Diagnosing Diseasesseasesseases: The Good, The Bad, and the Ugly!

Fred BakerFred Baker Department Wildland Resources State University DiseaseDisease

ƒƒ Any deviation from the normal function of a . . . DiseaseDisease

ƒƒ Any deviation from the NORMALNORMAL function of a ppplant . . .

FoliageFoliage

ƒƒ ColorColor ƒƒ Densityyy ƒƒ size and shape ƒƒ Wilting?Wilting? ƒƒ RetentionRetention TwigsTwigs

ƒƒ Annual Twig Growth (3(3--5 yrs)yrs)5 ƒƒ Abnormal buds –– color,,, number ƒƒ RetentionRetention ƒƒ Sapwood discoloration ƒƒ Evidence of pests Large Branches

ƒƒ Amount of dead wood ƒƒ Excessive ppgruning ƒƒ Wound closure rate ƒƒ CankersCankers ƒƒ Bacterial wetwood TrunkTrunk

ƒƒ CavitiesCavities ƒƒ CankersCankers ƒƒ Frost Cracks ƒƒ LightningLightning ƒƒ Mechanical injury RootsRoots

ƒƒ ColorColor ƒƒ Evidence of pppests ƒƒ Abundance ƒƒ Mechanical Injury RootsRoots

ƒƒ Rooting Area ƒƒ PavementPavement ƒƒ Disturbance ƒƒ Soil Typypype SoilSoil

ƒƒ DrainageDrainage ƒƒ Wateringgg ƒƒ pHpH ƒƒ TypeType ƒƒ PesticidesPesticides ƒƒ Ground cover Root Diseases

ƒƒ Kill by: ƒƒ Killinggg cambial tissue ƒƒ Weakening support and trees windthrow ƒƒ Stressinggg trees and bark beetles attack Root disease symptoms

ƒƒ Reduced leader growth ƒƒ OffOff--colorcolor foliaggge ƒƒ Less foliage ƒƒ Swollen butts ƒƒ Pitch flow at butt and on roots ƒƒ Bark beetle attack ƒƒ “Stress Cone Croppp” Root diseases:

ƒƒ Spread along roots slowly ƒƒ Cause syypmptoms in a patch or center ƒƒ Persist on the site in root biomass

Root Disease complexes

ƒƒ Root pathogens often occur together!

Ash yyyellows: a slowslow--declinedecline disease caused by ‘Candidatus Phytoplasma fraxinifraxini’’ Ash yellows in white ash

Incurable, perennial, often debilitating Tree

Symptoms: combinations of here slow growth subnormal greenness or chlorosis diminished or lost apical dominance reduced & seed set & viability witches'-brooms rootlet necrosis decline ending in death Symptoms of ash yellows conditioned by

• tolerance or resistance of hosts • aggressiveness of pathogen •environmental influences. Phytoplasmal diseases most common & severe in areas of warm to tropical climate; cold winters can cure some , kill vectors Drought stress can trigger dieback and decline in trees that are otherwise able to tolerate phytoplasmal infection Drought-triggered dieback in white ash affected by ash yellows Interspecific differences in apparent tol erance (nat ura l s tand s st udi ed)

Si&lSpecies & place AdilthAverage radial growth (diseased / healthy) velutina, Utah 1.0 several sites in Zion Canyon

F. pennsylvanica , 2 sites, NYS, 0700.70 5 yr after growth of healthy and diseased groups diverged

F. americana, 2 sites, NYS 0.61 5 yyrr aafterfter ggrowthrowth ooff healthyhealthy aandnd diseased groups diverged Phytoplasma detection

• microscopic — transmission EM (little used now)

— DAPI fluorescence (obsolete)

• immunological (little used)

• recombinant DNA-based techniques PCR + product analysis DAPI: a DNA-binding fluoro- chrome (4',6-diamidino-2- phenylindole.2HCl) Ash yellows

deliquescent branching

Rootlet necrosis in higgyhly susce pt. spp. Importance of rootstockrootstockrootstock tolerancetolerance

Velvet ash on its own or on white ash roots

V / V - healthy V / W - AshY V / V - AshY ƒƒ Special Thanks to Wayne Sinclair for his info on Ash Yellows Hazard Trees

ƒƒ A tree at risk of failure ƒƒ A targgget of value

SwollenSwollen branchbranch stubsstubs Fruiting bodies

CankersCankers CavitiesCavities Aspen Decline 180 160 140 Colorado 120 Utah f plots

100oo 80 60

umber umber 40 NN 20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 22 33 44 55 55 11 22 33 44 55 66 77 88 99 00 >1 41- 61- 71- 81- '1 - '1 '11- '21- 51- 31 - 91-1

Age Class 101-1 111-1 121-1 131-1 141-1 Too Old for the site. .

Utah Aspen

100

e age 80 ss 60

80) 40 dex (ba

nn 20 0 Site I 0 50 100 150 200 Age 14000 Latitude-elevation relationship of aspen Latitude-elevation relationship of affected aspen (>25% mortality of aspen component) 12000

10000 et) ee 8000 ation (f

vv 6000 Ele 4000

2000

0 30 32 34 36 38 40 42 44 46 48 50 Latitude (degrees) Aspen Decline

ƒƒ Too OldToo Old ƒƒ On Marggginal sites ƒƒ At lower elevations ƒƒ DroughtDrought Aspen Decline

ƒƒ Too OldToo Old ƒƒ On Marggginal sites ƒƒ At lower elevations ƒƒ DroughtDrought

The FIX: DISTURB ASPEN!!! Global Trade

ƒƒ So what?what?So

Pitch Canker What you can do: ƒƒ Know what is normal! ƒƒ KlKnow your plants ƒƒ Know your insects and diseases ƒƒ Know your plant sources ƒƒ Know your I&D man: ƒƒ County Extension Agent ƒƒ State Department of Agriculture ƒƒ USDA Forest Service Forest Health Mgmt