scholarly journals Effect of Inoculum Concentration and Interrupted Wetness Duration on the Development of Anthracnose Fruit Rot of Strawberry

Plant Disease ◽  
2017 ◽  
Vol 101 (2) ◽  
pp. 372-377 ◽  
Author(s):  
Bruna B. Forcelini ◽  
Fabricio Packer Gonçalves ◽  
Natalia A. Peres
Keyword(s):  
Disease Incidence ◽  
Warning System ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Inoculum Concentration ◽  
Immature Fruit ◽  
Different Levels ◽  
Strawberry Cultivars

Anthracnose fruit rot (AFR) of strawberry, caused by Colletotrichum acutatum, greatly affects production if not controlled. Application of fungicides in addition to the use of less susceptible cultivars are important tools for AFR control. The effects of interrupted wetness duration and inoculum concentration on the development of AFR were evaluated on strawberry cultivars with different levels of susceptibility. Fruit rot and flower blight incidence generally increased with increasing inoculum concentration. ‘Camarosa’ and ‘Treasure’ were more susceptible than ‘Strawberry Festival’ and flowers were more susceptible than immature fruit for most cultivars. Interruption in wetness periods had a significant effect on disease incidence when fruit where exposed to dry periods of 6 h or more compared with 24 h of continuous wetness. The results of this study will be used to refine a disease-warning system to predict AFR outbreaks in Florida strawberry production fields.

scholarly journals Assessing Rate-Reducing Foliar Resistance to Anthracnose Crown Rot and Fruit Rot in Strawberry

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 398-407 ◽  
Author(s):  
Raymond L. Jacobs ◽  
Tika B. Adhikari ◽  
Jeremy Pattison ◽  
G. Craig Yencho ◽  
Gina E. Fernandez ◽  
...  
Keyword(s):  
North Carolina ◽  
Durable Resistance ◽  
Crown Rot ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Breeding Lines ◽  
Progress Curve ◽  
Species Complexes ◽  
Controlled Environments ◽  
Strawberry Cultivars

Anthracnose fruit rot and anthracnose crown rot (ACR) caused by two species complexes of the fungus referred to as Colletotrichum acutatum and Colletotrichum gloeosporioides, respectively, are major pathogens of strawberry in North Carolina. Anthracnose epidemics are common when susceptible cultivars and asymptomatic planting stocks carrying quiescent Colletotrichum infection or hemibiotrophic infection (HBI) are planted. The main objective of this study was to assess resistance to HBI and ACR in strawberry. Strawberry cultivars and breeding lines were spray inoculated with isolates of C. acutatum or C. gloeosporioides. Four epidemiological parameters providing estimates of rate-reducing resistance to HBI and ACR in strawberry cultivars and lines were evaluated in repeated experiments in controlled environments in a greenhouse. HBI severity, measured as the percentage of total leaf area covered by acervuli, was estimated visually and by image analysis. ACR severity was rated weekly for wilt symptoms, and relative area under disease progress curve scores were calculated for comparing strawberry cultivars and lines. Significant differences (P ≤ 0.005) in HBI severity were found among strawberry genotypes; however, the correlations were not remarkable between Colletotrichum species (r = 0.4251). Although significant variation in resistance was observed for ACR, this was also weakly correlated (r = 0.2430) with resistance to C. gloeosporioides HBI. Overall, rate-reducing resistance to HBI and ACR in strawberry identified in this study could be utilized in breeding programs to develop durable resistance to anthracnose in North Carolina.

scholarly journals Elucidation of the Disease Cycle of Olive Anthracnose Caused by Colletotrichum acutatum

2009 ◽  
Vol 99 (5) ◽  
pp. 548-556 ◽  
Author(s):  
Juan Moral ◽  
Rodrígues de Oliveira ◽  
Antonio Trapero
Keyword(s):  
Latent Infection ◽  
Toxic Substance ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Phenological Stages ◽  
Disease Symptoms ◽  
Immature Fruit ◽  
Olive Cultivars ◽  
Detached Leaves ◽  
Branch Dieback

Anthracnose, caused by Colletotrichum acutatum and C. gloeosporioides, is a major fungal disease of olive in many countries. In Spain, the disease has been associated only with a characteristic rot and mummification of mature fruit. The purpose of this study was to determine whether C. acutatum could infect other plant tissues that may serve as sources of inoculum for anthracnose epidemics. Inoculations of young plants or detached leaves and field observations demonstrated that flowers and immature olive fruit are susceptible to the pathogen. Flower infection caused blight of inflorescences and infection of developing fruit. Immature fruit were infected in all phenological stages, although infection remained latent for 7 to 8 months, until the onset of fruit ripening. Fruit susceptibility increased and latent period decreased with maturity. Fruit were required for symptom development on inoculated plants. Plants without fruit were infected but they did not show any disease symptoms. Only plants with rotten fruit developed leaf wilting and branch dieback symptoms several weeks later. These results, together with the low level of pathogen isolation from affected leaves and branches and the toxicity of sterile fungal extracts to olive cuttings, suggest that a toxic substance produced by C. acutatum in rotten fruit may account for this syndrome. Both disease syndromes, fruit rot and branch dieback, developed in several olive cultivars, which were equally susceptible to the pathogen. However, olive cultivars differed in their response to flower and fruit infection. Latent infection of developing fruit during the spring may permit survival of the pathogen during the hot and dry summer and serve as an inoculum source for anthracnose epidemics that develop on ripening fruit in autumn.

scholarly journals Identification and Characterization of Fungal Pathogens Causing Fruit Rot of Deciduous Holly

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2430-2445 ◽  
Author(s):  
Shan Lin ◽  
Nancy J. Taylor ◽  
Francesca Peduto Hand
Keyword(s):  
Fungal Pathogens ◽  
Disease Incidence ◽  
Phylogenetic Analyses ◽  
Management Strategies ◽  
Morphological Characterization ◽  
Fruit Rot ◽  
Economic Losses ◽  
Yield Reduction ◽  
Inoculum Concentration ◽  
Fruit Samples

Cut branches of deciduous holly (Ilex spp. L.) harboring colorful berries are traditionally used as ornaments in holiday decorations. Since 2012, a fruit rot of unspecified cause has resulted in significant yield reduction and economic losses across Midwestern and Eastern U.S. nurseries. In this study, symptomatic fruit samples collected from nine different locations over five years were analyzed, and several fungal species were isolated. A combination of morphological characterization, multilocus phylogenetic analyses, and pathogenicity assays revealed that Alternaria alternata and Diaporthe ilicicola sp. nov. were the primary pathogens associated with symptomatic fruit. Other fungi including A. arborescens, Colletotrichum fioriniae, C. nymphaeae, Epicoccum nigrum, and species in the D. eres species complex appeared to be minor pathogens in this disease complex. In detached fruit pathogenicity assays testing the role of wounding and inoculum concentration on disease development, disease incidence and severity increased when fruit was wounded and inoculated with a higher inoculum concentration. These findings indicate that management strategies that can protect fruit from injury or reduce inoculum may lower disease levels in the field. This research established the basis for further studies on this emerging disease and the design of research-based management strategies. To our knowledge, it also represents the first report of species of Alternaria, Colletotrichum, Diaporthe, and Epicoccum causing fruit rot of deciduous holly.

scholarly journals Fruit Resistance to Colletotrichum acutatum in Strawberries

Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 549-553 ◽  
Author(s):  
B. Denoyes-Rothan ◽  
M. Lafargue ◽  
G. Guerin ◽  
M. Clerjeau
Keyword(s):  
Incubation Temperature ◽  
Disease Incidence ◽  
Lesion Size ◽  
Crown Rot ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Resistant Genotype ◽  
Small Fruit ◽  
Resistant Group ◽  
Strawberry Resistance

Evaluation of strawberry resistance to anthracnose is generally limited to the crown rot phase of the disease. The major objective of this study was to develop a screening test for resistance to anthracnose fruit rot (Colletotrichum acutatum) using detached strawberries under controlled-environment conditions. Inoculation was carried out on detached fruits harvested at the stage when they were turning white-pink. Lesion diameter and percentage of diseased fruits (disease incidence) were measured. An incubation temperature of 18°C allowed a better discrimination between resistant and susceptible genotypes than 25°C. At 18°C and 8 days after inoculation, 26 genotypes differed greatly in susceptibility to anthracnose fruit rot, and lesion size ranged from 0 to 17 mm with disease incidence of 10 to 100%. A relationship between lesion size and disease incidence was established. The 26 genotypes were classified into three groups of susceptibility according to lesion size and percentage of diseased fruits. The susceptible group included nine genotypes with lesion sizes of 8.2 to 14.4 mm and 81 to 100% diseased fruits. In this group, Pajaro and Elsanta were the most susceptible. The four genotypes belonging to the resistant group, Dover, Capitola, US159, and US438, showed small fruit lesion sizes of 0.4 to 1.0 mm and a limited disease incidence (10 to 17%). The resistance of two genotypes to anthracnose fruit rot was evaluated under field conditions (plastic tunnel). The relatively resistant genotype, Sequoia, displayed reduced incidence of anthracnose fruit rot in the sections closest to the source of inoculum compared with the susceptible genotype Elsanta.

scholarly journals Validation of a Florida Strawberry Anthracnose Fruit Rot (AFR) Warning System in Iowa

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Xiaoyu Zhang ◽  
Jean C. Batzer ◽  
Xun Li ◽  
Natalia A. Peres ◽  
Mark L. Gleason
Keyword(s):  
Warning System ◽  
Threshold Value ◽  
Field Trials ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Action Threshold ◽  
Equivalent Control ◽  
Strawberry Anthracnose ◽  
Spray Timing ◽  
Disease Pressure

Field validation of a disease-warning system for strawberry anthracnose fruit rot (AFR), caused by Colletotrichum acutatum sensu lato, that was originally developed for use in Florida was conducted in Iowa from 2012 to 2014. Day-neutral strawberry (cv. Tristar) was artificially inoculated with the pathogen at the start of the fruit maturation period. A factorial combination in replicated trials of two spray timing methods (the Florida warning system and prescheduled, calendar-based timing) and two fungicides (captan and pyraclostrobin) was compared, along with a nonsprayed control. The calendar-based and warning system-based treatments provided statistically equivalent control of AFR incidence compared with the nonsprayed control, and the warning system treatments required an average of 1.7 fewer fungicide sprays annually than the calendar-based treatments. Further analysis of the field data suggested that the warning system might underestimate AFR risk under high disease pressure; in these circumstances, a lower action threshold value may need to be adopted. Overall, these results indicated that the Florida warning system can be valuable for helping Midwest strawberry growers control AFR with less reliance on fungicide sprays, but it may require modification to account for periods of high inoculum pressure, subject to results of further field trials.

scholarly journals Preplant Fungicide Dips of Strawberry Transplants to Control Anthracnose Caused by Colletotrichum acutatum in California

2009 ◽  
Vol 19 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Oleg Daugovish ◽  
Hai Su ◽  
W. Douglas Gubler
Keyword(s):  
Tap Water ◽  
Disease Incidence ◽  
Fruit Production ◽  
Crown Rot ◽  
Fruit Rot ◽  
Colletotrichum Acutatum ◽  
Marketable Yield ◽  
Planting Dates ◽  
Bare Root ◽  
Canopy Size

Bare-root daughter plants of strawberry (Fragaria ×ananassa) were inoculated with Colletotrichum acutatum, the cause of crown rot, root rot, and fruit rot of strawberry in California. Plants were subsequently dipped in fungicide solutions or washed with running tap water immediately before planting in Summer and Fall 2002 and Fall 2004. Fungicide treatments reduced plant dieback by up to 92% in fruit production fields. Plants treated with azoxystrobin, the premixtures of boscalid + pyraclostrobin and cyprodinil + fludioxonil had 50% to 92% reduction in disease incidence, increased canopy size by more than 100%, and produced significantly higher marketable yields in all planting dates than the inoculated plants that were not treated with the fungicides. Chlorothalonil and captan also significantly reduced disease incidence but did not consistently increase marketable yield compared with the untreated, inoculated control. The effects of propiconazole and trifloxystrobin were inconsistent in reducing disease incidence. Water wash did not reduce root and crown disease incidence but significantly increased marketable yields by 13% over the untreated, inoculated controls in one of two plantings. No pretransplant treatments provided protection against fruit and foliar infection; thus, in-season fungicide applications would be necessary for disease control in commercial production fields if environmental conditions favored disease development.

scholarly journals Effect of Compost Amendments on Disease Severity and Yield of Tomato in Conventional and Organic Production Systems

Plant Disease ◽  
2002 ◽  
Vol 86 (2) ◽  
pp. 156-161 ◽  
Author(s):  
P. A. Abbasi ◽  
J. Al-Dahmani ◽  
F. Sahin ◽  
H. A. J. Hoitink ◽  
S. A. Miller
Keyword(s):  
Disease Severity ◽  
Production Systems ◽  
Disease Incidence ◽  
Organic Production ◽  
Fruit Rot ◽  
High Rate ◽  
Bacterial Spot ◽  
Marketable Yield ◽  
Tomato Production ◽  
Compost Amendments

Field trials were conducted over 2 years to assess the effects of compost amendments on disease development in organic and conventional processing tomato (Lycopersicon esculentum L.) production systems. The incidence of anthracnose fruit rot was reduced in organic tomato plots amended with a high rate of composted cannery wastes compared with the incidence in nonamended control plots in 1998 when disease incidence was high. Marketable yield was increased by 33% in compost-amended organic plots. Plots amended with a high compost rate had more ripe fruit than the nonamended control. The incidence of anthracnose and of total disease on fruit was less on the cultivar OH 8245 than on Peto 696. Total fruit yield of OH 8245 but not Peto 696 in organic plots was increased by amendment with composted cannery wastes. In conventional tomato production, composted yard wastes increased disease severity on foliage both years but reduced bacterial spot incidence on fruit in 1997, when disease pressure was high. The incidence of anthracnose was not affected by composted yard wastes. Marketable and total fruit yields of Peto 696 were not increased in compost-amended conventional plots. The plant activator Actigard reduced foliar disease severity and the incidence of bacterial spot and anthracnose on fruit, while increasing yield of marketable fruit.

scholarly journals Evaluation of a Disease Warning System for Downy Mildew of Grapes

Plant Disease ◽  
2000 ◽  
Vol 84 (5) ◽  
pp. 549-554 ◽  
Author(s):  
L. V. Madden ◽  
M. A. Ellis ◽  
N. Lalancette ◽  
G. Hughes ◽  
L. L. Wilson
Keyword(s):  
Linear Model ◽  
Downy Mildew ◽  
Environmental Conditions ◽  
Generalized Linear Model ◽  
Disease Incidence ◽  
Warning System ◽  
Plasmopara Viticola ◽  
Effective Control ◽  
Subsequent Infection ◽  
Grape Downy Mildew

An electronic warning system for grape downy mildew— based on models for the infection of leaves of Vitis lambrusca, production of sporangia by Plasmopara viticola in lesions, and sporangial survival—was tested over 7 years in Ohio. Grapevines were sprayed with metalaxyl plus mancozeb (Ridomil MZ58) when the warning system indicated that environmental conditions were favorable for sporulation and subsequent infection. Over the 7 years, plots were sprayed from one to four times according to the warning system, and from four to 10 times according to the standard calendar-based schedule (depending on the date of the initiation of the experiment). The warning system resulted in yearly reductions of one to six sprays (with median of three sprays). Disease incidence (i.e., proportion of leaves with symptoms) in unsprayed plots at the end of the season ranged from 0 to 86%, with a median of 68%. Incidence generally was very similar for the warning-system and standard-schedule treatments (median of 7% of the leaves with symptoms), and both of these incidence values were significantly lower (P < 0.05) than that found for the unsprayed control, based on a generalized-linear-model analysis. Simplifications of the disease warning system, where sprays were applied based only on the infection or sporulation components of the system, were also effective in controlling the disease, although more fungicide applications sometimes were applied. Effective control of downy mildew, therefore, can be achieved with the use of the warning system with fewer sprays than a with a standard schedule.

Fungicide Dip Treatments for Management of Botrytis cinerea Infection on Strawberry Transplants

2018 ◽  
Vol 19 (4) ◽  
pp. 279-283
Author(s):  
Michelle S. Oliveira ◽  
Leandro G. Cordova ◽  
Marcus V. Marin ◽  
Natalia A. Peres
Keyword(s):  
Botrytis Cinerea ◽  
Causal Agent ◽  
Fruit Rot ◽  
Plant Establishment ◽  
Fungicide Sensitivity ◽  
Strawberry Cultivars

Botrytis cinerea, the causal agent of Botrytis fruit rot, is annually introduced into Florida strawberry fields by infected transplants. The disease can be managed by fungicide sprays throughout the season; however, previous studies have demonstrated that several chemical classes are no longer effective owing to B. cinerea resistance. The objectives of this study were to evaluate the effectiveness of preplant fungicide-dip treatments of strawberry transplants on reducing B. cinerea colonization and to evaluate fungicide sensitivity of surviving B. cinerea isolates. Transplants of two strawberry cultivars, Winterstar ‘FL 05-107’ and ‘Florida Radiance’, were dipped in 11 different fungicides. After the plant establishment period, eight leaves per plot were collected before and 14 days after treatment to evaluate B. cinerea incidence. Isolates (n = 139) obtained from the transplants were tested for fungicide sensitivity. Plant diameter was measured 47 days after planting. All treatments, including the controls, reduced B. cinerea incidence by at least 77% compared with predip incidence. However, fungicide-resistant isolates were recovered from all treatments tested.

scholarly journals Association Between Weather Variables, Airborne Inoculum Concentration, and Raspberry Fruit Rot Caused by Botrytis cinerea

2018 ◽  
Vol 108 (1) ◽  
pp. 70-82 ◽  
Author(s):  
Odile Carisse ◽  
Vanessa McNealis ◽  
Alissa Kriss
Keyword(s):  
Meteorological Data ◽  
Fruit Rot ◽  
Weather Variables ◽  
Storage Duration ◽  
Inoculum Concentration ◽  
Crop Losses ◽  
Airborne Inoculum ◽  
Average Relative Humidity ◽  
And Storage ◽  
Field Plots

Botrytis fruit rot (BFR), one of the most important diseases of raspberry (Rubus spp.), is controlled primarily with fungicides. Despite the use of fungicides, crop losses due to BFR are high in most years. The aim of this study was to investigate the association between airborne inoculum, weather variables, and BFR in order to improve the management of the disease as well as harvest and storage decisions. Crop losses, measured as the percentage of diseased berries during the harvest period, were monitored in unsprayed field plots at four sites in three successive years, together with meteorological data and the number of conidia in the air. Based on windowpane analysis, there was no evidence of correlation between crop losses and temperature, vapor pressure deficit, wind, solar radiation, or probability of infection. There were significant correlations between crop losses and airborne inoculum and between crop losses and humidity-related variables, and the best window length was identified as 7 days. Using 7-day average airborne inoculum concentration combined with 7-day average relative humidity for periods ending 6 to 8 days before bloom, it was possible to accurately predict crop losses (R2 of 0.86 to 0.89). These models could be used to assist with managing BFR, timing harvests, and optimizing storage duration in raspberry crops.

Sign in / Sign up

Export Citation Format

Share Document