Comparison of Triticonazole Dissipation after Seed or Soil Treatment

Abstract

This study examined the long-term fate of the fungicide triticonazole (TTZ; 5-[(4-chlorophenyl)methylene]-2,2-dimethyl-1-(1H-1,2,4-triazol-1-ylmethyl)cydopentanol) applied at a normal field dose (8.9 g ha(-1)) via seed treatment, which is the normal alternative in practice. The TTZ was applied to wheat (Triticum aestivum L.) grains as a disinfectant before sowing or spraying on bare soil for comparison and reference to the seed treatment. The seeds were germinated and grown in pots in a greenhouse at 22 +/- 3 degrees C. The dissipation of TTZ was studied by gas chromatography-mass spectrometry (GC-MS) analysis of the residues every fourth week until no TTZ could be detected. The recovery for analysis of TTZ in soil was between 98 and 131%, and the quantification level was 0.002 mg kg(-1). After 56 d of incubation, 20 and 28% of the TTZ applied remained in the soil and seed treatments, respectively, with corresponding half-lives of 27 and 29 d. The microbial biomass initially decreased in the soil treatment but had recovered after 56 d. The active part of the biomass was not changed during the experimental time. Thus, with respect to dissipation of TTZ and its effect on the soil microbial biomass and activity, no long-lasting difference between soil and seed treatments could be found.

In Vitro Susceptibility of the Yeast Pathogen Cryptococcus to Fluconazole and Other Azoles Varies with Molecular Genotype

“…In our comparisons of FLC susceptibility among C. neoformans genotypes, we targeted veterinary isolates where prior exposure to antifungal agents was very unlikely. However, we cannot completely rule out prior exposure to all azoles, as azole-based formulations are used in many countries, including Australia, to protect crops from pathogenic fungi and as wood preservatives (2,16,28). Studies have shown that some environmental fungi of clinical importance can develop cross-resistance to medical azoles following exposure to agricultural azoles (34,39,46).…”

Enantioselective Fungicidal Activity and Toxicity to Early Wheat Growth of the Chiral Pesticide Triticonazole

“…TRZ is a chiral fungicide with one asymmetrically substituted C atom, consisting of two enantiomers, S -triticonazole and R -triticonazole (Figure S1). It is mostly used as a racemate for grains, soybeans, vegetables, and various fruits and can be used as a seed disinfectant to prevent seed-borne diseases . It has been reported that the degradation of the two enantiomers was enantioselective.…”

“…It is mostly used as a racemate for grains, soybeans, vegetables, and various fruits and can be used as a seed disinfectant to prevent seed-borne diseases. 12 It has been reported that the degradation of the two enantiomers was enantioselective. S-TRZ was more persistent than R-TRZ in fruits and vegetables.…”

Modeling Pesticide Fate and Nonideal Transport From Seeds Treated with a Slow-Release Pesticide in a Laboratory Soil Column

“…Pesticide-treated seeds are increasingly being formulated as a chemical application method for reducing environmental exposure (Agarwal and Sinclair, 1997;Maloy, 1993;Dawson, 1987;Bateman et al, 1986), but early studies only considered atmospheric movement, personal exposure during handling, or dissipation in the soil profile (Börjesson et al, 2003;Waite et al, 2001;Gray et al, 1983). Poag et al (2005) recently demonstrated the economic feasibility of fungicide seed treatment, suggesting that the insignificant input for seed treatment results in significant enhanced profitability.…”

“…Many of the pesticides being used for seed treatment exhibit time-dependent sorption (Börjesson et al, 2003). According to Brusseau (1998), the importance of nonlinear sorption is dependent on the degree of spreading, and ratelimited sorption is dependent on the magnitude of characteristic reaction time to contaminant residence time.…”