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 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 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 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 Effect of Prohexidione-Ca and IBA on Establishment and Yield of Green-Top Bare-root Strawberry Transplants

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 848C-848
Author(s):  
John R. Duval* ◽  
Elizabeth Golden ◽  
Julia Reekie ◽  
Peter Hicklenton
Keyword(s):  
Growth Regulator ◽  
Disease Incidence ◽  
Growth Yield ◽  
Plastic Mulch ◽  
Marketable Yield ◽  
Growing Seasons ◽  
Black Plastic ◽  
Bare Root ◽  
Block Experiment ◽  
Growth Regulator Treatment

Bare-root transplants received from high latitude nurseries for Florida production have limited root systems, very long petioles and wilt soon after planting. Further dessication occurs when leaves come in contact with black plastic mulch used in the annual production system. Conventional irrigation practices for the establishment of bare-root transplants of strawberry consist of overhead water application for at least 8 hours/day for 10-14 days after planting. Plant growth regulators (PGRs) have been used to modify the growth characteristics of many plants species. A split-block experiment was implemented at the GCREC-Dover, Dover Fla., to determine the effect of the use Prohexidione-Ca (PC) and IBA [(indole-3) butyric acid] on growth, yield and establishment of strawberry. Main blocks consisted of over head establishment irrigation for 4, 8, and 12 days, and sub-plots consisted of treatments of PC applied in the nursery at a rate of 62.5 mg·L-1 2, 4, or 6 weeks before digging, PC applied in the nursery at 31.25 mg·L-1 2 weeks before digging, a root dip of transplants in 100 mg·L-1 IBA just prior to transplanting. The experiment was conducted for four growing seasons. Data were recorded for marketable yield, number of marketable berries (>10g), and disease incidence. Significant differences were detected for duration of establishment irrigation and growth regulator treatment. No interaction was shown between establishment irrigation and growth regulator treatment.

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 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 Water and Temperature Parameters Associated with Winter Wheat Diseases Caused by Soilborne Pathogens

Plant Disease ◽  
2009 ◽  
Vol 93 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Richard W. Smiley
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
Disease Incidence ◽  
Simulation Models ◽  
Crown Rot ◽  
Yield Potential ◽  
Planting Dates ◽  
Wheat Diseases ◽  
Rhizoctonia Root Rot ◽  
Take All

Wheat in eastern Oregon is produced mostly as a 2-year rotation of winter wheat and summer fallow. Maximum agronomic yield potential is expected with early September planting dates but actual yields are generally highest for plantings made in mid-October. Field experiments with sequential planting dates from early September to December were performed over 4 years. Associations among yield, disease incidence, and 19 moisture and temperature parameters were evaluated. Incidence of Cephalosporium stripe, crown rot, eyespot, and take-all decreased as planting was delayed. Crown rot and eyespot were negatively correlated more significantly and more frequently with temperature than moisture parameters, and take-all was more associated with moisture than temperature. Rhizoctonia root rot was unrelated to planting date and climatic parameters. Crown rot was identified most frequently (4 of 5 tests) as an important contributor to yield suppression but yield was most closely associated (R2 > 0.96) with effects from a single disease in only two of five location–year tests. Yield was most related to combinations of diseases in three of five tests, complicating development of disease modules for wheat growth-simulation models.

scholarly journals Drip Irrigation in California Strawberry Nurseries to Reduce the Incidence of Colletotrichum acutatum in Fruit Production

HortScience ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 368-373 ◽  
Author(s):  
Oleg Daugovish ◽  
Mark Bolda ◽  
Sukhwinder Kaur ◽  
Maren J. Mochizuki ◽  
Daniel Marcum ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Quantitative Polymerase Chain Reaction ◽  
Sprinkler Irrigation ◽  
Fruit Production ◽  
Colletotrichum Acutatum ◽  
Post Transplantation ◽  
Crown Tissue ◽  
Mother Plants ◽  
The Impact ◽  
Canopy Size

Strawberry anthracnose caused by Colletotrichum acutatum is often asymptomatic on plants in sprinkler-irrigated nurseries but destructive after transplantation into fruiting fields. This study evaluated the impact of strawberry nursery sprinkler and drip irrigation in the presence or absence of C. acutatum on post-transplantation plant growth, mortality, and fruit yield in fruiting fields in California. In a 2005 nursery at Tulelake, CA, dip infestation of mother plants with C. acutatum reduced early-season mother plant canopy size by 21% and delayed runner production in mother plants but otherwise had no obvious disease symptoms. In comparison with sprinkler-irrigated treatments in the nursery, drip irrigation of infested nursery plots reduced plant losses in fruit production fields by 86% at Watsonville, CA, in 2005 and 50% and 75% at Oxnard, CA, in 2005 and 2008. Transplants from infested nursery treatments had a 33% to 60% smaller canopy and 11% to 42% lower yield than transplants from uninfested nursery treatments. However, transplant canopy size and yield from the infested and then drip-irrigated nursery treatment were similar to the sprinkler-irrigated, non-infested nursery treatment. Quantitative polymerase chain reaction measurements of C. acutatum in crown tissue of fruiting field plants seven weeks after transplanting showed significantly more C. acutatum (≈11×) in their crowns in sprinkler-irrigated than drip-irrigated, infested nursery transplant treatments. During the course of fruit production, the amount of C. acutatum in crown tissue increased in all treatments. However, at the end of the fruit season, there was still significantly more (≈8×) C. acutatum in the crowns of the plants produced by sprinkler irrigation than by drip irrigation in the nursery. These data suggest that if C. acutatum is present in the nursery, drip irrigation can reduce subsequent plant stunting and yield losses in strawberry production fields.

scholarly journals Management, Survival Strategies, and Host Range of Colletotrichum acutatum on Strawberry

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 66-68 ◽  
Author(s):  
Stanley Freeman
Keyword(s):  
Disease Incidence ◽  
Black Spot ◽  
Single Species ◽  
Crown Rot ◽  
Survival Strategies ◽  
Colletotrichum Acutatum ◽  
Weed Species ◽  
Disease Symptoms ◽  
Wide Range ◽  
Foundation Stock

Colletotrichum spp. are broad-range pathogens, meaning that many species can infect a single host and a single species can infect diverse hosts. For example, Colletotrichum acutatum J.H. Simmonds affects a wide range of crops, causing disease symptoms on apple, almond, anemone, citrus, lupin, peach, pecan, strawberry, and others, whereas Colletotrichum gloeosporioides Penz. (Penz. & Sacc.) can affect many of the previous hosts as well. Anthracnose is one of the major fungal diseases of strawberry occurring worldwide. In Israel, the disease is caused primarily by the species C. acutatum. The pathogen causes irregular leaf spot, bud rot, petiole and stolon necrosis, and black spot on fruit. The pathogen is most destructive when it causes root necrosis and crown rot, which usually kill the plants in nurseries and transplants in the field. To maintain a disease-free crop, nuclear and foundation stock material, as well as field nurseries, must be routinely monitored and tested for presence of the pathogen. Strawberry cultivation using plasticulture as an overhead cover of the crop can significantly control anthracnose disease incidence by reducing inoculum spread and infection, both in nurseries and in production fields. C. acutatum from strawberry can survive on several cultivated plant species, such as pepper, eggplant, tomato, bean, and weed species, without causing disease symptoms. This indicated that they may serve as a potential inoculum reservoir for strawberry infection between seasons. Although C. acutatum survives in soil under certain conditions, no specific resting structures have been observed indicating that the pathogen does not behave as a typical soilborne fungus.

scholarly journals Natamycin, a New Biofungicide for Managing Crown Rot of Strawberry Caused by QoI-Resistant Colletotrichum acutatum

Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1687-1695 ◽  
Author(s):  
Stacey E. Haack ◽  
Kelly L. Ivors ◽  
Gerald J. Holmes ◽  
Helga Förster ◽  
James E. Adaskaveg
Keyword(s):  
Field Studies ◽  
The United States ◽  
Pathogen Resistance ◽  
Fruit Production ◽  
Crown Rot ◽  
Colletotrichum Acutatum ◽  
Quinone Outside Inhibitor ◽  
Industry Standards ◽  
Important Disease ◽  
Qoi Resistance

Anthracnose crown rot of strawberry, caused by Colletotrichum acutatum, is an important disease affecting California nursery and fruit production. Preplant dip treatments of transplants with fludioxonil-cyprodinil or azoxystrobin are industry standards for managing the disease and have been used extensively. Following reports of reduced efficacy of azoxystrobin in the field, high levels of quinone outside inhibitor (QoI) resistance were detected in California isolates of the pathogen. Resistance was associated with the G143A mutation in the cytochrome b gene, similar to a previous report from Florida, and there were no detected fitness penalties in pathogenicity or virulence. Therefore, several alternative fungicides were investigated in laboratory and field studies. Subsequently, the new biofungicide natamycin was identified. Baseline sensitivities of 74 isolates of C. acutatum to natamycin were determined to be unimodal, with a range from 0.526 to 1.996 μg/ml (mean 0.973 μg/ml). Although this toxicity was considerably lower than that of azoxystrobin (using sensitive isolates), fludioxonil, or cyprodinil, dip treatments of transplants with natamycin (at 500 or 1000 mg/liter) were highly effective. Disease severity and plant mortality in field studies with inoculated transplants were reduced to similarly low levels as treatments containing fludioxonil, whereas azoxystrobin failed in inoculations with QoI-resistant isolates of C. acutatum. Fruit yield was also significantly increased by natamycin as compared with the inoculated control. Differences in disease susceptibility were observed among cultivars evaluated, with Monterey and Portola more susceptible than Fronteras. Natamycin has a unique mode of action that is different from other fungicides registered on strawberry and, based on this research, was registered in the United States as a preplant, biofungicide dip treatment of strawberry transplants for management of anthracnose crown rot.

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