pyrachlostrobin and prochloraz

This study aimed to establish the baseline sensitivity of Botrytis cinerea from Panax ginseng to prochloraz, and ensure the fitness of prochloraz-resistant mutants and the cross-resistance of B. cinerea to prochloraz and commonly used fungicides for the prevention and control of gray mold including boscalid, pyraclostrobin, iprodione, and pyrimethanil. The sensitivity of B. cinerea from P. ginseng to fungicides was determined by the mycelial growth rate method. The prochloraz-resistant mutants were screened out through fungicide domestication and ultraviolet(UV) induction. The fitness of resistant mutants was determined through the stability of subculture, mycelial growth rate, and pathogenicity test. The cross-resistance between prochloraz and the four fungicides was determined by Person correlation analysis. The results showed that all B. cinerea strains tested were sensitive to prochloraz, and the EC_(50) value ranged from 0.004 8 to 0.062 9 μg·mL~(-1), with an average of 0.022 μg·mL~(-1). The sensitivity frequency distribution diagram showed that 89 B. cinerea strains were located within the main peak with a continuous single peak curve, and the average EC_(50) value of 0.018 μg·mL~(-1) was taken as the baseline sensitivity of B. cinerea to prochloraz. The fungicide domestication and UV induction obtained 6 resistant mutants, among which 2 strains were unstable and the other 2 strains showed decreased resistance after multiple generations of culture. Furthermore, the mycelial growth rate and spore yield of all resistant mutants were lower than those of their parents, and the pathogenicity of most mutants was lower than that of their parents. In addition, prochloraz had no obvious cross-resistance with boscalid, pyraclostrobin, iprodione, and pyrimethanil. In conclusion, prochloraz has great potential for controlling gray mold in P. ginseng, and the resistance risk of B. cinerea to prochloraz is low.

Topics: Fungicides, Industrial; Humans; Panax

Fungicides are often applied to pears before they are kept in storage facilities. The scientific application of pesticides can reduce unnecessary exposure, which in turn could benefit both humans and the environment.. We investigated dissipation behavior and residue distribution, and conducted risk assessments for prochloraz, pyraclostrobin, and tebuconazole in pears stored under different conditions using ultra-performance liquid chromatography (UPLC). The recoveries of the three fungicides ranged from 76.5% to 114.5%, and the coefficients of variation were 1.0%-8.5%. The half-life (t. The results provide a scientific basis for rationalizing the use of prochloraz, pyraclostrobin, and tebuconazole, and improving the safety of pears for eating. © 2019 Society of Chemical Industry.

Topics: China; Consumer Product Safety; Food Contamination; Fruit; Fungicides, Industrial; Humans; Imidazoles; Kinetics; Pesticide Residues; Pyrus; Strobilurins; Tandem Mass Spectrometry; Triazoles