Colonization of rotation crops and weeds by the potato black dot pathogenColletotrichum coccodes

2006 ◽  
Vol 83 (6) ◽  
pp. 503-507 ◽  
Author(s):  
Nadav Nitzan ◽  
Billie S. Lucas ◽  
Barbara J. Christ
Keyword(s):  
Black Dot ◽  
Rotation Crops ◽  
Potato Black Dot

scholarly journals Effect of Seed-Tuber Generation, Soilborne Inoculum, and Azoxystrobin Application on Development of Potato Black Dot Caused by Colletotrichum coccodes

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1181-1185 ◽  
Author(s):  
N. Nitzan ◽  
T. F. Cummings ◽  
D. A. Johnson
Keyword(s):  
Disease Severity ◽  
Seed Tuber ◽  
Russet Burbank ◽  
Yield Reduction ◽  
Colletotrichum Coccodes ◽  
Potato Seed ◽  
Disease Development ◽  
Black Dot ◽  
Potato Black Dot

The effect of azoxystrobin on potato black dot and the role of seed- and soilborne inocula of Colletotrichum coccodes in the development of black dot were evaluated in the field using two potato seed generations (generation 1 and 3) of the susceptible cvs. Norkotah Russet and Russet Burbank over 3 years (2002 to 2004). Plants of Norkotah Russet and Russet Burbank treated with azoxystrobin had 13 and 23% higher yields, respectively, than nontreated plants in 2003. Disease severity on both cultivars was reduced 19 to 81%, and 22 to 81% on above- and belowground stem sections, respectively, when plants were treated with azoxystrobin. Plants of both cultivars that were treated with azoxystrobin had 9 to 26% less infected progeny tubers than the nontreated plants. These results indicated the efficacy of azoxystrobin to reduce black dot severity on both stems and progeny tubers. The roles of seed- and soilborne inocula in disease development were evaluated in 2003 and 2004 using generation 1 and 3 seed tubers. The incidence of C. coccodes in generation 1 mother tubers of Norkotah Russet and Russet Burbank were 2 and 16% in 2003, respectively, and 0 and 30% in 2004, respectively. The incidence of C. coccodes in generation 3 mother tubers of Norkotah Russet and Russet Burbank were 14 and 49% in 2003, respectively, and 12 and 38% in 2004, respectively. Generation 1 plants of Norkotah Russet had 36 and 13% greater yield than generation 3 plants in 2003 and 2004, respectively. In 2004, generation 1 plants of Norkotah Russet and Russet Burbank had 26 and 15% greater disease severity, respectively, on belowground stem than generation 3 plants. Generation 1 plants of Norkotah Russet had 7.5 and 11% more infected progeny tubers in 2003 and 2004, respectively, than generation 3. Significant differences for yield reduction and incidence of infected progeny tubers between the two seed generations were not recorded for Russet Burbank, suggesting that the effect of inoculum source of C. coccodes on black dot severity may be cultivar specific.

scholarly journals First Report of Potato Black Dot Caused by Colletotrichum coccodes in Hebei Province of China

Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2669-2669
Author(s):  
Zaimin Tian ◽  
Yuhuan Wu ◽  
Huijing Guo ◽  
Xuechen Gong ◽  
Hongjie Zhang
Keyword(s):  
Hebei Province ◽  
Colletotrichum Coccodes ◽  
Black Dot ◽  
First Report ◽  
Potato Black Dot

Potato Black Dot – The Elusive Pathogen, Disease Development and Management

2018 ◽  
Vol 95 (4) ◽  
pp. 340-350 ◽  
Author(s):  
Dennis A. Johnson ◽  
Brad Geary ◽  
Leah (Lahkim) Tsror
Keyword(s):  
Disease Development ◽  
Black Dot ◽  
Development And Management ◽  
Potato Black Dot

Partial Resistance to Potato Black Dot, Caused by Colletotrichum coccodes in Solanum tuberosum Group Andigena

2010 ◽  
Vol 87 (6) ◽  
pp. 502-508 ◽  
Author(s):  
Nadav Nitzan ◽  
Richard A. Quick ◽  
Will D. Hutson ◽  
John Bamberg ◽  
Chuck R. Brown
Keyword(s):  
Solanum Tuberosum ◽  
Partial Resistance ◽  
Colletotrichum Coccodes ◽  
Black Dot ◽  
Potato Black Dot

A method for direct measurement of specimen noise in HREM images

1993 ◽  
Vol 51 ◽  
pp. 458-459
Author(s):  
Sidnei Paciornik ◽  
Roar Kilaas ◽  
Ulrich Dahmen ◽  
Michael Adrian O'Keefe
Keyword(s):  
Random Noise ◽  
Image Interpretation ◽  
Thin Foil ◽  
High Resolution Electron Microscopy ◽  
Black Dot ◽  
Atomic Column ◽  
Amorphous Oxide ◽  
Resolution Electron ◽  
Imaging Conditions ◽  
Image Simulations

High resolution electron microscopy (HREM) is a primary tool for studying the atomic structure of defects in crystals. However, the quantitative analysis of defect structures is often seriously limited by specimen noise due to contamination or oxide layers on the surfaces of a thin foil.For simple monatomic structures such as fcc or bcc metals observed in directions where the crystal projects into well-separated atomic columns, HREM image interpretation is relatively simple: under weak phase object, Scherzer imaging conditions, each atomic column is imaged as a black dot. Variations in intensity and position of individual image dots can be due to variations in composition or location of atomic columns. Unfortunately, both types of variation may also arise from random noise superimposed on the periodic image due to an amorphous oxide or contamination film on the surfaces of the thin foil. For example, image simulations have shown that a layer of amorphous oxide (random noise) on the surfaces of a thin foil of perfect crystalline Si can lead to significant shifts in image intensities and centroid positions for individual atomic columns.

Five Cases of “Black Dot” Ringworm

1975 ◽  
Vol 37 (1) ◽  
pp. 20-23 ◽  
Author(s):  
Katsutaro NISHIMOTO ◽  
Kazuki MAEZIMA
Keyword(s):  
Black Dot

A grower survey of rotations used in the New South Wales cotton industry

1999 ◽  
Vol 39 (6) ◽  
pp. 743 ◽  
Author(s):  
J. L. Cooper
Keyword(s):  
Soil Structure ◽  
New South ◽  
New South Wales ◽  
Cotton Industry ◽  
Rotation System ◽  
System A ◽  
South Wales ◽  
Rotation Crops ◽  
Grower Survey ◽  
Rotation Crop

Summary. Cotton growers in the Macquarie, Namoi and Gwydir Valleys of New South Wales were surveyed in 1992 to determine what crops are grown in rotation with cotton, how frequently rotation crops are used, and what influences the grower’s choice of rotation system. A total of 155 properties were surveyed, covering 100, 49 and 58% of irrigated cotton produced in the Macquarie, Namoi and Gwydir Valleys, respectively. Although a large part of the 1992–93 cotton crop (61% by area) did not follow a rotation crop, there was widespread interest in rotations and 70% of properties had used rotations. Wheat was by far the most widely grown rotation crop, but there was considerable interest in other crops, especially legumes. The perceived benefits from rotation crops reported by most growers were better soil structure, less disease in following cotton, and more soil organic matter. However, when asked why they preferred certain rotation crops, these factors did not rate highly with growers. Crops that were easy to grow and gave the best financial returns possessed the main features sought in a rotation crop. The greatest problem in growing rotation crops was a lack of irrigation water. It is not surprising that this problem ranked highly because when the survey was conducted, the Namoi and Gwydir Valleys had water allocations of 15 and 0%, respectively. Not having suitable equipment to sow rotation crops was also a problem for 17% of growers, but 10% encountered no problems. The survey also investigated the use of permanent beds and retained hills. These practices have benefits for soil structure, and are almost essential for rotation crops which need to be sown as soon as the cotton is harvested. Over 80% of growers using rotations had adopted some form of permanent beds or retained hills. The benefit which ranked highest was a reduction in costs, followed by less soil compaction. Some growers (44%) who used permanent beds or retained hills had no problems, but handling the trash and keeping the rows straight were of concern to others.

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