The Effect of Fatty Acids on Growth and Sporulation of the Pecan Scab Fungus Cladosporium caryigenum

Mycologia ◽  
1984 ◽  
Vol 76 (2) ◽  
pp. 326 ◽  
Author(s):  
T. R. Gottwald ◽  
B. W. Wood
Keyword(s):  
Fatty Acids ◽  
Pecan Scab ◽  
Cladosporium Caryigenum

Taxonomy of the Pecan Scab Fungus Cladosporium caryigenum

Mycologia ◽  
1982 ◽  
Vol 74 (3) ◽  
pp. 382 ◽  
Author(s):  
T. R. Gottwald
Keyword(s):  
Pecan Scab ◽  
Cladosporium Caryigenum

scholarly journals Sensitivity of Cladosporium caryigenum to Propiconazole and Fenbuconazole

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 163-166 ◽  
Author(s):  
Katherine L. Reynolds ◽  
Timothy B. Brenneman ◽  
Paul F. Bertrand
Keyword(s):  
Previous History ◽  
Cross Resistance ◽  
Relative Growth ◽  
Colony Diameter ◽  
Pecan Scab ◽  
History Of ◽  
Dmi Fungicides ◽  
Cladosporium Caryigenum ◽  
Positive Correlations ◽  
Two Populations

Monoconidial isolates of the pecan scab fungus, Cladosporium caryigenum, were obtained in 1993 and 1994 from one pecan orchard each in Jeff Davis and Troup counties in Georgia, counties with no previous history of exposure to demethylation-inhibiting (DMI) fungicides. Isolates were grown on potato dextrose agar (PDA) amended with propiconazole or fenbuconazole at 0,0.0001, 0.0005, 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1.0, or 5.0 µg ml-1. After 4 to 5 weeks at 25°C, the diameter of each colony was measured. Relative growth was expressed as the colony diameter for each fungicide concentration as a percentage of the diameter on unamended PDA. (ED)50 values for both fungicides in all years and locations were lognormally distributed. Mean (ED)50 values ranged from 0.19 to 0.30 µg ml-1 for fenbuconazole and 0.12 to 0.17 µg ml-1 for propiconazole. There were highly significant positive correlations between sensitivity to propiconazole and sensitivity to fenbuconazole at all locations and years, indicating significant potential for development of cross-resistance to these compounds. A discriminatory concentration of 0.2 µg ml-1 propiconazole was selected for further monitoring of DMI sensitivity. With this discriminatory concentration, a sample size of 50 isolates was estimated to be sufficient to detect a difference of 8.3% in mean relative growth between two populations.

scholarly journals A Detached Leaf Technique for Studying Race-specific Resistance to Cladosporium caryigenum in Pecan

2002 ◽  
Vol 127 (5) ◽  
pp. 781-785 ◽  
Author(s):  
Patrick J. Conner
Keyword(s):  
High Frequency ◽  
Specific Resistance ◽  
Fungal Growth ◽  
Carya Illinoinensis ◽  
Detached Leaf ◽  
Pecan Scab ◽  
Detached Leaves ◽  
Cladosporium Caryigenum ◽  
Cape Fear ◽  
High Degree

A detached leaf screening technique was developed for studying specific interactions between pecan [Carya illinoinensis (Wangenh.) C. Koch] cultivars and isolates of the pecan scab fungus, Cladosporium caryigenum. Monoconidial isolates were obtained from leaf scab lesions on `Wichita', `Desirable', `Cape Fear', and `Elliot'. Each isolate was then inoculated onto detached leaves of each of the four cultivars and fungal growth was observed under the microscope after eight days. `Wichita', `Desirable', and `Cape Fear' isolates produced subcuticular hyphae at a much higher frequency when inoculated back onto the cultivar from which they were isolated in comparison to the other cultivars. The `Elliot' isolate was able to produce a high frequency of subcuticular hyphae when inoculated onto `Elliot' and `Cape Fear', but not when inoculated onto `Desirable' and `Wichita'. Field inoculations conducted with the `Wichita' and `Desirable' isolates validated the detached leaf protocol. The results obtained indicate that pecan scab is composed of multiple races with a high degree of specificity for host cultivars. A rapid whole-leaf staining system is presented which appears to have wide applicability to assessing fungal growth in leaves.

Fatty Acids and Glycerides

1979 ◽  
Vol 7 (4) ◽  
pp. 813-814
Author(s):  
J. L. HARWOOD
Keyword(s):  
Fatty Acids
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