scholarly journals Integrated Weed Management Systems Identified for Jointed Goatgrass (Aegilops cylindrica) in the Pacific Northwest

2010 ◽  
Vol 24 (4) ◽  
pp. 430-439 ◽  
Author(s):  
Frank L. Young ◽  
Daniel A. Ball ◽  
Donn C. Thill ◽  
J. Richard Alldredge ◽  
Alex G. Ogg ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Weed Management ◽  
Cropping Systems ◽  
Wheat Variety ◽  
Integrated Weed Management ◽  
Weed Density ◽  
Jointed Goatgrass ◽  
F Region ◽  
The Pacific

Jointed goatgrass is an invasive winter annual grass weed that is a particular problem in the low to intermediate rainfall zones of the Pacific Northwest (PNW). For the most part, single-component research has been the focus of previous jointed goatgrass studies. In 1996, an integrated cropping systems study for the management of jointed goatgrass was initiated in Washington, Idaho, and Oregon in the traditional winter wheat (WW)–fallow (F) region of the PNW. The study evaluated eight integrated weed management (IWM) systems that included combinations of either a one-time stubble burn (B) or a no-burn (NB) treatment, a rotation of either WW–F–WW or spring wheat (SW)–F–WW, and either a standard (S) or an integrated (I) practice of planting winter wheat. This study is the first, to our knowledge, to evaluate and identify complete IWM systems for jointed goatgrass control in winter wheat. At the Idaho location, in a very low weed density, no IWM system was identified that consistently had the highest yield, reduced grain dockage, and reduced weed densities. However, successful IWM systems for jointed goatgrass management were identified as weed populations increased. At the Washington location, in a moderate population of jointed goatgrass, the best IWM system based on the above responses was the B:SW–F–WW:S system. At the Washington site, this system was better than the integrated planting system because the competitive winter wheat variety did not perform well in drought conditions during the second year of winter wheat. At the Oregon site, a location with a high weed density, the system B:SW–F–WW:I produced consistently higher grain yields, reduced grain dockage, and reduced jointed goatgrass densities. These integrated systems, if adopted by PNW growers in the wheat–fallow area, would increase farm profits by decreasing dockage, decreasing farm inputs, and reducing herbicide resistance in jointed goatgrass.

Nitrogen Fertility and Weed Management Critical for Continuous No-Till Wheat in the Pacific Northwest

2006 ◽  
Vol 20 (3) ◽  
pp. 658-669 ◽  
Author(s):  
Frank L. Young ◽  
Mark E. Thorne ◽  
Douglas L. Young
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Crop Yield ◽  
Spring Wheat ◽  
Weed Management ◽  
Weed Density ◽  
N Level ◽  
No Till ◽  
The Pacific ◽  
Density And Biomass

No-till cropping is an option for growers needing to reduce soil erosion in the Palouse annual-cropped region of the Pacific Northwest, which is well suited for wheat production. A 6-yr field study was conducted to determine optimum levels of fertilizer and herbicide inputs in a no-till continuous wheat crop production system. Three levels of nitrogen (N) and two weed management levels (WML) were compared in a spring wheat (SW)–winter wheat (WW)–WW rotation through two rotation cycles. The high WML reduced weed densities about 50% compared with the low WML. In general, herbicide treatments were more effective on broadleaf weeds and may have facilitated a shift toward grass weeds. The high WML reduced grass weed biomass only at the reduced N levels, whereas the high WML reduced broadleaf weed density at all N levels. Variable environmental conditions affected wheat yield; however, yield tended to be highest where winter wheat immediately followed spring wheat. Nitrogen had little effect on weed density but increased crop yield about 13% with each increased N level. Crop yield was greater at the high versus low WML at each N level, even though weed density and biomass were reduced least between WMLs at the highest N level. The highest crop yield and net returns were obtained with the highest N and WML; however, none of the N and WML combinations were profitable.

Weed Management for Crop Production in the Northwest Wheat (Triticum aestivum) Region

Weed Science ◽  
1996 ◽  
Vol 44 (2) ◽  
pp. 429-436 ◽  
Author(s):  
Frank L. Young ◽  
Alex G. Ogg ◽  
Donn C. Thill ◽  
Douglas L. Young ◽  
Robert I. Papendick
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Weed Management ◽  
Crop Production ◽  
Conservation Tillage ◽  
Cropping Systems ◽  
Wild Oat ◽  
Downy Brome ◽  
Tillage Systems ◽  
The Pacific

A 9-yr large-scale integrated pest management (IPM) study was initiated in 1985 to develop and refine profitable conservation cropping systems in the Palouse wheat-growing region of the Pacific Northwest. Weed scientists from the USDA-ARS and the land-grant universities of ID and WA led a team of researchers and extension personnel from eight disciplines to investigate the interactions of crop systems, tillage systems, and weed management levels (WML) on crop production. Ineffective weed control has been a major deterrent to the adoption of conservation tillage by wheat growers. With this in mind, the primary focus of the scientists on the IPM project was integrated weed management (IWM) in conservation crop production systems for highly erodible land. For the first time in the Pacific Northwest, systems research developed a conservation production system using a 3-yr crop rotation that controlled weeds effectively, reduced erosion, was less risky than traditional farming systems, and was profitable. Broadleaf weeds were more prevalent in the 3-yr rotation of winter wheat-spring barley-spring pea compared to continuous wheat in both conservation and conventional tillage systems. In conservation tillage, troublesome grass weeds included wild oat and downy brome. Wild oat was controlled effectively at the moderate and maximum weed management levels under conservation tillage in the 3-yr rotation. Two years out of winter wheat (such as in the 3-yr rotation) reduced downy brome populations. In contrast, growing a spring crop 1 yr, followed by 2 yr of winter wheat was not effective for controlling downy brome. Effective weed control was instrumental in developing successful conservation IPM cropping systems, and education and technology transfer were important in helping action agencies assist growers in adopting these systems.

Effects of Herbicide, Tillage, and Grass Seeding on Wild Chervil (Anthriscus sylvestris)

2011 ◽  
Vol 4 (3) ◽  
pp. 326-331 ◽  
Author(s):  
Timothy W. Miller ◽  
Danielle E. D'Auria
Keyword(s):  
Pacific Northwest ◽  
Weed Management ◽  
Dry Weight ◽  
Integrated Weed Management ◽  
Native Plant ◽  
Forage Production ◽  
Perennial Weed ◽  
Native Plant Species ◽  
Herbicide Treatment ◽  
The Pacific

AbstractWild chervil is an invasive biennial or short-lived perennial weed introduced into North America that negatively impacts forage production and degrades habitat for native plant species. A 2-yr study using prebloom mowing followed by combinations of herbicide, tillage, and grass seeding was conducted in the Pacific Northwest to identify an effective integrated weed management strategy for this species. By 2 mo after herbicide treatment (MAHT), wild chervil control with glyphosate + ammonium sulfate (AMS) and clopyralid was 83 and 73%, respectively. Tillage with or without herbicide pretreatment resulted in 92 to 98% wild chervil control at 2 MAHT, whereas herbicide without tillage gave only 45% control across all treatments. Tillage with or without subsequent grass seeding reduced wild chervil density four-fold compared to herbicide alone at 9 MAHT. Herbicide + tillage + grass seeding resulted in similar wild chervil cover (1 to 5% cover) as herbicide + tillage (1 to 6% cover) without subsequent grass seeding. Wild chervil biomass at 1 yr after herbicide treatment (YAHT) was reduced to 487 kg ha−1 (439 lb ac−1) with herbicide + tillage compared to 4,256 kg ha−1 for herbicide treatment alone. Herbicide + tillage + grass seeding increased grass dry weight at 1 YAHT from 201 kg ha−1 for herbicide + tillage to 1,575 kg ha−1, compared to 351 kg ha−1 in herbicide-only plots.

Impact of integrated management systems on jointed goatgrass (Aegilops cylindrica) populations

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 1010-1017 ◽  
Author(s):  
Anthony D. White ◽  
Phillip W. Stahlman ◽  
Francis E. Northam
Keyword(s):  
Winter Wheat ◽  
Crop Rotation ◽  
Weed Management ◽  
Cultural Practices ◽  
Integrated Management ◽  
Wheat Variety ◽  
Field Studies ◽  
Grain Sorghum ◽  
Management Program ◽  
Jointed Goatgrass

Research during the past several decades on jointed goatgrass management has focused on individual cultural practices rather than on multi- or interdisciplinary components. Field studies were conducted at Hays, KS, from 1997 to 2003 to evaluate the interaction of crop rotation, fallow weed management, and winter wheat variety on jointed goatgrass density. Extending a wheat–fallow (W–F) rotation to include grain sorghum or grain sorghum and sunflower reduced jointed goatgrass populations more than other cultural practices tested. Fallow treatments were equal in most years, but mechanical fallow resulted in increased jointed goatgrass emergence compared with chemical fallow under drought conditions. Winter wheat cultivars had little effect on jointed goatgrass populations. However, taller, more competitive varieties are favorable for jointed goatgrass control in an integrated management program. No specific combination of crop rotation, fallow weed management, and wheat variety consistently reduced jointed goatgrass density more than other combinations during multiple years.

Temperature effects on jointed goatgrass (Aegilops cylindrica) seed germination

Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 594-599 ◽  
Author(s):  
Lynn Fandrich ◽  
Carol Mallory-Smith
Keyword(s):  
Seed Germination ◽  
Winter Wheat ◽  
Weed Management ◽  
Management Strategies ◽  
Wheat Variety ◽  
Wheat Seed ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass ◽  
Temperature Regimes ◽  
Radicle Protrusion

A better understanding of the persistence of jointed goatgrass seed in soil and its dormancy will lead to the development of more effective weed-management strategies. Three populations of jointed goatgrass were collected from winter wheat fields in Oregon, and grown together with the winter wheat variety ‘Madsen’ in nurseries at Moro and Pendleton, OR. Germination responses of jointed goatgrass and wheat seed were recorded over 14 d at 5/5, 15/10, 15/15, 25/15, 25/25, and 30/20 C day/night temperatures and a 12-h photoperiod. Because jointed goatgrass spikelets often contain two seed, primary and secondary seed germination values were recorded. Secondary seed germination was defined as 3-mm radicle protrusion, and primary seed germination was defined as 5-mm emergence of the second coleoptile. Jointed goatgrass secondary seed germinated when exposed to all temperature regimes. Jointed goatgrass secondary seed germination occurred 3 d earlier in temperature regimes involving 15 C compared to germination at 5/5, 25/25, and 30/20 C. Final germination values for jointed goatgrass secondary seed were greatest when seed were incubated at 25/15 C. Wheat seed germinated at all temperature regimes, although the onset of germination occurred 1 to 1.5 d later at 5/5 C compared to other temperature regimes. Jointed goatgrass primary seed germinated only at 15/10, 15/15, and 25/15 C, and maximum germination occurred at 25/15 C. Dormancy in jointed goatgrass might prevent germination of seed within freshly shattered spikelets until autumn when temperatures are low and moisture is available. Because final germination percentages in jointed goatgrass primary and secondary seed were less than 100%, additional research on factors regulating dormancy is needed.

Separating the effects of crop rotation from weed management on weed density and diversity

Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 729-735 ◽  
Author(s):  
Colleen Doucet ◽  
Susan E. Weaver ◽  
Allan S. Hamill ◽  
Jianhua Zhang
Keyword(s):  
Crop Rotation ◽  
Weed Management ◽  
Management Practices ◽  
Cropping Systems ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Direct Result ◽  
Weed Density ◽  
Richness Index ◽  
Rotation Study

Crop rotation is thought to reduce weed density and maintain species diversity, thus preventing the domination of a few problem weeds. Because cropping sequence dictates other agricultural management practices, variations in weed populations between cropping systems may be the direct result of crop rotation, the result of different weed management practices associated with crop rotation, or both. Studies that fail to separate the effects of crop rotation from weed management may generate misleading results. A 10-yr crop rotation study was undertaken to study the dynamics of the standing weed vegetation inZea maysL.,Glycine maxL., andTriticum aestivumL. The present paper compared total weed density and diversity between monocultures and rotations under three levels of weed management. Weed management accounted for 37.9% of the variation in total weed density, whereas crop rotation accounted for only 5.5%. Weed density varied between monocultures and rotations in plots where herbicides were applied. The effectiveness of rotations in reducing weed density was dependent upon the crop. Margalef's species richness index (DMG), a measure of diversity, varied among weed management strategies, with 38.4% of the variance attributed to this factor. In the 10th year, when all plots were sown withZ. mays, few cumulative effects of crop rotation were apparent, with two exceptions. In weedy and herbicide-treated plots, weed density was higher on plots cropped withZ. maysthe previous year. Also, under these weed management treatments, including a cereal in the crop rotation reduced weed density. Crop rotation, when used in combination with herbicides, provides additional weed control and is therefore an effective tool in integrated weed management.

Postharvest Tillage Reduces Downy Brome (Bromus tectorumL.) Infestations in Winter Wheat

2014 ◽  
Vol 28 (2) ◽  
pp. 418-425 ◽  
Author(s):  
Frank L. Young ◽  
Alex G. Ogg ◽  
J. Richard Alldredge
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Weed Management ◽  
Soil Surface ◽  
Wheat Crop ◽  
Downy Brome ◽  
No Till ◽  
The Pacific ◽  
Plant Densities ◽  
Summer Fallow

In the Pacific Northwest, downy brome continues to infest winter wheat, especially in low-rainfall areas where the winter wheat–summer fallow rotation is the dominant production system. In Washington, a study was conducted for 2 yr at two locations in the winter wheat–summer fallow region to determine the influence of four postharvest tillage treatments on vertical seed movement, seedbank depletion, and plant densities of downy brome. The four tillage implements included a disk, sweep plow, harrow, and skew treader. The study also included a no-till treatment for comparison. The sweep plow and disk led to the most vertical movement of downy brome seed compared with the no-till treatment. Approximately 75% of the fall postharvest seed in the no-till treatment was located either on the soil surface or in the 0- to 3-cm depth at both locations. In contrast, 75% of the seed in the disked treatment was located from 0 to 6 cm deep at both locations. The disk and sweep plow both decreased downy brome seed in the soil at the 0- to 3-cm depth compared with the harrow and no-till treatments. There was no difference in downy brome plant densities following postharvest tillage in the summer fallow due to any of the treatments. However, plant densities in the subsequent winter wheat crop were reduced by the disk and sweep plow compared with the no-till and skew-treader treatments. In general, seed densities as affected by the skew treader fell between the disk and the no-till treatments. The use of the sweep plow and the disk should be integrated into a weed management strategy for downy brome in the wheat–fallow region of the Pacific Northwest.

A Single-Time Survey Method to Predict the Daily Weed Density for Weed Control Decision-Making

Weed Science ◽  
2011 ◽  
Vol 59 (2) ◽  
pp. 270-275 ◽  
Author(s):  
Roberta Masin ◽  
Vasileios P. Vasileiadis ◽  
Donato Loddo ◽  
Stefan Otto ◽  
Giuseppe Zanin
Keyword(s):  
Decision Making ◽  
Weed Control ◽  
Weed Management ◽  
Cropping Systems ◽  
Estimation Method ◽  
Integrated Weed Management ◽  
Survey Method ◽  
The European Union ◽  
Weed Density ◽  
Crop Cycle

Decision-making processes must indicate if, how, and when weed control should be practiced. So far, Decision Support Systems (DSSs) for weed control to prevent crop yield losses can guide decisions on “if” and “how.” Experience shows that farmers need a DSS that can also guide when to treat, but this can only be done if the actual weed density observed in the field is known during the crop cycle. Emergence models allow the prediction of daily density, but precision depends on the survey date. This study focuses on the estimation of the date of the survey for the best prediction of the daily density throughout the crop cycle. The predicted daily density of each species can be used by DSSs without any further survey, saving time and money and improving the use of the DSSs. Results showed that the best date is when the actual density of each weed reaches or exceeds 50% emergence, and this is earlier than the critical point date, supporting the validity of the date estimation method. The possibility to provide specific advice for farmers considering a proper mortality rate of weed seedlings is then discussed. The ability to optimize the date of sampling can improve the reliability of decision-making tools for integrated weed management, in agreement with the European Union goal of sustainable use of pesticides and more environmentally sustainable cropping systems through the use of integrated pest management.

scholarly journals Effects of Crop Rotations and Tillage on Pratylenchus spp. in the Semiarid Pacific Northwest United States

Plant Disease ◽  
2013 ◽  
Vol 97 (4) ◽  
pp. 537-546 ◽  
Author(s):  
Richard W. Smiley ◽  
Stephen Machado ◽  
Jennifer A. Gourlie ◽  
Larry C. Pritchett ◽  
Guiping Yan ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Spring Wheat ◽  
Cropping Systems ◽  
Spring Barley ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
The Pacific ◽  
Spring Cereals ◽  
Chemical Fallow

There is interest in converting rainfed cropping systems in the Pacific Northwest from a 2-year rotation of winter wheat and cultivated fallow to direct-seed (no-till) systems that include chemical fallow, spring cereals, and food legume and brassica crops. Little information is available regarding effects of these changes on plant-parasitic nematodes. Eight cropping systems in a low-precipitation region (<330 mm) were compared over 9 years. Each phase of each rotation occurred each year. The density of Pratylenchus spp. was greater in cultivated than chemical fallow, became greater with increasing frequency of host crops, and was inversely associated with precipitation (R2 = 0.92, α < 0.01). Densities after harvesting mustard, spring wheat, winter wheat, and winter pea were greater (α < 0.01) than after harvesting spring barley or spring pea. Camelina also produced low densities. Winter wheat led to a greater density of Pratylenchus neglectus and spring wheat led to a greater density of P. thornei. Density of Pratylenchus spp. was correlated (R2 = 0.88, α < 0.01) but generally higher when detected by real-time polymerase chain reaction on DNA extracts from soil than when detected by a traditional method. Selection of different Pratylenchus spp. by different wheat cultivars or growth habit must be addressed to minimize the level of nematode risk to future plantings of intolerant crops.

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