The effects of different biological control agents (BCAs) and plant defence elicitors on cucumber powdery mildew (Podosphaera xanthii)

2012 ◽  
Vol 2 (2) ◽  
pp. 89-101 ◽  
Author(s):  
Charilaos Giotis ◽  
Emilia Markellou ◽  
Aphroditi Theodoropoulou ◽  
George Kostoulas ◽  
Stephen Wilcockson ◽  
...  
Keyword(s):  
Biological Control ◽  
Powdery Mildew ◽  
Plant Defence ◽  
Podosphaera Xanthii ◽  
Biological Control Agents ◽  
Cucumber Powdery Mildew

scholarly journals Oil Adjuvants Enhance the Efficacy of Pyraclostrobin in Managing Cucumber Powdery Mildew (Podosphaera xanthii) by Modifying the Affinity of Fungicide Droplets on Diseased Leaves

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1657-1664
Author(s):  
Lifei He ◽  
Xiaoxu Li ◽  
Yangyang Gao ◽  
Beixing Li ◽  
Wei Mu ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Powdery Mildew ◽  
Field Experiments ◽  
Plant Diseases ◽  
Work Of Adhesion ◽  
Podosphaera Xanthii ◽  
Effective Strategy ◽  
Cucumber Powdery Mildew ◽  
Fungicide Mixtures

Adding adjuvants improved the affinity of fungicide droplets to cucumber leaves infected with powdery mildew (Podosphaera xanthii) and subsequent efficacy of fungicide treatments in reducing the disease. The affinity of oil adjuvants was quantified by adhesional tension and “work of adhesion”. Oil adjuvant-fungicide mixtures were applied to plants in field experiments to evaluate their effectiveness in disease prevention. Both the adhesional tension and work of adhesion of the adjuvants at selected concentrations increased on powdery-mildew-infected cucumber leaves more than on healthy cucumber leaves. The adjuvant GY-Tmax (GYT) displayed the best surface activity or “surfactivity” in enhancing the affinity and adherence of droplets to powdery-mildew-infected cucumber leaves, while epoxidized soybean oil (ESO), methyl oleate, and biodiesel exhibited much lower effects in terms of the surface tension, contact angle, adhesional tension, and work of adhesion. Field experiments determined that the combination of GYT at 1,000 mg liter−1 and pyraclostrobin (150 g a.i. ha−1) was most effective (91.52%) in controlling cucumber powdery mildew. Pyraclostrobin with ESO was also highly effective (ranging from 77.54 to 89.65%). The addition of oil adjuvants, especially GYT and ESO, to fungicide applications can be an effective strategy to enhance the efficacy of pesticides in controlling plant diseases by modifying the affinity of fungicide droplets to symptomatic leaves.

Nighttime Application of UV-C to Control Cucumber Powdery Mildew

2020 ◽  
Vol 21 (1) ◽  
pp. 40-46 ◽  
Author(s):  
Jaimin S. Patel ◽  
Leora C. Radetsky ◽  
Rohan Nagare ◽  
Mark S. Rea
Keyword(s):  
Powdery Mildew ◽  
Leaf Area ◽  
Disease Severity ◽  
Uv Radiation ◽  
Podosphaera Xanthii ◽  
Laboratory Studies ◽  
Time Of Application ◽  
Cucumber Powdery Mildew ◽  
The Impact ◽  
Uv C

Nonionizing, ultraviolet (UV) radiation is effective for mitigating powdery mildew associated with a variety of crops including strawberry, grapes, rosemary, tomato, rose, and cucumber. The effectiveness of UV radiation depends upon the dose (irradiance × duration), the frequency of dosing, the time of application, and the sensitivity of the crop to UV radiation. Reported here are the results of two laboratory studies examining the impact of UV-C (254 nm) on cucumber and its obligate powdery-mildew-causing pathogen Podosphaera xanthii. In the first study, doses of UV-C (72 and 144 J m–2) applied every night were more effective at reducing disease severity than dosing every day. However, leaf area was reduced more following nighttime applications than daytime applications, suggesting that both day and night applications of UV-C could compromise yield without necessarily eliminating the disease. The second study showed that a dose of UV-C (7.2 J m–2) applied every night or a higher dose (70 J m–2) applied every fourth night were both effective for eliminating powdery mildew without significantly reducing leaf area. These findings, if confirmed in the field, could provide cucumber growers with additional options for controlling powdery mildew without compromising yield.

scholarly journals Biological Control of Cucumber Powdery Mildew by Bacillus amyloliquefaciens M27

2013 ◽  
Vol 41 (4) ◽  
pp. 268-273 ◽  
Author(s):  
Sang Yeob Lee ◽  
Hang Yeon Weon ◽  
Jeong Jun Kim ◽  
Ji Hee Han ◽  
Wan Gyu Kim
Keyword(s):  
Biological Control ◽  
Powdery Mildew ◽  
Bacillus Amyloliquefaciens ◽  
Cucumber Powdery Mildew

scholarly journals Evaluation of biological control agents for managing cucurbit powdery mildew on greenhouse-grown melon

2007 ◽  
Vol 56 (6) ◽  
pp. 976-986 ◽  
Author(s):  
D. Romero ◽  
A. de Vicente ◽  
H. Zeriouh ◽  
F. M. Cazorla ◽  
D. Fernández-Ortuño ◽  
...  
Keyword(s):  
Biological Control ◽  
Powdery Mildew ◽  
Biological Control Agents ◽  
Cucurbit Powdery Mildew

scholarly journals Activity, Translocation, and Persistence of Isopyrazam for Controlling Cucumber Powdery Mildew

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1139-1144 ◽  
Author(s):  
Lei-ming He ◽  
Kai-di Cui ◽  
Di-cheng Ma ◽  
Rui-ping Shen ◽  
Xue-ping Huang ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Causal Agent ◽  
Podosphaera Xanthii ◽  
Systemic Movement ◽  
Cucumber Powdery Mildew ◽  
Long Duration ◽  
Duration Of Efficacy

A cotyledon bioassay was conducted to assess the activity of isopyrazam against Podosphaera xanthii (Castagne) U. Braun & N. Shishkoff, causal agent of cucumber powdery mildew. Results showed that isopyrazam has protective and curative activity against P. xanthii, with EC50 values of 0.04 and 0.05 mg liter–1, respectively. These activities are higher than those for hexaconazole, difenoconazole, pyraclostrobin, kresoxim-methyl, and azoxystrobin, fungicides currently used against cucumber powdery mildew. Isopyrazam at 0.5 mg liter–1 damaged conidiophores. Results of inoculation tests in greenhouse pots indicate that isopyrazam demonstrates a level of systemic movement in cucumber plants, especially regarding translaminar and transverse translocation. Efficacy following translaminar and transverse translocations on cotyledons and leaves treated with 60 mg liter–1 was 94.40% and 88.96%, and 95.26% and 82.83%, respectively. In addition, isopyrazam at 60 mg liter–1 exhibited a long duration of efficacy against cucumber powdery mildew, almost 2 to 3 weeks longer than that of triazoles and strobilurins. Similar trends in residual durations were observed during 2014 and 2015 greenhouse trials. Isopyrazam at 30 and 60 a.i. g ha–1 provided efficacy ranging from 83.27 to 90.83% 20 days following treatment. In conclusion, isopyrazam has translaminar and transverse translocation in cucumber leaves, and long duration of activity against cucumber powdery mildew.

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