Bioefficacy studies of new fungicidal formulations against Cercospora leaf spot and powdery mildew of chilli (Capsicum annuum L.) cv. Punjab Guchhedar

2017 ◽  
Vol 18 (4) ◽  
pp. 758
Author(s):  
A. Ronil Kumar ◽  
B. K. Singh ◽  
A. K. Singh ◽  
D. P. Moharana ◽  
R. P. Singh
Keyword(s):  
Powdery Mildew ◽  
Capsicum Annuum ◽  
Leaf Spot ◽  
Cercospora Leaf Spot ◽  
Capsicum Annuum L

scholarly journals MGS Esmeralda: new large seed mungbean cultivar

2008 ◽  
Vol 43 (6) ◽  
pp. 781-782 ◽  
Author(s):  
Rogério Faria Vieira ◽  
José Eustáquio Souza Carneiro ◽  
Trazilbo José de Paula Júnior ◽  
Roberto Fontes Araújo
Keyword(s):  
Powdery Mildew ◽  
Research And Development ◽  
Leaf Spot ◽  
Seed Mass ◽  
Minas Gerais ◽  
The State ◽  
Cercospora Leaf Spot ◽  
Large Seed ◽  
Development Center

Mungbean cultivar MGS Esmeralda was developed by Asian Vegetable Research and Development Center (Shanhua, Taiwan), as a result of crossing between the lines VC 1973A and VC 2768A. In ten trials conducted in the State of Minas Gerais, Brazil, it produced 13.5% more grains than 'Ouro Verde MG-2' (control cultivar), and its highest yield was 2,550 kg ha-1. The cultivar MGS Esmeralda is more susceptible to lodging, and its pods mature more uniformly than Ouro Verde MG-2 pods. One hundred-seed mass of 'MGS Esmeralda' ranged between 5.5 and 6.8 g. Both cultivars are susceptible to powdery mildew and cercospora leaf spot.

scholarly journals Nitrogen and Flowering Dogwood. I. Impact of Nitrogen Fertilization Rate on the Occurrence of Spot Anthracnose, Powdery Mildew, and Cercospora Leaf Spot and Their Effect on Tree Growth

2008 ◽  
Vol 26 (4) ◽  
pp. 197-203
Author(s):  
A.K. Hagan ◽  
J.R. Akridge ◽  
K.L. Bowen
Keyword(s):  
Powdery Mildew ◽  
Nitrogen Fertilization ◽  
Leaf Spot ◽  
Tree Height ◽  
Fertilization Rate ◽  
Spot Intensity ◽  
Cercospora Leaf Spot ◽  
Trunk Diameter ◽  
Flowering Dogwood ◽  
N Rates

Abstract Impact of nitrogen (N) rate on spot anthracnose, powdery mildew, and Cercospora leaf spot as well as their impact on the growth of field-grown ‘Cloud 9’ and ‘Cherokee Chief’ flowering dogwood was assessed in 2003, 2004, and 2005. From 2001 to 2005, ammonium nitrate was applied at 4.1, 8.3, 16.5, 33.0 and 66.0 g N·m−2 (37.5, 75, 150, 300, 600 lb N·A−1). Heritage 50W fungicide was applied to one ‘Cherokee Chief’ and ‘Cloud 9’ flowering dogwood in each plot, while the second was untreated. Powdery mildew and Cercospora leaf spot were impacted by N rate more than spot anthracnose. In two of three years, powdery mildew intensified, particularly on the non-treated trees, as N rates increased. Cercospora leaf spot intensity (AUDPCI) and defoliation (AUDPCD) on the fungicide-treated and non-treated trees was influenced by N-rate in two of three and one of three years, respectively. Regardless of fungicide treatment, Cercospora leaf spot incited leaf spotting and defoliation was often lower at the two highest than the two lowest N rates. A reduction in the bract and leaf spot phases of spot anthracnose at the highest N rate was noted in 2004. While spot anthracnose was negatively correlated with trunk diameter in all three years and tree height in 2003 and 2004, Cercospora leaf spot intensity and defoliation were negatively correlated with tree height and trunk diameter in all three and two of three years, respectively. Powdery mildew had no impact on tree height or trunk diameter. Heritage 50W not only controlled spot anthracnose and powdery mildew but also slowed Cercospora leaf spot development sufficiently to enhance leaf retention and fall color.

scholarly journals CMS-Rf Genotype of Resistance Sources to Gray Leaf Spot in Pepper (Capsicum annuum L.)

2006 ◽  
Vol 22 (2) ◽  
pp. 115-118
Author(s):  
Byung-Soo Kim ◽  
Min-Jeong Kim ◽  
Ji-Seon Lee ◽  
Jeong-Hoon Kim ◽  
Su-Kyung Jun
Keyword(s):  
Capsicum Annuum ◽  
Leaf Spot ◽  
Gray Leaf Spot ◽  
Resistance Sources ◽  
Capsicum Annuum L

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.

Influence of Nitrogen Rate on Cercospora Leaf Spot and Growth of Crapemyrtle

2009 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
A. K. Hagan ◽  
J. R. Akridge ◽  
K. L. Bowen
Keyword(s):  
Powdery Mildew ◽  
Plant Growth ◽  
Ammonium Nitrate ◽  
Tree Growth ◽  
Leaf Spot ◽  
Spot Intensity ◽  
Cercospora Leaf Spot ◽  
Nitrogen Rate ◽  
N Rates ◽  
The Impact

The impact of N rate on development of Cercospora leaf spot on field grown ‘Carolina Beauty’ crapemyrtle and the impact of this disease, as well as N rate, on plant growth was assessed in Alabama. From 2002 to 2005, ammonium nitrate was applied at an N rate of 2, 4.1, 8.3, 16.5, 33.0, and 66.0 g/m2. Heritage 50W fungicide was applied to one tree in each plot, while the second tree was not treated. Powdery mildew was very sporadic and was not related to N rate. An N rate-related reduction in Cercospora leaf spot intensity and defoliation was noted on the non-fungicide and fungicide treated trees in 2005 but not in 2003 and 2004. In 2005, reductions in disease intensity and defoliation were obtained at the three highest N rates of 16.5, 33, and 66 g/m2 compared to the two lowest N rates of 2 and 4.1 g/m2. Regardless of N rate, Heritage 50W suppressed Cercospora leaf spot. Despite considerable leaf spotting and premature defoliation, Cercospora leaf spot did not impact crapemyrtle growth. Increasing N rates was less effective than Heritage 50W fungicide in controlling Cercospora leaf spot and also failed to enhance tree growth. Accepted for publication 10 September 2009. Published 14 December 2009.

scholarly journals First Report of the Perfect Stage of Powdery Mildew of Sugar Beet in North Dakota Caused by Erysiphe polygoni

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 470-470 ◽  
Author(s):  
C. A. Bradley ◽  
P. Burlakoti ◽  
R. S. Nelson ◽  
M. F. R. Khan
Keyword(s):  
Powdery Mildew ◽  
Sugar Beet ◽  
North Dakota ◽  
Leaf Spot ◽  
Genetic Recombination ◽  
The State ◽  
Cercospora Leaf Spot ◽  
First Report ◽  
Perfect Stage ◽  
Erysiphe Polygoni

Powdery mildew caused by Erysiphe polygoni was widespread on sugar beet (Beta vulgaris) in North Dakota during 2006. This disease is generally not prevalent in the state because of the application of fungicides, which also have efficacy against powdery mildew, for control of Cercospora leaf spot caused by Cercospora beticola. Because Cercospora leaf spot pressure was low in 2006, fewer fungicide applications were made in the state, thus allowing for more observations of powdery mildew. Leaf samples from four fields near Amenia, Minto, Prosper, and St. Thomas, ND were collected in mid-September to look for the perfect stage of E. polygoni, since this has recently been observed in Idaho, Colorado, Montana, and Nebraska (1–3). Only the leaves collected from the field near Amenia had visible immature (yellow and brown) globose ascomata; ascomata were not observed on the leaves collected in the other fields. Additional leaves were collected from the field near Amenia in early October; these leaves had immature and mature (black) globose ascomata that were 70 to 105 μm in diameter. Mature ascomata contained ovoid to elliptic asci with one to four hyaline-to-golden pigmented ascospores (20 to 25 × 12 to 20 μm). The color, shape, and size of ascomata, asci, and ascospores were similar to previously reported observations (1–4). The prevalence of the perfect stage in North Dakota is unknown, since no statewide surveys were conducted. To our knowledge, this is the first report of the perfect stage of E. polygoni on sugar beet in North Dakota. The occurrence of the perfect stage could lead to a means for overwintering in this area. Because of the means for genetic recombination, the risk of fungicide resistance and the development of races may increase. References: (1) J. J. Gallian and L. E. Hanson. Plant Dis. 87:200, 2003. (2) R. M. Harveson. Plant Dis. 88:1049, 2004. (3) B. Jacobsen et al. Plant Dis. 89:1362, 2005. (4) E. G. Ruppel. Powdery mildew. Pages 13–15 in: Compendium of Beet Diseases and Insects. E. D. Whitney and J. E. Duffus, eds. The American Phytopathological Society. St. Paul, MN, 1986.

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