This presentation summarizes abiotic disorders in forests. It begins with an introduction defining abiotic disorders as plant problems caused by non-living factors like weather, soil, chemicals, and mechanical injuries. It then outlines general symptoms like wilting, yellowing and stunted growth. The presentation proceeds to discuss specific abiotic disorders like nutrient deficiencies, climate/weather extremes, chemical injuries, mechanical injuries, and genetic predispositions. For each, it describes symptoms, affected plant organs, and management strategies. The goal is to educate about identifying and addressing abiotic factors impacting forest health.

1. FOREST PATHOLOGY
PRESENTATION ON
ABIOTIC DISORDERS
Presented by
OWEN CHISINGA & SAMUEL GONETA

2. OUTLINE OF PRESENTATION
• INTRODUCTION
• GENERAL SYMPTOMS OF ALL
ABIOTIC DISORDERS
• SPECIFIC ABIOTIC
DISORDERS, SYMPTOMS,
ORGANS AFFECTED AND
MANAGEMENT

3. INTRODUCTION
• Plant problems associated with non-living causal factors i.e
weather, soils, chemicals & mechanical injuries .
• In some cases, a genetic predisposition within the plant itself.
GENERAL SYMPTOMS
• Wilting, yellowing, stunted growth, branch death
• Water sprout formation, premature autumn leaf colouration
• Heavier than normal seed production.

4. SPECIFIC ABIOTIC DISORDERS
Grouped into;
• Nutrient deficiency
• Climate and weather extremes
• Chemical substance injuries
• Mechanical and physical injuries
• Genetic predisposition (abiotic abnormalities)

5. NUTRIENT DEFICIENCY
• In boron, calcium, iron,
magnesium, manganese &
nitrogen
• In phosphorus, potassium &
trace elements (molybdenum)
 Excess nutrients result in
toxicities
SYMPTOMS
• General chlorosis, necrosis &
loss of vigour
MANAGEMENT
• In deficiency apply fertilizer
• In excess increase irrigation
PLANT ORGAN AFFECTED
• Leaves, stems & shoots
Photo: Nutrient deficiency

6. CLIMATE AND WEATHER EXTREMES
• Includes; temperature, moisture &
gaseous extremes (high/low)
• Affects stand vigour, species and
age class diversity, soils & water
availability
SYMPTOMS
• Wilting, water soaking, yellowing &
decay
MANAGEMENT
• Plant resilient tree species
• Avoid planting low lying areas
• Practice irrigation or establish
drainage system
PLANT ORGAN AFFECTED
• Leaves, branches, twigs, bark, buds
and succulent stem
Photo; High temperature disorder

7. CHEMICAL SUBSTANCE INJURIES
• Grouped into; herbicides, salt &
pollution
• Caused by inappropriate,
improper & incorrect application
SYMPTOMS
• Yellowing, browning, drying ,
shedding of leaves & death
MANAGEMENT
• Plant salt tolerant tree species
• Plant trees away from roads
PLANT ORGAN AFFECTED
• Leaves, twigs, branches & bark

8. MECHANICALAND PHYSICAL INJURIES
• Damage to vegetation from using
equipment & from weather
related events
• Resulting into crushed, cut,
punctured, rubbed, or struck plant
parts
SYMPTOMS
• Slow growth, dieback, sunken or
sloughing bark
MANAGEMENT
• Avoid topping when pruning
• Use of shelter belts & keeping
machinery away from trunks
PLANT ORGAN AFFECTED
• Stems, branches, twigs, leaves and
bark
Photo: Wind damage

9. GENETIC PREDISPOSITION
• Includes; genetic mutation, reversions,
chimeras, leaf abscission, retention,
balls, burls, graft incompatibility &
branch architecture
• Expressed through its physiological &
morphological characteristics
SYMPTOMS
• Yellow blotched patches
• Discoloured longitudinal steaks
MANAGEMENT
• Maintain cultivar traits
• Quick & corrective pruning of genetic
reversions
PLANT ORGAN
AFFECTED
• Stems, leaves, branches,
flowers and twigs
Photo: Chimera leaves

10. All photos are sourced from google
THANK YOU (Zikomo Kwambiri)