Agriculture Reference
In-Depth Information
Commercial products include Etridiazole, Asterra, Koban, Pansoil, Terra-
zole, and Truban.
c.
Triazines
The only member of this group of pesticides with fungicidal activity is
anilazine. The manufacturer (Miles, Inc.) has canceled all uses in the U.S.
Labelling requires the signal word “Warning.”
Anilazine is supplied as wettable and flowable powders and is used on
vegetables, cereals, coffee, ornamentals, and turf.
Toxicity
This product has caused skin and eye irritation in exposed workers. Acute
oral and dermal toxicities in laboratory animals are low. Human systemic
poisonings have not been reported.
Commercial products include Anilazine: Dyrene, Kemate, and Triasyn.
d.
Substituted Aromatics (substituted benzenes and phenols)
This group of fungicides contains several different subgroups, the chloro-
benzenes, phenols, and the dicarboximide fungicides.
Pentachloronitrobenzene (PCNB) was introduced in the 1930s and is
widely used as a soil fungicide for seed treatment and foliar applications. Hex-
achlorobenzene was introduced in 1945 to treat seeds and foliage. (HCB, Anti-
carie, Ceku C.B., No Bunt). Chlorothalonil was introduced in 1964; it is a
broad spectrum foliar or soil-applied fungicide used on many crops. Dicloran
is a popular and widely used fungicide for the protection of a variety of fruits
and vegetables.
The majority of phenols, especially those containing chlorine, are too
phytotoxic to permit their use as agricultural fungicides. They are widely used
as industrial fungicides. Cresols contribute to the fungicidal action of creosote
which is used as a timber preservative. Pentachlorophenol, another chlorin-
ated phenol, and its esters are widely used as industrial biocides for the protec-
tion of such materials as wood and textiles.
Mode of Action
The mode of action of this group of compounds is diverse and depends on
the parental compound. The fungicidal activity of most phenols depends on
their ability to uncouple oxidative phosphorylation and therefore prevent the
production of ATP which is required for growth. Other substituted aromatics
reduce growth rates by reacting with the amino or sulfhydryl groups of essen-
tial metabolic compounds.
