• The Plant Pathology Journal
• /
• v.33 no.6
• /
• pp.589-596
• /
• 2017

Chemical management of dollar spot in turf may lead to the development of Sclerotinia homoeocarpa populations with reduced fungicide sensitivity. The objective of this study was to investigate resistance of S. homoeocarpa isolates to triazole fungicides and to test cross-resistance among three triazole fungicides. A total of 66 isolates of S. homoeocarpa were collected from 15 golf courses across Korea, and tested via in vitro sensitivity assay against hexaconazole, propiconazole and tebuconazole. $EC_{50}$ values of the isolates to these fungicides were distributed in the range of $0.001-1.1\;a.\;i.\;{\mu}g\;ml^{-1}$. Based on the $EC_{50}$ values, twelve representative strains were selected as sensitive isolates including control and insensitive isolates with respect to each fungicide. At a concentration of $0.1\;a.\;i.\;{\mu}g\;ml^{-1}$ for all fungicides, the selected strains were distinguished as sensitive or resistant isolates with the mycelial growth inhibition rate of 50% as the criterion. The $EC_{50}$ values of resistant strains exposed to hexaconazole, propiconazole and tebuconazole were 20-50 times, 50-70 times, and 77 times greater, respectively, than that of the control strains. Two isolates of S. homoeocarpa S0-41 and Sh14-2-1 showed sensitivity toward all the fungicides used, while two other isolates Sh7-5-1 and Sh2-1-1 showed resistance to all fungicides. Each isolate showed similar resistance to the three types of triazole fungicides, whereby cross-resistance of isolates was confirmed in the present study; all three triazole fungicide combinations displayed significant correlation coefficients equivalent to or greater than 0.8.

• Horticultural Science & Technology
• /
• v.18 no.6
• /
• pp.827-833
• /
• 2000

This study was carried out to investigate the effect of plant growth retardants (daminozide, chlormequat, uniconazole, paclobutrazole) and fungicides of triazole chemical (hexaconazole, microbutanil, difenoconazole, terbuconazole, bitertanol) on the growh of 'New Guinea' impatiens. Plant height and canopy were decreased by all kinds of plant growth retardants tested in both 'Anguilla' and 'Papete'. Especially, uniconazole and paclobutrazole were most effective in inhibition of top growth. However, the content of chlorophyll increased at all treatments of plant growth retardants and stem diameter tended to be increased at the highest concentration of all kinds of plant growth retardants tested. The results in all cultivars tested, with the experiment of triazole fungicides, were similar to the results of experiment with plant growth retardants. These results suggest that fungicides of triazole chemical such as hexaconazole, microbutanil, difenoconazole, terbuconazole and bitertanol can be used for the promotion of quality in potted 'New Guinea' impatiens.

• Research in Plant Disease
• /
• v.15 no.1
• /
• pp.13-16
• /
• 2009

In April 2008, cherry (Prunus yedoensis Matsumura) in Jeju exhibited severe disease of branches forming numerous twigs. Five isolates from diseased leaves were identified as Taphrina wiesneri on the basis of biological and genetic characteristics. Twenty one commercial fungicides were tested for control of the disease in vitro. Of the 21 fungicides, triazole compounds (difenoconazole, propiconazole and tebuconazole) showed relatively good antimicrobial activities. Results from the planta bioassays indicated that triazole compounds reduced the witches' broom disease showing control value $25.7{\sim}52.8%$ compared with the nontreated controls.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.1
• /
• pp.56-64
• /
• 2024

The widespread application of triazole fungicides (TFs) in agricultural practices can result in the considerable accumulation of active compound residues in the soil and a subsequent negative impact on the soil microbiota and crop health. In this study, we isolated three TF-degrading bacterial strains from contaminated agricultural soils and identified them as Klebsiella sp., Pseudomonas sp., and Citrobacter sp. based on analysis of morphological characteristics and 16S rRNA gene sequences. The strains used three common TFs, namely hexaconazole, difenoconazole, and propiconazole, as their only sources of carbon and energy for growth in a liquid mineral salt medium, with high concentrations (~ 500 mg/l) of each TF. In addition to the ability to degrade fungicides, the isolates also exhibited plant growth-promoting characteristics, such as nitrogen fixation, indole acetic acid production, phosphate dissolution, and cellulose degradation. The synergistic combination of three bacterial isolates significantly improved plant growth and development with an increased survival rate (57%), and achieved TF degradation ranging from 85.83 to 96.59% at a concentration of approximately 50 mg/kg of each TF within 45 days in the soil-plant system. Based on these findings, the three strains and their microbial consortium show promise for application in biofertilizers, to improve soil health and facilitate optimal plant growth.

• Horticultural Science & Technology
• /
• v.18 no.6
• /
• pp.823-826
• /
• 2000

This study was carried out to investigate the effect of plant growth retardants (daminozide, chlormequat, hexaconazole, uniconazole, paclobutrazole) and fungicides of triazole chemical (microbutanil, difenoconazole, terbuconazole, bitertanol) on the rooting of 'New Guinea' impatiens cuttings. In both 'Papete' and 'Anguilla', the formation of adventitious roots was promoted by all concentrations of chlormequat, hexaconazole, uniconazole, and paclobutrazole treated. More adventitious roots were formed with hexaconazole, uniconazole, and paclobutrazole than with chlormequat. Length of the longest root and rooting zone decreased at higher concentrations of chlormequat, hexaconazole, uniconazole, and paclobutrazole in 'Papete', while 'Anguilla' showed less responses. In contrast with plant growth retardants, the formation of adventitious roots was remarkably promoted by fungicides of triazole chemical such as microbutanil, difenoconazole, terbuconazole, and bitertanol in 'Pepete' and 'Martinique' impatiens, but was not in 'Pagopago'. However, length of the longest root and rooting zone showed more sensitive response in 'Martinique' and 'Pagopago' than in 'Pepete'. These results suggest that fungicides of triazole chemical can be effectively used for rooting promotion of impatiens cuttings.

• Korean Journal Plant Pathology
• /
• v.12 no.3
• /
• pp.316-323
• /
• 1996

비가림재배 포도원에서 발생하는 흰가루병에 대하여 triazole계 살균제 flusilazole, myclobutanil, difenoconazole, penconazole, triflumizole, triadimefon의 방제 효과를 검정한 결과는 다음과 같다. 살균제 처리구의 이병과방율과 이병엽율은 무처리구에 비해 현저히 감소하였고, 이들의 방제가는 과방에서 약제에 따라 94.7∼97.9%, 잎에서 85.5%∼90.9%였으며 대조약제인 polyoxin B의 방제가와 유사한 정도를 보였다. 공시살균제의 보호효과는 살균제를 병발생 1주일전에 살포하는 경우, 살포 3주 후에 방제가는 약제에 따라 72.2∼90.5%였으나 4주 후에는 21.2∼41.6%로 감소하여 대조약제 polyoxin B의 52.5%보다 감소시켰으나 myclobutanil의 발아억제 효과는 약제 농도증가에 크게 영향받지 않았다. 살균제에 침지한 cheesecloth를 포도원 선반에 매달아 조사한 공시살균제의 훈증효과는 살포농도의 2배로 처리했을 때 처리점으로부터 반경 30cm이내의 포도송이에서는 약제에 따라 57.2∼71.1%의 방제가를 보였으나 전체 식물체에서는 49.1∼65.8%로서 10일 간격으로 3회 살포한 것 보다 낮은 방제가를 보였다.

• Korean Journal Plant Pathology
• /
• v.13 no.4
• /
• pp.210-214
• /
• 1997

The experiment was conducted to obtain basic informations on the effects of key environments and fungicides on the sporulation, conidial germination and hitial growth of the hyphae of grape powdery mildew fungus Uncinula necator. Maximum sporulation occurred at RH 75~96% in vitro adiusted with sulfuric acid solution. Conidial germination and initial growth of the hyphae were better at 5% water agar than distilled water, and best at $26^{\circ}C$ and pH 5.0 of the substrates. Germination occurred equally well at light intensity of below 100 lux or dark condition, which was better at water agar supplemented with leaf extract 30% than pure water agar. The water agar supplemented with triazole fungicides reduced conidial germinations and initial growth of the hyphae signifcantly, in proportion to the increase in concentration of the fungicides, but the maguitude of reduction depended on the fungicides. Particularly in myclobutanil, reduction rate was very low as increased in concentration.

• Korean Journal of Environmental Biology
• /
• v.32 no.1
• /
• pp.1-15
• /
• 2014

Amphibians play a pivotal role in the ecosystem as a mediator between aquatic and terrestrial environment. Currently they are directly exposed to a variety of chemicals in the aquatic environment throughout their life cycle. Azole fungicides have been widely used in medical applications and agricultural activities. The direct exposure of azole fungicides causes an alarming situation for various ecosystem. Recently, teratogenesis and endocrine disruption by azole fungicides have been reported in amphibians. In an effort to provide the current information for amphibian toxicity of azole fungicides and to make the guidelines for safe usage of azole-based materials, the effects of azole fungicides including imidazole, triazole, thiazole, oxazole, and pyrazoleon on early development, differentiation and reproduction of amphibians were reviewed.

• The Korean Journal of Pesticide Science
• /
• v.19 no.1
• /
• pp.54-63
• /
• 2015

Streptomyces spp. isolated from turfgrass rhizosphere and tested for their response to large-patch control fungicides. The tested fungicides were actually used in golf course or turfgrass cultivation to prevent large-patch disease. Tolerance to 3 triazole group of the strains was the highest to the PR fungicide, and following the SR fungicide, whereas the isolated strains were no tolerance to HR fungicide. Tolerances to three kind of Strobilurin group were similar for the all of the tested Streptomyces spp.. Growth and sporulation of the all strain was normal in CB and AP fungicide treatments. However no spore formulated in double concentration. Strains, tolerance to acetanilide fungicides, appeared that KT fungicide tolerance was higher than MK fungicide. The selected strains showed strong tolerance against AT fungicide but have no tolerance to ATR fungicides. In conclusion, the bacterial strains showed tolerance against 1 carbamate, 1 organophosphate and 1 cyanopyrrole group, while have no tolerance against two mixture formulations (1 Quinone + Strobilurin and 1 Imidazole + Triazole).

• International Journal of Industrial Entomology and Biomaterials
• /
• v.5 no.2
• /
• pp.171-174
• /
• 2002

Two systemic fungicides, SF1 (Bavistin, a carbandazim fungicide 50% WP, Rallis India ltd., India) and SF2 (Bayleton 25% WP-Triadiamefon, a Triazole compound, Rallis India Ltd., India) were screened for control of muscardine disease in silkworm, Bombyx mori. One and two percent of SF1 and 0.05 and 0.1 % of SF2 in aqueous solution were found to be effective in in vivo condition for the control of the disease. These fungicides, on feeding through mulberry leaves continuously for two days to 4$^{th}$ and 5$^{th}$ instar silkworm larvae inoculated topically with conidia of Beauveria bassiana (4$\times$10$^{6}$ conidia/ml) resulted in reduction in mortality due to muscardine by over 90% as against 100% mortality in inoculated control. SF1 at 1% reduced the mortality by 90% in 4$^{th}$ instar and 91% in final instar silkworm while at 2%, the reduction was 92% and 96%, respectively. SF2 at 0.05 and 0.1 % concentration reduced the mortality by 82 and 88% during 4$^{th}$ instar and by 88 and 92% during 5$^{th}$ instar, respectively.