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 Resistance of apple varieties and selections to Erwinia amylovora in the Czech Republic

2008 ◽  
Vol 44 (No. 3) ◽  
pp. 91-96 ◽  
Author(s):  
J. Korba ◽  
J. Šillerová ◽  
V. Kůdela
Keyword(s):  
Czech Republic ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Relative Resistance ◽  
Lesion Development ◽  
The Czech Republic ◽  
Apple Cultivars ◽  
Moderately Resistant ◽  
Resistant Genotypes ◽  
Experimental Plots

Sixty-four apple cultivars and selections of potential interest to apple producers and plant breeders in the Czech Republic were tested for their relative resistance to the fire blight pathogen over six years. Level of fire blight resistance was evaluated according to the extent of lesion development on the shoots tips after artificial inoculation in experimental plots under insectproof nets. Cultivars Quinte (resistant) and Yellow transparent (high susceptible) were included in the tests. Of 64 apple cultivars and selections tested, none were high resistant, 3.1% were evaluated as resistant, 10.9% moderately resistant, 57.8% moderately susceptible, 21.9% susceptible and 6.3% high susceptible. Resistant apple genotypes, showing blight necrosis of shoots of 11–12%, were only cultivars Selena and Quinte. Moderately resistant genotypes (blight necrosis 13.1–25.0%) were Kordona, Golden Smoothee, Julia, HL 323, Melodie, HL 421 and S 634/3. High susceptible genotypes (blight necrosis more then 80.1%) were comprised cultivars Vesna, Topas, Yellow transparent and Vanda. The remaining genotypes were moderately susceptible (blight necrosis 26.1–60.0%) and susceptible (blight necrosis 60.1–80.0%). During six experimental years, quantitative variability was recorded in the blight score. Differences between cultivars in susceptibility to fire blight were often statistically significant.

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 Apple cultivars bred in Holovousy. Part 1 – Characteristics of the orchard

2013 ◽  
Vol 40 (No. 1) ◽  
pp. 8-15 ◽  
Author(s):  
J. Blažek ◽  
J. Křelinová
Keyword(s):  
Czech Republic ◽  
Powdery Mildew ◽  
Comparative Study ◽  
Sectional Area ◽  
Harvest Time ◽  
Cross Sectional ◽  
The Czech Republic ◽  
Golden Delicious ◽  
Apple Cultivars ◽  
The Mean

 Twenty-one standard apple cultivars bred in Holovousy and registered in the Czech Republic during 1994–2011 were included in a comparative study. Their tree parameters and yields were evaluated from 2004 till 2011 in a comparison to cvs Golden Delicious and Jonagold within experimental orchards planted on M 9 rootstock using a tree spacing of 4 × 1 m. The cultivars mutually differed in the mean term of flowering starting up to 6 days. The harvest time of 5 summer cultivars covered the harvest season from July 14 till the end of August. The remaining cultivars were storable, and on average, their harvest started between the September 8(Nabella) and November 8 (Rubimeg). Cvs Resista, Selena and Vysočina were evaluated as totally resistant to scab and 5 other cultivars were distinguished by very low susceptibility to the disease. In the case of powdery mildew this desirable level of tolerance was observed on 7 cultivars. The most vigorous according to trunk cross-sectional area was cv. Mivine, whereas the weakest growing cv. Selena was 52% smaller in this parameter. Significant differences among cultivars were also found in the case of yield precocity. In total, the most productive in this study was cv. Clijo, with mean annual harvest equal to 44.3 t/ha. The lowest level of annual harvest (25.6 t/ha) gave cv. Selena, but its crop efficiency was one of the highest.

scholarly journals Effect of rootstock clones on fire blight susceptibility in scion apple cultivars

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 552-554
Author(s):  
J. Korba ◽  
K. Patáková ◽  
V. Kůdela
Keyword(s):  
Relative Humidity ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Shoot Length ◽  
High Relative Humidity ◽  
Golden Delicious ◽  
Apple Cultivars

This study was performed on 24 clonal rootstocks and 4 scion apple cultivars to evaluate rootstock/cultivar combinations for susceptibility to fire blight (Erwinia amylovora). For this aim, the clonal rootstocks were planted in plastic greenhouse in 1992 and grafted with 4 cultivars (Golden Delicious, Dulcit, Domino and Dione) in 1998. A total of 96 rootstock/cultivar combinations were tested during 1998–2001. Each year, 10 to 30 actively growing shoots per one combination were inoculated with the pathogen. The shoots were inoculated by cutting through first unfolding leaves with scissors dipped into inoculum (109 cfu/ml). The trees were misted to create a high relative humidity. The susceptibility of the test roostock/cultivar combinations was evaluated by calculating the length of necrosis to the total shoot length 40 days after inoculation. The degree of susceptibility of cultivar tested varied depending on the rootstocks and years. In order of decreasing to increasing levels of fire blight susceptibility of four cultivars tested, the pattern observed was Dulcit, Golden Delicious, Domino (moderately susceptible) and Dione (very susceptible). The lowest susceptibility of four cultivars tested was observed on TE 52 rootstock (on average, the cultivars were evaluated as intermediate), the highest susceptibility was on JTE-E and M9 rootstocks (the cultivars were very susceptible). The influence of 21 remaining rootstocks on susceptibility in scion cultivars was not marked. Thus some rootstocks can render the scion cultivars more fire blight susceptible or more resistant.

Efficacy of Kaolin-Based Particle Films to Control Apple Diseases

2001 ◽  
Vol 2 (1) ◽  
pp. 4 ◽  
Author(s):  
D. Michael Glenn ◽  
Tom van der Zwet ◽  
Gary Puterka ◽  
Patricia Gundrum ◽  
Eric Brown
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Field Studies ◽  
Podosphaera Leucotricha ◽  
Malus Domestica Borkh ◽  
Sooty Blotch ◽  
Leaf Infection ◽  
Hydrophilic Particles

Studies were conducted from 1997 to 1999 to evaluate the effect of processed kaolin-based particle film applications on the incidence and severity of apple (Malus domestica Borkh.) diseases. Greenhouse and field studies demonstrated that pre-emptive application of hydrophobic and hydrophilic particles reduced the incidence of fire blight (Erwinia amylovora (Burrill) Winslow et al.) in blossoms and injured shoots. Hydrophobic and hydrophilic particles suppressed sooty blotch (Gloeodes pomigena (Schwein.)) and flyspeck (Schizothyrium pomi (Mont. & Fr.) Arx: anamorph Zygophiala jamaicensis Mason) to levels equivalent to conventional fungicides. In field studies, apple scab (Venturia inaequalis (Cooke) Wint.: anamorph Spilocaea pomi Fr.) was not suppressed by hydrophilic particles. Hydrophilic particles did not interfere with the action of conventional fungicides or the activity of calcium hydroxide to suppress apple scab. Hydrophilic particles did reduce powdery mildew (Podosphaera leucotricha (Ell. & Ev.) E.S. Salmon (anamorph Oidium farinosum Cooke)) russetting on fruit, but leaf infection was extensive. Accepted for publication 27 July 2001. Published 23 August 2001.

scholarly journals Evaluation of susceptibility level of pear cultivars to fire blight (Erwinia amylovora) in the Czech Republic

2013 ◽  
Vol 40 (No. 2) ◽  
pp. 58-64 ◽  
Author(s):  
J. Korba ◽  
J. Šillerová ◽  
F. Paprštein ◽  
J. Sedlák ◽  
E. Prokinová ◽  
...  
Keyword(s):  
Czech Republic ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
The Czech Republic ◽  
Resistant Genotype ◽  
Proof Nets ◽  
Breeding Selection ◽  
Moderately Resistant ◽  
Resistant Genotypes ◽  
Alexander Lucas

Thirty-three pear cultivars and selections of potential interest to pear producers and plant breeders in the Czech Republic were tested for relative field susceptibility to the fire blight (Erwinia amylovora) over five years. Level of fire blight susceptibility was evaluated according to the extent of lesion development on the shoot tips after artificial inoculation in experimental plots under insect proof nets. Old cvs Alexander Lucas (as resistant standard), Conference (as moderately resistant standard) and Beurré Bosc (as susceptible standard) were included in the tests. The 33 pear cultivars and selections were tested, only one of them was highly resistant (3.0%), 3.0% were evaluated as resistant, 12.1% moderately resistant, 36.4% moderately susceptible, 18.2% susceptible and 27.3% highly susceptible. Breeding selection US 625-63-10 was the only highly resistant pear genotype (necrosis of shoots of 0–7.0%). Resistant genotype group (necrosis 7.1–13.0%) comprised US 625-63-4. Moderately resistant genotypes (necrosis 13.1–25.0%) included cvs Alexander Lucas, Alfa, Bohemica and HL 31-50-31. Highly susceptible genotypes (necrosis more than 80.1%) included cvs Vonka, Karina, Bona, Decora, Elektra, Milka, Regina, Alice and TE 4763. The remaining genotypes were moderately susceptible (necrosis 26.1–60.0%) and susceptible (necrosis 60.1–80.0%).    

scholarly journals Testing of Czech cultivars and advanced selections of apples for fire blight (Erwinia amylovora) resistance

2011 ◽  
Vol 31 (No. 1) ◽  
pp. 7-11
Author(s):  
C. Fischer ◽  
K. Richter ◽  
J. Blažek
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Scab Resistance ◽  
Blight Resistance ◽  
The Czech Republic ◽  
Malus Floribunda ◽  
Apple Cultivars ◽  
High Level ◽  
Very High ◽  
Different Levels

Five apple cultivars from the Czech Republic and 26 selections from the same country (a majority of them were resistant to scab) were included in the present study. M. robusta strain (Nr. 5) was used as a control with the highest level of resistance to fire blight. Another 7 cultivars with different levels of resistance or susceptibility to the disease were also evaluated. Selena and Nabella were found to be resistant, whereas Angold, Resista and Topaz were susceptible. Two HL selections were previously identified as highly resistant, 3 selections as medium resistant and 7 others as moderately susceptible. The rest of the 14 selections ranged from very high susceptible to medium susceptible. A high level of resistance was confirmed in 3 cultivars from Dresden-Pillnitz: Reanda, Remo and Rewena. Comparison of the parentage of the tested cultivars or selections with their level of resistance to fire blight suggests that most of the resistance comes from Malus floribunda, which was used in the course of their breeding as a donor of scab resistance. In one case, the source of the fire blight resistance was Starking Delicious cv.  

Relative Susceptibility of Selected Apple Cultivars to Powdery Mildew Caused by Podosphaera leucotricha

2009 ◽  
Vol 10 (1) ◽  
pp. 3 ◽  
Author(s):  
Alan R. Biggs ◽  
Keith S. Yoder ◽  
David A. Rosenberger
Keyword(s):  
Powdery Mildew ◽  
Disease Incidence ◽  
Cultivar Differences ◽  
Susceptible Cultivar ◽  
Chronic Effect ◽  
Podosphaera Leucotricha ◽  
Yield Data ◽  
Golden Delicious ◽  
Regional Project ◽  
Apple Cultivars

Apple powdery mildew thrives during dry spring and summer weather wherever apples are grown. The fungus perennates in buds, making it difficult to control and, although it can cause fruit russet, it primarily causes losses due to its chronic effect on tree vigor and yield. Data were collected over several years from 1995 (23 entries) and 1999 (22 entries) plantings of new apple cultivars and selections established at multiple locations as part of regional project NE-183. The cultivars Golden Delicious and McIntosh were the standards in both plantings. Incidence of powdery mildew on leaves and fruit was observed and data were analyzed to determine differences due to location and cultivar. One of the two planting group analyses indicated the significance of cultivar differences due to location. In general, the cultivars Ginger Gold, Suncrisp, GoldRush, Crimson Crisp, and Delblush, and the selection CQR10T17 were the most susceptible, whereas the cultivars Gala Supreme, Enterprise, Zestar, September Wonder, Hampshire, and the selections NY 75414-1 and NY 79507-72 exhibited the lowest incidences of mildew. Pinova was the most highly susceptible cultivar to mildew on fruit in Virginia, followed by Crimson Crisp and the selection NY 65707-19. Percent leaf area with mildew was related to incidence of mildew on leaves; however, fruit symptoms were not significantly related to disease incidence or severity on the foliage. Accepted for publication 11 September 2009. Published 19 November 2009.

scholarly journals Long term cropping and selected parameters of 15 apple tree cultivars

2018 ◽  
Vol 45 (No. 1) ◽  
pp. 11-17
Author(s):  
Jan Blažek ◽  
Lubor Zelený ◽  
Jana Křelinová
Keyword(s):  
Czech Republic ◽  
Comparative Study ◽  
Apple Tree ◽  
Tree Canopy ◽  
The Czech Republic ◽  
Canopy Volume ◽  
Golden Delicious ◽  
Apple Cultivars ◽  
Spring Frosts

Fifteen apple cultivars registered in the Czech Republic were included in this comparative study. The most productive after eight years of cropping was ‘Rucla’, which had a mean yield of 50.9 t/ha. This cultivar was also the most tolerant to late spring frosts. In order of decreasing yields, it was followed by the cultivars ‘Rubinstep’, ‘King Jonagold’ and ‘Šampion’. The lowest yield was found for the cultivar ‘Fuji Nagafu’ (23.7 t/ha) followed by ‘Golden Delicious’ and ‘Rubinola’. The largest canopy volume in 2016 was achieved by ‘Rubín’ at a level of 2.74 m<sup>3</sup>, followed in decreasing order by ‘Rubinola’, ‘King Jonagold’ and ‘Meteor’. According to the final tree canopy volume, the least vigorous was ‘Selena’ with a mean of 1.50 m<sup>3</sup>. The largest canopy of 2.74 m<sup>3</sup> was exhibited by ‘Rubín’. The ‘Braeburn’ cultivar exhibited the highest degree of spur bearing, followed by ‘Lady Silvia’ and ‘Vysočina’. In contrast, the poorest spur patterns were observed in ‘Rubín’ and ‘Fuji Nagafu’. ‘Meteor’ was characterised by the densest canopy, whereas the ‘Rubín’ cultivar was the least dense.

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