Emergence Pattern of Five Weeds in the Central Great Plains

1996 ◽  
Vol 10 (4) ◽  
pp. 744-749 ◽  
Author(s):  
R. L. Anderson ◽  
D. C. Nielsen
Keyword(s):  
Great Plains ◽  
Seedling Emergence ◽  
Growing Season ◽  
Crop Canopy ◽  
Emergence Pattern ◽  
Proso Millet ◽  
Annual Crops ◽  
No Till ◽  
Green Foxtail ◽  
Wheat Stubble

Seedling emergence was characterized for five weeds that infest summer annual crops in the central Great Plains as affected by crop canopy or tillage. The study was established in winter wheat stubble between 1987 and 1990, with seedling emergence recorded weekly between April 1 and November 1. Kochia emerged primarily from early April to late June, whereas green foxtail, wild-proso millet, and redroot pigweed began emerging in late May and continued until August. Volunteer wheat emerged throughout the growing season. Tillage did not affect the emergence pattern of any species, but the numbers of kochia, volunteer wheat, and green foxtail seedlings were increased in no-till. Conversely, wild-proso millet emergence was greater with tillage. Only volunteer wheat's emergence was affected by crop canopy, as fall emergence of volunteer wheat was more than three times greater in corn than in proso millet.

Cultural Strategies Reduce Weed Densities in Summer Annual Crops

1999 ◽  
Vol 13 (2) ◽  
pp. 314-319 ◽  
Author(s):  
Randy L. Anderson
Keyword(s):  
Great Plains ◽  
Weed Management ◽  
Crop Residue ◽  
Residue Management ◽  
System Effect ◽  
Proso Millet ◽  
Annual Crops ◽  
No Till ◽  
Cultural Systems ◽  
The Impact

Producers in the central Great Plains are seeking alternative strategies to manage weeds because of herbicide resistance, narrow profit margins, and a lack of registered herbicides in some crops. Thus, we evaluated the impact of cultural systems in winter wheat and tillage on weed dynamics in corn, sunflower, and proso millet planted the year following wheat harvest. Weed seedling densities were 25 to 30% lower in a no-till system compared with minimum-till with a sweep plow. With no-till, cultural systems that produced more crop residue reduced weed densities an additional 15 to 30%, compared with the conventional system. Cultural system effect was eliminated in dry years and by tillage. Weed biomass was 10-fold less in proso millet than in corn. Crop residue management, critical for successful cropping in semiarid regions, also will help weed management by reducing weed density in summer annual crops, especially in no-till systems.

Weed Seedling Emergence and Survival as Affected by Crop Canopy

2008 ◽  
Vol 22 (4) ◽  
pp. 736-740 ◽  
Author(s):  
Randy L. Anderson
Keyword(s):  
Winter Wheat ◽  
Seed Production ◽  
Spring Wheat ◽  
Seedling Emergence ◽  
Crop Canopy ◽  
Cool Season ◽  
Common Lambsquarters ◽  
Green Foxtail ◽  
Seedling Emergence And Survival ◽  
Weed Dynamics

This study measured impact of cool-season crops on seedling emergence, survival, and seed production of weeds common in corn and soybean. Weed dynamics were monitored in permanently marked quadrats in winter wheat, spring wheat, and canola. Three species, green foxtail, yellow foxtail, and common lambsquarters, comprised more than 80% of the weeds observed in the study. Seedling emergence was reduced by winter wheat, but not by spring wheat or canola, when compared with adjacent quadrats without a crop canopy. Approximately 10% of seedlings in spring wheat and canola developed into seed-bearing plants, but no seed-bearing plants were present in winter wheat at harvest. Common lambsquarters produced more than 1,100 seeds/plant, whereas a foxtail plant produced 85 seeds, averaged across spring wheat and canola. At harvest, new seedlings were present in all crops; thus, control after harvest will be required to prevent seed production in the fall. Winter wheat may provide an opportunity to disrupt population dynamics of weeds common in corn and soybean without requiring herbicides.

Feasibility of Non-irrigated Soybean (Glycine max) Production in the Semi-arid Central Great Plains

1991 ◽  
Vol 5 (2) ◽  
pp. 369-375 ◽  
Author(s):  
Gail A. Wicks ◽  
Robert N. Klein
Keyword(s):  
Winter Wheat ◽  
Great Plains ◽  
The United States ◽  
Grain Sorghum ◽  
Production Costs ◽  
Wheat Grain ◽  
No Till ◽  
Wheat Stubble ◽  
Semi Arid Region ◽  
Semi Arid

We conducted research to determine if soybeans can be grown successfully in a no-till environment, in the semi-arid areas of the central Great Plains near North Platte, NE. Soybeans planted no-till into winter wheat stubble that was sprayed with glyphosate yielded more than when planted into soil that was rototilled in a winter wheat-soybean-fallow rotation. However, grain yield averaged only 420 kg ha-1during 1975, 1976, and 1977. No-till soybean grown in a winter wheat-grain sorghum-soybean rotation during 1982 through 1985 yielded an average of 1370 kg ha-1. Low yields were associated with lack of precipitation during the fallow period after winter wheat harvest or grain sorghum harvest and during the soybean pod elongation and filling period. Several herbicides gave excellent weed control in soybeans when applied either after wheat harvest, early preplant, or at planting time. None of the herbicides persisted long enough to reduce grain yields of winter wheat planted into the soybean residue. With present production costs these nonirrigated rotations are not economical in the semi-arid region of the central Great Plains of the United States.

Weed Community Response to Crop Rotations in Western South Dakota

2007 ◽  
Vol 21 (1) ◽  
pp. 131-135 ◽  
Author(s):  
Randy L. Anderson ◽  
Clair E. Stymiest ◽  
Bruce A. Swan ◽  
John R. Rickertsen
Keyword(s):  
Winter Wheat ◽  
Great Plains ◽  
Weed Management ◽  
Seedling Emergence ◽  
Warm Season ◽  
Community Response ◽  
Crop Rotations ◽  
Integrated Weed Management ◽  
Downy Brome ◽  
Proso Millet

Producers in the semiarid Great Plains are exploring alternative crop rotations, with the goal of replacing winter wheat–fallow. In 1993, a study was established to compare performance of eight rotations comprised of various combinations with winter wheat (W), spring wheat (SW), dry pea (Pea), safflower (Saf), corn (C), sunflower (Sun), proso millet (M), or fallow (F). After 8 years, we characterized weed communities by recording seedling emergence in each rotation. Seventeen species were observed, with downy brome, kochia, horseweed, and stinkgrass comprising 87% of the community. Rotations with the least number of weed seedlings were W–F and SW–W–C–Sun; in comparison, weed density was six-fold higher in W–M. Density of downy brome and kochia was highest in W–M compared with other rotations, whereas stinkgrass and green foxtail were prominent in proso millet of the W–M and W–C–M rotations. Horseweed established readily in safflower and dry pea. In the semiarid Great Plains, designing rotations in a cycle of four that includes cool- and warm-season crops can be a key component of integrated weed management.

Weed Community and Species Response to Crop Rotation, Tillage, and Nitrogen Fertility

1998 ◽  
Vol 12 (3) ◽  
pp. 531-536 ◽  
Author(s):  
Randy L. Anderson ◽  
Don L. Tanaka ◽  
Al L. Black ◽  
Edward E. Schweizer
Keyword(s):  
Great Plains ◽  
Spring Wheat ◽  
Northern Great Plains ◽  
Common Lambsquarters ◽  
Weed Density ◽  
Species Response ◽  
Alternative Crop ◽  
No Till ◽  
Green Foxtail ◽  
Tillage System

Producers in the northern Great Plains are exploring alternative crop rotations, with the goal of replacing spring wheat-fallow. We characterized the weed associations occurring with tillage system and nitrogen level in two rotations, spring wheat (SW)-fallow (F) and SW-winter wheat (WW)-sunflower (SUN). Weed density was measured 10 yr after initiation of the study. With both rotations, weed community density was highest with no-till. For SW-F, green foxtail, yellow foxtail, and fairy candelabra comprised 99% of the weed community, whereas 13 species were observed in SW-WW-SUN. Fairy candelabra, a rangeland species, was observed only in the no-till system of SW-F. In SW-WW-SUN, no-till favored kochia, Russian thistle, and foxtails, whereas common lambsquarters and annual sowthistle were more common in tilled systems. Nitrogen fertilizer increased crop competitiveness in SW-WW-SUN with no-till, subsequently reducing weed density. Cultural strategies that disrupt weed associations will aid producers in managing weeds.

Seedling Emergence of Winter Annual Grasses as Affected by Limited Tillage and Crop Canopy

1998 ◽  
Vol 12 (2) ◽  
pp. 262-267 ◽  
Author(s):  
R. L. Anderson
Keyword(s):  
Cultural Practices ◽  
Soil Seed Bank ◽  
Seedling Emergence ◽  
First Year ◽  
Downy Brome ◽  
Crop Canopy ◽  
Proso Millet ◽  
Jointed Goatgrass ◽  
Annual Grasses ◽  
Tillage Operation

Jointed goatgrass and downy brome continue to plague winter wheat producers in the western United States. Because there are no effective herbicides for in-crop control of these weeds, producers are seeking cultural practices that stimulate seed germination and deplete the soil seed bank. We determined the effect of limited tillage and crop canopy on seedling emergence of these grasses. One tillage operation with a sweep plow increased jointed goatgrass seedling emergence 74% in the first year but did not affect emergence in later years. Downy brome emergence was not affected by tillage. Jointed goatgrass seedlings emerged over 5 yr, whereas downy brome did not emerge after 3 yr. Seedling emergence of both species was two times greater in corn and barley than in proso millet. Producers will accrue more benefit for seedbank management with cultural strategies such as alternative rotations and competitive wheat canopies than with limited tillage using a sweep plow.

Downy Brome (Bromus tectorum) Emergence Variability in a Semiarid Region

1996 ◽  
Vol 10 (4) ◽  
pp. 750-753 ◽  
Author(s):  
R. L. Anderson
Keyword(s):  
Winter Wheat ◽  
Great Plains ◽  
Wind Erosion ◽  
Bromus Tectorum ◽  
Control Strategies ◽  
Seedling Emergence ◽  
Plant Diseases ◽  
Semiarid Region ◽  
Downy Brome ◽  
Wheat Stubble

This study characterized seedling emergence of downy brome from August to early December over a 6-yr period. Seedlings were counted weekly in quadrats established in winter wheat stubble at Akron, CO. Seedling emergence varied among years, which was caused by erratic seasonal precipitation. Producers delay planting of winter wheat to reduce downy brome density in the crop, but in only 1 yr out of 6 would producers have benefited from this control strategy. Furthermore, delayed planting has negative crop consequences: less grain yield and more susceptibility to plant diseases and wind erosion because of less fall plant growth. Because fall precipitation is erratic in the semiarid Great Plains, other control strategies, such as nitrogen placement and increased seeding rates of winter wheat, would be more effective for downy brome management, yet not detrimental to winter wheat production.

Emergence Pattern and Periodicity of Palmer Amaranth (Amaranthus palmeri) Populations from Southcentral Great Plains

2021 ◽  
pp. 1-21
Author(s):  
Rui Liu ◽  
Vipan Kumar ◽  
Prashant Jha ◽  
Phillip W. Stahlman
Keyword(s):  
Great Plains ◽  
Prediction Models ◽  
Agricultural Research ◽  
Control Strategies ◽  
Growing Season ◽  
Palmer Amaranth ◽  
Effective Control ◽  
Emergence Period ◽  
Emergence Pattern ◽  
Growing Seasons

Evolution of multiple herbicide-resistant Palmer amaranth warrants the development of integrated strategies for its control in the Southcentral Great Plains (SGP). In order to develop effective control strategies, an improved understanding of the emergence biology of Palmer amaranth populations from the SGP region is needed. A common garden study was conducted in a no-till (NT) fallow field at Kansas State University Agricultural Research Center near Hays, KS, during 2018 and 2019 growing seasons, to determine the emergence pattern and periodicity of Palmer amaranth populations collected from the SGP region. Nine Palmer amaranth populations collected from five states in the SGP region: Colorado (CO1, CO2), Oklahoma (OK), Kansas (KS1, KS2), Texas (TX), and Nebraska (NE1, NE2, NE3) were included. During the 2018 growing season, the CO1 and KS1 populations displayed more rapid emergence rates, with greater parameter b values (−5.4, and −5.3, respectively), whereas the TX and NE3 populations had the highest emergence rates (b = −12.2) in the 2019 growing season. The cumulative growing degree days (cGDD) required to achieve 10%, 50%, and 90% cumulative emergence ranged from 125 to 144, 190 to 254, and 285 to 445 in 2018 and 54 to 74, 88 to 160, and 105 to 420 in the 2019 growing season across all tested populations, respectively. The OK population exhibited the longest emergence duration (301 and 359 cGDD) in both growing seasons. All tested Palmer amaranth populations had peak emergence period between May 11 and June 8 in 2018, and April 30 and June 1 in the 2019 growing season. Altogether, these results indicate the existence of differential emergence pattern and peak emergence periods of geographically-distant Palmer amaranth populations from the SGP region. This information will help in developing prediction models for decision-making tools to manage Palmer amaranth in the region.

Microtopography, Microenvironments, and Weed Populations in Ridge-Tilled Soybean

2006 ◽  
Vol 20 (3) ◽  
pp. 593-604
Author(s):  
Thomas W. Jurik
Keyword(s):  
Seedling Emergence ◽  
Growing Season ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Species ◽  
Redroot Pigweed ◽  
Giant Foxtail ◽  
Green Foxtail ◽  
Weed Emergence

The effects of microtopographic position on soil microenvironment and weed populations in ridge-tilled soybean were evaluated on three farms in Iowa in 1989 and 1990. In both years, over all weed species (primarily giant foxtail, green foxtail, yellow foxtail, redroot pigweed, and Pennsylvania smartweed), seedling emergence was highest in late May and early June, with few seedlings emerging after mid-June. Weed populations were highest in May and early June, after which rotary hoeing and cultivation reduced weed numbers in all plots. Microtopographic position (row, shoulder, and furrow) had a large effect on soil microenvironment and weed populations. Furrows were the wettest position through most of the growing season. Rows were the warmest position early in the season and the coolest position late in the season. Cumulative weed emergence early in the season was closely related to growing degree days, which accumulated faster in the row position than the furrow position. Following rotary hoeing and cultivation, the row position had significantly more total weeds than the shoulder and furrow positions on all farms in August of both years.

Organic zero-till in the northern US Great Plains Region: Opportunities and obstacles

2011 ◽  
Vol 27 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Patrick M. Carr ◽  
Randy L. Anderson ◽  
Yvonne E. Lawley ◽  
Perry R. Miller ◽  
Steve F. Zwinger
Keyword(s):  
Crop Rotation ◽  
Great Plains ◽  
Cover Crops ◽  
Cover Crop ◽  
Growing Season ◽  
Northern Great Plains ◽  
Crop Species ◽  
Cash Crops ◽  
No Till ◽  
The Us

AbstractThe use of killed cover crop mulch for weed suppression, soil erosion prevention and many other soil and crop benefits has been demonstrated in organic no-till or zero-till farming systems in eastern US regions and in Canada. Implements have been developed to make this system possible by terminating cover crops mechanically with little, if any, soil disturbance. Ongoing research in the US northern Great Plains is being conducted to identify cover crop species and termination methods for use in organic zero-till (OZ) systems that are adapted to the crop rotations and climate of this semi-arid region. Current termination strategies must be improved so that cover crop species are killed consistently and early enough in the growing season so that subsequent cash crops can be grown and harvested successfully. Delaying termination until advanced growth stages improves killing efficacy of cover crops and may provide weed-suppressive mulch for the remainder of the growing season, allowing no-till spring seeding of cash crops during the next growing season. Excessive water use by cover crops, inability of legume cover crops to supply adequate amounts of N for subsequent cash crops and failure of cover crops to suppress perennial weeds are additional obstacles that must be overcome before the use of killed cover crop mulch can be promoted as a weed control alternative to tillage in the US northern Great Plains. Use of vegetative mulch produced by killed cover crops will not be a panacea for the weed control challenges faced by organic growers, but rather one tool along with crop rotation, novel grazing strategies, the judicious use of high-residue cultivation equipment, such as the blade plow, and the use of approved herbicides with systemic activity in some instances, to provide organic farmers with new opportunities to incorporate OZ practices into their cropping systems. Emerging crop rotation designs for organic no-till systems may provide for more efficient use of nutrient and water resources, opportunities for livestock grazing before, during or after cash crop phases and improved integrated weed management strategies on organic farms.

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