Effect of temperature and relative humidity on conidial germination of the causal agent of cucumber powdery mildew

2021 ◽  
Vol 01 (02) ◽  
pp. 15-25
Author(s):  
Nagah Milod ◽  
Gazala Saad ◽  
Hanan.A. Khalifa
Keyword(s):  
Relative Humidity ◽  
Powdery Mildew ◽  
Conidial Germination ◽  
Causal Agent ◽  
Effect Of Temperature ◽  
Cucumber Powdery Mildew

scholarly journals Effect of temperature, relative humidity and light on conidial germination of oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.) under controlled conditions

2013 ◽  
Vol 65 (3) ◽  
pp. 1069-1077 ◽  
Author(s):  
P. Pap ◽  
B. Rankovic ◽  
S. Masirevic
Keyword(s):  
Relative Humidity ◽  
Powdery Mildew ◽  
Germ Tube ◽  
Inhibitory Effect ◽  
Conidial Germination ◽  
Effect Of Temperature ◽  
Tube Length ◽  
Controlled Conditions ◽  
Germ Tube Length ◽  
Germ Tubes

The influence of temperature, humidity and light on the conidial germination and germ tube elongation of oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.) was studied in controlled conditions. The maximal germ tube length was attained at 25?C, whereas at lower and higher than optimal temperatures, germ tube growth was significantly lower. Germ tubes begin to develop at all values of relative humidity (10-100%), reaching the maximum length at 90%. The development of germ tubes was the most intense in full light and the lowest in total darkness. The artificial infection of floating leaves showed that an increasing age had an inhibitory effect on the mycelium development and spore formation. Since conidia play a crucial role in powdery mildew epidemiology, it is of particular importance to elucidate the influence of environmental factors in the complex relations that exist between the plant and its pathogen.

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.

scholarly journals Effect of Temperature, Relative Humidity on Germination and Development of Powdery Mildew (Leveillula taurica) on Pepper and Its Inoculation Method

2009 ◽  
Vol 15 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Dae-Hyun Kim ◽  
Jong-Han Park ◽  
Jung-Sup Lee ◽  
Kyung-Sook Han ◽  
You-Kyoung Han ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Powdery Mildew ◽  
Effect Of Temperature ◽  
Inoculation Method ◽  
Leveillula Taurica
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