Identifying and Characterizing Summer Diseases on ‘Babygold’ Peach in South Carolina

2006 ◽  
Vol 7 (1) ◽  
pp. 30 ◽  
Author(s):  
Guido Schnabel ◽  
Wenxuan Chai ◽  
Kerik D. Cox
Keyword(s):  
South Carolina ◽  
Dna Analysis ◽  
Management Strategies ◽  
Disease Outbreaks ◽  
Geotrichum Candidum ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Significant Yield ◽  
Rot Disease

Summer diseases can cause significant yield losses in processing peach varieties, such as the ‘Babygold’ lines. In this study we identified and characterized the pathogens responsible for disease outbreaks in two orchards (PH and JC) located in the northern ‘Piedmont’ area of South Carolina. Three pathogens, Geotrichum candidum, Colletotrichum acutatum, and Botryosphaeria dothidea, the causal agents of sour rot, anthracnose, and Botryosphaeria fruit rot disease respectively, were identified on fruit from orchard PH using symptomology, culture and spore morphology, and ribosomal DNA analysis. G. candidum and C. acutatum were also isolated from symptomatic fruit from orchard JC. The QoI fungicide azoxystrobin and a mixture of pyraclostrobin and boscalid were evaluated for their in vitro efficacy against five isolates of each of the three pathogens to investigate their possible usefulness in designing management strategies. Azoxystrobin inhibited mycelial growth of C. acutatum isolates (EC50 values of 0.01 to 0.55 mg/liter) but was ineffective against mycelium of G. candidum and B. dothidea isolates (EC50 values >300 mg/liter). The pyraclostrobin-boscalid mixture was highly effective against mycelium of C. acutatum (EC50 values of 0.01 to 0.05 mg/liter) and B. dothidea isolates (EC50 values of 0.02 to 0.03 mg/liter), but only marginally effective against mycelium of G. candidum (EC50 values 15.79 to 39.03 mg/liter). This study provides a diagnostic guide of pathogens that can cause summer diseases on ‘Babygold’ peaches and reports their in vitro sensitivity to registered respiration inhibitor fungicides. Accepted for publication 23 December 2005. Published 1 March 2006.

scholarly journals Isolatation and Identification of the Fungi Causing Tomato Fruit Rot Disease in the Vicinity of Tandojam, Sindh

2020 ◽  
Author(s):  
S. Nizamani ◽  
A. A. Khaskheli ◽  
A. M. Jiskani ◽  
S. A. Khaskheli ◽  
A. J. Khaskheli ◽  
...  
Keyword(s):  
Tomato Fruit ◽  
Aerial Mycelium ◽  
Alternaria Solani ◽  
Economic Loss ◽  
Geotrichum Candidum ◽  
Fruit Rot ◽  
Post Harvest ◽  
Standard Procedures ◽  
Fruit Samples ◽  
Rot Disease

Background: The post-harvest tomato fruit rot disease is common threat to the tomato fruit, causing huge economic loss as revealed by (GOP, 2018). The present study was conducted for isolatation and identification of causative agent of tomato fruit rot in order to formulate the proper management stretegies. Methods: Study was conducted in three phases. Phase one included collection of tomato fruit samples from vicinity of Tandojam. In phase two pathogens were isolated from the samples at laboratory, while in the phase three pathogens were identified using standard procedures. Result: The experimental results indicated Alternaria solani as the main cause of post-harvest tomato fruit rot. The symptoms observed were presence of brown to black rot lesions on tomato fruits with distinct rings ranging from small pin-heads to whole surface of fruit. A total of six different fungi viz., Alternaria alternata, Aspergillus niger, Alternaria solani, Geotrichum candidum, Fusarium oxysporum and Rhizopus stolonifer were found to be associated with post harvest tomato rot. Significantly higher infection was recorded for A. solani (53.667%) followed by A. niger (16.333%) and G. candidum (13.00%). The lowest infection percentage was observed for F. oxysporum (2.333%), followed by A. alternata (4.00%) and R. stolonifer (9.00%). A. solani produced aerial mycelium with yellowish to reddish diffusible pigments. A. niger cultures were typically black and colonies were initially whitish to yellow and later became brown to black in colour. G. candidum produced white and nonaerial colonies. F. oxysporum produced circular, aerial mycelium initially white, later changed to light pink. R. stolonifer produced whitish to grey fuzzy colonies.

scholarly journals Sensitivity of Colletotrichum Species, Including C. fioriniae and C. nymphaeae, from Peach to Demethylation Inhibitor Fungicides

Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2434-2441 ◽  
Author(s):  
S. N. Chen ◽  
C. X. Luo ◽  
M. J. Hu ◽  
G. Schnabel
Keyword(s):  
South Carolina ◽  
Colletotrichum Acutatum ◽  
In Vitro Activity ◽  
Internal Transcribed Spacer Region ◽  
Control Efficacy ◽  
Dmi Fungicides ◽  
Colletotrichum Spp ◽  
Colletotrichum Acutatum Species Complex ◽  
Demethylation Inhibitor

Few fungicides are effective against anthracnose, caused by Colletotrichum spp., and emerging resistance makes the search for chemical alternatives more relevant. Isolates of the Colletotrichum acutatum species complex were collected from South Carolina and Georgia peach orchards and phylogenetic analysis of the combined internal transcribed spacer region, glyceraldehyde-3-phosphate dehydrogenase, and β-tubulin gene sequences separated the isolates into C. nymphaeae and C. fioriniae. The sensitivity of these and three other previously reported Colletotrichum spp. from peach, including C. fructicola, C. siamense, and C. truncatum, to demethylation inhibitor (DMI) fungicides difenoconazole, propiconazole, tebuconazole, metconazole, flutriafol, and fenbuconazole was determined based upon mycelial growth inhibition. C. truncatum was resistant to tebuconazole, metconazole, flutriafol, and fenbuconazole and C. nymphaeae was resistant to flutriafol and fenbuconazole based on 50% effective concentration (EC50) values >100 μg/ml. C. fructicola and C. siamense were sensitive to all DMI fungicides (EC50 values of 0.2 to 13.1 μg/ml). C. fioriniae subgroup 2 isolates were less sensitive to DMI fungicides (EC50 values of 0.5 to 16.2 μg/ml) compared with C. fioriniae subgroup 1 (EC50 values of 0.03 to 2.1 μg/ml). Difenoconazole and propiconazole provided the best control efficacy in vitro to all five species, with EC50 values of 0.2 to 2.7 μg/ml. Tebuconazole and metconazole were effective against all Colletotrichum spp., except for C. truncatum. The strong in vitro activity of some DMI fungicides against Colletotrichum spp. may be exploited for improved anthracnose disease management of peach.

scholarly journals Control of Sphaeropsis Rot in Stored Apple Fruit Caused by Sphaeropsis pyriputrescens with Postharvest Fungicides

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1075-1079 ◽  
Author(s):  
C. L. Xiao ◽  
Y. K. Kim ◽  
R. J. Boal
Keyword(s):  
Mycelial Growth ◽  
Disease Incidence ◽  
Apple Fruit ◽  
Conidial Germination ◽  
Fruit Rot ◽  
Mitigation Measures ◽  
The Mean ◽  
Rot Disease ◽  
Sphaeropsis Rot

Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple grown in Washington State. The objective of this study was to develop chemical-based mitigation measures for Sphaeropsis rot in stored apple fruit. To determine in vitro sensitivity of S. pyriputrescens to the three registered postharvest fungicides thiabendazole, fludioxonil, and pyrimethanil, 30 isolates of S. pyriputrescens obtained from various sources were tested for mycelial growth and conidial germination on fungicide-amended media. Golden Delicious apple fruit were inoculated with the pathogen in the orchard at 2 or 5 weeks before harvest. After harvest, fruit were either nontreated or dipped in thiabendazole, fludioxonil, or pyrimethanil solutions, stored at 0°C, and monitored for decay development for up to 9 months after harvest. The mean effective concentration of a fungicide that inhibits mycelial growth or spore germination by 50% relative to the nonamended control (EC50) values of thiabendazole, fludioxonil, and pyrimethanil on mycelial growth were 0.791, 0.0005, and 2.829 μg/ml, respectively. Fludioxonil and pyrimethanil also were effective in inhibiting conidial germination of the fungus with EC50 values of 0.02 μg/ml for fludioxonil and 5.626 μg/ml for pyrimethanil. All three postharvest fungicides applied at label rates immediately after harvest were equally effective in controlling Sphaeropsis rot in stored apple fruit, reducing disease incidence by 92 to 100% compared with the nontreated control. The results indicated that Sphaeropsis rot may be effectively controlled by the currently registered postharvest fungicides thiabendazole, fludioxonil, and pyrimethanil.

scholarly journals First report of preharvest fruit rot of ‘Pink Lady’ apples caused by Colletotrichum fructicola in Italy

Plant Disease ◽  
2021 ◽  
Author(s):  
Marcel Wenneker ◽  
Khanh Pham ◽  
Engelien Kerkhof ◽  
Dalphy O.C. Harteveld
Keyword(s):  
Species Complex ◽  
Management Strategies ◽  
Morphological Characteristics ◽  
Late Summer ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Apple Orchards ◽  
First Report ◽  
Bitter Rot ◽  
Colletotrichum Fructicola

In late summer 2019, a severe outbreak of fruit rot was observed in commercial ‘Pink Lady’ apple orchards (>20 ha in total) in the region Emilia-Romagna (Northern Italy). The symptoms on the fruit appeared as small circular red to brown lesions. Disease incidences of over 50% of the fruits were observed. To isolate the causal agent, 15 affected apples were collected and small portions of fruit flesh were excised from the lesion margin and placed on potato dextrose agar (PDA). The plates were incubated at 20°C in the dark, and pure cultures were obtained by transferring hyphal tips on PDA. The cultures showed light to dark gray, cottony mycelium, with the underside of the culture being brownish and becoming black with age. Conidia (n=20) were cylindrical, aseptate, hyaline, rounded at both ends, and 12.5 to 20.0 × 5.0 to 7.5 μm. The morphological characteristics were consistent with descriptions of Colletotrichum species of the C. gloeosporioides species complex, including C. fructicola (Weir et al. 2012). The identity of two representative isolates (PinkL2 & PinkL3) from different apples was confirmed by means of multi-locus gene sequencing. Genomic DNA was extracted using the LGC Mag Plant Kit (Berlin, Germany) in combination with the Kingfisher method (Waltham, USA). Molecular identification was conducted by sequencing the ITS1/ITS4 region and partial sequences of four other gene regions: chitin synthase (CHS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), and beta-tubulin (TUB). The sequences have been deposited in GenBank under accession numbers MT421924 & MT424894 (ITS), MT424612 & MT424613 (CHS), MT424616 & MT424617 (GAPDH), MT424614 & MT424615 (ACT), and MT424620 & MT424621 (TUB). MegaBLAST analysis revealed that our ITS sequences matched with 100% identity to Colletotrichum fructicola (Genbank JX010177). The CHS, GAPDH, ACT and TUB sequences of both isolates were 100% identical with C. fructicola culture collection sequences in Genbank (JX009807, JX009923, JX009436 and JX010400, respectively), confirming the identity of these isolates as C. fructicola. Koch's postulates were performed with 10 mature ‘Pink Lady’ apples. Surface sterilized fruit were inoculated with 20 μl of a suspension of 105 conidia ml–1 after wounding with a needle. The fruits were incubated at 20˚C at high relative humidity. Typical symptoms appeared within 4 days on all fruit. Mock-inoculated controls with sterile water remained symptomless. The fungus was reisolated and confirmed as C. fructicola by morphology and sequencing of all previously used genes. Until recently the reported causal agents of bitter rot of apple in Europe belong to the Colletotrichum acutatum species complex (Grammen et al. 2019). C. fructicola, belonging to C. gloeosporioides species complex, is known to cause bitter rot of apple in the USA, Korea, Brazil, and Uruguay (Kim et al. 2018; Velho et al. 2015). There is only one report of bitter rot associated with C. fructicola on apple in Europe (France) (Nodet et al. 2019). However, C. fructicola is also the potential agent of Glomerella leaf spot (GLS) of apple (Velho et al. 2015; 2019). To the best of our knowledge this is the first report of C. fructicola on apples in Italy. It is important to stress that the C. gloeosporioides species complex is still being resolved and new species on apple continue to be identified, e.g. C. chrysophilum that is very closely related to C. fructicola (Khodadadi et al. 2020). Given the risks of this pathogen the presence of C. fructicola in European apple orchards should be assessed and management strategies developed.

scholarly journals Present status of strawberry fruit rot diseases in New Zealand

2005 ◽  
Vol 58 ◽  
pp. 74-79 ◽  
Author(s):  
O.E. Timudo-Torrevilla ◽  
K.R. Everett ◽  
N.W. Waipara ◽  
K.S.H. Boyd-Wilson Weeds ◽  
G.I. Langford ◽  
...  
Keyword(s):  
New Zealand ◽  
Room Temperature ◽  
Integrated Management ◽  
Management Strategies ◽  
Grey Mould ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Relative Importance ◽  
Strawberry Fruit ◽  
Ripe Fruit

The New Zealand strawberry industry experiences losses due to fungal diseases that can cost up to 44 million per annum or 20 of the crop value Disease control relies almost exclusively on applications of the fungicide captan During the 2003/2004 production season grower monitoring trials investigated the relative importance of grey mould (Botrytis cinerea) anthracnose (Colletotrichum acutatum) and leak (Rhizopus spp) in causing postharvest fruit rot The average fruit rot incidence (expressed per day) was 36 22 and 16 for grey mould leak and anthracnose respectively when ripe fruit was incubated at room temperature under high humidity In two grower trials and one replicated spray trial frequent captan applications did not reduce grey mould anthracnose or leak incidence compared to an unsprayed treatment Integrated management strategies for control of strawberry fruit rot diseases are urgently required for New Zealand strawberry growers

scholarly journals Baseline Sensitivity and Control Efficacy of Various Group of Fungicides against Sclerotinia sclerotiorum in Oilseed Rape Cultivation

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1758
Author(s):  
Nazanin Zamani-Noor
Keyword(s):  
Oilseed Rape ◽  
Sclerotinia Sclerotiorum ◽  
Fungicidal Activity ◽  
Management Strategies ◽  
Sclerotinia Stem Rot ◽  
Baseline Sensitivity ◽  
Cultural Management ◽  
Significant Yield ◽  
And Control

Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, is a devastating disease of oilseed rape that may cause significant yield losses if not controlled by cultural management strategies and fungicide applications. Studies were conducted to evaluate the efficacy of different group of fungicides as well as a biopesticide, including azoxystrobin, boscalid, fludioxonil, prothioconazole, tebuconazole, azoxystrobin/tebuconazole, boscalid/pyraclostrobin, prothioconazole/fluopyram and Bacillus amyloliquefaciens, on baseline sensitivity of S. sclerotiorum isolates under in-vitro conditions as well as control of SSR in the field. Artificial inoculation and mist irrigation prompt to reproducible SSR infection in oilseed rape cultivation. All compounds significantly reduced 36.7% to 86.9% SSR severity and increased 55.2% to 98.7% yield, 1.5% to 7.0% thousand grain-weight, 1.5% to 5.9% oil and 0.1% to 1.3% protein content. Fludioxonil, boscalid/pyraclostrobin and fluopyram/prothioconazole achieved strongest fungicidal activity against SSR. The biopesticide provided 36% of disease control. Under in vitro conditions, B. amyloliquefaciens not only strongly inhibited mycelial growth but also the formation of sclerotia in all concentrations. Boscalid and fludioxonil exhibited the highest level of fungicidal activity against S. sclerotiorum, with mean EC50 values of 1.23 and 1.60 μg a.s. mL−1. The highest variability of EC50 values between isolates was observed towards prothioconazole and azoxystrobin.

scholarly journals Anthracnose on Strawberry: Its Etiology, Epidemiology, and Pathology, Together with Management Strategies for Strawberry Nurseries: Introduction to the Workshop

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 59-65 ◽  
Author(s):  
E. Barclay Poling
Keyword(s):  
Key Management ◽  
Management Practices ◽  
Cultural Practices ◽  
Management Strategies ◽  
Video Recording ◽  
Fruit Production ◽  
Control Measures ◽  
Crown Rot ◽  
Fruit Rot ◽  
Colletotrichum Acutatum

In recent years, anthracnose fruit rot (AFR) caused by Colletotrichum acutatum J.H. Simmonds, has become an even more serious threat to strawberry plant and fruit producers in major strawberry-growing areas of North America. This highly virulent pathogen causes fruit rot, crown rot, root rot, and lesions on petioles and stolons. In fruit-production fields, the best way to control AFR is to prevent the introduction of the pathogen into the field by using anthracnose-free transplants. A critical step in controlling the disease then, lies in effective nursery management practices. Participants in this workshop outlined several key management strategies, including methods to eliminate pathogen inoculum, cultural practices that reduce host plant susceptibility, and chemical and biological control measures. Industry members stressed the importance of giving research priority to developing improved methods of nursery field sampling and detection of C. acutatum in asymptomatic plants with latent infection. Being able to rapidly and economically diagnose C. acutatum in symptomless plant material at each step in the multiyear nursery plant propagation cycle (foundation, registered, and certified plants), will help nursery growers minimize the potential of selling C. acutatum-infected transplants to fruit growers. A video recording of the 4-h workshop was produced by ASHS Video Workshop Series (http://ashs.org/resources/videoworkshopseries.html).

scholarly journals Heart Rot of Pomegranate: Disease Etiology and the Events Leading to Development of Symptoms

Plant Disease ◽  
2015 ◽  
Vol 99 (4) ◽  
pp. 496-501 ◽  
Author(s):  
David Ezra ◽  
Benny Kirshner ◽  
Michal Hershcovich ◽  
Dani Shtienberg ◽  
Itzhak Kosto
Keyword(s):  
Fruit Development ◽  
Management Strategies ◽  
Soft Rot ◽  
Fruit Rot ◽  
Black Rot ◽  
Causative Pathogen ◽  
Disease Etiology ◽  
Rot Disease ◽  
Pomegranate Fruit ◽  
Organ Colonization

Pomegranate fruit rot disease, known as “heart rot” or “black heart,” is a major pomegranate disease that impacts production worldwide. Heart rot is characterized by black rot of the fruit core that spreads from the calyx area, whereas the outer peel and the hard rind retain their healthy appearance. Aims of the present study were to identify the pathogen that causes pomegranate heart rot in Israel and to study the dynamics of fruit-organ colonization by fungi during fruit development, as the first steps toward the development of management strategies. Several fungi were isolated from pomegranate fruits, among which were species of Penicillium, Aspergillus, Botrytis, and Rhizopus, but the causative pathogen of the disease was identified as Alternaria alternata. This fungus was isolated from the pistils of more than 85% of open flowers and ∼20% of the loculi of asymptomatic fruits and from all tissues of the symptomatic fruits. The dynamics of fruit-organ colonization by fungi during fruit development was recorded in six commercial orchards in 2010 and 2011. It was found that A. alternata spores germinate on the stigmata of open flowers and develop into the style. In some fruits, the mycelium grows into the tunnel and reaches the lower loculus, where the fungus becomes latent for about 3 to 4 months pending initiation of fruit ripening. Then, in a small number of fruits, the fungus starts growing and invades the arils, causing black rot of the arils in the lower loculus. At the beginning of disease development, the fungus causes brown soft rot of the arils, which becomes black and dry as the fungus grows. Eventually, the fungus grows from the lower loculus into the upper loculi, causing rot of the entire fruit.

scholarly journals Evaluation of a Pomegranate Peel Extract as an Alternative Means to Control Olive Anthracnose

2017 ◽  
Vol 107 (12) ◽  
pp. 1462-1467 ◽  
Author(s):  
Sonia Pangallo ◽  
Maria G. Li Destri Nicosia ◽  
Giovanni E. Agosteo ◽  
Ahmed Abdelfattah ◽  
Flora V. Romeo ◽  
...  
Keyword(s):  
Disease Outbreaks ◽  
Field Trials ◽  
Sensu Stricto ◽  
Colletotrichum Acutatum ◽  
Pomegranate Peel ◽  
Bacterial Populations ◽  
Olive Fruit ◽  
Pomegranate Peel Extract ◽  
Peel Extract

Olive anthracnose is caused by different species of Colletotrichum spp. and may be regarded as the most damaging disease of olive fruit worldwide, greatly affecting quality and quantity of the productions. A pomegranate peel extract (PGE) proved very effective in controlling the disease. The extract had a strong in vitro fungicidal activity against Colletotrichum acutatum sensu stricto, was very effective in both preventive and curative trials with artificially inoculated fruit, and induced resistance in treated olive tissues. In field trials, PGE was significantly more effective than copper, which is traditionally used to control the disease. The highest level of protection was achieved by applying the extract in the early ascending phase of the disease outbreaks because natural rots were completely inhibited with PGE at 12 g/liter and were reduced by 98.6 and by 93.0% on plants treated with PGE at 6 and 3 g/liter, respectively. Two treatments carried out 30 and 15 days before the expected epidemic outbreak reduced the incidence of the disease by 77.6, 57.0, and 51.8%, depending on the PGE concentration. The analysis of epiphytic populations showed a strong antimicrobial activity of PGE, which sharply reduced both fungal and bacterial populations. Because PGE was obtained from a natural matrix using safe chemicals and did not have any apparent phytotoxic effect on treated olive fruit, it may be regarded as a safe and effective natural antifungal preparation to control olive anthracnose and improve olive productions.

scholarly journals Effects of Calcium Salts on the Cranberry Fruit Rot Disease Complex

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 747-752 ◽  
Author(s):  
A. B. Blodgett ◽  
R. W. Caldwell ◽  
P. S. McManus
Keyword(s):  
Calcium Chloride ◽  
Calcium Nitrate ◽  
Calcium Content ◽  
Growing Season ◽  
Fruit Rot ◽  
Calcium Salts ◽  
Calcium Propionate ◽  
Rot Disease ◽  
Time Of Harvest

Calcium salts were applied during the growing season to fresh-fruit cranberry beds to test their effects on cranberry fruit rot incidence and the incidence of specific fungi isolated from rotten and sound cranberry fruit at the time of harvest and after storage. Calcium salts did not affect fruit rot incidence, nor did they affect the recovery of specific fungi from berries. The field treatments did not result in higher calcium content in mature berries, nor did they affect the force required to penetrate the berry epidermis. Calcium propionate inhibited growth in vitro of Allantophomopsis cytisporea, A. lycopodina, Coleophoma empetri, Fusicoccum putrefaciens, and Physalospora vaccinii. Calcium chloride and calcium nitrate inhibited growth of Coleophoma empetri and Fusicoccum putrefaciens, but these salts enhanced growth of Physalospora vaccinii. P. vaccinii was the fungus most frequently isolated from rotten berries at the time of harvest. The fungi most frequently isolated from rotten berries after several weeks in storage varied among sites. P. vaccinii, which was common in sound fruit at harvest, persisted in sound fruit in storage but was also isolated frequently from rotten berries after storage. A. lycopodina and F. putrefaciens, which were isolated infrequently from sound berries at the time of harvest, were isolated frequently from rotten berries after storage. In two of four trials, no fungi were isolated from a large proportion of fruit that decayed in storage.

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