Evaluation of the systemic activity of simeconazole in comparison with that of other DMI fungicides

Abstract

The systemic activity of simeconazole (RS-2-(4-fluorophenyl)-1-(1H-1,2,4-triazol-1-yl)-3-trimethylsilylpropan-2-ol) in plants was compared with those of eight other sterol demethylation inhibitor (DMI) fungicides. Simeconazole prevented the infection of Blumeria graminis (DC) Speer f sp hordei Marchal on barley leaves within a radius of several centimeters from the edge of local treatment on the leaves when the compound was separated from the leaves by glass coverslips. This reveals that simeconazole has prominent vapour-phase activity. Simeconazole showed excellent curative activity against barley powdery mildew when treated 1-3 days after inoculation. Furthermore, this indicates that simeconazole has notable translaminar activity because, when the compound was applied onto either the adaxial or abaxial leaf surface, it showed excellent efficacy against powdery mildew on the opposite side of the leaf surface of barley and cucumber. Simeconazole also showed excellent efficacy against barley powdery mildew by soil drench 24h after inoculation. This suggests that simeconazole was absorbed very quickly into the barley plant after treatment. The permeability of the compound through cuticular membranes prepared from tomato fruits was about 20% at 22 h after the treatment and was much superior to that of the other DMI fungicides tested.

Effects of Planting Pattern and Fungicide Application Systems on Ascochyta Blight Control and Seed Yield in Chickpea

“…In our study, the customized triple‐nozzle system, with one nozzle above the canopy and one nozzle on each side, increased the capacity to apply more of the active ingredient into the center of the lower canopy layer compared with conventional spray. Active ingredients of most fungicide products are only minimally translocated within plants (Tsuda et al, 2004), thus the efficacy of pesticides for disease control is largely dependent on the deposition and retention of a sufficient concentration of the active ingredient on the crop canopy (Gossen et al, 2008). The application of fungicides with the triple‐nozzle systems, combined with the paired‐row spacing, was more efficient at directing fungicide droplets to the lower part of the crop canopy compared with a conventional horizontal boom sprayer.…”

Soybean cultivar performance in the presence of soybean Asian rust, in relation to chemical control programs

“…The active ingredients of the triazole group have curative effects, interfering with ergosterol biosynthesis in the fungal membrane and being absorbed by leaf tissues (Tsuda et al 2004). According to Koehle et al (2002), the fungicides of the strobilurin group interfere with spore germination and on the development of the germ tube and, like the triazols, move in a translaminar way.…”

Development of an Inoculation Method for Quantifying Fungicide Residues on Peanut Foliage

“…The systemic properties of DMI and QoI fungicides are far more defined than those of flutolanil. Studies conducted by Tsuda et al (2004) documented the translaminar (movement from the upper leaf surface to the lower leaf surface) and transcuticular (movement through the cuticle) activity of several DMI fungicides, including tebuconazole. They found that fungicide efficacy against powdery mildew (Sphaerotheca cucurbitae (Jaczewski) Zhao) on cucumber (Cucumis sativus L.) seedlings resulted from permeation and dissipation of the fungicides within leaves.…”