Applications Of Thiophanate-methyl Research Articles

Thiophanate-methyl and its major metabolite carbendazim weaken rhizobacteria-mediated defense responses in cucumbers against Fusarium wilt

AbstractThe effect of fungicides on the plant-rhizosphere microbiome is a subject of ongoing debate, but whether any alteration in the rhizosphere microbiome could affect plant health is an issue that has not been thoroughly investigated. To address this deficiency, we analyzed the rhizosphere microbiome of wilt disease—resistant and disease-susceptible cucumber cultivars to determine whether (and which) plant-associated microorganisms have a role in disease resistance. We further assessed whether the fungicides thiophanate-methyl and carbendazim affect the rhizosphere microbiome, which may contribute to the plant’s immune response. Based on results acquired with both radicle-inoculation and soil-inoculation methods, cultivars Longyuanxiuchun (LYXC) and Shuyan2 (SY2) were identified as being disease resistant, whereas Zhongnong6 (ZN6) and Zhongnong38 (ZN38) were susceptible. The microbiome structure differed substantially between the resistant and susceptible plants, with LYXC and SY2 each having a significantly greater Shannon index than Zhongnong38. These results revealed that the disease-resistant cucumber cultivars recruited more beneficial bacteria, i.e., Bacillus, in their rhizosphere soil; as such, Bacillus was identified as a keystone genus in the microbial co-occurrence network. Thus, the presence of Bacillus may help cucumbers defend against fungal pathogens within the rhizosphere. Bacillus subtilis strain LD15, which was isolated from LYXC rhizosphere soil, could suppress pathogen growth, in vitro, and reduce disease severity in pot assays. Moreover, evidence also confirmed the accumulation of LD1 in the rhizosphere soil of resistant cucumber cultivars. For LYXC, application of thiophanate-methyl or carbendazim altered the microbiome structure, decreased bacterial diversity, and reduced the abundance of Bacillus species. Finally, pot assays verified that fungicide application decreased the proportion of LD15 in rhizosphere soil. From a microbial perspective, thiophanate-methyl and carbendazim may weaken the rhizobacteria-mediated defense response of cucumbers against cucumber Fusarium wilt disease. Our findings reveal a role for the rhizosphere microbiome in protecting plants from pathogens and constitute a reference for assessing the ecotoxicological risk of pesticides to non-target soil microorganisms.

Residue dissipation and dietary intake risk assessment of thiophanate-methyl and its metabolite carbendazim in watercress under Chinese field conditions

ABSTRACT In this study,the QuEChERSand high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS)was applied to determine thiophanate-methyl and its metabolite carbendazim residue in watercress. The average recoveries of both analytes in watercress ranged from 96.2% to 102.9% with relative standard deviation (RSD) less than 8.2%. The limit of quantification (LOQ)of method for both analytes was 0.01 mg/kg. The field trials were carried out in 2018 to monitor the residues of thiophanate-methyl and its metabolite in six main cultivation areas inwatercressof China. Thiophanate-methylrapidly dissipated and transformed to carbendazim under watercress field conditions with half-lives less than 2.12 d.Carbendazim also rapidly dissipated with half-lives of 2.76 and 3.77d at two experiment sites. The terminal residue of thiophanate-methyl,carbendazim and total thiophanate-methyl were lower than 14.5 mg/kg, 5.26 mg/kg and 13.3 mg/kg, respectively. In order to ensure the safety, the acute and chronic dietary intake risks were evaluated. The ADI%of thiophanate-methyl, carbendazim and total thiophanate-methyl ranged from 21.1% to 84.9% and their%ARfDranged from 2.1% to 19.2%, which suggested that thiophanate-methyl and carbendazim has a low risk for Chinese populations caused by application of thiophanate-methyl.

EFFECTIVENESS OF DIFFERENT FUNGICIDES AGAINST PREDOMINANT AND VIRULENT FUNGUS FUSARIUM NIVALE THE CAUSE OF MANGO MALFORMATION DISEASE

Fusarium nivale (Fr.) Ces. a recently reported fungus of mango malformation disease (MMD)is a predominant and virulent fungus in mango orchards of Sindh, Pakistan. In the current study in vitro and in vivo attempts were made with commercial fungicides to reduce the severity of F. nivale. Mycelial growth of F. nivale was significantly inhibited at low and high doses of Thiophanate methyl and Fosetyl- Aluminium. Metalaxyl+Mancozeb and Mancozeb also reduced growth of fungus at their high doses (6.830 and 11.900mm), respectively, as compared to Copper oxychloride (18.083 mm) and control (40.750 mm). Thiophanate methyl and Fosetyl- Aluminium significantly reduced infection in Desi, Almas and Dusheri to 16.60 and 19.00%; 17.60 and 19.80%; and 20.60 and 22.00% after first spray, with decreased percent of malformation 72.33 and 68.33%; 71.11 and 67.54%; and 67.81 and 65.62% and over untreated control. The second spray of Thiophanate methyl and Fosetyl- Aluminium fungicides completely inhibited infection of F. nivale, and 100.0% reduction in malformation disease in Desi, Almas, and Dusheri as compared to Metalaxyl+Mancozeb (78.73, 73.84, 72.64%) and Mancozeb (73.65, 73.69, 69.41%), Copper oxychloride and in control. The application of Thiophanate methyl and Fosetyl- Aluminium would be useful in integrated management of MMD.

English

The constant assessment of methods of disease control is essential in achieving production regularity and for ongoing increments in soybean productivity. Among the various diseases, the intensity of the white mold has been increasing, caused especially by the fungus Sclerotinia sclerotiorum (Lib.) de Bary. The present work has the objective to assess different seed treatments in association with fungicide application to control the white mold in soybean. The experimental design used was complete randomized blocks design with split plots. In the plots, the treatments were: control - no seed treatment; Certeza® (thiophanate methyl + fluazinam 45 + 60 g ha-1) and Trichodermil® (Trichodermaharzianum ‘1306’ 1.250 mL 100 kg-1 - 109 viable spores mL-1). In each seed treatment, the application was done on aerial part of subplots.The treatmentsin aerial part were: control (with no fungicides application); three applications of Derosal® (carbendazim) 1.000 gi.a./ha-1 in R1, R2 and R5.1; three applications of Cercobin 700 WP® (thiophanate methyl) 600 gi.a./ha-1 in R1, R2 and R5.1;Cercobin 700 WP® (thiophanate methyl) in R1, Sumilex (procimidone) 750 gi.a./ha-1 in R2 and Frowncide (fluazinam) 750 gi.a./ha-1 in R5.1.There were assessments on the emergence and height of the plants in V3 and the severity of the disease at the phenological stages R1, R3, R5.5 and R7. The variables thousand-grain weight, productivity and the economic analysis were determined after the harvesting of the plots. The treatments of seeds with thiophanate methyl+ fluazinam and Trichoderma harzianum and the applications of thiophanate methyl, procimidone and fluazinam on the aerial part stood out in the control of the disease. The net income showed that despite the high cost of the plant protection products, there were increases in the profitability of the crop. Key words: White mold, Glycine max, Economic analysis.

Preliminary research on conversion of encapsulated somatic embryos of Citrus reticulata Blanco, cv. Mandarino Tardivo di Ciaculli

Somatic embryogenesis was obtained through anther culture of Citrus reticulata, cv. Mandarino Tardivo di Ciaculli. The work was carried out to evaluate the response of somatic embryos inside a sodium alginate coating to different storage periods, and to the effects of the germicide PPM (1 ml l−1) and the fungicide Thiophanate-methyl (100 mg l−1). The effect of these alone or in combination, added to the artificial endosperm on the performance of the encapsulated somatic embryos was tested. After 45 days of culturing, sprouting, root development and conversion were recorded. The encapsulated somatic embryos can be conveniently stored at 4°C, but not for a period longer than 60 days. The presence of Thiophanate-methyl in the artificial endosperm resulted in high levels of sprouting with promising frequencies of root development and conversion in to plantlets under invitro and ex vitro conditions. The concentration of PPM used, alone or in combination with the fungicide, showed some depressing effects in this regard. The prelimnary results obtained with the application of Thiophanate-methyl in a nutrient enriched alginate matrix are promising and warrant further experimentation in attempts to find a solution for the problems faced with ex vitro use of encapsulated somatic embryos.

Application of thiophanate-methyl at different host growth stages for management of sclerotinia stem rot in soybean

Application of thiophanate-methyl at different host growth stages for management of sclerotinia stem rot in soybean

Evaluation of fungicides for control of South American leaf blight of Hevea brasiliensis

SUMMARYOf 43 fungicides tested in vitro, 19 showed strong, seven moderate and 17 weak inhibition of germination of conidia and ascospores of Microcyclus ulei. The formation of lesions on Hevea brasiliensis leaf discs was also suppressed by the first category of fungicides as well as by the five adjuvants tested. Ascospores were not released when perithecia were treated with urea, thiabendazole or alcoholic mercury chloride at 10.00, 0.10, 1.00 g/1 respectively; other fungicides had no such inhibitory effect.In field trials, thiophanate methyl (0.07% a.i.) and benomyl (0.025% a.i.) were most effective in controlling leaf infection, followed by chlorothalonil (0.15% a.i.) and mancozeb (0.32% a.i.). Benomyl suppressed conidial sporulation, whereas one application of thiophanate methyl (0.14% a.i.) to perithecia inhibited ascospore release; half of this concentration applied to conidial lesions or pycnidia caused the perithecia formed subsequently to abort. Thiophanate methyl thus shows promise for SALB control and elimination and benomyl may be valuable as a supplement in later rounds of spraying to control conidial sporulation.After 6 days of showery rain (2 mm for 17 min per day), water collected from sprayed leaves still gave complete inhibition of spore germination. However, inhibition was markedly reduced after 6 days of heavy rain (over 8 mm for 24 min per day).