Weed Seed Wizard: A tool that demonstrates the value of integrated weed management tactics such as harvest weed seed destruction

Cooperative research was initiated by a multidisciplinary team of weed scientists and agricultural economists in 1975 that laid the foundation for integrated weed management research in Colorado. Colorado's integrated weed management research has four phases: weed seed bank decline, systems approach to weed management, bioeconomic modeling, and multiple weed management tactics. Each phase considered weed seed bank, weed control efficacy, weed control costs, crop yield, and gross margin. All four phases emphasize the need for a weed management system that minimizes seed production in situations where a high soil weed seed bank exists. However, once the weed seed bank is reduced, a weed management program with less than 100% weed control can be employed without increasing the seed bank. Intensive weed management systems are seldom justified when economics, weed control, and weed seed bank are considered. Integrated weed management approaches require integrating crop and weed biology with management tactics. Integrated weed management requires advanced managerial skills and often more time than traditional approaches.

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A “Stressed” Alfalfa-Based Cropping System Leads to the Selection of Quizalofop-Resistant Italian Ryegrass (Lolium perennessp.multiflorum)

Weed Science ◽

10.1614/ws-d-15-00193.1 ◽

2016 ◽

Vol 64 (4) ◽

pp. 683-694 ◽

Cited By ~ 1

Author(s):

Alberto Collavo ◽

Silvia Panozzo ◽

Antonio Allegri ◽

Maurizio Sattin

Keyword(s):

Ethyl Ester ◽

Seed Production ◽

Weed Management ◽

Cropping System ◽

Italian Ryegrass ◽

Integrated Weed Management ◽

Forage Production ◽

Weed Seed ◽

Quizalofop Ethyl ◽

Selection Of

Italian ryegrass populations investigated in this study were harvested in an alfalfa-based cropping system. In that system, the agronomic practices and chemical weed management, based on the use of aryloxyphenoxy-propionates herbicides (i.e., quizalofop ethyl ester), were optimized to obtain a dual seed–forage production. Five of seven populations tested were confirmed resistant to quizalofop ethyl ester with resistance indexes ranging from 4.5 to >209. Both target- and nontarget-site resistance mechanisms were most likely involved. Three allelic variants were detected (Ile-1781–Leu, Trp-2027–Cys, and Ile-2041–Asn) in four resistant populations, whereas no known mutations were found in one resistant population. The herbicide treatment on Italian ryegrass plants at different phenological stages suggested that to control regrowth, it is necessary to use two to fives times the herbicide dose suitable for younger plants. This situation is encountered in fields when Italian ryegrass plants need to be controlled to maximize the alfalfa seed production, and it is comparable to using a sublethal herbicide dose, leading to the selection of herbicide-resistant biotypes. In such a situation, the cropping system is not sustainable, and integrated weed management should be implemented to deplete the soil weed seed bank and prevent new weed seed production.

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Evaluation of New Harvesting Methods to Reduce Weeds on Arable Fields and Collect a New Feedstock

Energies ◽

10.3390/en12091688 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1688 ◽

Cited By ~ 7

Author(s):

Christoph Glasner ◽

Christopher Vieregge ◽

Josef Robert ◽

Johanna Fenselau ◽

Zahra Bitarafan ◽

...

Keyword(s):

Weed Management ◽

Growing Season ◽

Integrated Weed Management ◽

Management Approach ◽

Weed Seed ◽

Galium Aparine ◽

Bromus Hordeaceus ◽

Weed Seeds ◽

Arable Fields ◽

Combine Harvester

During harvesting, grain, straw, and chaff with weed seeds are separated. The chaff is returned to the fields, resulting in weed problems in the subsequent crops. We estimated the fraction of weed seeds a combine harvester could potentially harvest and used various methods to collect the chaff and treat it with heat to kill weed seeds or reduce weed seed germination. Chaff with weed seeds was placed on top of the straw and afterwards baled with the straw as a method to remove weed seeds from the field. We exposed chaff with weed seeds to exhaust gas with various temperatures and durations to study whether this heating method could be used to reduce the input of viable weed seeds to the soil during harvesting. By collecting the shed weed seeds during the growing season, we estimated that a combine harvester could potentially harvest 41%, 11%, and 100% of the seeds produced in the growing season by Bromus hordeaceus, Cirsium arvense, and Galium aparine, respectively. When the chaff was placed on top of the straw, 45% of the weed seeds stayed in the chaff fraction on top of the straw swath after one day, 35% got into the straw swath, and 20% past through the swath to the ground. Therefore, baling straw with chaff placed on the top only had a limited effect on reducing weed seed infestation. The study showed that thermal weed seed control during harvesting could potentially be applicable and incorporated in an integrated weed management approach.

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Compatibility and Efficiency of In-Row Cultivation for Weed Management in Corn (Zea mays)

Weed Technology ◽

10.1017/s0890037x00024167 ◽

1995 ◽

Vol 9 (4) ◽

pp. 754-760 ◽

Cited By ~ 14

Author(s):

Mark J. Vangessel ◽

Edward E. Schweizer ◽

Donald W. Lybecker ◽

Phil Westra

Keyword(s):

Weed Control ◽

Weed Management ◽

Integrated Weed Management ◽

Corn Yield ◽

Bioeconomic Model ◽

Gross Margin ◽

Early Season ◽

Annual Weeds ◽

The Cost ◽

Management Tactics

Information on the effects of multiple weed management tactics in corn is needed to develop integrated weed management systems. The effectiveness and compatibility of an in-row cultivator as compared to a standard interrow cultivator used with reduced rates of a soil-applied herbicide, rotary hoeing, and/or a bioeconomic model for POST herbicide selection was examined. Weed control with a single rotary hoeing at corn emergence controlled annual weeds similarly to two rotary hoeings. One-third recommended use rate of alachlor controlled weeds similarly to a two-thirds rate. Reduced rates of alachlor controlled more weeds than rotary hoeing over 2 yr. The in-row cultivator required early-season weed control (rotary hoeing or reduced alachlor rate) for optimum efficacy. The in-row cultivator provided better weed control than the standard cultivator while the cost of operating the two cultivators was similar. Thus, the in-row cultivator was more efficient than the standard cultivator. Furthermore, less intensive early-season weed control was required with the in-row cultivator for maximum weed control as compared to the standard cultivator. Rotary hoeing plus the in-row cultivator provided similar weed control to other weed management tactics that required both soil-applied and POST herbicides. Gross margin was influenced more by corn yield than cost of weed management tactics.

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Implications of weed seedbank dynamics to weed management

Weed Science ◽

10.1017/s0043174500092948 ◽

1997 ◽

Vol 45 (3) ◽

pp. 329-336 ◽

Cited By ~ 161

Author(s):

Douglas D. Buhler ◽

Robert G. Hartzler ◽

Frank Forcella

Keyword(s):

Weed Control ◽

Weed Management ◽

Plant Ecology ◽

Management Systems ◽

Integrated Weed Management ◽

Management Decision ◽

Plant Responses ◽

Weed Seed ◽

Weed Species ◽

Tillage Practices

The species composition and density of weed seed in the soil vary greatly and are closely linked to the cropping history of the land. Altering tillage practices changes weed seed depth in the soil, which plays a role in weed species shifts and affects efficacy of control practices. Crop rotation and weed control practices also affect the weed seedbank. Information on the influence of cropping practices on the weed seedbank should be a useful tool for integrated weed management. Decision aid models use information on the weed seedbank to estimate weed populations, crop yield loss, and recommend weed control tactics. Understanding the light requirements of weed seed may provide new approaches to weed management. Improving and applying our understanding of weed seedbank dynamics is essential to developing improved weed management systems. The principles of plant ecology must be integrated with the science of weed management to develop strategies that take advantage of basic plant responses in weed management systems for agronomic crops.

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Crop Seeding Rate Influences the Performance of Variable Herbicide Rates in a Canola–Barley–Canola Rotation

Weed Technology ◽

10.1614/wt-03-168r ◽

2004 ◽

Vol 18 (3) ◽

pp. 733-741 ◽

Cited By ~ 19

Author(s):

John T. O'Donovan ◽

Jeff C. Newman ◽

K. Neil Harker ◽

George W. Clayton

Keyword(s):

Seed Production ◽

Weed Management ◽

Crop Yields ◽

Management Practice ◽

Soil Seed Bank ◽

Integrated Weed Management ◽

Weed Seed ◽

Seeding Rate ◽

Wild Mustard ◽

Yield Responses

Glyphosate-resistant canola was seeded at Vegreville, Alberta, in 1997 and 1999 and barley in rotation with the canola in 1998 at three seeding rates. The effects, at each crop seeding rate, of variable glyphosate (canola) and tralkoxydim plus bromoxynil plus MCPA (barley) rates on crop yield, net economic return and seed production by wild oat, wild mustard, and wild buckwheat, and the amount of weed seed in the soil seed bank was determined. Crop seeding rate influenced the response of canola and barley yield and weed seed production to herbicide rate. At the lowest crop seeding rates, yield responses tended to be parabolic with yields increasing up to one-half and three-quarters of the recommended herbicide rates and trends toward reduced yields at the full rates. This response was not evident at the higher crop seeding rates, where, in most cases the yield reached a maximum between one-half and the full recommended rate. The effects of the herbicides on weed seed production, especially at the lowest rate, were often superior at the higher crop seeding rates. The results indicate that seeding canola and barley at relatively high rates may reduce risk associated with lower crop yields and increased weed seed production at lower than recommended herbicide rates. However, the current cost of herbicide-resistant canola seed may preclude the adoption of this integrated weed management practice by growers.

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Weed seed return as influenced by the critical weed-free period in corn (Zea mays L.)

Canadian Journal of Plant Science ◽

10.4141/p98-044 ◽

1999 ◽

Vol 79 (1) ◽

pp. 165-167 ◽

Cited By ~ 3

Author(s):

Clarence J. Swanton ◽

Kevin Chandler ◽

Anil Shrestha

Keyword(s):

Weed Management ◽

Zea Mays L ◽

Soil Surface ◽

Management Systems ◽

Integrated Weed Management ◽

Critical Periods ◽

Weed Seed ◽

Weed Population ◽

Weed Population Dynamics ◽

Total Seed

Seed return from later emerging weeds is a concern in weed management systems based on critical periods of control. A study in Ontario found that estimated weed seed return to the soil surface was influenced by the duration of weed control in corn and the prevailing environmental conditions. Weeds emerging after the 8- to 11-leaf stage of corn growth did not cause an increase in total seed number compared to the residual seed bank in the weed-free control. Key words: Seedbank, weed population dynamics, integrated weed management

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Modelling the Effect and Variability of Integrated Weed Management of Phalaris minor in Rice-Wheat Cropping Systems in Northern India

Agronomy ◽

10.3390/agronomy11112331 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2331

Author(s):

Chun Liu ◽

Makhan Singh Bhullar ◽

Tarundeep Kaur ◽

Jitendra Kumar ◽

Sriyapu Reddy Sreekanth Reddy ◽

...

Keyword(s):

Weed Control ◽

Crop Rotation ◽

Weed Management ◽

Integrated Weed Management ◽

Weed Seed ◽

Phalaris Minor ◽

Resistance Evolution ◽

Crop Establishment ◽

Seed Harvest ◽

Herbicide Mixtures

Phalaris minor Retz. (littleseed canarygrass) is the most problematic and herbicide-resistant weed in the rice-wheat cropping system in India. As such, it poses a severe threat to wheat yield and food security. A number of herbicidal and agronomic practices have been identified for the effective control of P. minor. These include crop rotation, crop establishment methods, herbicide spray technology, sowing time, weed seed harvest and effective herbicide mixtures. A population model of P. minor was built based on the life cycle of the species, herbicide resistance mechanisms and the effects of weed control practices. The model simulated the interactions of these factors and provided the best management recommendations for sustainably controlling this noxious weed species. Model results indicate that integration of chemical and non-chemical control methods was the most effective and sustainable strategy. For example, the integration of a happy seeder (a tractor-mounted mulching and sowing machine) with an effective post-emergence herbicide reduced the probability of weed control failure by 32% compared to the scenario with a rotavator and the same herbicide. Similarly, more conventional crop establishment methods such as a rotavator and conventional tillage could be accompanied by pre- or post-emergence applications of herbicide mixtures. Adoption of good herbicide spray technology and weed seed harvest delayed the onset of resistance evolution by up to four years. Furthermore, effective crop rotation such as the inclusion of sugarcane in place of rice in the summer season reduced the risk of resistance evolution by 31% within the 10 year simulation period. In addition to the scenarios using representative parameter values, the variability of model predictions was investigated based on some field experiments. The model provided a powerful tool for promoting Integrated Weed Management and the sustainable use of herbicides. Pragmatic ways of dealing with uncertainty in model prediction are discussed.

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Integrated Weed Management Systems to Control Common Ragweed (Ambrosia artemisiifolia L.) in Soybean

Frontiers in Agronomy ◽

10.3389/fagro.2020.598426 ◽

2021 ◽

Vol 2 ◽

Author(s):

Shawn C. Beam ◽

Charles W. Cahoon ◽

David C. Haak ◽

David L. Holshouser ◽

Steven B. Mirsky ◽

...

Keyword(s):

Weed Management ◽

Planting Date ◽

Ambrosia Artemisiifolia ◽

Integrated Weed Management ◽

First Year ◽

Weed Seed ◽

Common Ragweed ◽

Late Planting ◽

Winter Cover ◽

Second Year

As resistance to herbicides limits growers' weed management options, integrated weed management (IWM) systems that combine non-chemical tactics with herbicides are becoming critical. A 2 year integrated weed management (IWM) study was conducted at three locations in VA, USA. The factorial study evaluated: (1) soybean planting date (early or late planted) (2) with or without winter cover (cereal rye/wheat or no cover), and (3) with or without harvest weed seed control (HWSC). Prior to soybean planting in the first year, winter cover resulted in a 22% reduction in common ragweed density compared to no cover. At soybean harvest in the first year, the lowest common ragweed densities were in the late planted plots following winter wheat, and common ragweed aboveground biomass was reduced by 46 and 22% at two locations in late planted compared to early planted soybean. To evaluate the impact of the first year's treatments and HWSC, full season soybeans were planted across the trial in the second year. Prior to soybean planting in the second year, late planting in the first year common ragweed density was reduced by 83% at one location, but significant reductions were not observed elsewhere. When comparing winter cover to no cover, common ragweed densities were reduced by 31 and 49% at two locations and densities were similar at the third location. Harvest weed seed control reduced common ragweed density by 43% at one location compared to the conventional harvest plots but no significant reductions were observed at the other locations or at other rating timings. However, there was a significant location by planting date by winter cover interaction and the overall lowest common ragweed densities (4.1 to 10.3 plants m−2) were in the late planted plots with winter cover. This research indicated that winter cover, late planting, and HWSC can reduce common ragweed populations with late planting being the most influential. Therefore, double-cropping soybean after wheat is likely the most viable means to better control common ragweed using IWM as it combines both winter cover and late planting date.

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Weed seed return as influenced by the critical weed-free period and row spacing of no-till glyphosate-resistant soybean

Canadian Journal of Plant Science ◽

10.4141/p01-049 ◽

2001 ◽

Vol 81 (4) ◽

pp. 877-880 ◽

Cited By ~ 8

Author(s):

Kevin Chandler, Anil Shrestha, and Swanton

Keyword(s):

Weed Control ◽

Weed Management ◽

Soil Surface ◽

Integrated Weed Management ◽

Row Spacing ◽

Critical Periods ◽

Weed Seed ◽

No Till ◽

Weed Population Dynamics ◽

Glycine Max L

Seed return from later-emerging weeds is a concern in soybean management systems based on critical periods for weed control. This study in Ontario estimated the weed seed return to the soil surface as influenced by the duration of weed control in soybean and soybean row spacing. Weeds emerging after the 1- to 2-trifoliate stage of soybean development did not increase the weed seedbank population compared to the residual population in the weed-free control. Weed seed return was greater in 76 cm than in 38 cm or 19 cm (twin rows) soybean row spacings. Key words: Seedbank, weed population dynamics, integrated weed management, glyphosate-resistant soybean, [Glycine max (L.) Merr].

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