7. LOOK FOR PATTERNS
Sudden or gradual appearance of symptoms?
Many plant species affected or only one?
Symptoms on one side or area of the plant… or
all over the plant?
8. WILTING (COLLAPSE OF
TISSUES)
Causes:
Under-watering
Over-watering
Root loss
High soil salinity
Insects feeding on the
conducting tissues
Caused by boring insect
Caused by water stress
9. LEAF NECROSIS (DEATH)
Causes:
Lack of water
Too much sun
Frozen soil
Drying winds
Herbicide toxicity
Look for patterns
Winter burn on Creeping Oregon Grape
10. LOOK FOR PATTERNS OF
LEAF NECROSIS
Note the pattern of
necrosis on the entire
plant.
Interveinal necrosis
Leaf blotch Marginal necrosis
11. LEAF CHLOROSIS
(YELLOWING)
Nutrient deficiency
Disease or insects
Mechanical damage
Interveinal chlorosis
caused by lack of iron.
Often a problem in
alkaline soils.
General chlorosis
caused by nitrogen
deficiency
12. LEAF CHLOROSIS
Rose mosaic virus
Stippling caused by
leafhopper Variegated cultivar of spotted laurel
Potassium deficiency
14. BIOTIC VS. ABIOTIC
PROBLEMS
Biotic (caused by
living things)
Physical evidence
Spreads progressively
throughout a plant
Limited to plants of a
particular species or
family
Abiotic (caused by
environmental
stress)
No physical evidence
May or may not
develop progressively
throughout a plant
May affect many or all
plants in a landscape
Affects only the part
of the landscape
affected by the stress
15. EVIDENCE OF INSECT
DAMAGE:
Chewed leaves Caterpillars, beetles,
sawflies, leaf miners
Bleached, yellowed, or
stippled leaves
Leafhoppers, aphids,
thrips, mites
Distortion of plant part Thrips, aphids
Dieback of twigs/branches Borers, scales
Presence of excrement or
dew
Aphids, whiteflies, thrips
21. GUMMING (SAP FLOW)
Common stress symptom on
Prunus and Pinus sp.
Caused by water
deficit or mechanical injury.
If accompanied by foaming or
foul odor, may be biotic
(bacterial or fungal).
23. BIOTIC OR ABIOTIC?
Bacterial – occurs on
plants in the Rose
family
Twigs curl to form a
“shepherd’s crook”
Conditions:
Temperatures
between 65 F and 86
F and relative
humidity above 65%
28. USE REFERENCES
www.extension.org
www.google.com (look for sites with .edu or .gov)
Pests of Landscape Trees and Shrubs, UC-Davis
Abiotic Disorders of Landscape Plants, UC-Davis
Weeds of the West, U of Wyoming
Weeds of California and Other Western States,
Volumes 1 &2, UC-Davis
Garden Insects, Cranshaw
Pest ID cards
29. MOST PROBLEMS START
OUT AS WEATHER OR
CULTURAL ISSUES.
Eliminate the most
obvious causes first:
Improper watering
(cultural)
Winter damage
Alkaline and/or salty soil
Southern or western
exposure
Heavy, clay soils – poor
drainage
Herbicide damage
Insects and disease
are often a
secondary problem.
30. STATE YOUR TENTATIVE
DIAGNOSIS
Rarely can say with absolute certainty.
Often a choice among a few options.
Offer the most reasonable and common
diagnosis.
Provide a safe solution – and an alternate
strategy if that doesn’t resolve the problem.
Let them know they can call again if their
problem is not resolved.
33. WHAT IS LIGHT
MICROSCOPY?
Light passes through or falls on a sample.
Lenses focus that light (and the image of the
sample that the light carries).
The sample seems to be brought nearer our eyes
for our careful examination.
34. WHAT IS A STEREO
MICROSCOPE?
Uses two optical pathways (two eyepieces)
Provides slightly different viewing angles to the
left and right eyes
Produces a 3-dimensional image
We have a 4-D microscope!
You can focus and show your clients in real time.
And you can take a picture and save to a file or print.
35. THE PARTS OF THE
MICROSCOPE
Stage
Focus knob
Zoom magnification adjustment (8x – 35x)
Eyepieces
(oculars
10x)
On/off switch on back
Carrying handle
Light source
(below)
Light sources
Indicator light/button for computer connection
Green = connected
Orange = not connected
Ilumination direction/brightness controls
Integrated 3.0 megapixel CMOS camera
36. ADJUST THE OCULARS TO FIT THE
SPACING OF YOUR EYES
When the oculars are
too far apart, you will
see the sample as two
images.
Bring the oculars
together until you see
only one image.
39. RESOLUTION
Resolution is the minimum distance separating
two points which still allows them to be seen as
two distinct points.
The better the resolution, the better we see
details of the image.
Poor resolution results in a single blurry blob or
“pixelation” when viewing on a computer screen.
57. CARE OF THE MICROSCOPE
Focus using the black focus knob.
Do not use the zoom knob (smaller, upper knob)
to focus.
Use a petri dish under most samples.
Do not use dissecting tools directly on microscope
stage.
Turn light off as soon as you are done.
Cover when not in use to prevent dust and dirt
build up.
Hinweis der Redaktion
Maple, elm, ash, chestnut, and poplar
Interveinal necrosis due to herbicide toxicity or to severe manganese deficiency.
Pin oak and silver maple are particularly susceptible.
Viruses cannot be controlled with pesticides – cannot survive outside of their host, so control is by prevention of their spread.
Salt burn on strawberry – client used fresh horse manure on his plants
Leaves do not abscise – look for ooze on affected tissues (usually only leaves). Susceptible trees include rose family –especially crabapple, pear, and serviceberry. Avoid over-fertilization. Usually treated with copper sprays to prevent spread (not an eradicant). Also use Streptomycin.
Leaves do not abscise – look for ooze on affected tissues (usually only leaves). Susceptible trees include rose family –especially crabapple, pear, and serviceberry. Avoid over-fertilization. Usually treated with copper sprays to prevent spread (not an eradicant). Also use Streptomycin.