Understand the Principles and Identify the Signs of Pests and Diseases of Trees — City & Guilds Limited Occupational Qualification Horticulture & Land Management Revision

    This subtopic focuses on building a comprehensive understanding of tree pathology, enabling learners to diagnose disorders by distinguishing between biotic

    Topic Synopsis

    This subtopic focuses on building a comprehensive understanding of tree pathology, enabling learners to diagnose disorders by distinguishing between biotic (living) and abiotic (non-living) causal agents. It emphasises practical identification of common pests, pathogens, and environmental stressors affecting UK tree species, alongside the principles of integrated pest and disease management to maintain tree health. Mastery of these principles is essential for arboricultural professionals to implement effective monitoring, prevention, and control strategies in urban and woodland environments.

    Key Concepts & Core Principles

    Exam Tips & Revision Strategies

    Common Misconceptions & Mistakes to Avoid

    Examiner Marking Points

    Understand the Principles and Identify the Signs of Pests and Diseases of Trees

    CITY & GUILDS LIMITED
    vocational

    This element delves into the science of tree pathology, equipping learners to distinguish between biotic and abiotic disorders and accurately diagnose common pests and diseases affecting trees. It covers the identification of causal agents, their life cycles, and the environmental factors influencing outbreaks. Practical skills are developed in monitoring, prevention, and implementing integrated control measures to maintain tree health in arboricultural and forestry contexts.

    29
    Learning Outcomes
    40
    Assessment Guidance
    40
    Key Skills
    30
    Key Terms
    43
    Assessment Criteria

    Assessment criteria

    City & Guilds Level 3 Diploma in Forestry and Arboriculture
    City & Guilds Level 3 90-Credit Diploma in Forestry and Arboriculture
    City & Guilds Level 3 Extended Diploma in Forestry and Arboriculture
    City & Guilds Level 3 Subsidiary Diploma in Forestry and Arboriculture
    City & Guilds Level 3 Certificate in Horticulture
    City & Guilds Level 3 Subsidiary Diploma in Horticulture
    City & Guilds Level 3 90-Credit Diploma in Horticulture
    City & Guilds Level 3 Diploma in Horticulture
    City & Guilds Level 3 Extended Diploma in Horticulture
    City & Guilds Level 3 Certificate in Forestry and Arboriculture

    Topic Overview

    The City & Guilds Level 3 Subsidiary Diploma in Forestry and Arboriculture is a comprehensive vocational qualification designed for students aiming to pursue careers in woodland management, tree surgery, or conservation. This diploma covers essential theoretical and practical aspects of forestry and arboriculture, including tree biology, identification, planting, maintenance, and harvesting. Students learn about sustainable forest management, health and safety regulations, and the use of specialist equipment, preparing them for roles such as forestry worker, arborist, or estate manager.

    This qualification is part of the wider Horticulture & Land Management sector, bridging the gap between basic horticulture and advanced land management. It emphasizes practical skills and knowledge applicable to real-world scenarios, such as managing woodlands for timber production, biodiversity, and recreation. By studying this diploma, students gain a deep understanding of tree physiology, soil science, and environmental legislation, which are critical for maintaining healthy trees and forests in the UK.

    The Subsidiary Diploma is equivalent to one A-level and is often taken alongside other qualifications or as a standalone route into employment or higher education. It provides a solid foundation for further study in forestry, arboriculture, or environmental science, and is highly valued by employers in the sector. Students develop transferable skills in problem-solving, teamwork, and communication, making them well-rounded candidates for the green economy.

    Key Concepts

    Core ideas you must understand for this topic

    • →Tree identification and taxonomy: Understanding the key features of common UK tree species, including leaf shape, bark texture, and growth habit, using dichotomous keys and field guides.
    • →Tree biology and physiology: Knowledge of tree structure, photosynthesis, respiration, and nutrient transport, as well as how trees respond to environmental stresses and pruning.
    • →Sustainable forest management: Principles of silviculture, including thinning, coppicing, and clearfelling, to balance timber production with biodiversity conservation and recreational use.
    • →Health and safety in arboriculture: Compliance with UK regulations such as the Health and Safety at Work Act, use of personal protective equipment (PPE), and safe operation of chainsaws, chippers, and elevated work platforms.
    • →Soil science and tree nutrition: Understanding soil types, pH, drainage, and nutrient cycles, and how they affect tree growth and health, including diagnosis of nutrient deficiencies.

    Learning Objectives

    What you need to know and understand

    • Distinguish between signs and symptoms of biotic and abiotic tree disorders.
    • Evaluate the life cycles and modes of infection of common fungal, bacterial, and viral tree pathogens.
    • Identify key insect pests and describe the damage they cause to different tree species.
    • Apply appropriate diagnostic techniques to confirm pathogen presence in the field.
    • Analyse environmental and cultural factors that predispose trees to pest and disease outbreaks.
    • Assess the effectiveness of biological, chemical, and cultural control methods within an IPM framework.
    • Develop a monitoring schedule for early detection of pests and diseases in a given woodland or landscape setting.
    • Justify selection of prevention and control measures based on economic, ecological, and legal considerations.
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Differentiate between signs and symptoms of biotic and abiotic tree disorders using systematic observation methods
    • Classify common tree pathogens by type (fungal, bacterial, viral) and their characteristic damage patterns
    • Evaluate the influence of environmental factors on the development and spread of tree diseases
    • Apply appropriate monitoring techniques to detect early signs of pest and disease infestation in trees
    • Design integrated prevention and control strategies for common tree pathogens, incorporating cultural, biological, and chemical methods
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Differentiate between signs and symptoms of biotic and abiotic tree disorders
    • Evaluate the effectiveness of various monitoring techniques for common tree pests and diseases
    • Apply appropriate control measures based on identified pathogens and site conditions
    • Analyse the life cycles of key biotic pathogens to predict disease progression
    • Assess the impact of environmental factors on tree health and disease susceptibility
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Analyse the principles of tree pathology to distinguish between biotic and abiotic disorders.
    • Diagnose common biotic pathogens by identifying characteristic signs and symptoms in trees.
    • Classify major biotic pathogens (fungi, bacteria, insects) and their impacts on tree health.
    • Evaluate monitoring and prevention strategies for early detection and management of biotic diseases.
    • Design integrated pest and disease control plans appropriate to specific tree species and environments.

    Assessment Criteria

    Key criteria assessors look for in your portfolio

    • Award credit for accurately distinguishing between signs (e.g., fruiting bodies, mycelium) and symptoms (e.g., wilting, chlorosis) when identifying disorders.
    • Demonstrate the ability to link specific pathogens to characteristic damage patterns on leaves, stems, or roots, using correct Latin binomials where appropriate.
    • Credit is given for correctly describing a pathogen’s mode of dispersal and infection, and explaining how environmental conditions influence disease severity.
    • For pest identification, marks are awarded for recognising key morphological features of common insects and their larval stages, and linking them to feeding damage.
    • When proposing control measures, credit is given for referencing IPM principles, including cultural, biological, and chemical options in a logical hierarchy.
    • Assessors should look for evidence of accurate recording and monitoring techniques, such as using pheromone traps or visual surveys, and interpreting data to inform control decisions.
    • Award credit for accurately classifying disease-causing agents as biotic or abiotic with clear justification and evidence from case studies.
    • Expect learners to differentiate between signs (physical evidence of the pathogen, e.g., fungal fruiting bodies) and symptoms (host responses, e.g., chlorosis) in practical identification tasks.
    • Credit demonstration of understanding of pathogen life cycles when explaining symptom progression or timing of control interventions.
    • Require application of appropriate monitoring techniques, such as seasonal visual inspections or trapping methods, for specific pests and diseases.
    • Assess the ability to integrate knowledge of host susceptibility and environmental conditions when diagnosing tree health issues.
    • Award credit for accurately linking specific signs (e.g., fruiting bodies, ooze) to their causal pathogen groups
    • Credit demonstration of systematic inspection: crown, trunk, root collar, and root zone assessment
    • Look for evidence of distinguishing between drought stress and vascular wilt diseases in case study responses
    • Award marks for selecting context-appropriate control methods with justification (e.g., biological control in conservation areas)
    • Award credit for accurately differentiating between signs (e.g., fungal fruiting bodies, frass) and symptoms (e.g., chlorosis, dieback) during practical assessments.
    • The learner must demonstrate the ability to link specific pathogens to their typical host tree species and seasonal occurrence, citing current UK outbreaks where relevant.
    • Credit should be given for proposing evidence-based control measures that prioritise cultural and biological methods over chemical intervention, aligned with best practice guidelines.
    • Look for systematic use of diagnostic frameworks, such as examining site conditions, tree history, and progressive symptom development, when analysing disease scenarios.
    • Award credit for demonstrating accurate identification of at least three biotic pathogens from provided specimens or photographs, including correct naming and symptom description.
    • Award credit for outlining a comprehensive monitoring plan that includes seasonal checks, environmental condition assessments, and record-keeping.
    • Award credit for proposing appropriate control measures for a given tree disease, justifying the choice of chemical, biological, or cultural methods based on the pathogen's life cycle and mode of transmission.
    • Award credit for differentiating between abiotic and biotic diseases using systematic diagnostic steps (e.g., site history, pattern of damage).
    • Award credit for accurately describing the disease triangle and explaining how modifying one factor can prevent disease.
    • Assessors must look for clear differentiation between signs (visible pathogen structures) and symptoms (host response) in diagnostic scenarios.
    • Evidence of correct identification of at least three common biotic pathogens (e.g., fungi, bacteria, insects) with their typical damage patterns.
    • Demonstrate understanding of integrated pest management (IPM) by proposing a hierarchy of control measures: monitoring first, then cultural, biological, and chemical as a last resort.
    • Award credit for accurately diagnosing a tree disorder based on photographic or case study evidence, including justification of biotic/abiotic cause
    • Credit identification of specific signs (e.g., fungal fruiting bodies, insect frass) as distinct from symptoms
    • Award marks for linking control recommendations to Integrated Pest Management principles and environmental sustainability
    • Credit recognition of seasonal and host-specific patterns in pest and disease occurrence
    • Award credit for accurately differentiating between signs (visible pathogen structures) and symptoms (host plant responses) with clear examples.
    • Credit demonstration of systematic diagnostic process linking environmental assessment to pathogen identification.
    • Expect evidence of applying IPM principles: monitoring, cultural controls, biological agents, and responsible chemical use as last resort.
    • Award credit for accurately describing the difference between signs and symptoms with reference to specific pathogens.
    • Award credit for correctly identifying common biotic pathogens such as fungi, bacteria, viruses, and insects from provided case studies or specimens.
    • Award credit for linking abiotic factors (e.g., drought, pollution) to observed symptoms and distinguishing these from biotic causes.
    • Award credit for recommending appropriate integrated control measures, considering environmental and legislative constraints.
    • Award credit for accurately describing symptoms using technical terminology (e.g., chlorosis, necrosis, cankers).
    • Expect candidates to link specific signs (e.g., fungal fruiting bodies) to probable pathogens.
    • Credit for consideration of environmental factors in disease development when proposing control measures.
    • Mark for demonstrating knowledge of biosecurity protocols in monitoring.
    • Look for justification of control method choice (e.g., cultural, biological, chemical) based on pathogen lifecycle.

    Assessment Guidance

    Guidance for achieving higher grades

    • 💡When answering identification questions, always refer to both macroscopic signs and microscopic confirmation methods where relevant to demonstrate thorough diagnostic knowledge.
    • 💡Structure control measure responses using the IPM hierarchy: cultural prevention first, then biological and physical controls, with chemical use as a last resort, always justifying your choices.
    • 💡For longer written tasks, integrate knowledge of tree physiology and environmental stressors to show a holistic understanding of disease development, rather than just listing symptoms.
    • 💡Practice sketching or describing key diagnostic features from memory—many assessments include photographic identification or require detailed written descriptions.
    • 💡Stay updated with current biosecurity legislation and forestry best practice, as these often form part of assessment criteria for control recommendations.
    • 💡In identification assignments, accompany every observation with clear photographs, location notes, and a structured checklist of signs and symptoms.
    • 💡When proposing control measures, explicitly link each strategy to the pathogen's biology and lifecycle, showing how it disrupts the disease cycle.
    • 💡Use the disease triangle concept (host–pathogen–environment) as a framework for analysis in written exams to demonstrate a systematic approach.
    • 💡Reference relevant UK industry standards and legislation, such as the Plant Health Order and Forestry Commission guidelines, when discussing prevention.
    • 💡Familiarise yourself with high-profile UK tree pests and diseases—like ash dieback and oak processionary moth—and practice rapid identification drills.
    • 💡Use a structured approach in answers: describe the symptom, identify the likely cause, and justify your reasoning with evidence
    • 💡For identification tasks, always note the host species, site conditions, and distribution of symptoms on the tree
    • 💡Refer to specific scientific names of common pathogens to demonstrate precision in assessments
    • 💡When discussing control, prioritise prevention and cultural practices before chemical interventions to reflect sustainable arboriculture
    • 💡In written assignments, always structure your answers using the disease triangle (host, pathogen, environment) to show systematic understanding.
    • 💡When given a case study, first rule out abiotic causes (compaction, pollution, etc.) before considering pests or diseases to demonstrate a logical diagnostic process.
    • 💡For identification tasks, learn key diagnostic features of notifiable pathogens (e.g., Ash dieback, Acute oak decline) as these are frequently assessed.
    • 💡Support your control recommendations with reference to current legislation and guidance, such as the Plant Health Act and Forestry Commission advice.
    • 💡In practical assessments, follow a systematic approach: examine the entire tree (roots, trunk, branches, leaves), note distribution of symptoms, and consider site factors before diagnosing.
    • 💡For written assessments, learn the life cycles of key pathogens (e.g., Phytophthora, Armillaria) as questions often focus on vulnerable stages for effective control.
    • 💡When discussing control measures, always include cultural, biological, and chemical options where appropriate to demonstrate a holistic understanding.
    • 💡When answering diagnostic questions, always describe a systematic approach: start with environmental context, then examine the whole tree, then close-up of symptoms, and finally use a key or laboratory test.
    • 💡Link control measures directly to the known life cycle of the pathogen; for example, timing a fungicide application to spore release periods shows deep understanding.
    • 💡Include examples of proactive monitoring techniques, such as using pheromone traps or regular visual surveys, when discussing prevention strategies.
    • 💡Mention specific cultural practices like pruning for airflow, mulching, and selecting resistant cultivars as primary defences, demonstrating a professional IPM mindset.
    • 💡When identifying pests, always consider the season and tree species as key diagnostic clues
    • 💡Use a structured approach: observe location on tree, pattern of damage, and recent site history before concluding a diagnosis
    • 💡In coursework, provide explicit justification for each diagnosis, referencing signs, symptoms, and any relevant diagnostic tests
    • 💡For control measures, always discuss cultural, biological, and chemical options as part of an integrated strategy, not in isolation
    • 💡Use precise terminology: refer to specific pathogen genera/species and distinct symptom descriptions in written responses.
    • 💡In practical assessments, follow a structured approach: host identification, symptom description, site evaluation, and sample collection rationale.
    • 💡When proposing control measures, always justify selection with reference to pest/pathogen biology and environmental impact.
    • 💡In assessment scenarios, systematically document signs, symptoms, and site conditions before reaching a diagnosis, demonstrating a methodical approach.
    • 💡Use precise technical vocabulary (e.g., 'necrosis', 'chlorosis', 'mycelium') to convey competence in plant pathology.
    • 💡For control measures, always justify recommendations with reference to the pathogen’s life cycle and environmental impact, showing holistic understanding.
    • 💡Always structure answers with clear diagnostic steps: identify, classify, recommend.
    • 💡Use Latin names for pathogens to demonstrate precise knowledge.
    • 💡Reference current industry best practices and legislation (e.g., COSHH, Pesticide Regulations).
    • 💡In practical assessments, take thorough notes and photographs for accurate reporting.
    • 💡Practice distinguishing common look-alike diseases through specimen examination.
    • 💡Use correct terminology: In exams, always use precise arboricultural terms (e.g., 'apical dominance', 'cambium', 'root flare') rather than everyday language. This demonstrates depth of knowledge and earns higher marks.
    • 💡Link theory to practice: When answering questions, give specific examples from real-world scenarios, such as how you would manage a woodland for both timber and wildlife. This shows you can apply concepts.
    • 💡Show your working: For calculations (e.g., timber volume, chemical dilution), write out each step clearly. Even if the final answer is wrong, you can gain marks for correct method.

    Common Mistakes

    Common errors to avoid in your coursework

    • Confusing abiotic disorders (e.g., drought stress, nutrient deficiency) with biotic diseases due to similar visible symptoms.
    • Misidentifying insect frass or sooty mould as a primary pathogen rather than a secondary symptom of pest infestation.
    • Over-reliance on chemical controls without first considering cultural or biological alternatives, contrary to IPM principles.
    • Failing to recognise that multiple pests or pathogens can act simultaneously, and not linking contributing factors like tree stress or poor pruning.
    • Using common names for pests and diseases without accurate scientific identification, leading to inappropriate treatment selection.
    • Confusing signs and symptoms, e.g., labelling mycelium as a symptom rather than a sign of fungal infection.
    • Overlooking abiotic disorders such as drought stress or mechanical damage, attributing all decline to living pathogens.
    • Assuming that leaf discolouration always indicates disease without considering nutrient deficiencies or environmental stress.
    • Recommending chemical controls without first accurately identifying the pathogen, leading to ineffective or environmentally harmful interventions.
    • Underestimating the importance of regular monitoring, resulting in missed early-stage infestations like those of the emerald ash borer.
    • Confusing nutritional deficiency symptoms (e.g., chlorosis) with pathogen-induced foliar diseases
    • Overlooking abiotic factors such as soil compaction or waterlogging when diagnosing decline
    • Misidentifying saprophytic fungi on dead wood as primary pathogens
    • Applying control measures without confirming the pathogen life cycle stage
    • Confusing stress-induced symptoms (e.g., leaf scorch from drought) with infectious diseases, leading to incorrect control recommendations.
    • Over-reliance on chemical treatments as a first response, neglecting sanitation, pruning, and improving soil conditions which are often more sustainable.
    • Misidentifying saprophytic fungi as primary pathogens, resulting in unnecessary tree removal or treatment.
    • Failing to consider the role of vectors (e.g., bark beetles in Dutch elm disease) when explaining disease transmission cycles.
    • Confusing abiotic symptoms (e.g., drought stress) with biotic diseases, leading to misdiagnosis.
    • Incorrectly identifying fungal fruiting bodies as insect damage.
    • Over-reliance on chemical controls without considering integrated pest management (IPM) principles.
    • Failing to record and monitor environmental conditions alongside symptom development.
    • Confusing abiotic symptoms (e.g., drought stress, nutrient deficiency) with biotic damage, leading to misdiagnosis and inappropriate treatment.
    • Misidentifying saprophytic fungi as the primary pathogen when they are secondary colonisers of already damaged tissues.
    • Assuming all leaf spots or cankers are caused by fungi, overlooking bacterial or environmental causes.
    • Applying chemical controls without first confirming the pest or disease through monitoring, ignoring IPM principles.
    • Confusing drought stress symptoms with fungal infection signs
    • Overlooking abiotic causes such as soil compaction or nutrient deficiency when symptoms are non‑specific
    • Misidentifying saprophytic fungi as pathogenic without considering tree vigour
    • Applying control measures without first confirming the causal agent through systematic investigation
    • Confusing abiotic disorders (e.g., drought stress) with biotic diseases due to similar foliar symptoms.
    • Misidentifying saprophytic fungi as primary pathogens when assessing decay in living trees.
    • Overlooking the role of vectors and environmental conditions in disease development and control planning.
    • Confusing signs (direct evidence of the pathogen, such as fungal fruiting bodies) with symptoms (host response, such as wilting).
    • Failing to consider abiotic factors like soil compaction or nutrient deficiency when diagnosing tree decline.
    • Over-reliance on chemical controls without evaluating cultural or biological alternatives, neglecting IPM principles.
    • Misidentifying abiotic stress (e.g., drought, nutrient deficiency) as biotic disease due to similar symptoms.
    • Neglecting the importance of site hygiene and sanitation in disease prevention.
    • Applying chemical controls without first determining the specific pathogen and its susceptibility.
    • Overlooking the role of vector organisms in disease transmission.
    • Misconception: Pruning trees heavily in summer is always safe. Correction: Heavy pruning in summer can stress trees and increase risk of disease; it's often better to prune during the dormant season (winter) for most species, except for some that require summer pruning to reduce sap flow.
    • Misconception: All dead wood should be removed from trees. Correction: Dead wood provides important habitat for wildlife and can be left if it poses no safety risk; only remove dead wood that is hazardous or diseased.
    • Misconception: Tree roots grow deep and mirror the canopy. Correction: Most tree roots are shallow (top 60 cm of soil) and extend well beyond the canopy drip line; this affects planting, watering, and construction near trees.

    Frequently Asked Questions

    Common questions students ask about this topic

    Before You Start

    Prior knowledge that will help with this topic

    • •Basic understanding of plant biology and ecology, typically covered in GCSE Biology or Level 2 Horticulture.
    • •Familiarity with health and safety procedures in outdoor work environments.
    • •Numeracy skills for calculating areas, volumes, and chemical application rates.

    Key Terminology

    Essential terms to know

    • Tree pathology fundamentals
    • Biotic versus abiotic disorders
    • Fungal, bacterial and viral pathogens
    • Insect and pest identification
    • Integrated pest management (IPM)
    • Monitoring and surveillance techniques
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Pathology fundamentals
    • Biotic pathogen identification
    • Abiotic disorder diagnosis
    • Symptom recognition
    • Integrated pest management
    • Tree health monitoring
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Pathogen biology and life cycles
    • Symptom identification protocols
    • Abiotic vs biotic disorders
    • Integrated pest management
    • Monitoring and surveillance methods
    • Environmental stress factors
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Understand the principles of pathology and the common causes of disease., Be able to identify the signs and symptoms of common biotic and abiotic pathogens., Understand common biotic pathogens., Understand monitoring, prevention and control measures of common bioticpathogens.
    • Tree pathology principles
    • Symptom identification
    • Biotic pathogen classification
    • Abiotic vs biotic disorders
    • Integrated pest management
    • Monitoring and early detection

    Ready to learn?

    AI-powered learning tailored to this unit

    Related Topics in CITY & GUILDS LIMITED vocational Horticulture & Land Management

    Aerate turf by hand

    View Topic

    Aerate turf by hand

    View Topic

    Aerate turf by hand

    View Topic

    Apply fertiliser by hand to bare ground

    View Topic