The pure product is a white odorless and tasteless crystalline solid. m.p.210～212.5°C (decomposition at 217°C), vapor pressure 4×10-9Pa) (25°C). Solubility at 25°C: dimethyl sulfoxide>500g/L, dimethylformamide>500g/L, cyclohexanone 21.5g/L, acetone 8g/L, methanol 4.5g/L, ethyl acetate 0.8 g/L, hexane 6mg/L, insoluble in aliphatic and aromatic hydrocarbons, solubility in water 31mg/L. The partition coefficient is 59 (pH=7.3). Stable below 200°C; stable to water at room temperature, half-life > 24d; half-life in soil < 60d.
Thidiazuron is a non-purine containing urea derivative with cytokinin activity.
Thidiazuron is used as a cotton defoliant and a plant growth regulator in tissue culture.
Plant growth regulator used to defoliate cotton to facilitate harvesting.
ChEBI: Thidiazuron is a member of ureas.
Thidiazuron is a systemic herbicide, widely employed as an effective plant growth regulator and pre-harvest defoliant for crops such as cotton.
Herbicide, Defoliant, Plant growth regulator: Used primarily as a cotton defoliant in order to increase
the harvest yield. Not applied to food crops. Not approved
for use in EU countries. Registered for use in the U.S.
U.S. Maximum Allowable Residue Levels for Thidiazuron
and its aniline-containing metabolites in or on the following
food commodities: [40 CFR 180.403(a)]: cattle,
fat 0.4 ppm; cattle, meat 0.4 ppm; cattle, meat byproducts
0.4 ppm; cotton, gin byproducts 24.0 ppm; cotton,
undelinted seed 0.3 ppm; goat, fat 0.4 ppm; goat meat
0.4 ppm; goat, meat byproducts 0.4 ppm; hog, fat 0.4 ppm;
hog, meat 0.4 ppm; hog, meat byproducts 0.4 ppm; horse,
fat 0.4 ppm; horse, meat 0.4 ppm; horse, meat byproducts
0.4 ppm; milk 0.05 ppm; sheep, fat 0.4 ppm; sheep, meat
0.4 ppm; sheep, meat byproducts 0.4 ppm.
Thidiazuron is substituted urea that is used to defoliate
cotton plants. Thidiazuron, which has cytokinin activity,
is one of the many harvesting aids needed in agriculture.
DAZE®; DEFOLIT®; DROPP®;
GINSTAR EC® (thidiazuron + diuron); LEAFLESS®
Tthidiazuron; SN 49537®
Moderately toxic by
ingestion. Experimental reproductive
effects. When heated to decomposition it
emits toxic fumes of SOx and NOx.
Soil. The reported half-life in soil is approximately 26–144 days (Hartley and Kidd,
1987).
Photolytic. Rapidly converted to the photoisomer, 1-phenyl-3-(1,2,5-thiadiazol-3-
yl)urea (Worthing and Hance, 1991). When thidiazuron adsorbed by soil was exposed to
UV light (λ <290 nm), 1-phenyl-3-(1,2,5-thiadiazol-3-yl)urea formed as the majo
