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From sieloff@ideanet.doe.state.in.us Wed Oct 30 18:20:38 1996
Reply-To: Roger Sieloff ISDH <sieloff@ideanet.doe.state.in.us>
To: Aaron Hicks <ahicks@nmt.edu>
Subject: Fun with Fungisides
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The following is a synopsis of five major fungal diseases of
plants, their suggested fungisides and the chemical properties of these
compounds.
**************************** The BAD Guys *******************************
Anthracnose: This is the dread "black spot" disease chartacterized by
black lesions on leaves and stems. This disease is the bane of rose
growers but can also attack almost any other plant as well, even
houseplants like African violets and cacti. The only environmentally
friendly way to treat the disease is to "decontaminate" the plant. Burn
it. It is also necessary to sterilize everything around the victim as
well, i.e., soil, pots, tools, et. all. Less draconian methods (..?)
involve the use of the following fungisides:
Contact fungisides: folpet, maneb
Systemics: funginex
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Botrytis Blight: This fungal disease initially manifests itself as soft
looking blotches which spread and eventually aquire a white mouldy fuzz.
Especially troublesome in the warm, humid interiors of greenhouses, this
pestilence is an orchid grower's nightmare since it seems to target the
soft tissues of blossoms. Ironically, one of the cures turned out to be
worse than the disease. Benomyl was a widly used fungiside by orchid
growers, especially Phalenopsis breeders in the Borytis belt of south
Florida. In 1990, something seemed to be terribly wrong, Phalenopsis
plants began to sicken and die by the thousands, despite valliant efforts
by seasoned, though perplexed growers to salvage them. Only reciently it
was discovered that one batch of the fungiside had been accidentally
contaminated by an incredibly potent herbiside, a simple sulfur compound
which might as well have been the horticultural equivalent of the AIDS
virus. Once exposed to even minute traces of this stuff, most plants never
fully recovered, their genes damaged and biochemistry smashed.
Other "cures" for Borytis blight include:
Zineb, Phaltan, Thiram and Captan
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Powdery Mildew: Oh those crazy, lazy days of summer. Dog day afternoons,
baseball games that go on and on forever and the garden Phlox looking as
though it had been rolled in flour. This powdery, white nusiance is more
unsightly than fatal, targeting leaves more than anything else. Heavy
infestations can weaken plants, especially during the warm, humid weather
that this fungus favors.
Contact fungisides: acti-dione PM, folpet
Systemic fungisides: funginex, benomyl (oh,no!!!!!!!)
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Damping Off: Surely one of Pandora's terrors designed specifically with
the horticulturalist in mind... The senario is all too common. Wait 5
weeks for those rare seeds to arrive in the mail, sow them, water them,
warm them, tell them bedtime stories. The little green guys come poking
up one fine morning only to look, 24 hours later, as though they'd all
been kicked very solidly in the solar plexis. Your future garden now
prostrate and dying, you percieve a network of thin, white filaments
snaking insideously across the top of the soil. FAST FACT: Many
greenhouses are damaged more by heavy objects flying out of them than
by heavy objects flying into them.
Is there any hope? Well, sort of. Keeping one step ahead of this
fungus can mean autoclaving seedling trays and then drenching them with
the likes of:
Captan, Phygon or Spergon
The last two are fequently used to coat seeds destined to be sown in damp,
cool spring soils.
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Rust: Another serious Rose pest, but also the curse of many outdoor
ornamentals as well. The characteristic symptoms include raised
"pustles" on the underside of leaves which can be any shade between rusty
red to bright yellow. Heavy infestations weaken plants of course and
preventative maintenance inclues the destruction of all affected foliage
in the fall . Chemical warfare includes:
Ferbam, Zineb and maneb.
*************************** The Good(?) Guys **************************
ASPIRIN EQUIVALENT: LD50 dosages quoted in layman's terms. I am 75 Kg
(FAT!!) and an Aspirin contains 300 mg Acetylsalicylic Acid, the "active
ingredient". I have extrapolated how many "aspirin" I'd have to take to
equal the LD50 if the "active ingredient" were 300 mg of the following....
------------------------------------------------------------------------
ACTI-DIONE: Glutarimide,
3-(2-(3,5-dimethyl-2-oxycyclohexyl)-2-hydroxyethyl)-
ACTI-AID, ACTISPRAY, CYCLOHEXIMIDE, HIZAROCIN, KAKEN, NERAMYCIN, U-4527
Aspiin Equivalent: 1.25 tablets
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THIRAM: Disulfide, bis(dimethylthiocarbamoyl)
ACCELERATOR THIURAM, ARSAN 75, EKAGOM TB, ENT 987, FERNIDE, METHYL TUADS
PANORAM 75, ROYAL TMTD, SADOPLON, VANCIDA TM-95
BIS(DIMETHYL-THIOCARBAMOYL)-DISULFID (german)
DISOLFURO DI TETRAMETILTIOURAME (italian)
DISULFURE DE TETRAMETHYLTHIOURAME (french)
Aspirin Equivalent: 12.5 tablets
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MANEB: Manganese, (ethylenebis(dithiocarbamato))-
CHEM NEB, CHLOROBLE M, CR 3029, KYPMAN 80, POLYRAM M, TUBOTHANE, VANCIDE
MANEBE (french)
MANGAN (II)-(N,N'-AETHYLEN-BIS(DITHIOCARBAMATE))(german)
Aspirin Equivalent: 125 tablets
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FERBAM: Iron, tris(dimethyldithiocarbamato)-
AAFERTIS, FERBAM 50, FERMATE, HEXAFERB, KARBAM BLACK, TRIFUNGOL
Aspirin Equivalent: 125 TABLETS
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PHYGON: 1,4- napthoquinone, 2,3-dichloro-
ALGISAT, COMPOUND 604, UNIROYAL, U.S. RUBBER 604, PHYGON SEED PROTECTANT
Aspirin Equivalent: 125 tablets
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SPERGON: beta-Benzoquinone, 2,3,5,6-tetrachloro-
DOW SEED PROTECTANT NO. 5, GEIGY-444E, RERANIL, VULKLOR
Aspirin Equivalent: 125 tablets
CAPTAN: 4-Cyclohexe-,2-dicarboxamide, N-(trichloromethyl)thio-
AMERICIDE, ENT 26538, ORTHOCIDE 50, SR406, VANCIDE 89, VANGUARD K
Aspirin Equivalent: 2.67 bottles (100 tablets/bottle)
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FOLPET: Phthalimide, N-((trichloromethyl)thio)-
FOLPAN, FTALAN, ORTHOPHALTAN
Aspirin Equivalent: 12.5 bottles (100 tablets/bottle)
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ZINEB: Zinc, (Ethylenebis(dithiocarbamato))-
ASPOR, BILITEX, ASPORUM, CINEB, DITHANE Z, KYPZIN, NOVOZIR N 50,
MILTOX, PAMOSOL 2 FORTE, THIODOW, TIEZENE, ZIDEN, the list goes
on and on and on and on and on and on and on and on and on ....
Aspirin Equivalent: 12.5 bottles (100 tablets/bottle)
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FUNGINEX: Piperazine, 1,4-bis(-formamido-2,2,2-trichloroethyl)
CLEA W 524, SAPROL, TRIFORINE
Aspirin Equivalent: 15 bottles (100 tablets/bottle)
------------------------------------------------------------------------
BENOMYL: 2-Benizimidazolecarbamic acid,1-(butylcarbomyl)-,methyl ester
ARILATE, BENLATE 50 WP, DU PONT 1991, MCB
Aspirin Equivalent: 25 bottles (100 tablets/bottle)
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Are we having fun yet (?),
Roger L. Sieloff
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