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M ld A d St i iMold And Stain in Wood Products

Is It More Difficult Now?

AbsolutelyGlobal warming (only kidding)Slow markets/Long storage timesBuyers market/public perceptionEveryone has this problemUniversal Response- blame chemicalBlame congress: Why not? We blame them for everything else

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Outline

Fungi in generalTime in the woodsLog decksPost- sawingChemical capabilities

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A Fungal Primer

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Mold Life cycle

www.ecometrex.com/FungalLifeCycle.gif

FungiFungal Type Effect on WoodMolds Use sugars, increase g ,

permeability, pigmented spores on surface

Stain Use sugars, increase permeability, stain wood

Decay Use structural polymers,Decay Use structural polymers, increase permeability, weaken wood

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Requirements for Growth

OxygenygTemperatureWaterNutrientsNutrients

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PENICILLIUM

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(Courtesy: P. Merrick, 2011)

STACHYBOTRYS

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Important GeneraStachybotrysFusariumPenicilliumAspergillusChaetomiumTrichoderma

Mold Species

2 0 300 000 i250 to 300,000 species45 species on Douglas-fir sapwood lumber in thefir sapwood lumber in the first 6 weeks

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Mold vs Stain

Surface vs internal stainSpecies less importantBoth fungi grow in sapwoodRemoving surface fungus does not kill fungus inside

Factors Affecting Fungal Growth

Sapwood ContentpTemperatureWood Moisture ContentTime of YearTime of YearTreatments

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Insect Contributors: Ambrosia beetles

Ambrosia Beetle

Wood Deterioration Wood destroying Insects

Ambrosia Beetle Damage in a Peeler Core

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Metallic Wood borers

Longhorned beetles

farm4.static.flickr.com/3113/2847107680_8e229

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Role of Processing in Stain

How fungi get to wood

calhoun.env.duke.edu/files/Feller%20Buncher%2..

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www.forestryimages.org/browse/detail.cfm?imgn...

heavymachine.blogsome.com/images/909j-feller-...

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www.farmi.us/_borders/mxextentionpag8.jpg

evergreenmagazine.com/.../viewAlbum.html

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www.gilbeck.net/scaleday/scaling008.jpg

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Sapstain Spray

(Courtesy of P. Schneider, 2011)

Spray Boxes

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Chemical Dipping

Anti Stain/Mold ChemicalsPropiconazole3 i d 2 l b t l b t (IPBC)3-iodo-2-propynyl butyl carbamate (IPBC) didecyl dimethyl ammonium chloride (DDAC)Methylene bisthiocyanate (MBT)TetrachloroisophthalonitrileTetrachloroisophthalonitrileOxine copper

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Fungicide vs Fungistat

Fungicide can kill spores and hyphaeFungistat stops growth but may not kill fungusStain chemicals can be both- but do not function well against hyphae that are already in woodalready in wood

Treatment Delivery

Mostly surface- a little bit inside helpsMust have sufficient amount/unit area (varies with product)Periodic chemical assessment is usefulPeriodic trials are also useful since inerts in product can changein product can change

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Performance of Antisapstain Chemicals

100

120(%

)

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40

60

80

100

gree

of D

isco

lora

tion

PropiChloroCu-8IPBC/DDACControl

030 90 180

Days After Treatment

Deg

Chemical IssuesFungi growing through the g g g gprotective layerMills using too little chemicalFungal resistance?g

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Role of Preinfection

www.forestryimages.org/.../3072x2048/1669053.jpg

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Role of Storage before Planing

(Courtesy: P. Merrick, 2011)

Longterm Storage Issues

(Courtesy: D. Stallcop, 2011)

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Bundle Storage Issues

(Courtesy: P. Merrick, 2011)

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www.forestryimages.org/.../3072x2048/1669053.jpg

Who to Blame?

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Old Logs

Logs in deck 6 to 18 months- either in d i d (it ll t )woods or in yard (it all counts)

Wood is pre-infected- fungi more difficult to controlSpores and hyphae from infected wood carried on saws to clean woodcarried on saws to clean woodDelays between saw and planer

What to Do

Control time in woodsControl time in log deckSprinkle decksTreat lumber ASAP or soonerUse proper chemical levels

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Ideal Processing Times

We say 24 hoursYou use 14 daysObviously- 14 days is too long/24 hr is unreasonable2 to 3 days would be ideal- but it is seasonalseasonalOnce fungi in wood begin growing to surface - they become difficult to control

Reality

Logs in woods for days to monthsLogs in deck for weeks to monthsLumber held for days to weeks before final planning and treatmentLumber sits in depots for weeks to months

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Ideal System

Log flow tailored to production- 3 months tmax storage

Treatment within 72 hours of sawingGood maintenance of spray boothsRegular QC on lumber to ensure adequate treatment levelstreatment levels

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