scholarly journals Alternaria Leaf Spot, Twig Blight, and Fruit Rot of Highbush Blueberry in Argentina

Plant Disease ◽  
2004 ◽  
Vol 88 (12) ◽  
pp. 1383-1383 ◽  
Author(s):  
E. R. Wright ◽  
M. C. Rivera ◽  
J. Esperón ◽  
A. Cheheid ◽  
A. Rodríguez Codazzi
Keyword(s):  
Vaccinium Corymbosum ◽  
Fruit Rot ◽  
Fluorescent Light ◽  
Highbush Blueberry ◽  
Disease Symptoms ◽  
Potted Plants ◽  
Leaf Spots ◽  
Twig Blight ◽  
Polyethylene Bags ◽  
Plastic Trays

Disease symptoms have been observed since October 1997 on highbush blueberry (Vaccinium corymbosum L.) cvs. Georgia Gem, O'Neal, and Sharpblue cultivated in Buenos Aires. Lesions were observed on recently planted, as well as mature plants, in commercial fields. Circular-to-irregular, light brown-to-gray leaf spots with brownish red borders, initially 3 to 7 mm in diameter, enlarged and coalesced. Blight developed on twigs. Reddish circular spots appeared on stems, developing small cankers. Dark sunken lesions were observed on attached ripening berries. During December 2002, postharvest fruit rot was noted. Small pieces of diseased leaves, twigs, stems, and fruits were surface sterilized with 0.2% NaOCl, plated on 2% potato dextrose agar (pH 7), and incubated at 20 ± 3°C. Symptomatic fruits were placed in plastic trays in humid chambers. In all cases, olive mycelium developed after 3 days with septate hyphae and abundant ovoid and obclavate muriformly septate conidia. The isolate obtained from diseased leaves of cv. O'Neal was used to test pathogenicity on micropropagated potted plants of 20-cm height and ripe fruits contained in plastic trays. Both plants and fruits belonged to cv. O'Neal. A suspension of 2 × 105 conidia per ml was sprayed on needle-punctured young stems, fully expanded leaves, and mature fruits. Plants and trays were covered with polyethylene bags and kept at 24 ± 3°C under fluorescent light (12-hr photoperiod). The bags were removed after 72 hr. Symptoms appeared after 3 days on fruits and 8 days on leaves and stems. Controls remained symptomless. The inoculated pathogen was recovered from diseased organs and identified as Alternaria tenuissima (Kunze:Fr.) Wiltshire (1). To our knowledge, this is the first report on the presence of A. tenuissima affecting blueberry crops in Argentina. Reference: (1) E. G. Simmons. Mycotaxon 70:325, 1999.

scholarly journals 009 GENETIC VARIABILITY IN HIGHBUSH BLUEBERRY, VACCINIUM CORYMBOSUM L., FOR RESISTANCE TO THE BLIGHTING PHASE OF MUMMYBERRY, MONILINIA VACCINI-CORYMBOSII

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 428f-428
Author(s):  
Mark K. Ehlenfeldt ◽  
Vickie Brewster ◽  
Allan W. Stretch
Keyword(s):  
Genetic Variability ◽  
Vaccinium Corymbosum ◽  
Highbush Blueberry ◽  
Strongly Correlated ◽  
Infection Period ◽  
Potted Plants ◽  
Disease Progress ◽  
High Inoculum

Potted plants of 53 highbush and half-high blueberry cultivars were screened for resistance to the blighting phase of mummyberry, Monilinia vaccini-corymbosii under controlled nursery conditions over an 18 day infection period. Significant differences were observed in the susceptibility of different cultivars, with `Bluehaven', `Bluegold', and `Blueray' being among the most susceptible, and `Bluejay', `Jersey', and `Duke' being among the most resistant. Differences were also observed in the latent periods and rate of disease progress which may have a bearing on the severity of the secondary fruit infection phase. Preliminary observations suggest that shoot blighting and fruit infection frequencies are not strongly correlated under high inoculum conditions.

scholarly journals First Report of Root Rot Caused by Fusarium proliferatum on Blueberry in Argentina

Plant Disease ◽  
2011 ◽  
Vol 95 (11) ◽  
pp. 1478-1478 ◽  
Author(s):  
B. A. Pérez ◽  
M. F. Berretta ◽  
E. Carrión ◽  
E. R. Wright
Keyword(s):  
Root Rot ◽  
Its Region ◽  
Vaccinium Corymbosum ◽  
Fusarium Proliferatum ◽  
Highbush Blueberry ◽  
Buenos Aires Province ◽  
Distilled Water ◽  
First Report ◽  
Potted Plants ◽  
Water Plants

In 2009, a highbush blueberry (Vaccinium corymbosum L. ‘O'Neal’) field located in Rojas, Buenos Aires Province showed 30% of plants with dry or dead branches. Disinfected root pieces were placed on water agar and incubated at 24°C. A fungal colony was obtained and purified by successive transfers of an individual hyphal tip from a sparsely growing colony. Colony color and growth rate were evaluated in potato dextrose agar where the fungus produced white-to-pale pink colonies and grew 3.5 cm after 5 days. The fungus was studied on Spezieller Nährstoffarmer agar (2), carnation leaf-piece agar, and KCl agar where it produced abundant single-celled hyaline microconidia in moderate-length chains and in false heads originated from monophialides and polyphialides. Microconidia measured 6 to 12 × 2 to 3 μm (average 8 × 2.3 μm). On KCl, chains of microconidia and tan-to-light cream sporodochia with 3- to 5-septate, slender, relatively straight macroconidia were easily observed after 4 and 10 days, respectively. Macroconidia measured 38 to 48 × 3.5 to 4 μm (average 43.9 × 3.9 μm). Chlamydospores and sclerotia were not present. Data coincided with the description for Fusarium proliferatum (Matsush.) Niremberg ex Gerlach & Niremberg. The isolate was deposited in the IMYZA Microbial Collection as INTA-IMC 144. The fungus was cultured in 100 ml of Czapek-Dox supplemented with sucrose, peptone, yeast extract, sodium nitrate, and vitamins for 4 days. Genomic DNA was obtained with a DNA extraction kit, PCR amplified with primers ITS1 and ITS4 for the internal transcribed spacer (ITS) region of ribosomal genes, and sequenced. The nucleotide sequence (Accession No JF913468) was compared with GenBank records. The sequence shared 99% identity with Accession No HQ113948 for F. proliferatum. Pathogenicity was confirmed in 1-year-old ‘O'Neal’ plants. A 10-ml suspension (2.4 × 106 conidia/ml in sterile distilled water) was applied to six potted plants grown in sterilized potting mix. Roots were superficially wounded with a needle. Control plants were treated with sterile distilled water. Plants were incubated at 24°C and a 12-h photoperiod. After 90 days, plants showed root rot, leaf chlorosis, and branch necrosis followed by plant death. Control plants remained healthy. F. proliferatum was reisolated from diseased roots of inoculated plants. This fungus was previously cited in Argentina on asparagus (1), corn (1,3), and oat (4). To our knowledge, this is the first report of F. proliferatum as a root pathogen of highbush blueberry in Argentina. References: (1) G. Lori et al. Plant Dis. 82:1405, 1998. (2) H. I. Nirenberg. Releases Fed. Biol. Res. Ctr. Agric. For. (Berlin-Dahlem) 169:1, 1976. (3) D. A. Sampietro et al. Fung. Biol. 114:74, 2010. (4) S. A. Stenglein et al. Plant Dis. 94:783, 2010.

scholarly journals Comparison of Highbush Blueberry (Vaccinium corymbosum L.) under Ridge and Pot Production

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 929
Author(s):  
Tina Smrke ◽  
Robert Veberic ◽  
Metka Hudina ◽  
Domen Stamic ◽  
Jerneja Jakopic
Keyword(s):  
Organic Acid ◽  
Vaccinium Corymbosum ◽  
Highbush Blueberry ◽  
New Production ◽  
Primary And Secondary Metabolites ◽  
Potted Plants ◽  
Acid Ratio ◽  
Significant Difference ◽  
Microclimatic Conditions ◽  
The Impact

Due to the specific requirements for low soil pH, new production methods are being introduced for highbush blueberry (Vaccinium corymbosum L.). Planting in pots has gained popularity in recent years due to the easier control of the substrate pH. This study was carried out on 2-year-old ‘Duke’, ‘Aurora’ and ‘Brigitta’ cultivar blueberry plants that were planted along a ridge or in pots. The substrate temperature reached higher values for the pots, while the substrate water content was higher for the ridge. In the ‘Duke’ and ‘Aurora’ plants, significantly higher sugar/organic acid ratios were obtained for fruit from the ridge. However, significantly higher fruit total phenolics content, greater plant volumes and lower yields per plant were obtained for ‘Aurora’ as potted plants compared to the ridge. The ‘Brigitta’ fruit harvested from potted plants had significantly higher total organic acid content; however, no significant difference was seen for the sugar/organic acid ratio between the conditions. This study is the first to compare the responses of different highbush blueberry cultivars in terms of production on a ridge and in pots, and the impact on the substrate microclimatic conditions, plant volume and fruit yield and primary and secondary metabolites content.

scholarly journals First Report of Pestalotiopsis clavispora Causing Twig Blight on Highbush Blueberry (Vaccinium corymbosum) in Anhui Province of China

Plant Disease ◽  
2016 ◽  
Vol 100 (4) ◽  
pp. 859 ◽  
Author(s):  
Y. Chen ◽  
A.-F. Zhang ◽  
X. Yang ◽  
C.-Y. Gu ◽  
E. P. Kyaw ◽  
...  
Keyword(s):  
Vaccinium Corymbosum ◽  
Anhui Province ◽  
Highbush Blueberry ◽  
First Report ◽  
Twig Blight

scholarly journals Postharvest Highbush Blueberry Fruit Antimicrobial Volatile Profiles in Relation to Anthracnose Fruit Rot Resistance

2007 ◽  
Vol 132 (6) ◽  
pp. 859-868 ◽  
Author(s):  
James J. Polashock ◽  
Robert A. Saftner ◽  
Matthew Kramer
Keyword(s):  
Vaccinium Corymbosum ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Postharvest Disease ◽  
Highbush Blueberry ◽  
Volatile Emissions ◽  
Wide Range ◽  
Early Ripening ◽  
Volatile Profiles ◽  
Antimicrobial Volatiles

Fruit of highbush blueberry (Vaccinium corymbosum L.) produce antimicrobial volatiles, including trans-2-hexenal, that may confer resistance to anthracnose fruit rot, an important postharvest disease caused by Colletotrichum acutatum J.H. Simmonds. To investigate whether aromatic volatiles in highbush blueberry fruit are associated with postharvest fruit rot resistance, we compared volatiles emitted from whole fruit and extracts from fruit kept in air at 20 °C for 0 to 6 days postharvest from cultivars having a wide range of resistance to anthracnose. Antimicrobial volatiles detected included the aldehydes, trans-2-hexenal and hexanal; the monoterpenes, limonene, linalool, 8-hydroxylinalool, α-terpineol, and terpinyl acetate; and the sesquiterpenes, cadinene, caryophyllene, and α-farnesene. There were significant correlations between some detected volatiles and these differed in whole fruit and extracts. Hexanal (in fruit extracts), trans-2-hexenal, terpinyl acetate, and cadinene emissions increased in most cultivars when fruit were kept in air at 20 °C for various times postharvest. Volatile emissions from whole fruit and extracts varied widely among the cultivars with early ripening cultivars generally showing higher volatile emissions than later ripening cultivars. Although the cultivars tested differed in quantities, and in some cases, the types of volatiles produced, these differences were not related to pedigree (i.e., species composition) nor to known anthracnose resistance ratings. Except for the confounded emissions of terpinyl acetate and cadinene, more than 80% of the variation observed for each volatile was attributable to the cultivar (genetic), year (environmental), and cultivar–by-year interaction. The results suggest that, although antimicrobial aldehydes and terpenes emitted from fully ripe highbush blueberry fruit and extracts might be important flavor and aroma components, they do not significantly contribute to disease resistance against anthracnose fruit rot.

scholarly journals Anthracnose Fruit-rot Resistance in Highbush Blueberry Cultivars

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 768D-768
Author(s):  
Mark K. Ehlenfeldt ◽  
Allan W. Stretch ◽  
Vickie Brewster
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Vaccinium Corymbosum ◽  
Fruit Rot ◽  
Highbush Blueberry ◽  
High Humidity ◽  
Resistant Cultivars ◽  
Green Fruit ◽  
Wide Range ◽  
Fruit Stage

Thirty-three Vaccinium corymbosum selections and cultivars were artificially inoculated with spores of Colletotrichum gloeosporioides in the green fruit stage. Fruit was harvested when ripe and incubated under high-humidity conditions for 1 week, before evaluation. A wide range of susceptibility to anthracnose fruit-rot was found, ranging from 8% to 85%. Among the most-resistant cultivars were: `Elliott' (8%), `Murphy' (8.3%), `Stanley' (13%), and `Weymouth' (16.9%). Among the most-susceptible cultivars were: `Bluetta' (85%), `Spartan' (82.7%), `June' (69.9%), and `Northblue' (69.5%). Uninoculated checks had a maximum of 6% infection.

scholarly journals First Report of Dothichiza caroliniana Causing Double Spot on Highbush Blueberry in South America

Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1685-1685 ◽  
Author(s):  
O. Baino ◽  
A. C. Ramallo ◽  
S. Hongn ◽  
J. C. Ramallo
Keyword(s):  
South America ◽  
Vaccinium Corymbosum ◽  
Necrotic Area ◽  
Highbush Blueberry ◽  
First Report ◽  
Leaf Spots ◽  
Foliar Symptoms ◽  
Leaf Surfaces ◽  
Pathogenicity Tests ◽  
White Mycelium

A foliar disease affecting Jewell, Emerald, and O'Neal cultivars of highbush blueberry (Vaccinium corymbosum L.) was observed in commercial plantings in Tucuman, Argentina during February 2007. Typical symptoms were circular leaf spots that were 10 to 15 mm in diameter, light to dark brown with dark reddish borders, and frequently exhibiting a secondary necrotic area around the original spot. The final appearance was a large necrotic area surrounding a pale, smaller spot. On the abaxial leaf surfaces, white mycelia grew from the border of the initial or enlarged spots toward the healthy tissues. Frequently, black pycnidia bearing an amber rubbery cirrhi were observed. Fewer pycnidia were observed on the adaxial leaf lesions. The fungus was isolated by transferring cirrhi from affected leaves onto petri plates containing potato dextrose agar (PDA). Plates were incubated in darkness at 27°C and light brown concentric colonies with an aerial, effuse, white mycelium developed. After 5 days, dark brown cirrhi emerged from pycnidia in culture. Pycnidiospores were obtuse, hyaline, 1-celled (7 × 2 μm), and grew from the base of pycnidia on short conidiophores. Pycnidia were black, conical, obovoid, averaged 110 × 70 μm wide, and were lightly immersed in the mycelium. Pathogenicity tests were performed by spraying a 106 conidia/ml suspension on leaves of nine blueberry plants (cv. Jewell). Plants were incubated in a moist chamber at 25 to 29°C with a 12-h photoperiod. After 5 weeks, all inoculated leaves had foliar symptoms similar to the lesions previously observed in the field. Reisolation of the fungus completed Koch's postulates. Noninoculated leaves did not develop foliar symptoms. Morphological and cultural characteristics of the fungus conformed to the descriptions of Dothichiza caroliniana (Demaree & M.S. Wilcox) reported to cause “double spot” in blueberry (1,2). Symptoms were consistent with those described for double spot disease (2). To our knowledge, this is the first report of D. caroliniana on blueberry in South America. References: (1) J. B. Demaree and M. Wilcox. Phytopathology, 37:490, 1947. (2) R. D. Milholland. Double spot. Page 17 in: Compendium of Blueberry and Cranberry Diseases. F. L. Caruso and D. C. Ramsdell, eds. The American Phytopathological Society, St. Paul, MN 1995.

scholarly journals Nigrospora sphaerica Causing Leaf Spot and Twig and Shoot Blight on Blueberry: A New Host of the Pathogen

Plant Disease ◽  
2008 ◽  
Vol 92 (1) ◽  
pp. 171-171 ◽  
Author(s):  
E. R. Wright ◽  
M. Folgado ◽  
M. C. Rivera ◽  
A. Crelier ◽  
P. Vasquez ◽  
...  
Keyword(s):  
The United States ◽  
Vaccinium Corymbosum ◽  
Distilled Water ◽  
New Host ◽  
Potted Plants ◽  
Leaf Spots ◽  
Shoot Blight ◽  
Low Incidence ◽  
Environment Chamber ◽  
Entre Rios

Blueberries (Vaccinium corymbosum) have recently become an important alternative crop in different ecological regions of Argentina. In surveys, a new disease characterized by leaf spots and twig and shoot blight has been observed on plants cultivated in Arrecifes, Mercedes, and San Pedro (provinces of Buenos Aires) and Concordia (province of Entre Ríos) since July 2004. Spots initially appear brown, circular, 1 to 2 mm in diameter, and irregularly distributed on the leaves and they eventually coalesce. Fruiting twig and shoot blight developed from the tips toward the base. Affected plants of cvs. O'Neal and Reveille were distributed randomly in the field and with a low incidence (average of 2%). The objective of this work was to identify the causal agent of this disease. Symptomatic plant material was surface disinfested with 0.2% NaOCl for 1 min and 70% ethanol for 1 min, washed once with sterile distilled water, blotted dry with paper towels, and plated on potato dextrose agar. Colonies were initially white, becoming light to dark gray with the onset of sporulation with black, sphaerical to subsphaerical conidia that measured 14 to 19 × 12 to 16 μm. These characteristics agree with published descriptions of Nigrospora sphaerica (Sacc.) Mason (1,4). To evaluate pathogenicity, all leaves, petioles, and stems of seven healthy potted plants of cv. O'Neal were punctured with flamed needles and sprayed with a suspension of 1 × 108 spores of the fungus per milliliter of sterile distilled water. Another seven nonwounded plants were sprayed with the spore suspension. Seven plants similarly injured and seven nonwounded plants were sprayed with sterile distilled water and served as controls. Each plant was covered with a water-sprayed polyethylene bag and maintained in a controlled environment chamber at 20°C with a 12-h photoperiod. The bags were removed after 3 days. All wounded inoculated plants began to show disease symptoms similar to those observed in the field 20 days after inoculation. Controls and nonwounded inoculated plants remained symptomless. The pathogen was reisolated from diseased tissues fulfilling Koch's postulates. N. sphaerica is a well-known saprophyte on many plant species but has been mentioned as pathogen on many hosts (2,3). To our knowledge, this is the first reference of N. sphaerica as a wound pathogen of blueberry. In the field, the fungus would have gained access to the plant through wounds caused by insects or frost after a long-term wetness duration. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK, 1971. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN, 1989. (3) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA. 2007. (4) E. W. Mason. Trans. Brit. Mycol. Soc. 12:152, 1927.

scholarly journals First Report of Bacterial Leaf Scorch Caused by Xylella fastidiosa on Southern Highbush Blueberry in Florida

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1220-1220 ◽  
Author(s):  
P. F. Harmon ◽  
D. L. Hopkins
Keyword(s):  
Xylella Fastidiosa ◽  
Vaccinium Corymbosum ◽  
Pathogen Transmission ◽  
Highbush Blueberry ◽  
Disease Symptoms ◽  
Leaf Scorch ◽  
Three Samples ◽  
Southern Highbush ◽  
Das Elisa ◽  
Bacterial Leaf Scorch

In May of 2008, samples of southern highbush blueberry (interspecific Vaccinium corymbosum hybrids) exhibiting marginal leaf necrosis were collected at a farm in Interlachen, FL. The cv. Star showed severe leaf scorch, partial defoliation, and a generally unthrifty growth structure of many thin twigs as has been observed in Georgia (1). The block of Star plants was approximately 10 years old and incidence of the disease was 100%. The grower reported the planting had become increasingly unproductive in the most recent 4 to 5 years. Plants of the cv. Windsor also showed scorch symptoms and yellow-to-red discoloration of leaves. Proportionally fewer Windsor plants showed disease symptoms than Star plants and the disease was not as severe on this cultivar on the basis of visual estimates at the time. Each sample consisted of 5 to 10 cuttings of spring wood with attached leaves showing marginal necrosis taken from a single plant. Three samples, two from Star plants and one from a Windsor plant, were divided into two subsamples each. One subsample was submitted to Agdia for Xylella fastidiosa double-antibody sandwich (DAS)-ELISA assay (TSE XF; Agdia Inc., Elkhart IN). All three samples were reported as positive for X. fastidiosa by DAS-ELISA. A number of asymptomatic plants from this farm and other additional farms were tested in the same manner and results were negative. The other subsample was used for isolation of the causal bacterium. Petioles and main veins from symptomatic leaves were surface disinfested in 1% sodium hypochlorite, cut into segments (0.5 cm), and squeezed with forceps or pliers. Sap that exuded from the segment was blotted directly onto periwinkle wilt medium (2). Bacterial colonies consistent in morphology with X. fastidiosa that were DAS-ELISA positive were obtained from all three samples. One isolate from each sample was inoculated into four Star plants each with the pin-pricking method (3). Leaf scorch symptoms were first observed 8 weeks after inoculation. By 12 weeks after inoculation, all plants inoculated with the three isolates had developed symptoms, including defoliation. Plants inoculated without bacteria showed no symptoms. X. fastidiosa was reisolated from symptomatic plants. Bacterial leaf scorch is an important emerging disease that threatens the southern highbush blueberry industry in the south. On certain cultivars like Star, the potential to reduce yield appears to be great. Differences between cultivars are likely, but have not yet been explored. Additional research is needed into the epidemiology of the disease and potential vectors of pathogen transmission. References: (1) C. Chang et al. HortScience 44:413, 2009. (2) M. Davis et al. Curr. Microbiol. 6:309, 1981. (3) D. L. Hopkins et al. Phytopathology 75:713, 1985.

scholarly journals Alternaria alternata – the main causal agent of disease symptoms in juniper, rose, yew and highbush blueberry in nurseries in southern Poland

2018 ◽  
Vol 30 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Małgorzata Nadziakiewicz ◽  
Halina Kurzawińska ◽  
Stanisław Mazur ◽  
Dorota Tekielska
Keyword(s):  
Alternaria Alternata ◽  
Ground Cover ◽  
Growing Season ◽  
Vaccinium Corymbosum ◽  
Economic Consequences ◽  
Highbush Blueberry ◽  
Common Phenomenon ◽  
Natural Conditions ◽  
Disease Symptoms ◽  
Large Populations

Abstract Symptoms of discoloration and necrosis of the leaves/needles and shoots of plants are an increasingly common phenomenon in nurseries. They necessitate the withdrawal of the affected plants from sale, which has significant economic consequences. In 2010-2011, observations were conducted of the health of shrubs in nurseries of the Małopolska province. Disease symptoms were mostly found in juniper (Juniperus horizontalis ‘Wiltonii’), rose (ground-cover rose ‘Star Profusion’), yew (Taxus × media ‘Hillii’) and highbush blueberry (Vaccinium corymbosum ‘Patriot’). These species were selected for further study. The affected shrubs represented more than 46% of the population of a given species. Fragments of the diseased organs: the leaves or needles, the base of the shoots, and the roots, were collected from the borderline between healthy and diseased tissue, and used to isolate and identify the microorganisms colonizing the diseased parts. The affected organs were found to be inhabited to the largest extent by the fungus Alternaria alternata (Fr.) Keissl., which accounted for 19.7 to 47.5% of the isolates from the tested species of shrubs. There were also large populations of fungi of the genera: Botrytis (up to 9.82%), Cladosporium (up to 5.66%), Colletotrichum (up to 5.13%), Fusarium (up to 18.38%), Mortierella (up to 7.26%), Pestalotia (up to 5.36%), Rhizoctonia (up to 5.36%), Sclerotinia (up to 6.99%), and Trichoderma (up to 17.09%). The fungus A. alternata, being by far the dominant pathogen, was tested for its pathogenicity for the shoots of the chosen species of shrubs. The test was conducted for 14 days in a chamber with parameters so programmed that they reflected the natural conditions at the height of the growing season. The fungus A. alternata exhibited pathogenicity for all of the tested species of shrubs. Necrosis developed on all the inoculated fragments of shoots. The surface area of necrotic lesions was larger on the shoots of juniper and blueberry.

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