Agriculture Reference
In-Depth Information
2.
They can react directly with sulfhydryl groups of enzymes, e.g., glucose-
6-phosphate dehydrogenase or redox compounds such as cysteine or glu-
tathione.
3.
By reacting with specific substances of plants, they can promote the for-
mation or create different forms of transport for the active substance or
even for stronger fungicidal compounds. This type of reaction is observed
with sodium dimethyldithiocarbamate). As such, this compound has only
a slight fungicidal activity, but is more effective in combination with the
amino acid alanine or a glucoside (nabam, maneb, and zineb probably act
through this type of mechanism).
Toxicity— Thiram
Thiram dust is moderately irritating to human skin, eyes, and respiratory
mucous membranes. Contact dermatitis has occurred in occupationally ex-
posed workers. A few individuals have experienced sensitization to thiram.
Systemic human poisonings by thiram itself have been very few, proba-
bly due to limited absorption in most circumstances involving human expo-
sure. See
Table 5.30
for a listing of the commercially available products con-
taining thiram.
Thiocarbamates are commonly formulated as dusts, wettable powders, or
water suspensions. They are used to protect seeds, seedlings, ornamentals, turf,
vegetables, fruit, and apples.
Toxicity—Ziram and Ferbam
Ziram and Ferbam dusts are irritating to the skin, respiratory tract, and
eyes. Prolonged inhalation of ziram is said to have caused neural and visual
disturbances, and, in a single case of poisoning, a fatal hemolytic reaction.
See
Table 5.30
for a listing of the commercially available products con-
taining ziram and ferbam.
These are formulated as flowable and wettable powders used widely on
fruit and nut trees, apples, vegetables, and tobacco.
Toxicity—EBDC Compounds
These fungicides may cause irritation of the skin, respiratory tract, and
eyes. Both maneb and zineb have apparently been responsible for some cases
of chronic skin disease in occupationally exposed workers, possible by sensiti-
zation.
See
Table 5.30
for alisting of the commercially available products con-
taining maneb, zineb, nabam, and mancozeb.
Maneb and Zineb are formulated as wettable and flowable powders. Nabam
is provided as a soluable powder and in water solution.
