Effects of powdery mildew on cucumber yields, and its chemical control

1969 ◽  
Vol 63 (3) ◽  
pp. 401-414 ◽  
Author(s):  
PAULINE M. SMITH ◽  
W. H. READ ◽  
F. T. LAST
2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 583-587
Author(s):  
M. Vaverka ◽  
S. Vaverka

In the course of 1993–2001 extensive field trials were carried out to evaluate the resistance (susceptibility) level of 34 gooseberry cultivars to the American gooseberry powdery mildew Sphaerotheca mors uvae Schwein. Cultivars originated from the Czech Republic and from other European countries. Each tested cultivar had 7 trees (5–10 years old). Beside the resistance (susceptibility) evaluation, biological efficacy of 9 fungicides using EPPO methods has been checked at the same number of cultivars and at the same number of gooseberry trees. Highly significant differences of resistance or susceptibility were observed among gooseberry varieties. Analogical results (differences in biological activity of fungicides) have been attained in the course of chemical treatment. 18 cultivars has been classified as low resistant, 12 cultivars as moderate resistant and 4 cultivars as high resistant. None of the tested fungicides proved perfect biological efficacy (100% healthy berries). 4 of them proved high biological effect (more than 90% healthy berries), 3 proved low biological activity (less than 75% healthy berries) and 2 proved moderate biological activity (75–90% healthy berries).


1991 ◽  
Vol 20 (1) ◽  
pp. 16 ◽  
Author(s):  
LM Ransom ◽  
RG O'brien ◽  
RJ Glass

Author(s):  
I. J. Holb

Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. This review focuses on the control of apple powdery mildew. The first part of the study provides details of novel aspects of non-chemical control approaches, including agronomic measures, mechanical and biological control options as well as essential features of apple cultivar resistance. After this, developments in chemical control options are described sperately for integrated and organic apple orchards.


2013 ◽  
Vol 40 (1-2) ◽  
pp. 87-98
Author(s):  
Zbigniew Borecki

Field susceptibility of 13 scab-resistant apple cultivars to apple powdery mildew was evaluated in 1983-1986. Four groups of susceptibility were distinguished. None of the 13 tested scab-resistant apple trees exhibited complete field immunity to apple powdery mildew. Two cultivars, 'Prima' and 'Primula', were practically resistant. 'Liberty' and two numbered selections, NY-140-9 and NY-158-2, belonged to the group of lower susceptibility. Moderate susceptibility was shown by: 'Novamac', 'Freedom', 'Gavin', 'Prima' and 'Florina'. The group of apple trees most susceptible to <i>Podosphaera leucotricha</i> included: 'Macfree', 'Priscilla' and 'Nova Easygro'. It is not necessary to use chemical sprays to control powdery mildew on 'Prima' and 'Primula'. A reduced spraying program may be recommended only under high disease pressure on less susceptible apple cultivars. A regular spray schedule is needed on moderately susceptible apple trees, but improved chemical control is necessary on the most susceptible ones.


Author(s):  
Lucia MIHALESCU ◽  
Oana MARE ROSCA ◽  
Zorica VOSGAN ◽  
Anca DUMUTA ◽  
Mirela CORDEA ◽  
...  

The experiences were performed in the Tautii Magheraus locality, located at 3 km from Baia Mare. Five variety of grapevine were studied: Cramposie , Feteasca regala , Muscat Ottonel  , Perla de Zala and Italian Riesling . The resistance of the cultivated grapevine varieties against the attack of the main phytopathogenic fungi: Plasmopara viticola , Uncinula necator , Botryotinia fuckeliana  , in terms of the 2011 year, was studied. In order to assess the resistance of the grapevine varieties against the phytopathogenic agents attack, the frequency, intensity and degree of attack were determined. The most sensitive to the attack of downy mildew on leaves was the Italian Riessling , with a degree of attack of 71.5%; and the most resistant variety was Perla de Zala , with a degree of attack of 26%. The most resistant to the attack of grape powdery mildew on leaves was the Muscat Ottonel  variety, with a degree of attack of 8.1%; and the most sensitive was the Italian Riesling variety with 18.1%. In case of the attack of downy mildew on grapes, the most sensitive was the Italian Riesling  variety with a degree of attack of 11.5%; and the most resistant was Perla de Zala with 2.5%. During the vegetation of the 2011 year, the chemical protection was performed with fungicides that were administered by seven sprayings.


2017 ◽  
Vol 52 (9) ◽  
pp. 715-723 ◽  
Author(s):  
Amado Pérez-Rodríguez ◽  
Abraham Monteón-Ojeda ◽  
José Antonio Mora-Aguilera ◽  
Elías Hernández-Castro

Abstract: The objective of this work was to evaluate phytosanitary strategies for the chemical control of powdery mildew (Oidium mangiferae) in mango, based on the alternation of active ingredients with different modes and sites of action, and to determine the environmental and epidemiological conditions that favor the development of the disease. The experiment was conducted in Guerrero, México, in commercial orchards, within a program for the development of fungicide spraying strategies. Epidemic curves were used on temporal analyses of the disease for: incidence; area under disease progression curve (AUDPC); severity; and conidial seasonality and its relationships with meteorological parameters. The disease was better controlled with the application of systemic fungicide followed by contact fungicide with multisite activity. The first symptoms appeared 30 days after the issuance of shoots, and the most susceptible phenological (critical) stages were at full bloom and at the onset of fruit with 8-15 mm. Optimum conditions for the development of powdery mildew, which maximizes the density of airborne spores, are temperatures higher than 30°C and relative humidity over 90%.


Sign in / Sign up

Export Citation Format

Share Document