Float Bed Disease

Diseases - Bacterial Black leg - Erwinia sp.

Same as hollow stalk & barn Same as hollow stalk & barn rot (houseburn)rot (houseburn)

Black area at base of stalk Black area at base of stalk (often splits stalk)(often splits stalk)

UbiquitousUbiquitous influenced by N fertilityinfluenced by N fertility Control Control

by monitoring fertility (not by monitoring fertility (not over 150 ppm N)over 150 ppm N)

Streptomycin Streptomycin Limited benefitLimited benefit

Diseases - Bacterial Angular Leaf Spot -

Pseudomonas syringae Limited by leaf veins Limited by leaf veins

making spots angular making spots angular in shape in shape

More prevalent in More prevalent in outside beds exposed outside beds exposed to rainfallto rainfall

May be zonal on May be zonal on windward side of leafwindward side of leaf

ControlControl Stretomycin Stretomycin

Diseases - Fungal

Damping-off - Damping-off - PythiumPythium sp. sp. Brown to black rot at base of plant Brown to black rot at base of plant

and rootsand roots Roots are often straw colored and Roots are often straw colored and

hang limp down the tray when tray is hang limp down the tray when tray is held verticalheld vertical

Water/soil borne fungiWater/soil borne fungi Clean water sourceClean water source

Pythium sp.

Pythium sp. Control Control

Terramaster 4ECTerramaster 4EC0.7 fl oz/100 gal Preventative0.7 fl oz/100 gal Preventative1.4 fl oz/100 gal Curative 1.4 fl oz/100 gal Curative

Possible Root Stimulation

Source: W. Gutierrez & T. Melton, North Source: W. Gutierrez & T. Melton, North Carolina State University, 2000Carolina State University, 2000

TerramasterTerramaster 4EC controls growth 4EC controls growth of algaeof algae

Terramaster phytotoxicity

- Shoots

Phytotoxicity -Roots &

Recovery

Does Terramaster Cause Premature Bloom?

Diseases - Fungal Target Spot - Target Spot - RhizoctoniaRhizoctonia leaf spot - leaf spot -

Rhizoctonia solaniRhizoctonia solani Small water-soaked spot initiallySmall water-soaked spot initially Concentric circles or targetConcentric circles or target Favored by Favored by

low fertilitylow fertility

• Rainfall dilution of outside bedRainfall dilution of outside bed

• Reduction of N to slow plantsReduction of N to slow plantsMaturityMaturity

Target Spot

Target Spot - Control - Dithane- Dithane

1 tsp/gal using 3 to 12 gals per 1000 sq ft 1 tsp/gal using 3 to 12 gals per 1000 sq ft or 400 trays depending on size of plants.or 400 trays depending on size of plants.Start when plants are at least the size of a Start when plants are at least the size of a dimedime

CarbamateCarbamate 1.5 to 3 tsp/gal using 3 to 12 gals per 1000 1.5 to 3 tsp/gal using 3 to 12 gals per 1000

sq ft or 400 trays depending on size of sq ft or 400 trays depending on size of plants.plants.Leaves black residue/easy to seeLeaves black residue/easy to see

Sore shin Rhizoctonia solani

Reddish-brown sunken lesions on stem Reddish-brown sunken lesions on stem of plantsof plants

Can come from target spot infectionsCan come from target spot infections See aboveSee above

Collar rot Sclerotinia sclerotiorum

Small black-brown (straw colored) lesion at Small black-brown (straw colored) lesion at base of plant that may increase in size to base of plant that may increase in size to encircle plant, killing plantencircle plant, killing plant

May spread into leavesMay spread into leaves Noticed as softball sized dead areaNoticed as softball sized dead area White mycelium White mycelium SclerotiaSclerotia

Collar rot - Sclerotinia

Anthracnose Colletotrichum gloeosporoides

Small, light green, water-soaked pinpoint Small, light green, water-soaked pinpoint spots that enlarge to oily circular spots up spots that enlarge to oily circular spots up to 3 mm in sizeto 3 mm in size

develop into thin, papery, gray-whitedevelop into thin, papery, gray-white Known to spread from grassesKnown to spread from grasses ControlControl

SanitationSanitation Same for Target SpotSame for Target Spot

Anthracnose

Tray sterilization

Contaminated traysContaminated trays New trays versus oldNew trays versus old

Bleach 10%Bleach 10% Steam Steam

much reach 140much reach 140oo F for F for 30 min 30 min 180180oo F damages Trays F damages Trays

Methyl BromideMethyl Bromide CheapCheap QuickQuick DangerousDangerous

TemperatureTemperature dependentdependent

Environmental concerns Environmental concerns