Tolprocarb is a carbamate fungicide developed by Mitsui Chemicals Co., Ltd. (referred to as "Mitsui Chemicals"). It has a unique mechanism of action and has no cross-resistance with other melanin biosynthesis inhibitor fungicides. It can be used for resistance management . Tolprocarb has excellent control effect on rice blast. At the same time, it is effective against pear scab, peach anthracnose, peach gray spot, gray mold and sclerotinia of many fruit trees and vegetables. It has strong adaptability, not only can be compatible with fungicides, but also can be compounded with a variety of insecticides, and is widely used in rice and seedling boxes.
Physical and chemical properties and toxicity
Tolprocarb development code MTF-0301; IUPAC name: 2,2,2-trifluoroethyl(S)-[2-methyl-1-(p-toluoylaminomethyl)propyl]carbamate 2,2, 2-Trifluoroethyl ester; CAS accession number: 911499-62-2; molecular formula: C16H21F3N2O3; relative molecular mass: 346.35.
The structural formula of Tolprocarb
Pure Tolprocarb is a white odorless powdery solid; vapor pressure: 1.8×10-6Pa (25°C); density: 1.3 g/cm3 (20°C); melting point: 133.7～135.0 (25°C); boiling point: 259°C break down. Octanol/water partition coefficient logPow=3.28 (25°C). It is insoluble in water.
Tolprocarb has low toxicity to rats, the acute oral LD50 (24 h) of female rats is >2,000 mg/kg, the acute percutaneous LD50 of female and male rats is >2,000 mg/kg, and the acute inhalation of female and male rats is >5.12 mg/L. Slightly irritating to rabbit eyes and rabbit skin, no sensitization to guinea pig skin.
Tolprocarb’s acute toxicity to carp (Cyprinus carpio) LC50 (96 h) > 18 mg/L, Daphnia magna acute toxicity EC50 (swimming, 48 h) > 22.6 mg/L; Crescent algae (Pseudokirchneriella subcapitata) ErC50 (72 h) > 17.9 mg/L.
Tolprocarb has no carcinogenicity, teratogenicity, reproductive toxicity and genotoxicity.
Mechanism and application
Rice blast is a disease that seriously affects rice production and occurs in almost all rice growing areas. Through in-depth research on the infection mechanism of the rice blast pathogen, scientists found that the invasion of rice blast is related to the formation of melanin in the appressorium of the pathogen, that is, melanin promotes the generation of swelling pressure of the appressorium, which is conducive to the invasion of the pathogen into the plant. Inhibiting the melanin biosynthesis of pathogenic bacteria is an effective way to control rice blast, and a series of fungicides targeting the reductase and dehydratase in the melanin biosynthesis process have been developed, such as tricyclazole, tetrachlorophthalide, Pyroquilon, blastamide, cyproamide, etc.
Tolprocarb is a carbamate fungicide with a unique mechanism of action. It is a polyketide synthase (PKS) inhibitor (MBI-P) in melanin biosynthesis, which inhibits melanin by regulating polyketide synthesis and cyclization of pentaketide Biosynthesis.
Tolprocarb has excellent control effect on rice blast and has a unique action site. It only exhibits inhibitory effect on polyketide synthase under in vitro conditions, so there is no cross-resistance with other commercialized melanin biosynthesis inhibitor fungicides. It is expected to be used to control resistant rice blast fungus.
Tolprocarb has systemic activity and has good control effect on rice blast. At the same time, it is effective against pear scab, peach anthracnose, peach gray spot, gray mold and sclerotinia of many fruit trees, vegetables and other crops, with a concentration of 50-100 mg/L.
3% Tolprocarb granules are applied once 5-30 days before rice panicle emergence, and the dosage is 300-400 g/hm2. ; or 3 days before rice transplanting to the day of transplanting, evenly spread tolprocarb dinotefuran granules (tolprocarb 12%+ Dinotefuran 2%) once, 50 g per box, can not only control rice blast, but also control common rice field pests such as Oulema oryzae, rice water weevil, rice planthopper and black-tailed leafhopper , the total number of medications should not exceed 2 times.
Source: AgroPages
