scholarly journals The activity of some carbohydrases produced by Cochliobolus miyabeanus, the causal fungus of Helminthosporium leaf spot of rice plants

1965 ◽  
Vol 30 (4) ◽  
pp. 192-196
Author(s):  
Hiroyasu TANAKA
Keyword(s):  
Leaf Spot ◽  
Rice Plants ◽  
Causal Fungus ◽  
Cochliobolus Miyabeanus

scholarly journals Impact of Application Rate and Interval on the Control of Powdery Mildew and Cercospora Leaf Spot on Bigleaf Hydrangea with Azoxystrobin

2004 ◽  
Vol 22 (2) ◽  
pp. 58-62 ◽  
Author(s):  
A. K. Hagan ◽  
J. W. Olive ◽  
J. Stephenson ◽  
M. E. Rivas-Davila
Keyword(s):  
Powdery Mildew ◽  
Leaf Spot ◽  
Application Rate ◽  
Cercospora Leaf Spot ◽  
Thiophanate Methyl ◽  
Hydrangea Macrophylla ◽  
Application Rates ◽  
Erysiphe Polygoni ◽  
Causal Fungus ◽  
Paraffinic Oil

Abstract Efficacy of azoxystrobin (Heritage 50W™) was assessed over a range of application rates and intervals for the control of powdery mildew (Erysiphe polygoni) and Cercospora leaf spot (Cercospora hydrangea) on bigleaf hydrangea (Hydrangea macrophylla) ‘Nikko Blue’. Rooted hydrangea cuttings were transplanted in a pine bark/peat mixture. In 1998 and 1999, azoxystrobin at 0.16 g ai/liter and 0.32 g ai/liter, as well as 0.24 g ai/liter myclobutanil (Eagle 40W™) and 0.84 g ai/liter thiophanate methyl (3336 4.5F™), greatly reduced the incidence of powdery mildew compared with the untreated control where 75% of the leaves of were infected by the causal fungus. When applied at 1-, 2-, and 3-week intervals, both rates of azoxystrobin were equally effective in both years in preventing the development of powdery mildew on bigleaf hydrangea. In 1998, all fungicides except for thiophanate methyl protected bigleaf hydrangea from Cercospora leaf spot. In the last two trials, the incidence of powdery mildew increased significantly as the application rate for azoxystrobin decreased from 0.16 to 0.04 g ai/liter and the application interval was lengthened from 1 to 3 weeks. In general, all rates of azoxystrobin applied on a 3-week schedule failed to provide the level of powdery mildew control needed to produce quality bigleaf hydrangea for the florist and landscape market. When applied at 2-week intervals, myclobutanil was equally or more effective in controlling powdery mildew than any rate of azoxystrobin applied on the same schedule. When compared to the untreated controls, significant reductions in the incidence of powdery mildew on bigleaf hydrangea were obtained with weekly applications of paraffinic oil. No symptoms of phytotoxicity were associated with the use of any of the fungicides screened.

scholarly journals Seed Transmission of Corynespora melonis, Causal Fungus of Target Leaf Spot, on Cucumber.

1993 ◽  
Vol 59 (2) ◽  
pp. 175-179
Author(s):  
Wataru HASAMA ◽  
Tokuhiro KATO ◽  
Suzumi MORITA
Keyword(s):  
Leaf Spot ◽  
Seed Transmission ◽  
Causal Fungus
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