Phytoparasitica (1999) 27, 140-141

Y. Mesika, Y. Elad, Y. Nitzani, B. Kirshner, Y. Shmulevitz, Dalia Rav David, A. Sztjenberg, Hanna Yehezkel, D. Shmuel, E. Taari, Y. Posalski, Y. Cohen and M. Fuchs (1999)
Powdery mildew (Leveillula taurica) of bell pepper in heated greenhouses
Phytoparasitica 27 (2), 140-141
20th Congress of the Israeli Phytopathological Society, February 15-16, 1999, Bet Dagan, Israel, lecture
Abstract: Powdery mildew (Leveillula taurica) causes severe epidemics in bell pepper. Growers rely on chemical control in order to prevent damages. Experiments were carried out in a greenhouse and nethouses. Leaf coverage by powdery mildew symptoms at various plant heights (nodes), leaf shed and yields were evaluated throughout the growth seasons. Symptoms on leaves appeared in October and increased until February; leaf shedding started in December. Of three cultivars, cv. 'Kumbia' was the most susceptible, cv. 'Mazurka' was 30% less infected and cv. 'Turkal' was the most resistant. Heating of the greenhouse plots was done so minimum night temperatures in the various plots along the rows of the three cultivars varied between 13° and 16°C. Plots of lower night temperatures in cvs. Mazurka and Kumbia were infected more severely than plots of warmer night temperatures; the temperature effect on disease was less pronounced in cv. Turkal. A positive and significant correlation was found between powdery mildew leaf coverage and shed leaves of cvs. Kumbia and Turkal maintained at higher temperature regimes. It seems that different microclimatic conditions promote these disease symptoms. Disease was lower in plots of higher average temperature and shorter duration of relative humidity above 80% (or in the range of 80-90%). This issue is being studied further. Fruit yield was negatively affected in the heavily infected plots. In such plots intensity of leaf coverage was negatively correlated wtih yields of cvs. Mazurka and Turkal and leaf shedding was negatively correlated only with yield of cv. Turkal.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Yigal R. Cohen, Yigal Elad

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Leveillula taurica	Green pepper/chilli (Capsicum)	Israel