Agriculture Reference
In-Depth Information
nausea, vomiting, dizziness, and sometimes convulsions and loss of con-
sciousness.
Table 5.29
Commercial products containing phenyltin compounds.
Active Ingredients
Trade Names
Fentin hydroxide
Du-Ter, Duter, Haitin, Phenostat-A H,
Suzu-H, TPTH, TPTOH, Triple Tin, Tubotin
Fentin chloride
Aquatin, Phenostat-C, Tinmate
Fentin acetate
Batasan, Brestan, Phenostat-A, Phentinoace-
tate, Suzu, Tinestan, TPTA
All are formulated as wettable and flowable powders for use mainly as
fungicides to control blights on field crops and orchard trees. Fentin chloride
i s al so prepared as an em ul s i fi abl e concent rat e for use as a m ol l u sci ci de (Aq-
uatin 20 EC).
Tributyltin salts are used as fungicides and antifouling agents on ships.
They are somewhat more toxic by the oral route than triphenyltin, but toxic
actions are otherwise probably similar.
2.
Organic Fungicides
Many organic fungicides have been developed during the past 50 years to
replace the more toxic, non-selective inorganic predecessors. The first group
of organics developed were the dithiocarbamates, developed in the 1930s and
1940s.
a.
Dithiocarbamates (ethylenebis-dithiocarbamates—EBDCs)
The development of purely organic fungicides began with the discovery of
the fungicidal activity of the dithiocarbamates. These compounds and their
derivatives comprise one of the most important groups of fungicides for con-
trolling plant diseases.
Thiram, mancozeb, maneb, ferbam, ziram, and zineb are among the most
popular and used fungicides. They are employed for every use known for fun-
gicides.
Mode of Action
The active agent of the dithiocarbamates is the dithiocarbamate ion, which
can interfere with the fungal metabolism in several different ways.
1.
They can react with metal-containing enzymes (e.g., polyphenoloxidase
and ascorbic acid oxidase) to form a copper-dithiocarbamate complex with
high fungicidal activity (thiram and ziram probably owe their fungicidal
activity to this type of reaction).
