An Attempt at Integrated Control of Cucumber Downy Mildew (Pseudoperonospora cubensis)

2001 ◽  
Vol 7 (2) ◽  
pp. 21-32 ◽  
Author(s):  
J. Robak
Keyword(s):  
Downy Mildew ◽  
Integrated Control ◽  
Pseudoperonospora Cubensis ◽  
Cucumber Downy Mildew

scholarly journals Effects of Temperature and Moisture on Sporulation and Infection by Pseudoperonospora cubensis

Plant Disease ◽  
2017 ◽  
Vol 101 (4) ◽  
pp. 562-567 ◽  
Author(s):  
Shiling Sun ◽  
Sen Lian ◽  
Shulian Feng ◽  
Xiangli Dong ◽  
Caixian Wang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Downy Mildew ◽  
Weibull Model ◽  
Infection Process ◽  
Effect Of Temperature ◽  
Effective Control ◽  
Pseudoperonospora Cubensis ◽  
Cucumber Downy Mildew ◽  
Effects Of Temperature ◽  
Modified Weibull

Cucumber downy mildew, caused by Pseudoperonospora cubensis, is a worldwide disease that causes severe damage to cucumber production. The effects of temperature and moisture on sporulation and infection by P. cubensis were investigated by inoculating cucumber (‘85F12’) cotyledons with sporangia and examining the sporangia produced on the inoculated cotyledons under artificially controlled environments. The result showed that the temperature required for sporangium infection by P. cubensis and sporulation of the downy mildew lesions occurred at 5 to 30°C. The optimal temperature estimated by the fitted model was 18.8°C for sporangium infection and 16.2°C for downy mildew lesion sporulation. The pathogen formed plenty of sporangia when disease cotyledons were wetted or in the environment with relative humidity = 100%. The downy mildew lesions produced only a few sporangia when placed in the environment with relative humidity = 90%. The inoculated cotyledons, which incubated for 5 days at about 20°C in a dry greenhouse, began to form sporangia 4 h after being wetted when incubated in darkness. The quantity of sporangia produced on the downy mildew lesions increased with extension of incubating period (within 12 h), and the relationship between produced sporangia and the incubation period at 15, 20, and 25°C can be described by three exponential models. The observed minimum wetness durations (MWD) required for sporangia to complete the infection process and cause downy mildew were 12, 4, 2.5, 1, 1, and 6 h for 5, 10, 15, 20, 25, and 30°C, respectively. The effect of temperature and wetness duration on infection by sporangia of P. cubensis can be described by the modified Weibull model. The shortest MWD was 0.45 h, about 27 min, estimated by model. The experimental data and models will be helpful in the development of forecasting models and effective control systems for cucumber downy mildew.

scholarly journals Effectiveness of Azoxystrobin in the Control of Erysiphe Cichoracearum and Pseudoperonospora Cubensis on Cucumber

2008 ◽  
Vol 48 (2) ◽  
pp. 147-159 ◽  
Author(s):  
Theerthagiri Anand ◽  
Angannan Chandrasekaran ◽  
Sasthamoorthy Kuttalam ◽  
Govindasamy Senthilraja ◽  
Thiruvengadam Raguchander ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Downy Mildew ◽  
Field Trial ◽  
Field Studies ◽  
Field Trials ◽  
Optimum Dose ◽  
Pseudoperonospora Cubensis ◽  
Erysiphe Cichoracearum ◽  
Cucumber Downy Mildew ◽  
Phytotoxic Effect

Effectiveness of Azoxystrobin in the Control ofErysiphe CichoracearumandPseudoperonospora Cubensison CucumberThe bioefficacy of azoxystrobin (Amistar 25 SC) was tested against cucumber downy mildew and powdery mildew diseases. The two season trials of field studies revealed that the disease progression of cucumber downy mildew and powdery mildew was successfully arrested by azoxystrobin. Spraying of azoxystrobin at various doses (31.25, 62.50 and 125g a.s./ha) revealed that 125 g a.s./ha (500 ml/ha) was considered as the optimum dose for the control of these diseases of cucumber. The treatment also recorded the highest yield of 13.23 and 14.46 tonnes/ha in the first and second season, respectively. No phytotoxic effect of azoxystrobin was observed in the both field trials even at four times of the recommended dose 125 g a.s./ha. The persistence of azoxystrobin at 250 and 500 g a.s./ha was observed up to seven days after last spraying. However, the persistence of azoxystrobin at 31.25, 62.50 and 125 a.s./ha was observed up to three to five days after last spraying. The safe waiting period for the harvest of cucumber fruits was 1.53 days in the first field trial and 2.37 days in the second field trial, respectively at azoxystrobin 125 g a.s./ha. The residues of azoxystrobin were at below detectable level (BDL) in the harvested cucumber fruits.

scholarly journals Relationships Between Airborne Pseudoperonospora cubensis Sporangia, Environmental Conditions, and Cucumber Downy Mildew Severity

Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 674-681 ◽  
Author(s):  
L. L. Granke ◽  
J. J. Morrice ◽  
M. K. Hausbeck
Keyword(s):  
Leaf Area ◽  
Downy Mildew ◽  
Disease Severity ◽  
Leaf Wetness ◽  
Pseudoperonospora Cubensis ◽  
Disease Occurrence ◽  
Benton Harbor ◽  
Cucumber Downy Mildew ◽  
High Disease Severity ◽  
Symptomatic Leaf

Airborne Pseudoperonospora cubensis sporangia were collected 0.5 m above the ground from May to late September or early October 2010 and 2011 in unsprayed cucumber (Cucumis sativus) fields in Benton Harbor and Frankenmuth, MI. Cucumber downy mildew incidence and severity were evaluated weekly within each field from June until September or October. The first airborne sporangium was detected before the crop was planted for each site-year. The greatest numbers of airborne sporangia were detected when moderate to high disease severity (≥5% symptomatic leaf area) was detected within the field. Fewer airborne sporangia were present with low disease severity (<5% symptomatic leaf area), and even fewer were detected prior to planting the cucumber crop. The number of airborne sporangia detected, time post planting, planting number (first versus second versus third planting), temperature, and leaf wetness were positively associated and solar radiation was negatively associated with disease occurrence for at least one site-year. Michigan growers currently use an aggressive, calendar-based fungicide program to manage cucumber downy mildew. Because airborne sporangium concentrations were one of the most important factors identified in this study, the current fungicide recommendation of decreasing the spray interval following disease detection in an area is warranted.

scholarly journals Susceptibility level of cucumber downy mildew (Pseudoperonospora cubensis) to metalaxyl

2009 ◽  
pp. 141-147 ◽  
Author(s):  
Ferenc Bagi ◽  
Ferenc Balaz ◽  
Vera Stojsin ◽  
Dragana Budakov ◽  
Tatjana Sokolovski ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Pseudoperonospora Cubensis ◽  
Cucumber Downy Mildew ◽  
Young Leaves ◽  
Cucumber Cultivar

Level of susceptibility of Pseudoperonospora cubensis isolate from Ratkovo to metalaxyl in concentrations 50, 100, 200, 400 and 800 ?g/ml was investigated. The trials were conducted on cotyledon and fully developed young leaves using cucumber cultivar Haros. Reduced level of susceptibility was detected in metalaxyl concentrations of 50, 100 and 200 ?g/ml because the intensity of sporulation in these treatments was on the same level as in control. Sporulation was also observed on developed leaves treated with metalaxyl in concentrations of 400 and 800 ?g/ml.

Efficacy of azoxystrobin for the control of cucumber downy mildew (Pseudoperonospora cubensis) and fungicide residue analysis

2014 ◽  
Vol 61 ◽  
pp. 74-78 ◽  
Author(s):  
Ferenc F. Bagi ◽  
Dragana B. Budakov ◽  
Vojislava P. Bursić ◽  
Vera B. Stojšin ◽  
Sanja D. Lazić ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Residue Analysis ◽  
Pseudoperonospora Cubensis ◽  
Cucumber Downy Mildew ◽  
Fungicide Residue

scholarly journals Polyethylene Mulch Modifies Greenhouse Microclimate and Reduces Infection of Phytophthora infestans in Tomato and Pseudoperonospora cubensis in Cucumber

2010 ◽  
Vol 100 (1) ◽  
pp. 97-104 ◽  
Author(s):  
D. Shtienberg ◽  
Y. Elad ◽  
M. Bornstein ◽  
G. Ziv ◽  
A. Grava ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Downy Mildew ◽  
Pseudoperonospora Cubensis ◽  
Control Efficacy ◽  
Cucumber Downy Mildew ◽  
To Come ◽  
The Individual ◽  
Substantial Control ◽  
Polyethylene Mulch

The individual and joint effects of covering the soil with polyethylene mulch before planting and fungicides commonly used by organic growers on tomato late blight (caused by Phytophthora infestans) were studied in three experiments conducted from 2002 to 2005. Application of fungicides resulted in inconsistent and insufficient late blight suppression (control efficacy ± standard error of 34.5 ± 14.3%) but the polyethylene mulch resulted in consistent, effective, and highly significant suppression (control efficacy of 83.6 ± 5.5%) of the disease. The combined effect of the two measures was additive. In a second set of three experiments carried out between 2004 and 2006, it was found that the type of polyethylene mulch used (bicolor aluminized, clear, or black) did not affect the efficacy of late blight suppression (control efficacy of 60.1 to 95.8%) and the differences in the effects among the different polyethylene mulches used were insignificant. Next, the ability of the mulch to suppress cucumber downy mildew (caused by Pseudoperonospora cubensis) was studied in four experiments carried out between 2006 and 2008. The mulch effectively suppressed cucumber downy mildew but the effect was less substantial (control efficacy of 34.9 ± 4.8%) than that achieved for tomato late blight. The disease-suppressing effect of mulch appeared to come from a reduction in leaf wetness duration, because mulching led to reductions in both the frequency of nights when dew formed and the number of dew hours per night when it formed. Mulching also reduced relative humidity in the canopy, which may have reduced sporulation.

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