Susceptibility of apple cultivars to apple scab and powdery mildew in Victoria, Australia

1998 ◽  
Vol 38 (6) ◽  
pp. 625 ◽  
Author(s):  
W. S. Washington ◽  
O. N. Villalta ◽  
J. Ingram ◽  
D. Bardon
Keyword(s):  
Powdery Mildew ◽  
Venturia Inaequalis ◽  
Natural Infection ◽  
Apple Scab ◽  
Podosphaera Leucotricha ◽  
Commercial Cultivars ◽  
Apple Cultivars ◽  
High Level

Summary. Twenty apple cultivars were assessed over 3 seasons for their susceptibility to natural infection with scab (caused by Venturia inaequalis) and powdery mildew (caused by Podosphaera leucotricha). It was evident that a number of important commercial cultivars are highly susceptible to leaf scab (average incidence of leaf scab: Pink Lady, 40.2% of leaves; Lady William, 37.1%; Braeburn, 20.0%; and New Jonagold, 18.7%) and powdery mildew (average incidence of leaf mildew: New Jonagold, 23.0%; Pink Lady, 17.8%). There was a high level of resistance to leaf scab in the cultivars Florina-Quérina, Redfree and Jonafree (all less than 1% incidence on leaves) and to powdery mildew in the cultivar Earlidel (no infection observed). The cultivars Jonathan, Bonza and Red Elstar showed a useful level of resistance to scab (average incidence of leaf scab between 1.6 and 3.2%), while the cultivars Red Fuji, HiEarly and Redfree all showed some resistance to powdery mildew (average incidence of mildew between 2.6 and 5.9%). Observations made on the low and variable numbers of fruit produced by some trees in their third year after planting showed that Pink Lady and Lady William were highly susceptible to fruit scab (67.6 or 57.6% scabbed fruit respectively). Twig infection by scab was also observed on shoots of the current season’s growth of Pink Lady.

scholarly journals The efficacy of essential oils against Venturia inaequalis (Cooke) G. Winter and Podosphaera leucotricha (Ellis & Everh.) E. S. Salmon in vivo

2018 ◽  
Vol 10 (1) ◽  
pp. 5-19
Author(s):  
Tamás Hochbaum ◽  
Marietta Petróczy ◽  
Márta Ladányi ◽  
Géza Nagy
Keyword(s):  
Powdery Mildew ◽  
Essential Oils ◽  
Crop Production ◽  
Plant Protection ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Volatile Oils ◽  
Podosphaera Leucotricha ◽  
Synthetic Pesticides

Abstract Though profitable crop production can be more simply achieved by using synthetic pesticides, the research of alternative plant protection solutions is necessary. The effect of the volatile oils of cinnamon, thyme, and a copper ingredient fertilizer were tested for their activity against apple scab and powdery mildew in apple orchards in 2014 and 2017. Oils applied alone or in combination were effective against apple scab in 2014 and in 2017 and against powdery mildew on leaves in 2017. The copper ingredient fertilizer product improved the efficacy of the oils. The results of these trials show that the tested volatile oils are suitable candidates for further research and for the development of organic fungicides against the diseases of apple.

scholarly journals Apple cultivars resistant to scab (Venturia inaequalis (Cke) Aderh.) Part I. Pomological evaluation of apple cultivars

2013 ◽  
Vol 42 (1-2) ◽  
pp. 105-122
Author(s):  
Zbigniew Borecki ◽  
Aleksander Rejman ◽  
Ryszard Nowakowski ◽  
Beata Słowińska
Keyword(s):  
Powdery Mildew ◽  
Biochemical Analysis ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
High Susceptibility ◽  
High Productivity ◽  
Flowering Season ◽  
Lower Productivity ◽  
Apple Cultivars

Sixteen apple cultivars and numbered selections resistant to apple scab were investigated in the years 1982-1986. The investigations concerned the following questions: vigour of growth, flowering, season of ripening, evaluation of fruits and their biochemical analysis. Three groups of apple cultivars were distinguished. The first group included 'Freedom', 'Liberty' and 'Novamac' which showed high productivity, satisfactory winterhardiness and best taste of fruits. Four cultivars: 'Primula', 'Prima', 'Priam' and 'Liberty Sister', were recognized as interesting because. of their ripening season and original taste but their winterhardiness was insufficient. Seven cultivars: 'Florina', 'Sir Prize', 'Priscilla', 'Macfree', 'Nova Easygro', 'Gavin' and 'Jonafree', as well as two numbered selections, NY 55-158-2 and NY 61-345-2, were disqualified because of lower productivity, high susceptibility to apple powdery mildew, poor taste, low acidity of fruits and low winterhardiness.

scholarly journals Evaluation of reactions of commercial and autochthonous apple cultivars to common diseases in Serbia under natural infection

2017 ◽  
Vol 32 (3-4) ◽  
pp. 157-172 ◽  
Author(s):  
Jelica Balaz ◽  
Vladislav Ognjanov ◽  
Zoran Keserovic ◽  
Aleksandra Sucur ◽  
Jaap Janse ◽  
...  
Keyword(s):  
Erwinia Amylovora ◽  
Venturia Inaequalis ◽  
Natural Infection ◽  
Gold Rush ◽  
Podosphaera Leucotricha ◽  
The Czech Republic ◽  
Golden Delicious ◽  
The Usa ◽  
Apple Cultivars ◽  
Moderately Resistant

This study presents the results of a multiple-year evaluation (1991-1996; 2005-2007) of susceptibility of more than 100 apple cultivars to Venturia inaequalis, Podosphaera leucotricha and Erwinia amylovora under agroecological conditions existing in Serbia. Some of the most popular cultivars were found highly susceptible to V. inaequalis (Cripps Pink, Mutsu, Gloster 69, Wellspur); while Golden Delicious, Richared, Gala, Cacanska pozna, Cadel and Jonagold were susceptible; Idared, Granny Smith and Jonathan moderately susceptible; Lord Lamburne and London Pepping, as well as several autochthonous cultivars were moderately resistant; and a group of resistant cultivars included Prima, Priscilla, Williams Pride, Dayton, Enterprise, Gold Rush, Golden Orange, many of the Re-cultivars (Germany), as well as Baujade, Selena, Duk?t, Produkta, Topaz, some older cvs. (Worcester Pearmain, Merton Worcester, James Grieve, Akane, Astilish, Astrachan Red and Discovery), some Co-op selections (USA) and NS hybrids (Serbia). Regarding powdery mildew, Idared and Jonathan were highly susceptible; Gala, Akane, Jonagold, Priscilla, Mutsu, Cacanska pozna, Golden Delicious, Granny Smith, Cadel and GoldRush were susceptible; Wellspur, Astrachan Red, Richared, Jonadel, Dayton and several autochthonous cultivars were moderately susceptible; Lord Lamburne, Astlisch, Prima, Champagne Reinette, Discovery and many autochthonous cultivars were moderately resistant; while most Re-cvs. (Germany), several cultivars from the Czech Republic, some selections from the USA and UK and most NS hybrids (Serbia) were resistant. Also, some cultivars showed variable susceptibility depending on location (Williams Pride, Gloster 69, Baujade and Produkta). E. amylovora was observed only in 2007 and at relatively low intensity (up to 12% infection). The highest disease severity was observed on cv. Elstar, then Granny Smith, Idared and Jonagored; while the lowest was found on Red Chief and Hapke apple trees.

scholarly journals Effect of pruning on disease incidence of apple scab and powdery mildew in integrated and organic apple production

2005 ◽  
Vol 11 (1) ◽  
Author(s):  
I. J. Holb
Keyword(s):  
Powdery Mildew ◽  
Production System ◽  
Production Systems ◽  
Venturia Inaequalis ◽  
Disease Incidence ◽  
Apple Scab ◽  
Organic Production ◽  
Environmentally Benign ◽  
Apple Cultivars ◽  
Apple Production

In a three-year study, the effect of two winter pruning treatments (strong and weak) on apple scab (Venturia inaequalis) and powdery mildew (Podosphaera leucotricha) was evaluated on six apple cultivars (`Rewena', `Elstar', 'Liberty', 'Gala', 'Pilot' and `Jonica') in two environmentally-benign apple production systems (integrated and organic). Results on apple scab showed that compared to the integrated production system, the pathogen caused significantly more infection on the leaves of cvs. `Elstar', 'Gala' and `Jonica' in the organic production system. The effect of pruning treatments on apple scab was mainly detectable on the cultivars susceptible to the disease such as cvs. 'Gala' and `Jonica'. The weak pruning correlated with a higher level of apple scab infection than the strong pruning, especially in the organic production system. Primary mildew infection was very low in both protection systems (below 2 %), therefore, effect of pruning on primary mildew infection could not be analysed. Low secondary mildew incidence was detected in the organically treated orchard part; however, incidence of powdery mildew was significantly higher (P> 0.05) on cvs. 'Elstar', 'Pilot' and `Jonica' in the integrated orchard part compared to cvs. 'Gala', 'Rewena' and 'Liberty'. The highest incidence of mildew was on cv. 'Elstar'. Pruning had very low effect on incidence of secondary mildew infection on leaves.

scholarly journals Identification of apple scab and powdery mildew resistance genes in Czech apple (Malus × domestica) genetic resources by PCR molecular markers

2011 ◽  
Vol 47 (No. 4) ◽  
pp. 156-165 ◽  
Author(s):  
J. Patzak ◽  
F. Paprštein ◽  
A. Henychová
Keyword(s):  
Molecular Markers ◽  
Powdery Mildew ◽  
Genetic Resources ◽  
Resistance Genes ◽  
Powdery Mildew Resistance ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Scab Resistance ◽  
Mildew Resistance ◽  
Apple Cultivars

The presence of genes for resistance to scab (Venturia inaequalis) and powdery mildew (Podosphaera leucotricha) was studied using molecular markers in a sample of 279 apple cultivars from the Czech collection of apple genetic resources. The sample comprised 37 cultivars supposed to have the Vf gene for scab resistance, 97 reference world cultivars and 145 old and local cultivars. Six PCR molecular markers for the scab resistance genes Vf, Vm, Vbj, Vr and Vh and three PCR molecular markers for the powdery mildew resistance genes Pl-w, Pl-1 and Pl-d were used. The marker for the major scab resistance gene Vf was detected in all cultivars supposed to have Vf, except in Romus 1, and in the three small-fruited cultivars Malus Evereste, Golden Gem and Hilleri. The markers of the Vr and Vh scab resistance genes were detected in 22 cultivars in combination with the marker for Vf, in 56 reference world cultivars and in 82 old and local apple cultivars. PCR molecular markers for one or two of the powdery mildew resistance genes were detected in the small-fruited cultivars Malus Evereste, Golden Gem, prof. Sprengeri and Hilleri; and in the larger fruited cultivars Hagloe Crab, Borovinka and Tita Zetei. We did not find markers for the scab resistance genes Vm and Vbj in any of the studied cultivars. They are absent also in the remaining part of the Czech collection of apple genetic resources. PCR molecular markers are useful tools for the identification of resistance genes within apple germplasm collections and can be used to increase the number of sources for disease resistance in breeding programmes.

scholarly journals Apple Autotetraploids with Enhanced Resistance to Apple Scab (Venturia inaequalis) Due to Genome Duplication-Phenotypic and Genetic Evaluation

2021 ◽  
Vol 22 (2) ◽  
pp. 527
Author(s):  
Małgorzata Podwyszyńska ◽  
Monika Markiewicz ◽  
Agata Broniarek-Niemiec ◽  
Bożena Matysiak ◽  
Agnieszka Marasek-Ciolakowska
Keyword(s):  
Venturia Inaequalis ◽  
Leaf Shape ◽  
Apple Scab ◽  
Early Period ◽  
Physiological Parameters ◽  
Aflp Analysis ◽  
Poor Growth ◽  
Enhanced Resistance ◽  
Apple Cultivars ◽  
Old Trees

Among the fungal diseases of apple trees, serious yield losses are due to an apple scab caused by Venturia inaequalis. Protection against this disease is based mainly on chemical treatments, which are currently very limited. Therefore, it is extremely important to introduce cultivars with reduced susceptibility to this pathogen. One of the important sources of variability for breeding is the process of polyploidization. Newly obtained polyploids may acquire new features, including increased resistance to diseases. In our earlier studies, numerous tetraploids have been obtained for several apple cultivars with ‘Free Redstar’ tetraploids manifesting enhanced resistance to apple scab. In the present study, tetraploids of ‘Free Redstar’ were assessed in terms of phenotype and genotype with particular emphasis on the genetic background of their increased resistance to apple scab. Compared to diploid plants, tetraploids (own-rooted plants) were characterized with poor growth, especially during first growing season. They had considerably shorter shoots, fewer branches, smaller stem diameter, and reshaped leaves. In contrast to own-rooted plants, in M9-grafted three-year old trees, no significant differences between diplo- and tetraploids were observed, either in morphological or physiological parameters, with the exceptions of the increased leaf thickness and chlorophyll content recorded in tetraploids. Significant differences between sibling tetraploid clones were recorded, particularly in leaf shape and some physiological parameters. The amplified fragment length polymorphism (AFLP) analysis confirmed genetic polymorphism of tetraploid clones. Methylation-sensitive amplification polymorphism (MSAP) analysis showed that the level of DNA methylation was twice as high in young tetraploid plants as in a diploid donor tree, which may explain the weaker vigour of neotetraploids in the early period of their growth in the juvenile phase. Molecular analysis showed that ‘Free Redstar’ cultivar and their tetraploids bear six Rvi genes (Rvi5, Rvi6, Rvi8, Rvi11, Rvi14 and Rvi17). Transcriptome analysis confirmed enhanced resistance to apple scab of ‘Free Redstar’ tetraploids since the expression levels of genes related to resistance were strongly enhanced in tetraploids compared to their diploid counterparts.

scholarly journals Response of Pisum sativum germplasm resistant to Erysiphe pisi to inoculation with Erysiphe baeumleri, a new pathogen of pea

2010 ◽  
Vol 41 (No. 3) ◽  
pp. 95-103 ◽  
Author(s):  
M. Ondřej ◽  
R. Dostálová ◽  
L. Odstrčilová
Keyword(s):  
Powdery Mildew ◽  
Pisum Sativum ◽  
Natural Infection ◽  
Erysiphe Pisi ◽  
Field Screening ◽  
Susceptible Control ◽  
High Level ◽  
Screening Trials

Cultivars, homozygous sources and lines of pea (<I>Pisum sativum</I> L.) resistant to <I>Erysiphe pisi</I> had recently been attacked by another powdery mildew species, <I>Erysiphe</I> <I>baeumleri,</I> in the field and in glasshouse conditions. Inoculation with <I>E. baeumleri</I> was carried out in the glasshouse to evaluate the level of resistance of 16 pea genotypes. Susceptible pea lines produced abundant conidia and cleistocarps on petioles and leaves. Only the genotype Tudor (Cebeco 4119) was found to be completely resistant to <I>E. baeumleri</I>. Nineteen pea genotypes (with gene <I>er-1</I>) were tested to natural infection by <I>E. baeumleri</I> in field screening trials. Only few of them demonstrated a high level of resistance (Fallon, AC Melfort and Joel). Consort R, SGL 2024, SGL 1977 and Franklin were very susceptible to <I>E. baeumleri</I>. Cleistocarps with 1–4× dichotomously branching apices of appendages were formed only on susceptible and very susceptible plants of genotypes SGL 444/2185, Consort R, SGL 2024, SGL 1977, LU 390-R2, Lifter, Highlight, Cebeco 1171 and Carneval R in the field and glasshouse. Susceptible control genotypes without gene <I>er-1</I> (Komet, Adept and Gotik) were attacked in the trials by <I>E.&nbsp;pisi</I> only.

scholarly journals Apple powdery mildew caused by Podosphaera leucotricha: some aspects of disease management

2014 ◽  
Vol 20 (1-2) ◽  
Author(s):  
I. J. Holb
Keyword(s):  
Biological Control ◽  
Disease Management ◽  
Powdery Mildew ◽  
Chemical Control ◽  
Apple Cultivar ◽  
Apple Orchards ◽  
Cultivar Resistance ◽  
Podosphaera Leucotricha ◽  
Control Options ◽  
Apple Cultivars

Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. This review focuses on the control of apple powdery mildew. The first part of the study provides details of novel aspects of non-chemical control approaches, including agronomic measures, mechanical and biological control options as well as essential features of apple cultivar resistance. After this, developments in chemical control options are described sperately for integrated and organic apple orchards.

scholarly journals Farm-scale evaluation of two widely used sanitation practices for reducing primary inoculums of apple scab in organic apple production

2013 ◽  
Vol 19 (3-4) ◽  
Author(s):  
I. J. Holb ◽  
A. Rózsa ◽  
F. Abonyi
Keyword(s):  
Primary Infection ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Apple Orchard ◽  
Scale Level ◽  
Scale Evaluation ◽  
Farm Scale ◽  
Apple Cultivars ◽  
Apple Production ◽  
Fallen Leaves

Effects of two widely used sanitation practices were evaluated at farm-scale level on leaf degradation and primary infection by Venturia inaequalis in an organic apple orchard (Eperjeske) on two apple cultivars (Jonathan and Prima) from 2011 to 2013. The tested sanitation practices were eradication of fallen leaves by collection and disc cultivation. Treatments of eradication of fallen leaves by collection and disc cultivation reduced signifi cantly (P< 0.001) leaf litter density with 70–85 and 40–55%, respectively, compared to untreated plots in both years. Above treatments in the same order reduced spring scab incidence with 40–50, and 10–20%, respectively, compared to untreated plots. Incidence of leaf scab in autumn was not signifi cantly lower (P< 0.05) in the treatments in the years.

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