scholarly journals Number of Experiments Needed to Determine Wheat Disease Phenotypes for Four Wheat Diseases

Plant Disease ◽  
2007 ◽  
Vol 91 (1) ◽  
pp. 103-108 ◽  
Author(s):  
William W. Bockus ◽  
Zhaohui Su ◽  
Karen A. Garrett ◽  
Bikram S. Gill ◽  
James P. Stack ◽  
...  
Keyword(s):  
Field Experiments ◽  
Tan Spot ◽  
Disease Phenotype ◽  
Head Blight ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Disease Phenotypes ◽  
Wheat Diseases ◽  
Margin Of Error ◽  
Phenotype Data

Disease phenotypes for winter wheat cultivars were determined in numerous inoculated greenhouse and field experiments over many years. For four diseases, Fusarium head blight, tan spot, Septoria leaf blotch, and Stagonospora leaf blotch, at least 20 cultivars each had been evaluated in a minimum of five experiments. Reference cultivars of known disease reaction were included in each experiment, which allowed transformation of the percent disease severity data to a 1-to-9 scale for comparisons between experiments. Variations in scale values obtained for individual cultivars among the different experiments were used to calculate standard deviations for disease phenotype data. Standard deviations were used to calculate the number of experiment repetitions needed within each disease to achieve different levels of accuracy (margins of error). A margin of error of ±1.5 for the 1-to-9 scale was chosen as the best level of accuracy. Rounding values within this range would put the estimated disease phenotype within ±1 unit of the actual phenotype. To achieve a margin of error of ±1.5 for Fusarium head blight, tan spot, Septoria leaf blotch, and Stagonospora leaf blotch would require a mean that was calculated from a minimum of five, five, seven, and eight experiments, respectively. Personnel who report disease phenotype data to wheat producers or breeders should be aware of the number of experiments upon which they are basing their reports and adjust any disclaimers accordingly. Similarly, wheat breeders should be aware of the inherent variability in phenotyping these four wheat diseases and make appropriate adjustments to their selection protocols. With a minimum of five experimental repetitions, disease phenotype values obtained from inoculated greenhouse and field experiments had very high correlations (r = 0.81 to 0.92, P < 0.0001) with published Kansas State University Research and Extension ratings obtained from commercial fields.

scholarly journals Practical application of integrated disease management

2002 ◽  
Vol 38 (SI 1 - 6th Conf EFPP 2002) ◽  
pp. 212-220 ◽  
Author(s):  
V. Zinkernagel ◽  
H. Hausladen ◽  
H. Habermeyer
Keyword(s):  
Decision Support ◽  
Disease Management ◽  
Powdery Mildew ◽  
Tan Spot ◽  
Integrated Disease Management ◽  
Practical Application ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Advisory Service ◽  
Glume Blotch

A decision support system for cereal diseases and late blight of potatoes has been developed at the Chair of Phytopathology,<br />Technische Universität München. The Wheat and Barley Prognosis System has been in use for many years by the<br />Bavarian official advisory service. It is based on an exact diagnosis and established biological thresholds influenced by<br />weather. Certain fungicides are recommended also covering diseases which have not reached the threshold. Diseases under<br />consideration are eye spot disease, powdery mildew, Septoria leaf blotch, Septoria leaf and glume blotch, tan spot, brown<br />and yellow rusts.The PhytophthoraModel Weihenstephan consists of two parts, weather based prognosis and monitoring in<br />the unsprayed control plots. Spraying recommendations are given based on the results of the above-mentioned parts and<br />considering cultivar behaviour and blight development in the field. The first spraying in the season as well as the timing<br />of the following ones are crucial. This model does not give any recommendations regarding which active ingredient should<br />applied. However there is a distinction made with regard to contact (protective) fungicides and systemic fungicides. The<br />PhytophthoraModel Weihenstephan has been in use for several years in Germany as well as in Austria.

scholarly journals Tan spot - the most harmful wheat leaf disease in Latvia

2012 ◽  
Vol 58 (1) ◽  
pp. 5-10
Author(s):  
Biruta Bankina
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Stem Elongation ◽  
Leaf Age ◽  
Tan Spot ◽  
Wheat Varieties ◽  
Wheat Diseases ◽  
Wheat Development ◽  
Ripening Rate ◽  
The Relationship

Tan spot (<i>Pyrenophora tritici</i>-<i>repentis</i>) is one of the most important wheat diseases in Latvia. Significant spreading of this disease was observed from 1998. Field experiments were carried out at the Research and Training Farm "Peterlauki" of the Latvia University of Agriculture, during 1998-2003. Development of diseases was observed on 14 winter wheat varieties, dynamics of development was investigated on 'Donskaja polukarlikovaja' and 'Stava'. Assessments of the disease severity were carried out on the upper three leaves each week from the start of stem elongation to full ripening. Tan spot was observed at the stage of stem elongation in 2003, and only after flowering in 1999. Increase of the disease severity was slow until stage of milk ripeness, and only in late stages of wheat development sharp increase of the disease was observed. Total rate of infection (through the session of vegetation) was very slow (0,01-0,19), but during ripening rate achieved 0,5-0,6. The main reason of so unequal development of the disease seems changes in amount of infection sources. Other possible reason of rapid increase of the disease development is the relationship between leaf age and susceptibility to the disease. Further research is necessary for better understanding of tan spot life cycle.

scholarly journals Tramesan Elicits Durum Wheat Defence Against the Septoria Leaf Blotch Complex

2020 ◽  
Author(s):  
VALERIA Scala ◽  
Chiara Pietricola ◽  
valentina farina ◽  
marzia beccaccioli ◽  
slaven zjalic ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Field Experiments ◽  
Animal Health ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Animal Cells ◽  
Zymoseptoria Tritici ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Wheat Field

The Septoria Leaf Blotch Complex (SLBC), caused by the two ascomycetes Zymoseptoria tritici and Parastagonospora nodorum, can reduce global yearly yield of wheat by up to 50%. In the last decade in Italy, SLBC incidence has increased; notably, durum wheat has proven to be more susceptible than common wheat. Field fungicide treatment can efficiently control these pathogens, but it leads to the emergence of resistant strains and adversely affects human and animal health, and the environment. Our previous studies indicated that active compounds produced by Trametes versicolor can restrict the growth of mycotoxigenic fungi and the biosynthesis of their secondary metabolites (e.g. mycotoxins). Specifically, we identified Tramesan: a 23 KDa -heteropolysaccharide secreted by T. versicolor that acts as a pro-antioxidant molecule in animal cells, fungi, and plants. Foliar-spraying of Tramesan (3.3 &micro;M) in SLBC-susceptible varieties of durum significantly diminished symptoms of Stagonospora Nodorum Blotch (SNB) and Septoria Tritici Blotch (STB) by 75% and 65%, respectively. Tests were conducted under controlled conditions as well as in field. We show that Tramesan elicits wheat defence against SNB and STB augmenting the synthesis of defence-related hormones, notably JA and SA, that in turn switch on the expression of markers of defence (PR1, PR4 inter alia). In field experiments, yield of durum wheat plants treated with Tramesan was similar to that of untreated ones. The results suggest the use of Tramesan for protecting durum wheat against SLBC.

scholarly journals Tan spot development peculiarities in Latvia

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 381-383
Author(s):  
B. Bankina
Keyword(s):  
Field Experiments ◽  
Tan Spot ◽  
Severity Of Disease ◽  
Pyrenophora Tritici Repentis ◽  
Wheat Diseases ◽  
Flowering Rate ◽  
Severity Of The Disease ◽  
First Time ◽  
And Training ◽  
Very High

Tan spot, caused by Pyrenophora tritici-repentis (Died.) Drechs., anamorph Drechslera tritici-repentis is one of the most important wheat diseases in the world, especially in the regions of intensive wheat growing. Tan spot had established for the first time in Latvia in 1994. Epidemic of this disease was observed in Latvia in 1998. Development of tan spot were investigated in field experiments at the Research and Training Farm “Peterlauki” of Latvia University of Agriculture in 1998–2001. Level of incidence and severity of tan spot differed depending on varieties and years. Severity of the disease was 16–71% in 1999; 0.1–5% in 2000 and 4–18% in 2001 depending on varieties at the time of ripening. 1999 summer was extremely dry, and development of disease was not observed. Explosion of disease was observed at the second half of June in 2000 and 2001, without reference to varieties. Date of increasing start differed, but in all cases important development was observed after flowering. Rate of increasing of disease was very high, during two weeks severity of disease increased from 0.1 till maximum of severity. Amount and frequency of rainy differed in 2000 and 2001, but increase on disease was very similar, it means, we need more information about favourable conditions for Drechslera tritici-repentis. Sexual stage Pyrenophora tritici-repentis was observed in Latvia for the first time. Further investigations are necessary, because relationships between meteorological conditions and stages of development are unclear.

scholarly journals Evaluation of Efficacy and Compatibility of Herbicides with Fungicides in Durum Wheat (Triticum durum Desf.) under Different Environmental Conditions: Effects on Grain Yield and Gluten Content

2018 ◽  
Vol 46 (2) ◽  
pp. 601-607 ◽  
Author(s):  
Anestis Christos KARKANIS ◽  
Evangelos VELLIOS ◽  
Filippos GRIGORIOU ◽  
Theodoros GKRIMPIZIS ◽  
Persephoni GIANNOULI
Keyword(s):  
Durum Wheat ◽  
Field Experiments ◽  
Stem Elongation ◽  
Temperature Fluctuations ◽  
Cold Temperatures ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Arid Conditions ◽  
Triticum Durum Desf ◽  
Semi Arid

In the present study, field experiments were conducted to determine the efficacy and compatibility of herbicides and fungicides in durum wheat under Mediterranean semi-arid conditions, in Central Greece. Our results indicate that the herbicide florasulam+2.4-D was safe and did not cause any injury when applied alone or with fungicides, while bromoxynil+2.4-D mixed with azoxystrobin or trifloxystrobin+prothioconazole caused injury symptoms on leaves. The injury symptoms were transient, and observed only at Velestino area, where low temperatures and broad diurnal temperature fluctuations were recorded during the pesticides application period. Regarding septoria leaf blotch control, good results showed strobilurin alone or in mixture with a triazole, regardless the herbicide that was added to the mixture. The results of this study showed that bromoxynil+2.4-D caused injury when mixed with fungicides and applied under cold temperatures, while one fungicide application at stem elongation provided adequate Septoria leaf blotch control.

scholarly journals Genetic Protection of Soft Wheat from Diseases in the Southern Ural of Russia and Virulence Variability of Foliar Pathogens

Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 703
Author(s):  
Igor Kushnirenko ◽  
Ekaterina Shreyder ◽  
Nadezhda Bondarenko ◽  
Ekaterina Shaydayuk ◽  
Nadezhda Kovalenko ◽  
...  
Keyword(s):  
Leaf Rust ◽  
High Efficiency ◽  
Genetic Material ◽  
Puccinia Triticina ◽  
Wheat Breeding ◽  
Tan Spot ◽  
Aegilops Speltoides ◽  
Wheat Cultivars ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch

The southern Ural is consistently among the 10 best regions in Russia for agricultural production, including wheat. Breeding in the Chelyabinsk Research Institute of Agriculture aims to develop wheat cultivars genetically protected from the main diseases (leaf and stem rust, septoria leaf blotch and tan spot). The genes for resistance to leaf rust, Lr1, Lr9, Lr10 and Lr26/Sr31, alone or in combination, are widespread in cultivars grown in the southern Ural. In 2012, a new wheat cultivar, Chelyaba 75, was proposed for commercial production in the southern Ural, being highly resistant to leaf rust with the highly effective genes LrSp and SrSp transferred from the cuckoo line with the genetic material Aegilops speltoides. Isolates virulent to cv. Chelyaba 75 were not found in Russian populations of Puccinia triticina. Additionally, for a long period, genes Lr29, Lr 41, Lr42, Lr45, Lr47, Lr50, Lr51, Lr53 and Lr57 were characterized by high efficiency. Virulence frequencies to other Lr genes vary annually, but no races with new virulence have been identified. The resistance of lines with the Sr31 and Sr24 genes indicates that the Puccinia graminis population does not contain genotypes with the potentially damaging race Ug99. Mixed septoria and tan spot infections occurred in the southern Ural, with the latter dominating. Races producing the exotoxin ToxA are widely distributed in Pyrenophora tritici-repentis populations. Two causal agents of septoria leaf blotch (Parastagonospora nodorum and P. avenae f. sp. tritici) occur in the region, with the first dominating. Aggressiveness of P. nodorum isolates to wheat cultivars was higher than that of P. avenae f. sp. tritici. All Parastagonospora isolates showed the presence of the SnTox3 marker. SnToxA and SnTox1 markers were found in P. nodorum isolates, usually separately, but in one isolate, these genes were found together. The analysis of the genetic diversity of wheat cultivars grown in the southern Ural, and the pathogenic complex present, indicate that pathogens continuously evolve under the influence of the host plant.

scholarly journals Characteristics of spring wheat genotypes exhibiting high resistance to FHB in terms of their resistance to other fungal diseases

2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Danuta Kurasiak-Popowska ◽  
Jerzy Nawracała ◽  
Tomasz Kosiada ◽  
Zuzanna Sawinska ◽  
Agnieszka Tomkowiak ◽  
...  
Keyword(s):  
Spring Wheat ◽  
High Resistance ◽  
Agricultural Research ◽  
Research Station ◽  
Point Scale ◽  
Head Blight ◽  
Septoria Leaf Blotch ◽  
Leaf Blotch ◽  
Wheat Genotypes ◽  
Sumai 3

<p>The field experiment was carried out in 2010–2012 at the Dłoń Agricultural Research Station, the Poznań University of Life Sciences, Poland. The study was designed to evaluate the degree of infection by powdery mildew, brown rust, and septoria leaf blotch in 61 spring wheat genotypes differing in their resistance to <em>Fusarium</em> ssp.</p><p>The vast majority of spring wheat genotypes in the collection of gene resources in the USA defined as resistant to <em>Fusarium</em> ssp. confirmed their resistance under Polish climatic conditions. The <em>B .graminis</em> infection rate of genotypes that are considered to be resistant to Fusarium head blight was high. The resistance ranged from 7 for Sumai 3 (PL2) up to 8.8 for Ning 8331 (in a 9-point scale). Most of the genotypes (56.5%) were infected by <em>Puccinia recondita</em> at a level of 1–3 (in a 9-point scale). The genotypes of Sumai 3 exhibited high resistance to septoria leaf blotch, amounting to 1–2 in a 9-point scale; the resistance of Frontana ranged from 1 to 3.5, while the genotypes of Ning were infected by <em>Mycosphaerella graminicola</em> at 5–6.</p>

scholarly journals The impact of cultivar resistance and fungicide treatment on mycotoxin content in grain and yield losses caused by Fusarium head blight in wheat

2010 ◽  
Vol 46 (No. 1) ◽  
pp. 21-26 ◽  
Author(s):  
V. Šíp ◽  
J. Chrpová ◽  
O. Veškrna ◽  
L. Bobková
Keyword(s):  
Grain Yield ◽  
Fusarium Head Blight ◽  
Field Experiments ◽  
Yield Loss ◽  
Joint Effect ◽  
Yield Losses ◽  
Cultivar Resistance ◽  
Head Blight ◽  
Fungicide Treatment ◽  
The Impact

Reactions to artificial infection with Fusarium graminearum isolates and a new fungicide Swing Top were studied in nine winter wheat cultivars evaluated in field experiments at two sites for three years for expression of symptoms, deoxynivalenol (DON) content in grain and grain yield. The results demonstrate a pronounced and relatively stable effect of cultivar resistance on reducing head blight, grain yield losses and contamination of grain by the mycotoxin DON. It is advantageous that the moderate level of resistance to Fusarium head blight (FHB) was detected also in two commonly grown Czech cultivars Sakura and Simila. Average fungicide efficacy for DON was 49.5% and 63.9% for a reduction in yield loss, however, it was found highly variable in different years and sites. The joint effect of cultivar resistance and fungicide treatment was 86.5% for DON and even 95.4% for reducing the yield loss. A very high risk was documented for susceptible cultivars and also the effects of medium responsive cultivars were found to be highly variable in different environments and therefore not guaranteeing sufficient protection against FHB under different conditions.

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