scholarly journals Factors Affecting Infection of Yellow Starthistle (Centaurea solstitialis) by Synchytrium solstitiale, Causal Agent of False Rust Disease

Plant Disease ◽  
2006 ◽  
Vol 90 (4) ◽  
pp. 425-428 ◽  
Author(s):  
T. L. Widmer ◽  
F. Guermache
Keyword(s):  
United States ◽  
Classical Biological Control ◽  
The United States ◽  
Carthamus Tinctorius ◽  
Centaurea Solstitialis ◽  
Yellow Starthistle ◽  
Rust Disease ◽  
Invasive Weed ◽  
Factors Affecting ◽  
Centaurea Calcitrapa

Yellow starthistle (Centaurea solstitialis) is an annual invasive weed in the United States with Mediterranean origins. The expense of chemical control and the vast area of invasion make this weed an appropriate target for classical biological control. Observations of a field site in southern France revealed small orange galls on the leaves of yellow starthistle seedlings caused by the fungus Synchytrium solstitiale. Inoculation of yellow starthistle seedlings with a suspension of zoospores released from infected tissue resulted in infection. Ten days after inoculation, typical orange galls appeared on the exposed tissue. Preliminary host range testing showed up to 100% infection of C. solstitialis seedlings from both France and the United States and infection of Carthamus tinctorius, Centaurea americana, C. diffusa, C. rothrockii, C. squarrosa, and Helianthus annuus seedlings. No symptoms were observed on seedlings of Centaurea calcitrapa, C. maculosa, C. sulfurea, Cirsium californica, C. occidentale, Cynera cardunculus, and Taraxacum officinale. Zoospores were released in a pH range between 4.45 and 8.25 and optimally at temperatures between 5 and 15°C. Infection of yellow starthistle seedlings occurred after a minimum 1-h exposure to a zoospore suspension at 20°C.

scholarly journals Field Damage to Yellow Starthistle Infected by Synchytrium solstitiale, and Greenhouse Maintenance and Host Range of the Fungus

Plant Disease ◽  
2011 ◽  
Vol 95 (8) ◽  
pp. 907-912
Author(s):  
F. M. Eskandari ◽  
W. L. Bruckart ◽  
T. L. Widmer
Keyword(s):  
United States ◽  
Biological Control ◽  
Host Range ◽  
Leaf Tissue ◽  
The United States ◽  
Carthamus Tinctorius ◽  
Yellow Starthistle ◽  
Potted Plants ◽  
Host Range Determination ◽  
Range Determination

Yellow starthistle (YST, Centaurea solstitialis) is a major weed pest of the western United States. Synchytrium solstitiale, a pathogen of YST, caused significant damage to symptomatic (versus asymptomatic) plants in a field study in France. Before it was evaluated as a candidate for biological control of YST in the United States, protocols for pathogen maintenance under greenhouse conditions were developed. Maintenance, increase, and host range determination protocols involved incubation at 10/15°C (night/day) with an 8-h photoperiod either of potted or exhumed (i.e., roots of 4-week-old plants grown in flasks of water) plants inoculated with galled leaf tissue, or potted plants in which inoculum was wrapped within healthy leaves by a plastic wrap. The leaf-wrap protocol, used during the host range determination, always resulted in disease of YST. Several safflower (Carthamus tinctorius) cultivars and other plants related to YST became diseased following this protocol, thus raising concern about host specificity. Development of disease on nontarget species precludes proposal of S. solstitiale for biological control of YST at this time.

Distribution of Yellow Starthistle (Centaurea solstitialis) and Russian Knapweed (Centaurea repens)

Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 315-327 ◽  
Author(s):  
Donald M. Maddox ◽  
Aubrey Mayfield ◽  
Noah H. Poritz
Keyword(s):  
United States ◽  
The United States ◽  
Economic Importance ◽  
Western United States ◽  
Centaurea Solstitialis ◽  
Yellow Starthistle ◽  
Russian Knapweed ◽  
Centaurea Repens ◽  
The World ◽  
Made In

The world distributions of yellow starthistle (Centaurea solstitialis L. ♯ CENSO) and Russian knapweed (Centaurea repens L. ♯ CENRE) are mapped based on information from world regional floras. A survey of weed specialists and herbaria was made in the United States, and the extent of the infestations and economic importance of these weeds was determined for the 48 contiguous states. Yellow starthistle currently occurs in 209 counties in 23 states and has apparently increased in abundance since 1970. Russian knapweed was reported in 412 counties in 21 states and does not seem to be spreading. Both of these weedy plant species are of greater economic importance in the western United States than in the east.

Factors affecting water quality in selected carbonate aquifers in the United States,1993-2005

2009 ◽  
Author(s):  
Bruce D. Lindsey ◽  
Marian P. Berndt ◽  
Brian G. Katz ◽  
Ann F. Ardis ◽  
Kenneth A. Skach
Keyword(s):  
United States ◽  
Water Quality ◽  
The United States ◽  
Factors Affecting ◽  
Carbonate Aquifers

scholarly journals Core Elements Affecting Sharing: Evidence from the United States

2021 ◽  
Vol 13 (7) ◽  
pp. 3943
Author(s):  
Aurelija Burinskienė ◽  
Edita Leonavičienė ◽  
Virginija Grybaitė ◽  
Olga Lingaitienė ◽  
Juozas Merkevičius
Keyword(s):  
United States ◽  
The United States ◽  
Collaborative Consumption ◽  
Factors Affecting ◽  
Use Of Resources ◽  
Personal Consumption ◽  
Depth Analysis ◽  
Core Elements ◽  
Long Time ◽  
Number Of Visits

The new phenomenon called sharing or collaborative consumption emerged a decade ago and is continuously growing. It creates new possibilities for society, and especially for business, is beneficial for the environment, makes more efficient use of resources, and presents a new competitive business model. The scientific literature lacks a more in-depth analysis of the factors influencing sharing activity growth; therefore, the paper’s authors attempt to fill this gap. The authors aim to identify the factors affecting the use of sharing platforms. To reach the goal, the authors developed a regression model and constructed a list of 71 variables. The study used monthly United States data from January 2017 to June 2020 from the publicly available Federal Reserve Economic Data (FRED)and Google trends databases. The comparison to other indexes proves that the proposed index, representing the number of visits to sharing platforms (SEP), is a unique one. The first index allowed us to revise the sharing activity monthly. The authors identified that variables such as wage level, social network users, import level, and personal consumption are critical in affecting the number of visits to sharing platforms. The presented framework could be helpful for practitioners and policymakers analysing the stimulation of sharing or collaborative consumption. It includes indicators representing different areas, such as society, technology, and country, and allows for monthly investigations. Such activity was evident for a long time when online platforms contributed to its wider accessibility. The results help to forecast the number of visits monthly. Sharing is still an emerging area for research; thus, the authors tried to explore the phenomenon of sharing to expand the conceptual level of knowledge.

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