scholarly journals First Report of Charcoal Rot of Sunflower in Minnesota, USA

2010 ◽  
Vol 11 (1) ◽  
pp. 48
Author(s):  
T. Gulya ◽  
A. Mengistu ◽  
K. Kinzer ◽  
N. Balbyshev ◽  
S. Markell

Charcoal rot was first observed on sunflower in North and South Dakota in 1998, and was widespread on soybeans recently in Iowa, suggesting that Macrophomina may becoming more common in cooler growing areas of Midwestern United States. With the multitude of Macrophomina hosts in the northern Great Plains and the high incidence of microsclerotia we detected in soil, high disease potential may exist, suggesting that in drier, hotter years the sunflower crop may be affected by this disease. Accepted for publication 17 May 2010. Published 7 July 2010.

Author(s):  
Andrew Hoell ◽  
Trent W. Ford ◽  
Molly Woloszyn ◽  
Jason A. Otkin ◽  
Jon Eischeid

AbstractCharacteristics and predictability of drought in the Midwestern United States, spanning the Great Plains to the Ohio Valley, at local and regional scales are examined during 1916-2015. Given vast differences in hydroclimatic variability across the Midwest, drought is evaluated in four regions identified using a hierarchical clustering algorithm applied to an integrated drought index based on soil moisture, snow water equivalent, and three-month runoff from land surface models forced by observed analyses. Highlighting the regions containing the Ohio Valley (OV) and Northern Great Plains (NGP), the OV demonstrates a preference for sub-annual droughts, the timing of which can lead to prevalent dry epochs, while the NGP demonstrates a preference for annual-to-multi-annual droughts. Regional drought variations are closely related to precipitation, resulting in a higher likelihood of drought onset or demise during wet seasons: March-November in the NGP and all year in the OV, with a preference for March-May and September-November. Due to the distinct dry season in the NGP, there is a higher likelihood of longer drought persistence, as the NGP is four times more likely to experience drought lasting at least one year compared to the OV. While drought variability in all regions and seasons are related to atmospheric wave trains spanning the Pacific-North American sector, longer-lead predictability is limited to the OV in December-February because it is the only region/season related to slow-varying sea surface temperatures consistent with El Niño-Southern Oscillation. The wave trains in all other regions appear to be generated in the atmosphere, highlighting the importance of internal atmospheric variability in shaping Midwestern drought.


1990 ◽  
Vol 122 (3) ◽  
pp. 579-581 ◽  
Author(s):  
R.W. Kieckhefer ◽  
N.C. Elliott

Coccinellids are a conspicuous group of aphidophagous predators in maize, Zea mays L., in the Northern Great Plains of the United States. Numerous studies have been conducted on the ecology of coccinellids in maize in North America (Ewert and Chiang 1966a, 1966b; Smith 1971; Foott 1973; Wright and Laing 1980; Corderre and Tourneur 1986; Corderre et al. 1987). However, there have been few long-term surveys of coccinellids in maize. Foott (1973) reported on the abundance of coccinellid species inhabiting maize in eastern Canada over a 4-year period; no surveys of this type have been reported for the Northern Great Plains. We sampled coccinellids in maize fields at three sites in eastern South Dakota for 13 consecutive years to determine the species inhabiting the crop and levels of variation in their abundances among sites and years.


2006 ◽  
Vol 45 (7) ◽  
pp. 995-1002 ◽  
Author(s):  
Andrew J. Grundstein ◽  
Qi Qi Lu ◽  
Robert Lund

Abstract This paper estimates return levels of extreme snow water equivalents (SWE) in the northern Great Plains region, containing North and South Dakota, Iowa, Minnesota, and Nebraska. The return levels are estimated from extreme-value methods using a new hybrid SWE dataset that improves the spatial resolution of existing data in the area. A novel aspect of the methods is the use of standard error margins to spatially smooth the estimated SWE return levels computed on individual grid cells. The end product is a reliable return-level estimate that controls for uncertainties in the raw observations. The methods should prove useful in analyses of other geographical regions.


1987 ◽  
Vol 119 (12) ◽  
pp. 1131-1137 ◽  
Author(s):  
Laurence D. Charlet

AbstractThe sunflower stem weevil, Cylindrocopturus adspersus (LeConte), is a pest of cultivated sunflower in the major production areas of North and South Dakota, Minnesota, and Texas. Adults appeared in sunflower plots between 5 and 25 June in 1980–1985, when plants had 4–14 leaves. Oviposition began soon after adults were present and continued into late August. Peak densities of both eggs and adults occurred in mid-July. Larvae hatched between 6 and 11 July, when plants were in the early flower bud growth stages. Larvae fed in the sunflower stalk and moved to the stalk base or root crown to construct overwintering chambers. The seasonal patterns of the weevil’s life stages in 6 years were similar, but population densities varied. Regression equations were developed to predict larval numbers in stalks from number of adults to aid in making control decisions.


2016 ◽  
Vol 113 (37) ◽  
pp. 10430-10435 ◽  
Author(s):  
Clint R. V. Otto ◽  
Cali L. Roth ◽  
Benjamin L. Carlson ◽  
Matthew D. Smart

Human reliance on insect pollination services continues to increase even as pollinator populations exhibit global declines. Increased commodity crop prices and federal subsidies for biofuel crops, such as corn and soybeans, have contributed to rapid land-use change in the US Northern Great Plains (NGP), changes that may jeopardize habitat for honey bees in a part of the country that supports >40% of the US colony stock. We investigated changes in biofuel crop production and grassland land covers surrounding ∼18,000 registered commercial apiaries in North and South Dakota from 2006 to 2014. We then developed habitat selection models to identify remotely sensed land-cover and land-use features that influence apiary site selection by Dakota beekeepers. Our study demonstrates a continual increase in biofuel crops, totaling 1.2 Mha, around registered apiary locations in North and South Dakota. Such crops were avoided by commercial beekeepers when selecting apiary sites in this region. Furthermore, our analysis reveals how grasslands that beekeepers target when selecting commercial apiary locations are becoming less common in eastern North and South Dakota, changes that may have lasting impact on pollinator conservation efforts. Our study highlights how land-use change in the NGP is altering the landscape in ways that are seemingly less conducive to beekeeping. Our models can be used to guide future conservation efforts highlighted in the US national pollinator health strategy by identifying areas that support high densities of commercial apiaries and that have exhibited significant land-use changes.


2020 ◽  
Author(s):  
Paul Baldauf ◽  
◽  
Gregory Baker ◽  
Patrick Burkhart ◽  
Allen Gontz ◽  
...  

2010 ◽  
Vol 11 (1) ◽  
pp. 42 ◽  
Author(s):  
F. Mathew ◽  
B. Kirkeide ◽  
T. Gulya ◽  
S. Markell

Widespread infection of charcoal rot was observed in a commercial sunflower field in Minnesota in September 2009. Based on morphology, isolates were identified as F. sporotrichioides and F. acuminatum. Koch's postulates demonstrated pathogencity of both species. To our knowledge, this is the first report of F. sporotrichoides and F. acuminatum causing disease on Helianthus annuus L. in the United States. Accepted for publication 23 August 2010. Published 15 September 2010.


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