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… orall over the plant?
WILTING (COLLAPSE OFTISSUES)Causes: Under-watering Over-watering Root loss High soil salinity Insects feeding on theconducting tissuesCaused by boring insectCaused by water stress
LEAF NECROSIS (DEATH)Causes: Lack of water Too much sun Frozen soil Drying winds Herbicide toxicity Look for patternsWinter burn on Creeping Oregon Grape
LOOK FOR PATTERNS OFLEAF NECROSIS Note the pattern ofnecrosis on the entireplant.Interveinal necrosisLeaf blotch Marginal necrosis
LEAF CHLOROSIS(YELLOWING) Nutrient deficiency Disease or insects Mechanical damageInterveinal chlorosiscaused by lack of iron.Often a problem inalkaline soils.General chlorosiscaused by nitrogendeficiency
BIOTIC VS. ABIOTICPROBLEMSBiotic (caused byliving things) Physical evidence Spreads progressivelythroughout a plant Limited to plants of aparticular species orfamilyAbiotic (caused byenvironmentalstress) No physical evidence May or may notdevelop progressivelythroughout a plant May affect many or allplants in a landscape Affects only the partof the landscapeaffected by the stress
EVIDENCE OF INSECTDAMAGE:Chewed leaves Caterpillars, beetles,sawflies, leaf minersBleached, yellowed, orstippled leavesLeafhoppers, aphids,thrips, mitesDistortion of plant part Thrips, aphidsDieback of twigs/branches Borers, scalesPresence of excrement ordewAphids, whiteflies, thrips
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
MOST PROBLEMS STARTOUT AS WEATHER ORCULTURAL ISSUES.Eliminate the mostobvious causes first: Improper watering(cultural) Winter damage Alkaline and/or salty soil Southern or westernexposure Heavy, clay soils – poordrainage Herbicide damage Insects and diseaseare often asecondary problem.
STATE YOUR TENTATIVEDIAGNOSIS Rarely can say with absolute certainty. Often a choice among a few options. Offer the most reasonable and commondiagnosis. Provide a safe solution – and an alternatestrategy if that doesn’t resolve the problem. Let them know they can call again if theirproblem is not resolved.
WHAT IS LIGHTMICROSCOPY? Light passes through or falls on a sample. Lenses focus that light (and the image of thesample that the light carries). The sample seems to be brought nearer our eyesfor our careful examination.
WHAT IS A STEREOMICROSCOPE? Uses two optical pathways (two eyepieces) Provides slightly different viewing angles to theleft 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.
THE PARTS OF THEMICROSCOPEStageFocus knobZoom magnification adjustment (8x – 35x)Eyepieces(oculars10x)On/off switch on backCarrying handleLight source(below)Light sourcesIndicator light/button for computer connectionGreen = connectedOrange = not connectedIlumination direction/brightness controlsIntegrated 3.0 megapixel CMOS camera
ADJUST THE OCULARS TO FIT THESPACING OF YOUR EYES When the oculars aretoo far apart, you willsee the sample as twoimages.Bring the ocularstogether until you seeonly one image.
MAGNIFICATION Magnification is making a sample appearlarger.
RESOLUTION Resolution is the minimum distance separatingtwo points which still allows them to be seen astwo distinct points. The better the resolution, the better we seedetails of the image. Poor resolution results in a single blurry blob or“pixelation” when viewing on a computer screen.
USE TOP-LIGHTING FOR OPAQUEOBJECTS$5 bill magnified to show the striations of Lincoln’s beard
DIM LIGHT BRINGS OUT MOREDETAILPollen covering the stigma and style of a flower
TOP-LIGHT ON A LEAF SHOWS SURFACEDETAILHairs on a Rosemary leaf
LIGHT FROM BELOW SHOWSINTERNAL STRUCTURE INTRANSPARENT OBJECTSStem of Sphagnum moss
FULL LIGHT FROM ABOVE ANDBELOWDracaena plant dead leaf (8x)
DIM LIGHT FROM ABOVE ANDBELOWDracaena plant dead leaf (8x)
DIM LIGHT FROM ABOVEONLYDracaena plant dead leaf (8x)
LIGHT FROM BELOW ONLYDracaena plant dead leaf (8x)
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 microscopestage. Turn light off as soon as you are done. Cover when not in use to prevent dust and dirtbuild up.