scholarly journals Prohexadione-calcium on downy mildew and botrytis bunch rot epidemiology, and yield and technological and phenolic parameters of the Merlot vine cultivar in the highland region of southern Brazil

2021 ◽  
Vol 51 (7) ◽  
Author(s):  
Juliana Reinehr ◽  
Amauri Bogo ◽  
Leo Rufato ◽  
Ricardo Trezzi Casa ◽  
Fabio Nascimento Silva ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Disease Incidence ◽  
Gibberellin Biosynthesis ◽  
Southern Brazil ◽  
Highland Region ◽  
Growing Seasons ◽  
Full Flowering ◽  
Significant Difference ◽  
Bunch Rot ◽  
Prohexadione Calcium

ABSTRACT: Prohexadione-calcium (ProCa) is a gibberellin biosynthesis inhibitor and the objective of this study was to evaluate the effect of ProCa on the downy mildew (DM) and Botrytis bunch rot (BBR) epidemiology, and the yield and technological and phenolic parameters of grape Merlot cultivar. Experiments were carried out in a commercial vineyard in São Joaquim Municipality/SC, Southern Brazil, during the 2017-2018 and 2018-2019 growing seasons. ProCa was applied at four doses and three phenological stages: A) 0 g ha−1 (control); B) 1000 g ha−1 (inflorescence fully developed); C) 500 + 500 g ha−1 (inflorescence fully developeted and full flowering); D) 500 + 500 + 500 g ha−1 (inflorescence fully developed, full flowering, and berries pea-sized). DM and BBR incidence and severity were quantified weekly from the first symptom appearance until harvest, and their epidemiology was compared according to: a) the beginning of symptom appearance; b) the time to reach the maximum disease incidence and severity; c) the maximum value of disease incidence and severity; d) the area under the disease progress curve. In general, there were significant differences in the ProCa doses for all epidemiologic parameters of DM and BBR compared with the control plot; however, there was no significant difference among the ProCa doses. The principal epidemiological variables that differentiated the effect of ProCa on the DM and BBR control were the Smax and AUSDPC. Some yield and technological and phenolic parameters were negatively affected by different doses of ProCa, but it was still a good option for DM and BBR control in highland region of southern Brazil during the 2017-2018 and 2018-2019 growing seasons.

scholarly journals Occurrence and intensity of more important fungal diseases on soybean (Glycine max (L.) Merrill) cultivars

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 590-592
Author(s):  
T. Duvnjak ◽  
M. Vrataric ◽  
A. Sudaric ◽  
J. Cosic
Keyword(s):  
Genetic Diversity ◽  
Downy Mildew ◽  
Disease Incidence ◽  
Stem Canker ◽  
Climatic Conditions ◽  
Planting Date ◽  
Fungal Diseases ◽  
Stem Blight ◽  
Growing Seasons ◽  
Glycine Max L

The main objective of this study was to determinate the occurrence and intensity of attack by the more important fungal diseases on soybean in Eastern Croatia. Four-year investigation (1998–2001) was undertaken on 10 domestic soybean cultivars with different level of disease resistance. The investigation was set in two planting date (optimal and delayed) on experimental fields of the Agricultural Institute Osijek. Following more important diseases were established: Downy mildew, Pod and stem blight and Stem canker. Significant differences in disease incidence were caused by genetic diversity of tested materials as well as different climatic conditions among growing seasons. According to planting date, significantly higher incidence of Downy mildew and Pod and stem blight was in optimal planting date.

Response of PIWI grapevine cultivars to downy mildew in highland region of southern Brazil

2019 ◽  
Vol 154 (4) ◽  
pp. 1051-1058 ◽  
Author(s):  
Jean A. Zanghelini ◽  
Amauri Bogo ◽  
Lirio L. Dal Vesco ◽  
Beatriz R. Gomes ◽  
Cristian V. Mecabô ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Southern Brazil ◽  
Highland Region

scholarly journals Critical yield-point model to estimate damage caused by brown spot and powdery mildew in barley

2014 ◽  
Vol 44 (6) ◽  
pp. 957-963 ◽  
Author(s):  
Lenita Agostinetto ◽  
Ricardo Trezzi Casa ◽  
Amauri Bogo ◽  
Cristiano Sachs ◽  
Erlei Melo Reis ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Grain Yield ◽  
Disease Incidence ◽  
Block Design ◽  
Damage Threshold ◽  
Brown Spot ◽  
Economic Damage ◽  
Growth Stages ◽  
Southern Brazil ◽  
Growing Seasons

Barley (Hordeum vulgaris L.) is the second most important winter crop in Southern Brazil. The excessive rainfall in this region during the crop-growing season increases the frequency and intensity of foliar fungal diseases. The research aimed to determine the damage function equations (DFE) for the multiple pathosystem of barley brown spot and powdery mildew based on the relationship between grain yield and diseases intensity at different 'BRS Cauê' cultivar growth stages (GS) during 2009 and 2010 growing seasons in Southern Brazil. The experiments were arranged in a randomized complete block design with nine treatments and four replicates. The disease gradients were generated by strobilurins and triazols fungicides rates and number of applications on barley cv. Cauê. The fungicide applications and disease incidence and severity assessments were performed at the 22, 31, 39, 45 and 56 plant GS. The DFE were obtained by variance analysis and linear regression between grain yield and diseases intensity. Significant and negative DFE were obtained and the damage coefficients (DC) varied from 29.48 to 100.08 (2009) and from 36.08 to 113.57kg ha-1 (2010) for incidence, and from 219.5 to 6,276.6 (2009) and 102.3 to 5,292.5kg ha-1 (2010) for severity. The largest damage coefficients were obtained when diseases assessments were made on GS 22 and 31 on both growing seasons evaluated. DFE were used to calculate the economic damage threshold (EDT) as a criterion to indicate the fungicide application moment to control the diseases in cultivars similar to 'BRS Cauê' in Southern Brazil.

scholarly journals Effect of Y-trellis and vertical shoot positioning training systems on downy mildew and botrytis bunch rot of grape in highlands of southern Brazil

2015 ◽  
Vol 185 ◽  
pp. 162-166 ◽  
Author(s):  
Betina Pereira de Bem ◽  
Amauri Bogo ◽  
Sydney Everhart ◽  
Ricardo Trezzi Casa ◽  
Mayra Juline Gonçalves ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Southern Brazil ◽  
Training Systems ◽  
Bunch Rot

scholarly journals Behavior of Vine Varieties Resistant to Fungal Diseases in the Somontano Region

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 738
Author(s):  
José Casanova-Gascón ◽  
Carla Ferrer-Martín ◽  
Antonio Bernad-Eustaquio ◽  
Andrea Elbaile-Mur ◽  
José M. Ayuso-Rodríguez ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Downy Mildew ◽  
Principal Component ◽  
Climatic Conditions ◽  
Fungal Diseases ◽  
Real Field ◽  
Sauvignon Blanc ◽  
Growing Seasons ◽  
Resistant Varieties ◽  
Bunch Rot

The vine is highly susceptible to numerous fungal diseases, the incidence and severity of which are increasing because of climate change. To fight them, large amounts of phytosanitary products are generally used, although they entail important economic and environmental costs. The new fungus resistant vine varieties (PIWI) constitute one of the most active lines of research on plant material in viticulture and are regarded as a viable solution to respond to the requirements of European Directive 2009/128/EC. In the present work, the evolution and impact of the three main fungal diseases (powdery mildew, downy mildew and botrytis bunch rot) were monitored in plots in the Somontano region (Huesca, Spain), comparing three PIWI varieties (Sauvignon Kretos, Souvignier gris and Muscaris) with a susceptible control variety (Sauvignon blanc) in real field growing conditions over three successive years (2016–2018). The main ampelographic characters of each variety were studied and a weekly follow-up was carried out to track the development of each disease, relating it to climatic variables. Regardless of the climatic conditions (one of the growing seasons was rainy and the other two corresponded to dry years, with differences in the distribution of rainfall), the three PIWI varieties hardly presented any symptoms, demonstrating a high resistance to downy mildew and powdery mildew and even to botrytis. Principal component analysis results pointed to a differential behavior versus the control and treated Sauvignon blanc plants in terms of disease resistance. Based on production results, despite the youth of the plantation, the excellent potential of Sauvignon Kretos variety was observed. However, from the analysis of the quality of wine obtained in microvinifications from these fungus resistant varieties in the second and third year, the one obtained from Muscaris seemed to have the best organoleptic properties. Apart from environmental considerations, given that these fungus resistant varieties can significantly contribute to the sustainability of wineries, they may also respond to the demand of consumers who want zero-pesticide products or of the supporters of ecological products adjusted to European regulations.

scholarly journals Identification of Maize Downy Mildew Pathogen in Lampung and the Effects of Varieties and Metalaxyl on Disease Incidence

2020 ◽  
pp. 23-35
Author(s):  
Cipta Ginting ◽  
Joko Prasetyo ◽  
Suskandini Ratih Dirmawati ◽  
. Ivayani ◽  
Paul Benyamin Timotiwu ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Seed Treatment ◽  
Disease Incidence ◽  
Molecular Techniques ◽  
Natural Conditions ◽  
Peronosclerospora Sorghi ◽  
Maize Varieties ◽  
Significant Difference ◽  
Test Plants ◽  
Scanning Electron

Introduction: Maize downy mildew (MDM) is considered as a major problem in all maize growing areas in Indonesia including the Province of Lampung. Objectives: The objectives of this study were (i) to identify the species of Peronosclerospora causing maize downy mildew (MDM) in Lampung, (ii) to determine the influence of varieties on the intensity of downy mildew and (iii) to determine the efficacy of metalaxyl to control MDM on some maize varieties. Methodology: To identify Peronosclerospora causing MDM, the pathogens were observed under light microscope and scanning electron microscope. Maize varieties response against pathogens and efficacy metalaxyl were studied in the field with the test plants exposed to plants showing MDM symptoms as the sources of inocula to mimic natural conditions. Results: Peronosclerospora sorghi, P. maydis, and P. philippinensis were found to cause MDM in Lampung. On both varieties Pioneer 27 (P-27) and NK-22, AUDPC on F1 plants was greater than that on F2 plants. On P-27, the production of F2 was higher than that of F1 plants, but there was not significant difference in production between F1 and F2 of NK-22 variety. Seed treatment using metalaxyl was not effective to control downy mildew of maize. Conclusion: Three species of Peronosclerospora were identified as disease-causing pathogen of MDM in Lampung, but these results were tentatively pending for further studies through molecular techniques. F1 plants were more susceptible than F2 plants to MDM in both P-27 and NK-22. Metalaxyl was not effective in controlling MDM.

Avaliação da Eficácia da Administração de Dexametasona ou Metilprednisolona para Produzir Osteoporose em Ratas/ Evaluating the Effectiveness of Dexamethasone or Methylprednisolone to Produce Osteoporosis in Rats

2011 ◽  
Vol 1 (1) ◽  
pp. 22
Author(s):  
Nilo César do Vale Baracho ◽  
Alexandre Mata de Paula ◽  
Roberto Franzini Junior ◽  
Rogério Mariotto Bitetti da Silva ◽  
Bruno Appolari ◽  
...  
Keyword(s):  
Bone Mass ◽  
Disease Incidence ◽  
Public Health Problem ◽  
Bone Thickness ◽  
Good Marker ◽  
Significant Difference ◽  
Group Control ◽  
Successful Induction ◽  
Calcium Phosphorus ◽  
De Medicina

Introdução: A osteoporose é considerada um grave problema de saúde pública em todo o mundo. No Brasil ainda não há dados estatísticos sobre a real incidência desta doença. Os glicocorticóides representam uma classe de drogas muito usada, sendo que podem influenciar significativamente a massa óssea. Entretanto, após tratamento com glicocorticóides em ratos, esses podem ou não apresentar alterações na massa óssea. Objetivo: Avaliar a eficácia da administração de dexametasona ou metilprednisolona em produzir osteoporose em ratas. Métodos: Vinte e quatro ratas, oriundas do biotério da Faculdade de Medicina de Itajubá, foram utilizadas e divididas em três grupos: controle, metilprednisolona e dexametasona. Foram avaliados íons e proteínas totais sanguíneos e feita a análise histopatológica de tecido ósseo. Resultados e conclusão: Pela análise histológica da espessura trabecular óssea, houve redução da massa óssea dos grupos tratados com glicocorticóides em comparação com o grupo controle, evidenciando o sucesso da indução de osteoporose. Além disso, houve uma maior redução da massa óssea no grupo tratado com dexametasona, em comparação com o grupo tratado com metilprednisolona. A análise bioquímica de cálcio, fósforo, magnésio e proteínas totais não sofreram diferença significativa entres os grupos, não sendo um bom marcador para remodelamento ósseo e para diagnóstico de osteoporose.Evaluating the Effectiveness of Dexamethasone or Methylprednisolone to Produce Osteoporosis in RatsIntroduction: Osteoporosis is considered a serious public health problem in worldwide. In Brazil we do not have statistics on the real disease incidence. Glucocorticoids are a class of drugs widely used, and can significantly influence bone mass. However, after treatment with glucocorticoids in rats, these may or may not show changes in bone mass. Objective: Evaluating the effectiveness of dexamethasone or methylprednisolone to produce osteoporosis in rats. Methods: Twenty-four rats, originated from the vivarium of the Faculty of Medicine Itajubá were used and divided into three groups: control, methylprednisolone and dexamethasone. Ions was evaluated blood and histopathology of bone tissue. Results and conclusion: by histologic analysis of trabecular bone thickness, a reduction of the mass bone in the groups treated with glucocorticoids compared with the group control, demonstrating the successful induction of osteoporosis. Furthermore, there was a greater reduction in bone mass in the group treated with dexamethasone compared with the group treated with methylprednisolone. The analysis biochemistry of calcium, phosphorus, magnesium and total protein did not undergo significant difference among the groups, there is a good marker for bone remodeling and osteoporosis diagnosis.

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

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.

scholarly journals Effect of nitrogen fertilization on camelina seed yield, yield components, and downy mildew infection

2016 ◽  
Vol 96 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Yunfei* Jiang ◽  
Claude D. Caldwell
Keyword(s):  
Downy Mildew ◽  
Seed Yield ◽  
Yield Components ◽  
Disease Incidence ◽  
Block Design ◽  
Interactive Effect ◽  
Yield Potential ◽  
Eastern Canada ◽  
Set Up ◽  
N Rates

Camelina [Camelina sativa (L.) Crantz] has potential in aquaculture, livestock feed production, and the biofuel industry. It is necessary to determine the appropriate production technology for the newly introduced crop under different environmental conditions. The objective of this 2-year study was to measure the response of five camelina genotypes in terms of seed yield, yield components, and disease incidence to applied nitrogen (N) at multiple sites in the Maritime provinces of eastern Canada. The factorial experiment was set up as a randomized complete block design. The two factors were six N rates (0, 25, 50, 100, 150, and 200 kg ha−1 N) and five genotypes of camelina (Calena, CDI002, CDI005, CDI007, and CDI008). The interactive effect of N rates and genotypes was considered. Results showed that camelina, which is usually considered a low-input crop, responded positively to increased applied N at rates up to 200 kg ha−1 N. Seed yield responded differently to applied N rates depending on genotype. Branch and pod development were decisive for seed yield. The advanced line CDI007 had the highest yield potential among the five genotypes. Downy mildew infection was positively correlated with applied N rates; however, seed yield was not significantly affected by downy mildew infection.

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