenches.
4. Chemical Control:
a. The use of chemicals in diseases control is limited only for nursery and plantation because of
its expensiveness and side effects.
b. Fungicides chemical may act in preventing infection. A fungicide must have the characteristics
to have desirable effects:
1. Able to attack the pathogen at weakest point of its life cycle and non-
toxic to the host to wild dosage used.
2. Should not cause any pollution hazards to wild life.
3. Should be long lasting even exposed to rain.
4. It must ne adhere well to produces a lasting effect.
80. B. Indirect Measures;
1. Choice and improvement of site.
2. Choice of species: A pure stand is ideal for a pathogen to build up to epidemic and infection is
direct and rapid from tree to tree. For these reasons, mixed stands are suitable for controlled
some kinds of disease.
3. Silvicultural and Management Practices.
4. Cultural Practices.
5. Biological control.
6. Resistance breeding.