scholarly journals Characterization, Virulence, Epidemiology, and Management of Anthracnose in Celery

Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1832-1840 ◽  
Author(s):  
Lina M. Rodriguez-Salamanca ◽  
Lina M. Quesada-Ocampo ◽  
Rachel P. Naegele ◽  
Mary K. Hausbeck
Keyword(s):  
Disease Incidence ◽  
Field Studies ◽  
Crop Damage ◽  
Apium Graveolens ◽  
Colletotrichum Acutatum ◽  
Banding Patterns ◽  
Growing Seasons ◽  
Colletotrichum Acutatum Species Complex ◽  
Species Specific ◽  
Disease Pressure

Leaf curling and petiole twisting of celery (Apium graveolens) were observed in several commercial fields in five Michigan counties in 2010 through 2012, causing significant crop damage and loss. Prior to this time, the pathogen Colletotrichum acutatum species complex had not been previously associated with celery in Michigan. In this study, the pathogen’s genotype and phenotype were characterized, the influence of environmental conditions determined, and fungicides tested. Pathogen identification was based on conidial morphology and molecular identification using species-specific primers. Intersimple-sequence repeat (ISSR) banding patterns were similar between C. acutatum isolates from celery (n = 51) and blueberry (n = 1) but different from C. dematium and C. gloeosporioides. Four ISSR primers resulted in 4% polymorphism when tested on isolates from celery. Pathogenicity and virulence of C. acutatum sensu lato isolated from celery (n = 81), tomato (n = 2), and blueberry (n = 1) were evaluated in greenhouse experiments, which revealed differences in virulence among isolates but no significant differences specific to collection year, county, or field. In dew chambers and growth chambers, high temperatures (≥25°C) or long leaf wetness duration (>24 h) increased disease incidence. Twelve fungicides were tested in field studies over two growing seasons to determine their efficacy against celery anthracnose. The fungicides azoxystrobin, pyraclostrobin, mancozeb, and chlorothalonil reduced disease by 27 to 50% compared with the untreated control when disease pressure was moderate.

scholarly journals Management of Severe Curly Top in Sugar Beet with Insecticides

Plant Disease ◽  
2012 ◽  
Vol 96 (8) ◽  
pp. 1159-1164 ◽  
Author(s):  
Carl A. Strausbaugh ◽  
Erik J. Wenninger ◽  
Imad A. Eujayl
Keyword(s):  
Sugar Beet ◽  
Insect Pest ◽  
Severe Disease ◽  
Field Studies ◽  
Seed Treatments ◽  
Growing Seasons ◽  
Moderate Disease ◽  
Untreated Check ◽  
Commercial Sugar ◽  
Disease Pressure

Curly top, caused by Curtovirus spp., is a widespread disease problem vectored by the beet leafhopper in semiarid sugar beet production areas. The insecticide seed treatment Poncho Beta has proven to be effective in controlling curly top in sugar beet but was only evaluated under light to moderate disease pressure. Thus, the insecticide seed treatments Poncho Beta, NipsIt INSIDE, and Cruiser Force were evaluated under severe curly top pressure (six viruliferous beet leafhoppers per plant) in field studies during the 2010 and 2011 growing seasons on two commercial sugar beet cultivars. In addition, the foliar insecticides Movento, Provado, and Scorpion were also evaluated. The seed treatments and Scorpion reduced curly top symptoms by 33 to 41% (P < 0.0001) and increased root yield by 55 to 95% (P < 0.0001), sucrose content by 6.5 to 7.2% (P = 0.0013 to <0.0001), and estimated recoverable sucrose by 58 to 96% (P < 0.0001) when compared with the untreated check. Movento and Provado did not improve control beyond that provided by Poncho Beta. Even under severe disease pressure 50 to 55 days after planting, neonicotinoid seed treatments can effectively reduce curly top, increase yield, and help protect against early-season insect pest pressure.

scholarly journals Effect of Fungicide Applications on Grain Sorghum (Sorghum bicolor L.) Growth and Yield

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Dan D. Fromme ◽  
Trey Price ◽  
Josh Lofton ◽  
Tom Isakeit ◽  
Ronnie Schnell ◽  
...  
Keyword(s):  
Gulf Coast ◽  
Field Studies ◽  
Grain Sorghum ◽  
Test Weight ◽  
Growth And Yield ◽  
Texas Gulf Coast ◽  
Growing Seasons ◽  
Weight Yield ◽  
Percent Protein ◽  
Disease Pressure

Field studies were conducted in the upper Texas Gulf Coast and in central Louisiana during the 2013 through 2015 growing seasons to evaluate the effects of fungicides on grain sorghum growth and development when disease pressure was low or nonexistent. Azoxystrobin and flutriafol at 1.0 L/ha and pyraclostrobin at 0.78 L/ha were applied to the plants of two grain sorghum hybrids (DKS 54-00, DKS 53-67) at 25% bloom and compared with the nontreated check for leaf chlorophyll content, leaf temperature, and plant lodging during the growing season as well as grain mold, test weight, yield, and nitrogen and protein content of the harvested grain. The application of a fungicide had no effect on any of the variables tested with grain sorghum hybrid responses noted. DKS 53-67 produced higher yield, greater test weight, higher percent protein, and N than DKS 54-00. Results of this study indicate that the application of a fungicide when little or no disease is present does not promote overall plant health or increase yield.

scholarly journals First Report of Bitter Rot Caused by Colletotrichum acutatum on Apple in China

Plant Disease ◽  
2008 ◽  
Vol 92 (10) ◽  
pp. 1474-1474 ◽  
Author(s):  
R. Zhang ◽  
S. F. Wang ◽  
J. Q. Cui ◽  
G. Y. Sun ◽  
M. L. Gleason
Keyword(s):  
Apple Fruit ◽  
Crop Damage ◽  
Shaanxi Province ◽  
Colletotrichum Acutatum ◽  
Commonwealth Mycological Institute ◽  
High Humidity ◽  
First Report ◽  
Bitter Rot ◽  
Plastic Bag ◽  
Species Specific

Bitter rot of apple caused by Colletotrichum gloeosporioides was first reported in China in 1985 (3). In China, apples are grown on approximately 2 million ha, and bitter rot occurs in almost all production areas, with crop damage ranging from 30 to 70%. During the summer of 2007, fungi were isolated from apple fruit exhibiting bitter rot symptoms in 12 and 9 orchards in Shaanxi and Henan provinces, respectively, in China. Symptoms included 2- to 3-cm-diameter, sunken, brown lesions on the fruit surface that contained black, pinhead-size fruiting structures producing orange conidial masses under high humidity, similar to that of C. gloeosporioides. On potato dextrose agar (PDA), colonies were white, pale gray, or pale orange when grown at 25°C. Conidia were 8 to 16 × 2.5 to 4 μm, fusiform, pointed at one or both ends, one celled, thin walled, aseptate, and hyaline. Appressoria were 6.5 to 11 × 4.5 to 7.5 μm, clavate to circular, and light to dark brown. These characteristics matched published descriptions of C. acutatum (2). To confirm pathogenicity, three mature, healthy apples (cv. Fuji) were surface disinfested with 70% ethanol and then wounded with a sterile needle. After being inoculated with a spore suspension (1 × 105 conidia/ml) prepared from a 2-week-old culture on PDA, these apples were sealed in a plastic bag and incubated at 25°C. Symptoms appeared 3 to 5 days after inoculation and began to enlarge 7 days later, forming lesions with fruiting structures. Under high humidity, cream-to-salmon pink spore masses were produced on lesions. As the lesions enlarged, the rot progressed to the core of the fruit in a V-shaped pattern. When the pathogen was reisolated from lesions of inoculated fruit onto PDA and incubated at 25°C, colony and conidial morphology were identical to those of the original isolates. Tests were performed three times with similar results. PCR with species-specific primer pair CaInt2/ITS4 (1) of genomic DNA from the isolates resulted in an amplification product of approximately 490 bp, which is specific for C. acutatum. The sequences exhibited 99% similarity with those of C. acutatum isolates AB273195 from GenBank. Approximately 20 of 103 symptomatic fruit from the field survey yielded fungal cultures whose morphology was consistent with that of C. acutatum, whereas the other cultures were C. gloeosporioides and Botryosphaeria dothidea. To our knowledge, this is the first report of bitter rot of apple caused by Colletotrichum acutatum in China. References: (1) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996. (2) B. C. Sutton. Page 523 in: The Coelomycetes. Commonwealth Mycological Institute, Kew, Surrey, England, 1980. (3) X. M. Wang. M.S. thesis. (In Chinese). College of Northwest Agriculture, Shaanxi Province, China, 1985.

scholarly journals Improving Yields and Managing Dry Bean Bacterial Diseases in Nebraska with New Copper-Alternative Chemicals

2019 ◽  
Vol 20 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Robert M. Harveson
Keyword(s):  
Production Systems ◽  
Disease Incidence ◽  
Field Studies ◽  
Brown Spot ◽  
Effective Control ◽  
Dry Bean ◽  
Bacterial Diseases ◽  
Halo Blight ◽  
Time Period ◽  
Disease Pressure

Bacterial diseases, common blight, halo blight, brown spot, and wilt are major constraints to the production of dry edible beans in western Nebraska. Owing to a lack of effective control options, these diseases have been difficult to properly manage. Cultivars with partial disease resistance are available for some diseases, but not for all. Furthermore, few chemical products are accessible other than copper-based products, which have proven to be erratic in efficacy, depending on variables such as pathogen involved, disease pressure, and environmental conditions. Therefore, field studies were conducted in western Nebraska for 7 years (13 site years) evaluating newly emerging copper-alternative chemicals for managing these diseases in dry beans. Over this time period, five different products were tested for at least 2 years each and were compared with two commercially available copper compounds (Kocide and MasterCop). The new alternatives included two growth-promoting chemicals (ecoAgra A300, WakeUP Summer), and three contact sanitizers (Goldshield 5, SaniDate, and OxiDate). Treatments with SaniDate and ecoAgra A300 more consistently produced higher yields than other treatments, while not reducing disease incidence. These improvements were achieved primarily under high levels of disease, providing promise for use in production systems in western Nebraska.

scholarly journals Soybean (Glycine maxL.) Response to Fungicides in the Absence of Disease Pressure

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
W. James Grichar
Keyword(s):  
Gulf Coast ◽  
Field Studies ◽  
Yield Response ◽  
Disease Development ◽  
Growing Seasons ◽  
Dry Conditions ◽  
Disease Pressure ◽  
Gulf Coast Region ◽  
Soybean Diseases ◽  
Coast Region

Field studies were conducted during the 2010 and 2011 growing seasons along the Texas Upper Gulf Coast region to study the effects of fungicides on soybean disease development and to evaluate the response of four soybean cultivars to prothioconazole plus trifloxystrobin and pyraclostrobin. In neither year did any soybean diseases develop enough to be an issue. Only NKS 51-T8 responded to a fungicide treatment in 2010 while HBK 5025 responded in 2011. Prothioconazole plus trifloxystrobin increased NKS 51-T8 yield by 23% in 2010 while in 2011 the yield of HBK 5025 was increased 14% over the unsprayed check. No yield response was noted with pyraclostrobin on any soybean cultivar. Only prothioconazole + trifloxystrobin applied to either NKS 51-T8 or DP5335 in 2010 resulted in a net increase in dollars per hectare over the unsprayed check of the respective cultivar. In 2011, under extremely dry conditions, all fungicides with the exception of prothioconazole + trifloxystrobin applied to HBK 5025 resulted in a net decrease in returns over the unsprayed check.

scholarly journals Evaluation of New High Oleic Virginia-Type Peanut Cultivars for Disease Tolerance, Yield, and Quality

2017 ◽  
Vol 44 (2) ◽  
pp. 100-110 ◽  
Author(s):  
H.L. Mehl
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
High Yield ◽  
Disease Tolerance ◽  
High Oleic ◽  
Growing Seasons ◽  
Yield And Quality ◽  
Sclerotinia Blight ◽  
Peanut Cultivars ◽  
Disease Pressure

ABSTRACT As new cultivars are developed and released by peanut breeding programs, their levels of tolerance to common diseases and the overall profitability of production needs to be determined. Virginia-type peanut cultivars were evaluated for disease resistance/tolerance, yield, and quality when grown under different fungicide programs and in locations varying in disease pressure. Cultivars included a disease susceptible (CHAMPS) and tolerant (Bailey) cultivar and two new high-oleic cultivars, Sullivan and Wynne. Fungicide programs consisted of a leaf spot program, a leaf spot plus Cylindrocladium black rot (CBR) program, a leaf spot plus Sclerotinia blight program, or an untreated check. Cultivars and fungicide programs were arranged in a randomized split-plot design with fungicide treatments in 16-row main plots and cultivars in 4-row subplots. Disease incidence and severity varied among growing seasons and the five fields where experiments were conducted. Overall, Sullivan had good leaf spot tolerance and both Sullivan and Bailey had Sclerotinia and CBR tolerance. All cultivars yielded well in the absence of disease pressure, but Sullivan was consistently the highest yielding cultivar. Grade characteristics varied among cultivars, but while fungicide treatments impacted yield, they had little effect on grade. Net value and profitability of different fungicide programs varied by experiment, but overall Sullivan had the highest net value regardless of fungicide program. Due to slightly higher disease tolerance compared to Bailey, good agronomic characteristics, high yield and quality under a variety of growing environments, and the presence of the high-oleic trait, Sullivan is an excellent cultivar for Virginia-type peanut production in the Virginia-Carolina region.

Duplex DNA barcoding allows accurate species determination of morphologically similar limpets (Patella spp.) from non-destructive sampling

2016 ◽  
Vol 97 (7) ◽  
pp. 1479-1482 ◽  
Author(s):  
Thomas J. Ashton ◽  
Meriem Kayoueche-Reeve ◽  
Andrew J. Blight ◽  
Jon Moore ◽  
David M. Paterson
Keyword(s):  
Dna Barcoding ◽  
Species Abundance ◽  
Microscopic Analysis ◽  
Cost Effective ◽  
Field Studies ◽  
Similar Species ◽  
Species Determination ◽  
Destructive Sampling ◽  
Species Specific ◽  
Non Destructive

Accurate discrimination of two morphologically similar species of Patella limpets has been facilitated by using qPCR amplification of species-specific mitochondrial genomic regions. Cost-effective and non-destructive sampling is achieved using a mucus swab and simple sample lysis and dilution to create a PCR template. Results show 100% concurrence with dissection and microscopic analysis, and the technique has been employed successfully in field studies. The use of highly sensitive DNA barcoding techniques such as this hold great potential for improving previously challenging field assessments of species abundance.

Response of wildlife to forest herbicide applications in northern coniferous ecosystems

1993 ◽  
Vol 23 (10) ◽  
pp. 2286-2299 ◽  
Author(s):  
R.A. Lautenschlager
Keyword(s):  
Small Mammal ◽  
Growing Season ◽  
Sampling Techniques ◽  
Mammal Species ◽  
Growing Seasons ◽  
Disturbed Areas ◽  
Herbicide Treatments ◽  
Species Specific ◽  
Small Mammal Species ◽  
Coniferous Ecosystems

Reviewed studies of the effects of forest herbicide applications on wildlife often lacked replication, pretreatment information, and (or) were conducted for only one or two growing seasons after treatment. Because of these problems, as well as the use of dissimilar sampling techniques, study conclusions have sometimes been contradictory. A review of eight studies of the effects of herbicide treatments on northern songbird populations in regenerating clearcuts indicates that total songbird populations are seldom reduced during the growing season after treatment. Densities of species that use early successional brushy, deciduous cover are sometimes reduced, while densities of species which commonly use more open areas, sometimes increase. A review of 14 studies of the effects of herbicide treatments on small mammals indicates that like songbirds, small mammal responses are species specific. Some species are unaffected, while some select and others avoid herbicide-treated areas. Only studies that use kill or removal trapping to study small mammal responses show density reductions associated with herbicide treatment. It seems that some small mammal species may be reluctant to venture into disturbed areas, although residents in those areas are apparently not affected by the disturbance. Fourteen relevant studies examined the effects of conifer release treatments on moose and deer foods and habitat use. Conifer release treatments reduce the availability of moose browse for as long as four growing seasons after treatment. The degree of reduction during the growing season after treatment varies with the herbicide and rate used. Deer use of treated areas remains unchanged or increases during the first growing season after treatment. Eight years after treating a naturally regenerated spruce–fir stand browse was three to seven times more abundant on treated than on control plots (depending on the chemical and rate used). Forage quality (nitrogen, ash, and moisture) of crop trees increased one growing season after the soil-active herbicide simazine was applied to control competition around outplanted 3-year-old balsam fir seedlings.

scholarly journals Effects of Rootstock and Budding Height on Bacterial Canker in French Prune

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 543-546 ◽  
Author(s):  
R. J. Sayler ◽  
S. M. Southwick ◽  
J. T. Yeager ◽  
K. Glozer ◽  
E. L. Little ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Prunus Persica ◽  
Disease Incidence ◽  
Fruit Trees ◽  
Field Trials ◽  
Bacterial Canker ◽  
Prunus Domestica ◽  
Severity Of Disease ◽  
Prunus Cerasifera ◽  
Disease Pressure

Bacterial canker is one of the most economically important diseases of stone fruit trees, including ‘French’ prune (Prunus domestica). Field trials were conducted to evaluate the effect of rootstock selection and budding height on the incidence and severity of bacterial canker in four orchards with low to high disease pressure. Treatments included French prune scions low-grafted on ‘Lovell’ peach (Prunus persica) rootstocks as well as Myrobalan 29C (Prunus cerasifera) plum rootstocks grafted at 15, 50, and 90 cm above the rootstock crown. Another treatment consisted of growing Myrobalan 29C plum rootstocks in the field for one growing season, then field-grafting French prune buds onto rootstock scaffolds. Lovell peach rootstock provided the greatest protection from bacterial canker as measured by disease incidence and tree mortality in all orchards. Field-budded rootstocks and rootstocks grafted at the highest budding height provided moderate levels of resistance to bacterial canker. These treatments reduced the incidence but not the severity of disease.

scholarly journals Managing Bees for Delivering Biological Control Agents and Improved Pollination in Berry and Fruit Cultivation

2015 ◽  
Vol 4 (3) ◽  
pp. 89 ◽  
Author(s):  
Heikki M. T. Hokkanen ◽  
Ingeborg Menzler-Hokkanen ◽  
Marja-Leena Lahdenpera
Keyword(s):  
Crop Protection ◽  
Field Tests ◽  
Weather Conditions ◽  
Field Studies ◽  
Field Trials ◽  
Marketable Yield ◽  
Dissemination Activity ◽  
Grey Mold ◽  
Commercial Farms ◽  
Disease Pressure

<p>Targeted precision biocontrol and improved pollination were studied Europe-wide in the EU ERA-NET CORE ORGANIC 2 project BICOPOLL (Biocontrol and Pollination). A case study was conducted on the management of strawberry grey mold <em>Botrytis cinerea</em>, with the biocontrol fungus, <em>Gliocladium catenulatum</em>, vectored by honey bees or bumble bees. A joint field trial carried out in five countries targeted strawberry cultivations in open field, and included four treatments: untreated control, chemical fungicide, entomovectored biocontrol, and chemical and biocontrol combined. In organic fields, no pesticide treatments were included. The proportion of moldy berries, and/or the marketable yield of healthy berries were recorded from each treatment, along with other parameters of local interest. A pilot study was started in Finland in 2006, and, by 2012, large commercial farms were using entomovectoring. In 2012, field trials were started in Estonia and in Italy, and in 2013-14, these experiments were expanded to Slovenia and Turkey. In total, 26 field tests were conducted using entomovectoring and <em>Gliocladium catenulatum</em> (Prestop<sup>®</sup> Mix) on strawberry, with five additional trials on raspberry. Efficacy results have been excellent throughout the field studies. The results show crop protection equalling or exceeding that provided by a full chemical fungicide program, under all weather conditions, and over a wide geographical range (from Finland to Turkey). Under heavy disease pressure, entomovectoring provided on average a 47% disease reduction, which was the same as multiple fungicide sprays. Under light disease pressure, biocontrol decreased grey mold by an average of 66%, which was greater than fungicide sprays. The concept has proven to be effective on strawberries, raspberries, pears, apples, blueberries, cherries, and grapes. A conservative estimate for Finland is that over 500 ha of strawberry cultivation currently use the technique (≈15% of the strawberry growing area). To make full use of the entomovectoring technique, organic berry and fruit growers are encouraged to (i) keep bees, or to hire the service from local beekeepers for entomovectoring; and (ii) manage vegetation within and around the target crop to support the activity of bees and other pollinators, which can help to disseminate the beneficial microbial populations within the crop. Beekeepers are encouraged to (i) market pollination and biocontrol services to fruit and berry growers, and (ii) ensure that all operations are effective in mananging bees and their microbe dissemination activity. Biocontrol product manufacturers are encouraged to further develop products and their formulations specifically for entomovectoring, because current formulations are suboptimal as they are initially optimized for other uses (e.g., mixing into the soil).</p>

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