Mancozeb resistance patterns among Kampimodromus aberrans and Typhlodromus pyri (Acari: Phytoseiidae) strains from French vineyards

2004 ◽  
Vol 136 (5) ◽  
pp. 663-673 ◽  
Author(s):  
Philippe Auger ◽  
Romain Bonafos ◽  
Serge Kreiter
Keyword(s):  
Application Rate ◽  
Field Application ◽  
Typhlodromus Pyri ◽  
Phytoseiid Mites ◽  
Kampimodromus Aberrans ◽  
Resistance Factors ◽  
Resistance Patterns ◽  
Resistant Strains ◽  
Maximum Field ◽  
Laboratory Bioassays

AbstractLaboratory bioassays were carried out on two species of phytoseiid mites to investigate their resistance to the fungicide mancozeb. Susceptible and suspected resistant strains of Kampimodromus aberrans (Oudemans) and Typhlodromus pyri Scheuten were tested. Mancozeb resistance factors were low to moderate: they reached 6.3 and 11.7 for K. aberrans and T. pyri, respectively. Intrinsic toxicity of mancozeb was approximately 5–10-fold more pronounced in females of K. aberrans than in females of T. pyri. The female susceptibility pattern of the most resistant strain of K. aberrans was quite close to that of the most susceptible strain of T. pyri. The LC50 values for the most resistant strains of K. aberrans and T. pyri were 4.6 and 43 times higher, respectively, than the maximum field application rate of mancozeb recommended for control of downy mildew in vineyards. Using a diagnostic concentration, a limited survey in vine plots indicated that most of the K. aberrans strains we tested were susceptible to mancozeb, but a few consisted of both resistant and susceptible individuals. All strains of T. pyri collected in Burgundy were susceptible. Half of the T. pyri strains from Bordeaux were susceptible and the other half were mixed populations of resistant and susceptible individuals.

Effects of asulam spraying on non-target ferns

2005 ◽  
Vol 83 (12) ◽  
pp. 1622-1629 ◽  
Author(s):  
J.K. Rowntree ◽  
E. Sheffield
Keyword(s):  
Experimental Evidence ◽  
Application Rate ◽  
Field Application ◽  
Pteridium Aquilinum ◽  
Buffer Zones ◽  
Application Rates ◽  
Highly Sensitive ◽  
Fern Species ◽  
Aerial Spraying ◽  
Work Supports

The systemic herbicide asulam is used extensively to control the weedy fern bracken ( Pteridium aquilinum (L.) Kuhn). Other ferns were thought to be highly sensitive to asulam exposure, but there has been a dearth of experimental evidence. Eight fern species were exposed to asulam spray at three different application rates or a control of water. Asulam was applied at the recommended field application rate for bracken clearance, and at two further rates corresponding to 10 and 50 m downwind of an aerial spray event. Damage was assessed over two seasons. All ferns tested were severely damaged by exposure to the highest application rate, but sensitivity varied between species. Maximum damage occurred 1 year after spraying, and limited signs of recovery could be seen by the second season. The effects of adding the adjuvant Agral® to applications of asulam were tested on the threatened pteridophyte Pilularia globulifera L. No damage additional to that caused by exposure to asulam was observed. This work supports the view that 50 m buffer zones are sufficient to protect sensitive ferns from the effects of aerial spraying with asulam, provided that drift-reducing nozzles are used and the manufacturer’s application guidelines are observed.

scholarly journals Untersuchungen zum Vorkommen der Phytoseiidae (Acari: Mesostigmata) und Roten Spinne, Panonychus ulmi im Südtiroler Apfelanbau

2021 ◽  
Vol 2 ◽  
Author(s):  
Martin Parth ◽  
Stefanie Fischnaller ◽  
Manuel Messner ◽  
Manfred Wolf
Keyword(s):  
Typhlodromus Pyri ◽  
Panonychus Ulmi ◽  
Neoseiulus Californicus ◽  
Amblyseius Andersoni ◽  
Kampimodromus Aberrans ◽  
Euseius Finlandicus

Von 2014 bis 2017 wurden intensive Untersuchungen zum Raubmilbenvorkommen (Mesostigmata: Phytoseiidae) und Auftreten der Roten Spinne Panonychus ulmi (Prostigmata: Tetranychidae) in ausgewählten Apfelanalgen in Südtirol (Italien) angestellt. Die Populationsdichten der Milben wurden wiederholt an bis zu 50 Standorten im Etschtal und Vinschgau erhoben. In 27 Apfelanlagen wurde im Verlauf der Jahre 2015-2017 die Artenzusammensetzung blattbesiedelnder sowie an Aststrukturen überwinternder Raubmilben eingehend untersucht. Insgesamt wurden 5581 Raubmilben einer morphologischen Artbestimmung unterzogen. Sechs Phytoseiiden-Arten wurden nachgewiesen. Amblyseius andersoni (Chant 1957) konnte an allen Untersuchungstandorten gefunden werden und wies eine Individuendominanz von 80% auf. Ein permanentes Vorkommen von Typhlodromus pyri (Scheuten 1857) und Euseius finlandicus (Oudemans 1915) wurde an 18,5% bzw. 7,4% der Standorte festgestellt. Kampimodromus aberrans (Oudemans 1930), Paraseiulus talbii (Athias-Henriot 1960) und Typhlodromus bakeri (Garman 1948) wurden sporadisch nachgewiesen. Neoseiulus californicus (McGregor 1954) wurde erstmals am Apfel in Südtirol nachgewiesen. Der P. ulmi-Befall im Untersuchungsgebiet erwies sich, sofern gegeben, als äußerst gering. Eine wesentliche Zunahme der Populationsdichten von P. ulmi und eine diesbezügliche Schadwirkung wurden nicht festgestellt.

scholarly journals Biochar increases tobacco yield by promoting root growth based on a three-year field application

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tianbao Ren ◽  
Huanhuan Wang ◽  
Ye Yuan ◽  
Huilin Feng ◽  
Bo Wang ◽  
...  
Keyword(s):  
Field Experiments ◽  
Growth Index ◽  
Application Rate ◽  
Field Application ◽  
Root Tips ◽  
Tobacco Plants ◽  
Root Area ◽  
Tobacco Production ◽  
Physiological Indexes ◽  
Tobacco Roots

AbstractIn order to explore the effects of biochar on root system and growth characteristics of flue-tobacco, three years of field experiments were conducted to study the influence of different biochar application levels [600 (T1), 1200 (T2), 1800(T3), 2400 (T4), 3000 (T5) kg/ha] and no fertilizer (CK) on the root physiological indexes and growth index of tobacco. Compared with local conventional fertilization, the application rate of N fertilizer in each treatment (except for control) was reduced by 40% to analyze the effects of different amount of biochar on the physiological indexes of tobacco roots and leaf photosynthesis during flourishing. The results showed that tobacco plants' root development status in the flourishing period was consistent with the photosynthetic physiological indexes, chlorophyll content, and leaf-area coefficient. Compared with the control, the application of biochar could increase the root vigor by 177.8%. Biochar improved the roots, increasing the total root area by 91.35% and the number of root tips by 100.9%. Meanwhile, biochar increased the net photosynthetic rate of tobacco leaves by 77.3% and the total tobacco biomass by 72.5%. Studies have shown that biochar can promote the development of tobacco roots, and then enhance the photosynthesis of leaves, so that tobacco plants can grow healthily, which is conducive to the tobacco production and the cultivation of soil.

scholarly journals Molecular Analysis of Codon 548 in therpoBGene Involved in Mycobacterium tuberculosis Resistance to Rifampin

2014 ◽  
Vol 59 (3) ◽  
pp. 1542-1548 ◽  
Author(s):  
Yu-Tze Horng ◽  
Wen-Yih Jeng ◽  
Yih-Yuan Chen ◽  
Che-Hung Liu ◽  
Horng-Yunn Dou ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Bacterial Resistance ◽  
Drug Susceptibility ◽  
Content Type ◽  
Stable Hydrogen Bond ◽  
Resistance Patterns ◽  
Resistant Strains ◽  
Rifampin Resistance ◽  
Susceptibility Tests ◽  
Dna Complex

ABSTRACTMostMycobacterium tuberculosisrifampin-resistant strains have been associated with mutations in an 81-bp rifampin resistance-determining region (RRDR) in the generpoB. However, if this region alone were targeted, rifampin-resistant strains with mutations outside the RRDR would not be detected. In this study, among 51 rifampin-resistant clinical isolates analyzed by sequencing 1,681-bp-long DNA fragments containing the RRDR, 47 isolates contained mutations within the RRDR, three isolates contained mutations both within and outside the RRDR, and only one isolate had a single missense mutation (Arg548His) located outside the RRDR. A drug susceptibility test of recombinantMycobacterium smegmatisandM. tuberculosisisolates carrying mutatedrpoB(Arg548His) showed an increased MIC for rifampin compared to that of the control strains. Modeling of the Arg548His mutant RpoB-DNA complex revealed that the His548 side chain formed a more stable hydrogen bond structure than did Arg548, reducing the flexibility of the rifampin-resistant cluster II region of RpoB, suggesting that the RpoB Arg548His mutant does not effectively interact with rifampin and results in bacterial resistance to the drug. This is the first report on the relationship between the mutation in codon 548 of RpoB and rifampin resistance in tuberculosis. The novel mutational profile of therpoBgene described here will contribute to the comprehensive understanding of rifampin resistance patterns and to the development of a useful tool for simple and rapid drug susceptibility tests.

Drug Resistance of Enterobacteriaceae Isolated from Chicken Carcasses

1997 ◽  
Vol 60 (8) ◽  
pp. 1001-1005 ◽  
Author(s):  
MARIA A. TESSI ◽  
MARIA S. SALSI ◽  
MARIA I. CAFFER ◽  
MARIA A. MOGUILEVSKY
Keyword(s):  
Nalidixic Acid ◽  
Processing Plant ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Resistance Patterns ◽  
R Plasmids ◽  
Resistant Strains ◽  
Different Strains ◽  
K 12 ◽  
R Factors

The antibiotic resistance profiles and transferable R factors of Salmonella and Escherichia coli isolates from 104 broiler carcasses taken from one processing plant were determined. Carcasses were sampled after immersion chilling. All samples were transported iced and immediately analyzed upon arrival to the laboratory. The resistance patterns of isolates to 12 antibiotics were determined (i.e., ampicillin, cephalothin, streptomycin, sulfisoxazole, trim-ethoprim-sulfamethoxazole, nalidixic acid, tetracycline, neomycin, chloramphenicol, gentamicin, colistin, and nitrofurantoin). Isolates resistant to one or more antibiotics were utilized as donors of resistance to completely antibiotic-sensitive strains, an E. coli K-12, F−, J5, azide-resistant strain and a Salmonella serovar Enteritidis. Transfer of the different R plasmids was confirmed by the determination of the resistance patterns of the transconjugants. Of the 93 Salmonella and 71 E. coli strains isolated from these samples, the largest numbers were resistant to tetracycline (52.7% and 49.3%), sulfisoxazole (45.2% and 42.3%), and streptomycin (37.6% and 39.4%). Large percentages of the Salmonella (33.3%) and the E. coli (30.0%) strains transferred all or part of their resistance to E. coli K-12 in mixed cultures. Great variation was observed between different strains in the frequency at which they transferred resistance. Resistance to tetracycline, sulfisoxazole, and streptomycin was found to be conferred by 31.7%, 29.8%, and 21.6% of the 19 R factors identified. No transfer of resistance to nalidixic acid, gentamicin, cephalothin, nitrofurantoin, and chloramphenicol was detected. When 30 antibiotic-resistant E. coli strains were cultured with a sensitive strain of Salmonella serovar Enteritidis,7 (23.3%) of the resistant strains were found capable of transferring R factors. Only 2 (6.7%) of the resistant strains could transfer R factors and unusual β-galactosidase activity.

Sugarcane (Saccharum spp. hybrids) Response to Simulated Fallow Field Residues of Metribuzin and Sulfometuron

1998 ◽  
Vol 12 (3) ◽  
pp. 454-457 ◽  
Author(s):  
Donnie K. Miller ◽  
Edward P. Richard ◽  
James L. Griffin
Keyword(s):  
Adverse Effect ◽  
Soil Surface ◽  
Application Rate ◽  
Field Application ◽  
Sugar Yield ◽  
Saccharum Spp ◽  
Lateral Buds ◽  
Fallow Field

Sulfometuron at 17 g ai/ha in the planting furrow (13% of the anticipated fallow-field application rate) inhibited sugarcane emergence and development and ultimately reduced sugar yields in the initial production year by 13% when compared to a weed-free control that contained no herbicide in the planting furrow. Residual levels of metribuzin in the planting furrow representing 100% of the standard fallow-field application rate of 1,680 g ai/ha had no adverse effect on sugarcane development or sugar yield. When applied only to the soil surface immediately after planting, sulfometuron did not injure sugarcane, and sugar yields were equivalent to standard, at-planting, preemergence (PRE) applications of either metribuzin at 2,020 g/ha or a mixture of pendimethalin plus atrazine each at 2,240 g ai/ha. To minimize sugarcane injury, sulfometuron should be kept out of the germinating zone of lateral buds along planted sugarcane stalks.

scholarly journals Effect of Glyphosate Application on Foliar Diseases in Glyphosate-Tolerant Alfalfa

Plant Disease ◽  
2012 ◽  
Vol 96 (8) ◽  
pp. 1104-1110 ◽  
Author(s):  
Deborah A. Samac ◽  
Dawn Foster-Hartnett
Keyword(s):  
Active Ingredient ◽  
Symptom Severity ◽  
Application Rate ◽  
Field Application ◽  
Treatment Control ◽  
Necrotrophic Pathogen ◽  
Complete Control ◽  
Foliar Diseases ◽  
Colletotrichum Trifolii ◽  
Fungistatic Activity

Glyphosate, the active ingredient in Roundup herbicide, inhibits 5-enol-pyruvyl shikimate 3-phophate synthase (EPSPS), an enzyme found in plants, fungi, and bacteria. Plants engineered for glyphosate tolerance with a glyphosate-insensitive EPSPS take up and translocate the herbicide throughout the plant. In greenhouse experiments, we found that application of glyphosate at the recommended field application rate completely controlled alfalfa rust (Uromyces striatus) on 4-week-old plants inoculated with the fungus 3 days after glyphosate treatment. Control was effective in all seven cultivars tested. The level of protection declined with time after application, indicating that control transitory and protection declined with time after inoculation, suggesting that protective treatments have fungistatic activity. Complete control of rust was obtained when glyphosate was applied up to 10 days after inoculation with rust spores, indicating that the herbicide also has curative activity. Treatment increased protection from anthracnose, caused by Colletotrichum trifolii, a hemibiotrophic pathogen, and reduced symptom severity for spring black stem and leaf spot, caused by Phoma medicaginis, a necrotrophic pathogen. These results indicate that glyphosate could be used to help manage foliar diseases in glyphosate-tolerant alfalfa.

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