Efficacies of fungicides for control of stem rust of wheat

1985 ◽  
Vol 25 (2) ◽  
pp. 440 ◽  
Author(s):  
AH Mayfield
Keyword(s):  
Grain Yield ◽  
Stem Rust ◽  
Field Experiments ◽  
Early Stage ◽  
Puccinia Graminis ◽  
Disease Development ◽  
Cost Of Treatment ◽  
Commercial Use ◽  
Rust Severity ◽  
The Cost

The potential commercial use of fungicides for control of stem rust (Puccinia graminis) of wheat was assessed in field experiments at two sites. Foliar sprays containing either triadimefon or propiconazole were the most effective in reducing disease severity. Chlorothalonil was effective only when applied at an early stage of disease development and where stem rust was not severe in control plots. Dichlone, fenarimol, nuarimol and 2-(thiocyanomethylthio) benzothiazole did not significantly reduce stem rust severity at either site. Even though treatments were applied at an early stage ofthe disease epidemic at one site, disease control on heads, peduncles and sheaths did not exceed 63,36 and 19%, respectively, with any treatment. Increases in grain yield and density, of up to 0.27 t/ha and 8.6 kg/hectolitre, respectively, were barely sufficient to cover the cost of treatment.

Inoculum pressure and the development of stem rust epidemics in barley

1991 ◽  
Vol 42 (5) ◽  
pp. 769 ◽  
Author(s):  
R Dill-Macky ◽  
RG Rees ◽  
GJ Platz
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Initial Inoculum ◽  
Barley Cultivars ◽  
Yield And Quality ◽  
Rust Severity ◽  
Grain Yield And Quality ◽  
Moderately Resistant ◽  
Different Levels ◽  
Inoculum Pressure

The effects of inoculum pressure on the development of epidemics of Puccinia graminis tritici in two barley cultivars with different levels of resistance were examined in two field experiments. Treatments were established by inoculation of foci within plots and/or the strategic use of fungicides. Additional 'rust-free' treatments were maintained to provide comparisons of grain yield and quality. Relationships between rust severity, rust incidence and grain yield and quality were also examined. Initial inoculum levels were important in determining disease severity and incidence for individual epidemics; however, severe epidemics developed under most 'rusted' treatments of the susceptible cultivar Galleon and reduced grain yield by up to 58%. Epidemics under corresponding treatments of the moderately resistant cultivar Grimmett were less severe, and the value of the resistance was evident with yield losses not exceeding 12%. Yield reductions were usually associated with reduced grain size and weight.

scholarly journals Analyzing Genetic Diversity for Virulence and Resistance Phenotypes in Populations of Stem Rust (Puccinia graminis f. sp. secalis) and Winter Rye (Secale cereale)

2016 ◽  
Vol 106 (11) ◽  
pp. 1335-1343 ◽  
Author(s):  
Thomas Miedaner ◽  
Ann-Kristin Schmitt ◽  
Bettina Klocke ◽  
Brigitta Schmiedchen ◽  
Peer Wilde ◽  
...  
Keyword(s):  
Stem Rust ◽  
Resistance Breeding ◽  
The United States ◽  
Shannon Index ◽  
Adult Plant ◽  
Leaf Segment ◽  
Winter Rye ◽  
Puccinia Graminis ◽  
Plant Stage ◽  
Rust Severity

Stem rust (Puccinia graminis f. sp. secalis) leads to considerable yield losses in rye-growing areas with continental climate, from Eastern Germany to Siberia. For implementing resistance breeding, it is of utmost importance to (i) analyze the diversity of stem rust populations in terms of pathotypes (= virulence combinations) and (ii) identify resistance sources in winter rye populations. We analyzed 323 single-uredinial isolates mainly collected from German rye-growing areas across 3 years for their avirulence/virulence on 15 rye inbred differentials. Out of these, 226 pathotypes were detected and only 56 pathotypes occurred more than once. This high diversity was confirmed by a Simpson index of 1.0, a high Shannon index (5.27), and an evenness index of 0.97. In parallel, we investigated stem rust resistance among and within 121 heterogeneous rye populations originating mainly from Russia, Poland, Austria, and the United States across 3 to 15 environments (location−year combinations). While German rye populations had an average stem rust severity of 49.7%, 23 nonadapted populations were significantly (P < 0.01) more resistant with a stem rust severity ranging from 3 to 40%. Out of these, two modern Russian breeding populations and two old Austrian landraces were the best harboring 32 to 70% fully resistant plants across 8 to 10 environments. These populations with the lowest disease severity in adult-plant stage in the field also displayed resistance in leaf segment tests. In conclusion, stem rust populations are highly diverse and the majority of resistances in rye populations seems to be race specific.

scholarly journals Stem rust (Puccinia graminis ssp. graminicola Urban) its hosts and harmfulness in grasses grown for seed

2013 ◽  
Vol 55 (1) ◽  
pp. 285-298
Author(s):  
Maria Prończuk
Keyword(s):  
Stem Rust ◽  
Morphological Analysis ◽  
Field Experiments ◽  
Poa Pratensis ◽  
Late Summer ◽  
Early Summer ◽  
Festuca Rubra ◽  
Puccinia Graminis ◽  
Spring Temperature ◽  
Deschampsia Caespitosa

Stem rust development on four species of grasses was studied in field experiments conducted at Radzików in 1997-2001. Population of <i>Puccinia graminis</i> ssp. <i>graminicola</i> from different hosts was characterised and their harmfulness for grass grown for seed was estimated. The materials for study were ecotypes and strains of <i>Lolium perenne</i>, <i>Festuca rubra, Poa pratensis</i> and <i>Deschampsia caespitosa</i> collected in breeding nursery and cultivars and strains of <i>L.perenne, F.rubra, P.pratensis</i> cultivated for seed. It was found that the changes in environmental conditions during last years influenced earlier occurrence of stem rust on grasses in Poland. All examined species were the host of <i>P.graminis</i> ssp. <i>graminicola</i>, however the period of infection of particular hosts were different. <i>L.perenne</i> and <i>D.caespitosa</i> were infected in early summer but <i>F.rubra</i> and <i>P.pratensis</i> in late summer or in the autumn. Morphological analysis of spores of <i>P.graminis</i> ssp. <i>graminicola</i> have shoved significant differences between populations obtained from <i>L.perenne</i> and <i>D.caespitosa</i>. Some differences were found between populations from <i>F.rubra</i> and <i>P.pratensis</i> also, but they need more study. Every year occurrence of stem rust on <i>L.perenne</i> and <i>D.caespitosa</i> and its relation with spring temperature in Radzików indicated that populations of patogen could overwinter in local turf. Incidental appearance of stem rust on <i>F.rubra</i> and <i>P.pratensis</i> in centre of Poland allowed to suppose that spores of these forms might be transfer by wind from other regions. The investigation revealed that stem rust can be dangerous for <i>L.perenne</i> grown for seed when infection occurs at flowering time. It has been established that infection of <i>F.rubra</i> and <i>P.pratensis</i> in autumn should not be disregarded. Damages of leaves by <i>P.graminis</i> ssp. <i>graminicola</i> substantially limited plant heading in the next year.

The field reaction to stem rust of 'Chinese Spring' substitution lines carrying chromosomes from 'Hope' and 'Thatcher' wheats

1986 ◽  
Vol 28 (1) ◽  
pp. 12-16
Author(s):  
D. R. Knott
Keyword(s):  
Stem Rust ◽  
Chinese Spring ◽  
Rust Resistance ◽  
Adult Plant Resistance ◽  
Triticum Aestivum L ◽  
Adult Plant ◽  
Puccinia Graminis ◽  
Substitution Lines ◽  
Field Reaction ◽  
Rust Severity

Studies were done in an attempt to determine the inheritance of adult plant resistance to stem rust (Puccinia graminis f. sp. tritici Eriks. and E. Henn.) in the wheat (Triticum aestivum L.) cultivars 'Hope' and 'Thatcher'. 'Chinese Spring' substitution lines carrying individual chromosomes from 'Hope' and 'Thatcher' were tested in field rust nurseries, three times each with races 15B-1 and 56, and twice with multirace mixtures. In 1976 it was found that the date of heading often had a significant effect on rust severity, with early lines showing less rust. In 1977 and 1984 the lines were divided into three groups based on maturity and were planted on three dates about 10 days apart to make heading dates more uniform. The data indicate that 'Hope' has genes for resistance to race 56 on chromosomes 3B (Sr2) and 4D, and to a multirace mixture on 1B, 3B, and 7B. 'Thatcher' possibly has genes for resistance to race 56 on chromosomes 6A and 3B (Sr12). The results show that the resistance of both cultivars is complex and most genes have only small effects.Key words: Triticum, Puccinia, rust resistance, substitution lines.

Stem rust epidemics and their effects on grain yield and quality in Australian barley cultivars

1990 ◽  
Vol 41 (6) ◽  
pp. 1057 ◽  
Author(s):  
R Dill-Macky ◽  
RG Rees ◽  
GJ Platz
Keyword(s):  
Grain Size ◽  
Grain Yield ◽  
Stem Rust ◽  
Puccinia Graminis ◽  
Seedling Resistance ◽  
Barley Cultivars ◽  
Yield And Quality ◽  
Epidemic Development ◽  
Grain Yield And Quality ◽  
Field Plots

The progress of epidemics of Puccinia graminis f. sp. tritici strain 343-Anz-1,2,3,5,6 was examined in field plots of the Australian barley cultivars Clipper, Corvette, Galleon, Grimmett, Prior and Schooner. The barley Purple Nudum, reported to possess seedling resistance to Puccinia graminis f. sp. tritici, and the susceptible wheat Oxley were also examined. Additional rust-free treatments were maintained to provide comparisons of grain yield and quality. Differences in the rate of epidemic development between cultivars were found. Moderate epidemics developed in Clipper, Schooner, Grimmett and Prior and no significant losses in yield were detected in Grimmett or Prior. Severe epidemics developed in Galleon, Corvette and Oxley and reduced grain yield by about half. Yield reductions were generally associated with reduced grain size and weight.

Yield loss and fungicide control of stem rust of wheat

2005 ◽  
Vol 56 (1) ◽  
pp. 91 ◽  
Author(s):  
R. Loughman ◽  
K. Jayasena ◽  
J. Majewski
Keyword(s):  
Disease Severity ◽  
Stem Rust ◽  
Grain Quality ◽  
Yield Loss ◽  
Disease Incidence ◽  
Puccinia Graminis ◽  
Plant Parts ◽  
Moderate Disease ◽  
Rust Severity ◽  
Fungicide Control

Yield loss in wheat from natural infections with Puccinia graminis f.sp. tritici ranged from 10 to 45% in 3 experiments over 2 years. Fungicide reduced subsequent stem rust severity on plant parts that were only slightly infected at the time of fungicide application, but was not effective on plant parts that were more heavily infected when treated. Fungicide control of stem rust was economic in a range of situations. Fungicide applied at head emergence with low disease incidence (5% of stems) increased yield by 0.3 t/ha. When applied prior to head emergence with high disease incidence at low disease severity, yield increased by 0.8–1.5 t/ha, depending on duration of control. At a high disease incidence and moderate disease severity, yield increases of 0.4–0.6 t/ha were observed. Grain quality was also significantly improved with fungicide. Fungicide was more effective when applied immediately following detection compared with a 3-week delay. Folicur was more effective at reducing disease and increasing yield or quality than Impact or Triad.

scholarly journals Interaction of Fungicide Physical Modes of Action and Plant Phenology in Control of Stem Rust of Perennial Ryegrass Grown for Seed

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1225-1232 ◽  
Author(s):  
W. F. Pfender
Keyword(s):  
Perennial Ryegrass ◽  
Stem Rust ◽  
Flag Leaf ◽  
Leaf Sheath ◽  
Plant Phenology ◽  
Disease Development ◽  
Modes Of Action ◽  
Secondary Infections ◽  
Time Of Infection ◽  
Rust Severity

Azoxystrobin provided protective and curative effects against stem rust (caused by Puccinia graminis subsp. graminicola) of inoculated perennial ryegrass under field conditions, significantly reducing disease severity compared with the nontreated check when applied as much as 15 days before infection or 14 days after infection. Propiconazole had a significant effect when applied 13, but not 15, days before infection or 7, but not 9, days after infection. Either fungicide was very effective when applied near the time of infection, and the effectiveness of each fungicide was well described by a second- or third-order polynomial with time (days or stem rust latent periods) as the independent variable. When symptomatic plants were sprayed with a fungicide, subsequent urediniospore production per pustule was reduced by 73% in propiconazole-treated plants and by 95% in azoxystrobin-treated plants. Azoxystrobin modestly but significantly reduced germinability of urediniospores from sprayed pustules, unlike propiconazole. These differences between the two fungicides in physical modes of action resulted in a marked difference in their effects on secondary, within-plant spread of the disease. In normal disease development, sporulation from the inner (adaxial) face of pustules on the flag-leaf sheath produces inoculum that leads to numerous contiguous secondary infections along the length of the emerging inflorescence, but only 7% of azoxystrobin-treated sheath pustules had sporulation from the adaxial surface compared with 72 and 90% of propiconazole-treated and nontreated pustules, respectively. Tillers treated with propiconazole early in the process of within-plant spread had significantly greater final stem rust severity than those treated with azoxystrobin at this time. Results of these experiments will allow effects of fungicide application to be incorporated into quantitative epidemic models that describe disease development as a function of environment and plant phenology.

Relationships between stripe rust severity and grain yield loss at Dooen, Victoria

1988 ◽  
Vol 39 (4) ◽  
pp. 563 ◽  
Author(s):  
JS Brown
Keyword(s):  
Grain Yield ◽  
Disease Severity ◽  
Stripe Rust ◽  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Rust Severity ◽  
Cent Disease ◽  
The Relationship ◽  
Best Estimator

The relationship between stripe rust severity and grain yield loss in wheat was studied in two field experiments. Wheat cultivars varying in response to the disease were used to produce epidemics of differing severity. Regression models were used to examine the relationship between disease severity and yield loss. The best estimator of yield loss was an estimate of disease severity at the end of anthesis-early berry growth stage. The relationship between per cent yield loss (YL) and per cent disease severity (DS) at that growth stage was established to be YL = 0.479DS + 0.84.

Epidemics of stem rust and their effects on grain yield in the wheat WW15 and some of its derivatives

1981 ◽  
Vol 32 (5) ◽  
pp. 725 ◽  
Author(s):  
RG Rees ◽  
JR Syme
Keyword(s):  
Grain Yield ◽  
Stem Rust ◽  
Nitrogen Concentration ◽  
Significant Loss ◽  
Yield Reduction ◽  
Puccinia Graminis ◽  
Slow Rusting ◽  
Yield And Quality ◽  
Grain Nitrogen ◽  
Field Plots

The progress of epidemics of Puccinia graminis tvitici strain 343-Anz-1,2,3,5,6 was examined in field plots of the wheat WW15, its hard-grained derivatives Condor, Oxley and Banks, the slow-rusting cv. Celebration and the fully resistant cv. Timgalen. Additional rust-free treatments were maintained to provide yield and quality comparisons. Severe epidemics developed in WW15, Condor and Oxley, and reduced grain yield in each cultivar by approximately 50 %. Epidemics in Celebration and Banks developed more slowly, and no significant loss in yield occurred. Reduced grain size accounted for most of the yield reduction in WW15, Condor and Oxley. Grain nitrogen concentration was higher in rusted Condor and Oxley than in rust-free treatments. WW15, Condor and Oxley possess little slow-rusting ability and the dependence on Condor and Oxley in the eastern wheat-belt of Australia should be decreased. Banks has effective stem rust resistance and offers potential as a replacement for Condor.

scholarly journals Foliar Fungicides to Control Wheat Stem Rust, Race TTKS (Ug99), in Kenya

Plant Disease ◽  
2009 ◽  
Vol 93 (9) ◽  
pp. 929-932 ◽  
Author(s):  
R. Wanyera ◽  
J. K. Macharia ◽  
S. M. Kilonzo ◽  
J. W. Kamundia
Keyword(s):  
Grain Yield ◽  
Stem Rust ◽  
Untreated Control ◽  
Block Design ◽  
Kernel Weight ◽  
Control Treatment ◽  
Wheat Stem Rust ◽  
Progress Curve ◽  
Rust Severity ◽  
Field Plots

The emergence of a new virulent race of stem rust (Puccinia graminis f. sp. tritici) of wheat (Triticum aestivum), TTKS (Ug99), calls for urgent measures to contain the disease, which is a serious threat to wheat production in Kenya. Nine commercial fungicides were evaluated for control of stem rust in the field in three locations in 2005 and 2006. Ten treatments, including untreated control, were applied on field plots in a randomized complete block design with four replications. Assessment of stem rust severity was done at growth stage (GS) 55 (heading), GS 65 (flowering), and GS 75 (late milk) and expressed in terms of mean rust severity and area under the disease progress curve (AUDPC). In general, fungicide treatment significantly (P ≤ 0.05) reduced rust severity, AUDPC, and losses in grain yield and 1,000-kernel weight for cv. Duma compared with the untreated control. Stem rust was severe in both years across all sites, resulting in significantly less grain yield in the control treatment. The 1,000-kernel weight was significantly less at two locations in 2006. Fungicides azoxystrobin at 200 g/liter + cyproconazole at 80 g/liter (AmistarXtra 280 SC), tebuconazole (Folicur 250 EC), tebuconazole + tridimenol (Silvacur 375 EC), and tebuconazole (Orius 25 EW) were more effective in reducing stem rust across the sites. Fungicides trifloxystrobin + propiconazole (Stratego 250 EC), hexaconazole (Cotaf 5 EC), epoxiconazole + carbendazim (Swing 250 EC), cyproconazole at 80 g/liter + propiconazole at 250 g/liter (Artea 330EC), and epoxiconazole at 125 g/liter + carbendazim at 125 g/liter (Soprano C 250 EC) were inconsistent in the reduction of the disease. The results suggest that fungicides can be used effectively in reducing stem rust severity and increasing yield of susceptible wheat cultivars in stem-rust-prone areas.

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