Effect of Kochia (Kochia scoparia) Interference on Sunflower (Helianthus annuus) Yield

Weed Science ◽  
2014 ◽  
Vol 62 (1) ◽  
pp. 158-165 ◽  
Author(s):  
Derek W. Lewis ◽  
Robert H. Gulden
Keyword(s):  
Great Plains ◽  
Growth And Development ◽  
Seed Quality ◽  
Seedling Recruitment ◽  
Soil Surface ◽  
Northern Great Plains ◽  
Limited Information ◽  
Leaf Stage ◽  
Action Threshold ◽  
Sunflower Crop

Kochia is a weed found in many sunflower fields across the Northern Great Plains. There is limited information about the ability of sunflower plants to compete with kochia, specifically when the weed grows both in the crop row and in the inter-row space, as in zero tillage systems that rely solely on herbicides to manage weeds. An experiment was conducted over seven site–yr, from 2009 to 2011, to determine the effect of kochia density and relative time of kochia seedling recruitment on sunflower growth and development, yield and seed quality. Kochia seed was broadcast on the soil surface at six densities, into sunflowers planted in 75-cm rows, either at the same time as the sunflower crop was planted (early weed seedling recruitment), or when the sunflowers were at the four-leaf stage (late weed seedling recruitment). When kochia plants emerged at the same time as the sunflowers, yield was reduced by up to 76% and sunflower head diam was reduced in four site–yr, stem diam was reduced in three site–yr, height was reduced in two site–yr and the number of leaves per sunflower plant was reduced in two site–yr The 5% action threshold for early emerging kochia was four kochia plants m−2in the combined site–yr analysis. Additionally, early recruiting kochia seedlings reduced sunflower seed size and seed weight at two and three site–yr, respectively. Kochia plants that emerged after the four-leaf stage of the sunflower crop did not affect sunflower growth and development, yield, or seed quality. To reduce the potential for yield and seed quality losses, sunflower growers should be proactive with respect to managing kochia in sunflowers, particularly when the kochia plants emerge at about the same time as the sunflowers.

Effect of Biennial Wormwood (Artemisia biennis) Interference on Sunflower Yield and Seed Quality

Weed Science ◽  
2016 ◽  
Vol 64 (1) ◽  
pp. 154-160
Author(s):  
Derek W. Lewis ◽  
Andrea Cavalieri ◽  
Robert H. Gulden
Keyword(s):  
Growth And Development ◽  
Field Experiments ◽  
Seed Quality ◽  
Seedling Recruitment ◽  
Crop Yields ◽  
Soil Surface ◽  
Relative Time ◽  
Leaf Stage ◽  
Sunflower Crop ◽  
Growth Development

Biennial wormwood has been increasing in Manitoba, Canada, but information is limited on the potential of biennial wormwood to reduce crop yields. Field experiments were conducted over 5 site-yr throughout southern Manitoba in 2010 and 2011 to determine the effect of biennial wormwood density and relative time of biennial wormwood seedling recruitment on sunflower growth, development, yield, and seed quality. Biennial wormwood was broadcast on the soil surface at six densities into sunflowers planted in 75-cm rows, either at the same time the sunflower crop was planted (early weed seedling recruitment) or when the sunflowers were at about the four-leaf stage (late weed seedling recruitment). When biennial wormwood emerged at about the same time as the sunflowers, yield was reduced by up to 46%. Early-recruiting biennial wormwood had minimal effect on sunflower growth and development, but sunflower achene size and individual achene weight were reduced, even when no effect on sunflower yield was observed. Biennial wormwood plants that recruited after the four-leaf stage of the sunflower crop had no effect on sunflower yield or seed quality.

Evaluation of fungicide efficacy on sunflower rust (Puccinia helianthi) on oilseed and confection sunflower

2021 ◽  
Author(s):  
Brandt Berghuis ◽  
Andrew Friskop ◽  
Michelle Gilley ◽  
Jessica Halvorson ◽  
Bryan Hansen ◽  
...  
Keyword(s):  
Great Plains ◽  
Field Experiments ◽  
Field Trials ◽  
Northern Great Plains ◽  
Puccinia Helianthi ◽  
Action Threshold ◽  
The Us ◽  
Fungicide Efficacy ◽  
Rust Severity ◽  
Important Disease

Sunflower rust, caused by Puccinia helianthi, is an economically and globally important disease of sunflower. Two types of sunflowers are produced in the US Northern Great Plains; the oilseed type and the confection type. Although approximately 80% of the acreage in this region is planted as the oilseed type sunflower, fungicide efficacy and timing studies have been conducted primarily on the more rust-susceptible confection type. A total of ten sunflower rust efficacy field experiments were conducted on oilseed type and confectionary type hybrid trials from 2016-2018. Eleven fungicides from three FRAC groups were evaluated for efficacy and protection of yield. Severity differences among fungicide treatments were identified in both confection and oilseed type sunflower trials. A combined analysis of all confection field trials (five) indicated that rust severity was lower in all fungicide treatments as compared to the non-treated control. Despite rust severity levels below the fungicide action threshold for confection sunflower, seven of the eleven fungicide treatments had yield higher than the non-treated control. In oilseed trials, rust severity was lower in all fungicide treatments as compared to the non-treated control, similar to the findings of the confection type. Rust severity was too low to detect yield differences in oilseed trials. Additional work is needed to elucidate yield-loss potential on oilseed type sunflower and refine the fungicide action threshold on confection type sunflower.

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
Keyword(s):  
United States ◽  
South Dakota ◽  
Great Plains ◽  
Northern Great Plains ◽  
Charcoal Rot ◽  
Midwestern United States ◽  
First Report ◽  
High Incidence ◽  
Sunflower Crop ◽  
North And South

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.

scholarly journals Breeding Alfalfa for Semiarid Regions in the Northern Great Plains: History and Additional Genetic Evaluations of Novel Germplasm

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1686
Author(s):  
Arvid Boe ◽  
Kevin D. Kephart ◽  
John D. Berdahl ◽  
Michael D. Peel ◽  
E. Charles Brummer ◽  
...  
Keyword(s):  
Seed Production ◽  
Great Plains ◽  
Seedling Recruitment ◽  
The United States ◽  
Northern Great Plains ◽  
United States Department ◽  
Production Traits ◽  
Plant Introductions ◽  
Semiarid Regions ◽  
Commercial Seed

Yellow-flowered alfalfa (Medicago sativa subsp. falcata) (also known as sickle medic) has been the cornerstone for breeding alfalfa for dual grazing and hay production in the semiarid regions of the northern Great Plains in the US and Canada. Most, if not all, of the cultivars developed for the northern Great Plains during the 20th century, had parentage tracing back to introductions by Niels Ebbesen Hansen that were obtained from expeditions to Russia, primarily the province of Siberia, on behalf of the United States Department of Agriculture during the early 1900s. The M. falcata genome contains alleles for high levels of drought-tolerance, winter hardiness, and tolerance to grazing, but is generally deficient for commercial seed production traits, such as non-shatter, compared with common alfalfa (M. sativa). A naturalized population, tracing to USDA plant introductions to Perkins County South Dakota by N.E. Hansen in early 1900, and subsequently, facilitated by the determined seed increase and interseeding of a population by a local rancher, Norman ‘Bud’ Smith, has shown highly desirable in situ characteristics for improving rangelands in the northern Great Plains. This includes adequate seed production to build a seed bank in the soil for natural seedling recruitment and population maintenance/expansion and support the production of a commercial seed source. This review documents the seminal events in the development of cultivars to date and describes novel germplasm with potential for new cultivars in the future.

scholarly journals Phenotypic and Molecular Diversity of Cochliobolus sativus Populations from Wheat

Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 62-73 ◽  
Author(s):  
Suraj Gurung ◽  
Baidya N. Mahto ◽  
Sanjaya Gyawali ◽  
Tika B. Adhikari
Keyword(s):  
Great Plains ◽  
Molecular Diversity ◽  
The United States ◽  
Dna Polymorphisms ◽  
Cochliobolus Sativus ◽  
Fixation Index ◽  
Northern Great Plains ◽  
Limited Information ◽  
Population Genetic Analysis ◽  
Phenotypic Data

Spot blotch, caused by Cochliobolus sativus, is a devastating foliar disease of wheat in Nepal and in the Northern Great Plains of the United States. However, limited information on variation in virulence and genetic structure of C. sativus from wheat is available. In this study, pathogenic variation of 96 isolates of C. sativus from the Hill and Plain areas in Nepal (n = 48) and in the Central and Northern areas in North Dakota (n = 48) were evaluated on 12 differential wheat lines. DNA polymorphisms in all isolates were analyzed using eight selected amplified fragment length polymorphism primer combinations. Phenotypic data analysis showed the isolates varied greatly and were classified into 47 pathotypes. Cluster analysis indicated the isolates fell into three distinct groups with low, intermediate, and high virulence. Population genetic analysis revealed significant linkage disequilibrium ([Formula: see text] = 0.066 to 0.292), indicating that sexual reproduction plays little or no role in evolution and disease epidemiology in wheat fields. Furthermore, the corrected standardized fixation index (G″ST = 0.05 and 0.02) showed no evidence of genetic differentiation in C. sativus populations. Collectively, these results confirmed high pathogenic and molecular diversity in the C. sativus populations collected from wheat foliar infections and will be useful to assist in developing resistant cultivars to manage this disease.

Limiting Green and Yellow Foxtail (Setaria viridisandS. glauca) Seed Production Following Spring Wheat (Triticum aestivum) Harvest

1999 ◽  
Vol 13 (1) ◽  
pp. 43-47 ◽  
Author(s):  
George O. Kegode ◽  
Frank Forcella ◽  
Beverly R. Durgan
Keyword(s):  
Seed Production ◽  
Great Plains ◽  
Spring Wheat ◽  
Soil Surface ◽  
The United States ◽  
Northern Great Plains ◽  
University Of Minnesota ◽  
Tillage Systems ◽  
Hard Red Spring Wheat ◽  
Main Plot

Green and yellow foxtail seed production following harvest of spring wheat is a concern of producers in the northern Great Plains of the United States and the Prairie Provinces of Canada. Experiments were conducted in 1996 and 1997 in three tillage systems, no till (NT), chisel plow (CP), and moldboard plow (MP), at the University of Minnesota West Central Experiment Station, Morris, MN, to determine whether time of glyphosate application or tillage after spring wheat harvest could reduce postharvest foxtail seed production. In both years, hard red spring wheat was planted in late April and a packaged mixture of fenoxaprop and 2,4-D ester and MCPA ester was applied at a rate of 53 g and 81 g and 246 g ai/ha for grass and broadleaf weed control. Following spring wheat harvest, each main plot was subdivided into seven subplots, including an untreated control. One subplot was disked twice at 4 to 6 d after harvest (DAH) of spring wheat, and five other subplots had glyphosate (0.25 kg ai/ ha) applied on different days (1 to 31 DAH). Foxtail seeds were collected from the soil surface following first frost, and the number of green and yellow foxtail seeds were determined. Tillage immediately after spring wheat harvest eliminated foxtail plants, and no new foxtail seedlings emerged in either tilled or glyphosate-treated plots despite ideal postharvest conditions for foxtail germination and emergence in 1997. Most viable green foxtail seeds were consistently obtained in NT plots, whereas yellow foxtail seed production varied among tillage systems. Either tillage soon after spring wheat harvest or glyphosate application within 16 DAH reduced green and yellow foxtail seed production by greater than 70%.

scholarly journals Niger Tolerance to Flucarbazone

2015 ◽  
Vol 29 (3) ◽  
pp. 529-535 ◽  
Author(s):  
William E. May
Keyword(s):  
Weed Control ◽  
Great Plains ◽  
Growing Season ◽  
Northern Great Plains ◽  
Treatment Combination ◽  
Seed Filling ◽  
Application Timing ◽  
Good Balance ◽  
Leaf Stage ◽  
Crop Tolerance

Niger is a potential crop for the Northern Great Plains, but not until volunteer canola can be controlled. A study at Indian Head, SK, was conducted from 2007 to 2009 to determine the tolerance of niger to flucarbazone, a herbicide that controls volunteer canola. The tolerance was determined by applying three rates of flucarbazone (19, 28.5, and 38 g ai ha−1) at four application stages (two, four, six, and eight-leaf stage). Mean injury did not exceed 22% for any year by treatment combination. Injury was most prominent in 2007, and dissipated as the growing season progressed. Increasing the rate of flucarbazone increased crop injury depending on the year, application timing, and evaluation timing. Injury under 20% in 2007 and under 10% in 2008 and 2009 was observed at the start of flowering when flucarbazone was applied at the two, four, and six-leaf stage. Injury from applications at the two, four, and six-leaf stage decreased as the growing season progressed. When the labelled rate of flucarbazone for wheat (19 g ha−1) was applied at the two, four, or six leaf stage, injury was below 10%. Injury when flucarbazone was applied at the eight-leaf stage was highest during seed filling. Volunteer canola was controlled by flucarbazone. The application of flucarbazone relative to a weedy control increased yield by about 50% (138 to 213 kg ha−1) in 2008 and 2009. Flucarbazone rate did not affect niger yield except in 2007 where yield was about 100 kg ha−1 less with the two highest rates. Delaying flucarbazone application decreased niger yield, especially in the year (2007) with most niger injury. Flucarbazone application at the two- or four-leaf niger stage at a rate of 19 g ha−1 provided a good balance of weed control and crop tolerance.

Seed burial by tillage promotes field recruitment of false cleavers (Galium spurium) and catchweed bedstraw (Galium aparine)

Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 578-585 ◽  
Author(s):  
Danielle J. Reid ◽  
Rene C. Van Acker
Keyword(s):  
Soil Moisture ◽  
Bulk Density ◽  
Great Plains ◽  
Field Experiments ◽  
Soil Depth ◽  
Soil Surface ◽  
Northern Great Plains ◽  
Galium Aparine ◽  
Tillage Operation ◽  
Galium Spurium

False cleavers and catchweed bedstraw are problematic weeds of field crops in high-latitude regions of the northern Great Plains of North America. The abundance of these species has been increasing in areas of greater tillage intensity and frequency. Field experiments were established over 4 site-yr in Manitoba, Canada, and results indicated that the recruitment of false cleavers and catchweed bedstraw was strongly promoted by a single shallow tillage operation with a sweep cultivator in the spring. Percent recruitment levels in 2001 (pooled over sites) were 17 and 46% for the untilled and tilled treatments, respectively. In 2002, the percent recruitment levels for the untilled and tilled treatments, respectively, were 28 and 38% for the Komarno site and 13 and 28% for the Petersfield site. Only a few and minor differences in microsite conditions (soil temperature, soil moisture, and bulk density) resulted from the single spring tillage pass. The single tillage pass caused a significant relocation of simulated seeds (plastic beads) to below the soil surface and deeper into the soil profile (2–4 cm). Mean bulk density and volumetric soil moisture increased significantly with soil depth. The results of this study suggest that the positive effect of tillage on cleavers recruitment was not due to the effect of tillage on microsite conditions per se. Rather, the vertical redistribution of seed by tillage moved these seeds to a place in which the microsite conditions differed from those on the surface and were more favorable for recruitment. False cleavers and catchweed bedstraw recruitment is clearly promoted by tillage (even minor tillage) under field conditions, and farmers might be able to limit recruitment by limiting spring tillage.

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