Highlights of Urban Plant Protection ESRM451 These are the reading materials:

We decided to be real practical in selecting a text for the course.

But there is a lot of great reading material on pest management in the urban environment.

The University of California has other books useful in the area of urban plant protection.

Other books that will be placed on reserve: Agrios, George: Plant Pathology. Academic Press. Edmonds, R.L. et al Forest Health and Protection. The Pacific Northwest insect management handbook and the Pacific Northwest disease management handbook (these books are published each year). Johnson, W.T. and H.H. Lyon Insects that feed on trees and shrubs. Cornell University Press. Sinclair, W.A., and H.H. Lyon Diseases of trees and shrubs. Cornell University Press.

Two classic books: Agrios on plant pathology, and Metcalf and Flint on entomology. Do you have Agrios? Also, I need Metcalf and Flint?

If you go to any agricultural library you’ll find Agrios.

George Agrios

Original book was by C.L. Metcalf and W.P. Flint.

INSECTS OF The two “Cornell Books”

Why the “Cornell Books” are so good.

Two good insect handbooks

Diagnosis of Plant Problems: An Overview By: Bob Gara & Bob Edmonds

Diagnosing plant problems is simply good detective work: often done on basis of a few simple cues involves working through a series of steps - steps start from the largest overview - then down to individual plants showing the damage - ultimately down to the pathogen the insect, the weather factor, the bulldozer etc.

From experience, we practice a series of steps that must be followed to determine cause: a cause can be a living agent or an abiotic factor. - living agents can be pathogens such as fungi, viruses, protozoans, insects, and other pests - non-living factors can be mechanical wounding, breakage, abrasions, soil compaction, flooding etc. - non-living can also be temperature extremes excessive moisture, drought, oxygen deficiency, nutritional deficiency, chemical damage etc.

Now, this is important – especially to plant pathologists! If we are dealing with a living factor, we look immediately for SIGNS & SYMPTOMS. “It’s hilarious that you would confuse signs and symptoms, my children…”

A Symptom: the physical expression of a change in the appearance and function of a plant. A Sign: is the visible presence of the pathogen, such as a fruiting body or mycelia etc., or the damaging insect or its parts etc. Signs and Symptoms

Diagnosing plant damage

Defining the problem:  Identify the plant, its species and cultivar. Why? - leaves may be naturally chlorotic - leaves may have a natural viral-mosaic - weird lenticels or extra-floral nectaries - strange spore producing bodies e.g. ferns  Identify the symptom: - Necrotic, symptoms are those in which death of the cells occur. - Atrophic, symptoms are those in which the multiplication, growth, or differentiation of cells are slowed or stopped; result in sub-development of plant. - Hypertrophic, symptoms are those in which there is an excessive multiplication of cells.

Defining the problem:  Identify the plant, its species and cultivar. Why? - leaves may be naturally chlorotic - leaves may have a natural viral-mosaic - weird lenticels or extra-floral nectaries - strange spore producing bodies e.g. ferns  Identify the symptom: - Necrotic, symptoms are those in which death of the cells occur. - Atrophic, symptoms are those in which the multiplication, growth, or differentiation of cells are slowed or stopped; result in sub-development of plant. - Hypertrophic, symptoms are those in which there is an excessive multiplication of cells.

Fruit Spots Leaf Spots Shoot Blight Leaf Blight Wilt Root Rot Crown Gall Vascular Wilt Fruit Rot Determine the symptoms: Necrotic? Atrophic? Hypertrophic?

 Gain an overview of the problem: - Find the actual cause of the problem without being fooled, for example: - A foliage symptom may be chlorotic, yellowing of leaves, but this might be due to severe root damage. - You start developing your “rule of thumbs” e.g. if the entire top of the plant is dying, or if an entire branch is wilting you have to look downward at the primary cause of the problem. - If you see a wide spread symptom across a site, you think, “there must be a 1° cause of the problem here.”

Dying Douglas-firs at the Arboretum are infested with wood boring insects – but woodborers only attack dying trees! Primary problems that would occur to you: - drought - root rots - pollution

Other examples: Premature leaf drop; Premature needle drop of scale drop in conifers; Evergreen plants normally retain foliage for 3-6 yrs and lose the oldest gradually during each growing season – this is not what happens in a quick foliar thinning. Prolonged dry seasons, however, my accelerate normal needle or scale drop. Western red cedar in the Puget Sound urban environment – scale drop in fall is really noticed!

Normal “Cedar Flagging” – an Autumn Problem

 Be aware of patterns: Generally, non-uniform damage is caused by living factors, while uniform damage is caused by abiotic factors. Remember insects and fungi are specific in their feeding habits & don’t INITIALLY produce wide-spread discernable damage patterns.

Patterns (continued): pathogens and pests destroy plant tissues; tissues are removed, deformed, or grow into galls; these agents grow with time; don’t damage 100% of the host plants at one time; damage is progressive; generally, damage is initially limited to one part of the plant and spreads from that initial point of attack; organisms leave signs: fruiting bodies, mycelia, eggs, cast skins, excrement etc.

Patterns (continued): non-living factors (e.g. frost, herbicides, toxic pollutants etc.) tend to be wide-spread: - damage appears on all leaves of a certain age, e.g. on all leaves forming at time of toxic application; - damage appears on exposed foliage (i.e. leaves not shaded by overlapping leaves); - damage likely will appear on other plants of an area.

Foliar Chemical Spray Injury Pattern on leaf Leaf Damage by Non-living Factors: Leaf Scorch Caused by Drought Typical Uniform Symptoms Caused by Non-living Factors

Uniform pattern – Iron deficiency in Rhododendron abiotic damage

Abiotic mortality: poor planting technique plus a dry growing season.

 Development of a problem: - remember, non-living problems develop quickly & are static (don’t keep getting worse); - pathogens and insect pests grow in numbers over time & damage patterns develop over time.

Organismal damage multiplies over time Abiotic damage strikes suddenly July 5 th August 1 st

 Determination of the cause: - distinguish among the living damage-factors For example, look at the symptoms & signs of fungal vs. bacterial leaf spots. AbnormalityBacterialFungal

Again, look at the difference between fungal & bacterial leaf spots.

Tree Canopy Decline Patterns

Tree Decline Patterns (continued)

Finding symptoms and signs in entomology Easier than in plant pathology

Symptom Sign

Let’s review

…involves working through a series of steps - steps start from the largest overview - then down to individual plants showing the damage - ultimately down to the pathogen the insect, the weather factor, the bulldozer etc. …the sign! Diagnosis

A Symptom: the physical expression of a change in the appearance and function of a plant. A Sign: is the visible presence of the pathogen, such as a fruiting body or mycelia etc., or the damaging insect or its parts etc.

(1) Identify the plant, its species and cultivar. Why? - leaves may be naturally chlorotic - leaves may have a natural viral-mosaic - weird lenticels or extra-floral nectaries - strange spore producing bodies e.g. ferns (2) Identify the symptom : - Necrotic, symptoms are those in which death of the cells occur. - Atrophic, symptoms are those in which the multiplication, growth, or differentiation of cells are slowed or stopped; result in sub-development of plant. - Hypertrophic, symptoms are those in which there is an excessive multiplication of cells. - Etc. Rules in Diagnosis

(3) Be aware of patterns: Generally, non-uniform damage is caused by living factors, while uniform damage is caused by abiotic factors. Remember insects and fungi are specific in their feeding habits & don’t INITIALLY produce wide-spread discernable damage patterns.

Foliar Chemical Spray Injury Pattern on leaf Leaf Damage by Non-living Factors: Leaf Scorch Caused by Drought Typical Uniform Symptoms Caused by Non-living Factors Uniform Damage! Uniform Damage Along The Leaf Edges!

Uniform damage – Iron deficiency in Rhododendron spp.

Non-uniform problems: Are mostly caused by pathogens and insect pests & these organisms grow in numbers over time thus damage patterns develop over time. “On the other hand remember how non-uniform problems develop.”

Organismal damage multiplies over time Abiotic damage strikes suddenly July 5 th August 1 st An okay tree Wha- happened?

Finding symptoms and signs in entomology Easier than in plant pathology