Influence of a Rye Cover Crop on the Critical Period for Weed Control in Cotton

Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 346-352 ◽  
Author(s):  
Nicholas E. Korres ◽  
Jason K. Norsworthy
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Cover Crop ◽  
Critical Period ◽  
Yield Loss ◽  
Growing Season ◽  
Weed Biomass ◽  
Weed Density ◽  
Presence And Absence ◽  
Weed Removal

Cover crops are becoming increasingly common in cotton as a result of glyphosate-resistant Palmer amaranth; hence, a field experiment was conducted in 2009 and 2010 in Marianna, AR, with a rye cover crop used to determine its effects on the critical period for weed control in cotton. Throughout most of the growing season, weed biomass in the presence of a rye cover crop was lesser than that in the absence of a rye cover crop. In 2009, in weeks 2 through 7 after planting, weed biomass was reduced at least twofold in the presence of a rye cover compared with the absence of rye. In 2009, in both presence and absence of a rye cover crop, weed removal needed to begin before weed biomass was 150 g m−2, or approximately 4 wk after planting, to prevent yield loss > 5%. Weed density was less in 2010 than in 2009, so weed removal was not required until 7 wk after planting, at which point weed biomass values were 175 and 385 g m−2in the presence and absence of a cover crop, respectively.

scholarly journals Determining the critical period for weed control in high-yielding cotton using common sunflower as a mimic weed

2019 ◽  
Vol 33 (6) ◽  
pp. 800-807 ◽  
Author(s):  
Graham W. Charles ◽  
Brian M. Sindel ◽  
Annette L. Cowie ◽  
Oliver G. G. Knox
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Field Studies ◽  
Growing Degree Days ◽  
Degree Days ◽  
Weed Density ◽  
High Level ◽  
The Cost ◽  
Planting Season

AbstractField studies were conducted over six seasons to determine the critical period for weed control (CPWC) in high-yielding cotton, using common sunflower as a mimic weed. Common sunflower was planted with or after cotton emergence at densities of 1, 2, 5, 10, 20, and 50 plants m−2. Common sunflower was added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 growing degree days (GDD) after planting. Season-long interference resulted in no harvestable cotton at densities of five or more common sunflower plants m−2. High levels of intraspecific and interspecific competition occurred at the highest weed densities, with increases in weed biomass and reductions in crop yield not proportional to the changes in weed density. Using a 5% yield-loss threshold, the CPWC extended from 43 to 615 GDD, and 20 to 1,512 GDD for one and 50 common sunflower plants m−2, respectively. These results highlight the high level of weed control required in high-yielding cotton to ensure crop losses do not exceed the cost of control.

Cotton Planting Date Affects The Critical Period of Benghal Dayflower (Commelina benghalensis) Control

Weed Science ◽  
2009 ◽  
Vol 57 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Theodore M. Webster ◽  
Timothy L. Grey ◽  
J. Timothy Flanders ◽  
A. Stanley Culpepper
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Maximum Yield ◽  
Growing Season ◽  
Field Studies ◽  
Cotton Field ◽  
Commelina Benghalensis ◽  
Critical Range ◽  
Benghal Dayflower

Benghal dayflower (formerly known as tropical spiderwort) is one of the most troublesome weeds in Georgia cotton. Field studies were conducted from 2003 to 2005 to evaluate the relationship between the duration of Benghal dayflower interference and cotton yield to establish optimum weed-control timing. To determine the critical period of weed control (CPWC), Benghal dayflower interference with cotton was allowed or prohibited in 2-wk intervals between 0 to 12 wk after crop planting. Maximum yield loss from Benghal dayflower in May-planted cotton was 21 to 30% in 2004 and 2005, whereas cotton planting delayed until June resulted in maximum yield losses of 40 to 60%. June-planted cotton had a CPWC of 190 to 800 growing degree days (GDD) in 2004 (52-d interval beginning at 16 d after planting [DAP]) and 190 to 910 GDD in 2005 (59-d interval beginning at 18 DAP). In contrast, May-planted cotton in 2005 had a narrower CPWC interval of 396 to 587 GDD (18 d) that occurred 3 wk later in the growing season (initiated at 39 DAP). May-planted cotton in 2004 did not have a critical range of weed-free conditions. Instead, a single weed removal at 490 GDD (44 DAP) averted a yield loss greater than 5%. It is recommended that fields infested with Benghal dayflower be planted with cotton early in the growing season to minimize weed interference with the crop.

scholarly journals Determination of the critical period of weed control in corn using a thermal basis

1999 ◽  
Vol 34 (2) ◽  
pp. 188-193 ◽  
Author(s):  
Francisco Bedmar ◽  
Pablo Manetti ◽  
Gloria Monterubbianesi
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Zea Mays L ◽  
Critical Time ◽  
Field Studies ◽  
Weed Biomass ◽  
Logistic Equations ◽  
Weed Interference ◽  
Weed Removal

Field studies were conducted over 3 years in southeast Buenos Aires, Argentina, to determine the critical period of weed control in maize (Zea mays L.). The treatments consisted of two different periods of weed interference, a critical weed-free period, and a critical time of weed removal. The Gompertz and logistic equations were fitted to relative yields representing the critical weed-free and the critical time of weed removal, respectively. Accumulated thermal units were used to describe each period of weed-free or weed removal. The critical weed-free period and the critical time of weed removal ranged from 222 to 416 and 128 to 261 accumulated thermal units respectively, to prevent yield losses of 2.5%. Weed biomass proved to be inverse to the crop yield for all the years studied. When weeds competed with the crop from emergence, a large increase in weed biomass was achieved 10 days after crop emergence. However, few weed seedlings emerged and prospered after the 5-6 leaf maize stage (10-20 days after emergence).

The Critical Period of Weed Control for Lentil in Western Canada

Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 517-526 ◽  
Author(s):  
L. K. Fedoruk ◽  
E. N. Johnson ◽  
S. J. Shirtliffe
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Inverse Relationship ◽  
Yield Loss ◽  
Western Canada ◽  
Crop Canopy ◽  
Herbicide Application ◽  
Weed Biomass ◽  
Weed Interference ◽  
Residual Herbicide

Weed control in lentil is difficult because lentil is a poor competitor with weeds and few POST broadleaf herbicides are available. Imadazolinone-tolerant lentils have more herbicide options, but the optimum timing for herbicide application is not known. The critical period of weed control (CPWC) is the period in a crop's life cycle when weeds must be controlled in order to prevent yield loss. The objective of this research was to determine the CPWC for lentil. We made lentil remain weedy or weed-free from 0 to 11 aboveground nodes to investigate the durations of weed interference and weed-free period, respectively. It was found that lentil has a CPWC beginning at the five-node stage and continuing to the 10-node stage. There was an inverse relationship between weed biomass and lentil yield; that is, lentil yield was highest when weed biomass is minimal. We propose that the CPWC begins when weeds start to accumulate significant biomass and ends with crop canopy closure. Therefore, to maximize lentil yields, growers should consider using a POST residual herbicide that can control weeds during the CPWC.

scholarly journals Mechanical and thermal weed control in organic crops

2017 ◽  
Author(s):  
◽  
Ricardo Costa Silva
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Cover Crop ◽  
Hot Water ◽  
Limiting Factors ◽  
Corn Yield ◽  
Weed Biomass ◽  
No Till ◽  
Potential Alternative ◽  
Grass Biomass

Effective weed control is one of the most yield-limiting factors in organic corn and soybean production. Additionally, the amount of tillage needed to control weeds in organic practice is often criticized for its negative impacts on soil quality. This research was conducted in central Missouri from 2016-2017 to compare cultivation, flame application, between-row mowing, and hot water spray for in-season weed control in organic corn and soybeans. Between-row mowing and hot water application were paired with notillage and a crimped winter cover crop of cereal rye (Secale cereale L.). When weeds reached 10.2 cm, weed control practices were implemented and repeated as necessary until canopy closure. Grass and broadleaf weed biomass between crop rows was determined at multiple dates throughout the 2016 and 2017 seasons and in-row weed levels were determined at the final collection date for each crop each year. Broadleaf weed biomass at the end of the soybean season in 2016 was lower in the two treatments utilizing no-till and cover crops as primary weed control and hot water and mowing as secondary control. Soybean yield was adversely affected by flaming but not significantly different for the cultivation, mowing and hot water treatments. In 2017, soybean had less between-row grass biomass in the cultivation and flaming treatments than in hot water and mowing, but broadleaf levels were the same in the mowed treatment as the cultivated and flamed treatments. In 2016, grass biomass was lower in the no-till treatments between corn rows and higher in the crop rows than the other two treatments. Weed control treatments led to no significant differences in corn yield in 2016 and higher yields in the no-till treatments in 2017. In-row weed levels were significantly higher in corn in 2017 for the hot water treatment. Hot water at the levels applied in this research was not an effective weed control method. Since the overuse of cultivation can decrease soil organic matter levels and increase soil erosion, alternatives techniques are important to grant farmers the possibility to use their land for a long time. The crimped cover crop used in the no-till treatments limited weed growth in early-season corn and soybean and when coupled with between-row mowing is a potential alternative to cultivation in organic crop production. Flaming is also a potential alternative to cultivation in corn production.

scholarly journals Cover crops as green mulching for weed management in rice

2021 ◽  
Author(s):  
Silvia Fogliatto ◽  
Lorenzo Patrucco ◽  
Fernando De Palo ◽  
Barbara Moretti ◽  
Marco Milan ◽  
...  
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Low Temperatures ◽  
Cover Crop ◽  
Rice Yield ◽  
Frost Damage ◽  
Weed Suppression ◽  
Italian Ryegrass ◽  
Crop Species ◽  
Weed Density

A field study was carried out in 2017 and 2018 in two Italian rice farms (at Livorno Ferraris and Rovasenda) to assess the effect of using cover crops as green mulching on weed control and rice yield. In each site, three different rice fields were sown after rice harvest with either Vicia villosa, Lolium multiflorum, or a mixture of both (V. villosa 40% + L. multiflorum 60%); at Rovasenda a small percentage of Brassica napus and Triticale was also present in the mixture. An additional field at both sites without cover crop was considered as a control reference. Rice was broadcasted sown within the cover crop in May. After few days, the cover crop was terminated in half of each field using a roller-crimper, while in the other half it was terminated by shredding. Within 10 days, the fields were flooded for about a week to promote the degradation of the cover crop biomass. Then, the fields were cultivated in flooding conditions without further weed control. Weed density and weed cover were evaluated thrice during the growing season. At harvest, rice yield and harvest index were determined. Mixed nested ANOVAs were performed for each site to assess the effect of cover crop species, termination technique, and the interaction between cover crop and year. L. multiflorum showed a high biomass before termination, while V. villosa had a more variable development. At Rovasenda, V. villosa growth was limited because of the combination of scarce emergence due to sod-seeding and frost damage. In general, green mulching significantly affected weed density. The best weed suppression was observed with L. multiflorum and mix at Rovasenda, with values of weed density <40 plants m-2 recorded in 2018. At both sites, rice yield was variable in the two years. The highest rice yield (>5 t ha-1) was observed in 2018 in the shredded mixture at Rovasenda and in V. villosa at Livorno Ferraris in 2017. Generally, control fields showed lower yields (1-3 t ha-1) at both sites. The termination methods did not significantly affect both weed density and rice yield. The results highlighted that green mulching could reduce weed infestations, even though alone is not able to completely avoid weed development. Some critical issues of the technique were observed, such as the need of a good cover crop establishment, that eventually results in abundant biomass production and significant weed suppression.   Highlights - Green mulching reduces weed pressure but it should be integrated with other weed control techniques. - Hairy vetch showed poor establishment because of the combination of scarce emergence due to sod-seeding and low temperatures. - Italian ryegrass was more tolerant to low temperatures and showed a good cover that contained weed growth. - Cover crop mixture showed variable results with higher suppression probably related to the number of cover crop species present in the mixture. - The termination methods (crimping and shredding) did not affect weed density and rice yield.

Optimal planting date, row width, and critical weed-free period for grain amaranth and quinoa grown in Ontario, Canada

2016 ◽  
Vol 96 (3) ◽  
pp. 360-366 ◽  
Author(s):  
Robert E. Nurse ◽  
Kristen Obeid ◽  
Eric R. Page
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Growing Season ◽  
Planting Date ◽  
Planting Dates ◽  
Southern Ontario ◽  
Grain Amaranth ◽  
Physiological Maturity ◽  
Row Width

The popularity of grain amaranth and quinoa is growing in Ontario, increasing the interest in their cultivation. Two experiments were conducted in southern Ontario in 2013 and 2014 to evaluate optimal planting date (every two weeks from early May to late July), row width (38 or 75 cm), and critical weed-free period (the component of the critical period of weed control that defines the number of days that the crop must remain weed-free to prevent yield loss) in each crop. Grain amaranth and quinoa both reached physiological maturity and produced yields when planting dates ranged from mid-May to late-June. When either crop was seeded in July, yields decreased by more than 50% and the crop did not always reach maturity before the first frost. While row width did not have an impact on yield, it is advisable to grow the crops in wider rows (75 cm) to facilitate weed control early in the growing season (up to 30 d after emergence (DAE)). The critical weed-free period was 24 and 16 DAE for grain amaranth and quinoa, respectively, after which yields were maintained at 95% of the weed-free control. Based on these data, both crops could easily be integrated into the normal cropping rotations found in southern Ontario.

Rate and Time of Bentazon/Atrazine Application for Broadleaf Weed Control in Corn (Zea mays)

1997 ◽  
Vol 11 (3) ◽  
pp. 549-555 ◽  
Author(s):  
Allan S. Hamill ◽  
Jianhua Zhang
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Lower Cost ◽  
Yield Loss ◽  
Small Range ◽  
Corn Yield ◽  
Weed Density ◽  
Time Of Application ◽  
Intermediate Rate ◽  
Range Of Variation

The effects of herbicide–adjuvant combinations and times of application on weed density and corn yield were determined in a 3-yr field study. At a given rate and time of application of bentazon/atrazine, Assist and Merge were equally effective adjuvants. Assist would be the adjuvant of choice for bentazon/atrazine rather than Merge because of its currently lower cost. Weed density depended on the rate and time of application of bentazon/atrazine. In general, bentazon/atrazine applied at early stages (7 d after emergence) of the development of corn seedlings or at high or intermediate rate (1.6 or 0.8 kg ai/ha) maintained low weed densities, with a relatively small range of variation over years. Delay in time (14 or 21 d after emergence) or reduction in herbicide rate (0.4 kg ai/ha) increased the risk of high weed pressure, although it was not always associated with yield loss. The best time for the application of postemergence herbicide appears to be a few days prior to the onset of the critical period of weed control.

Determining the critical period for broadleaf weed control in high-yielding cotton using mungbean as a mimic weed

2020 ◽  
Vol 34 (5) ◽  
pp. 689-698
Author(s):  
Graham W. Charles ◽  
Brian M. Sindel ◽  
Annette L. Cowie ◽  
Oliver G. G. Knox
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Yield Loss ◽  
Critical Time ◽  
Field Studies ◽  
Cotton Field ◽  
Control Input ◽  
Degree Days ◽  
Weed Density ◽  
The Relationship

AbstractResearch using the critical period for weed control (CPWC) has shown that high-yielding cotton crops are very sensitive to competition from grasses and large broadleaf weeds, but the CPWC has not been defined for smaller broadleaf weeds in Australian cotton. Field studies were conducted over five seasons from 2003 to 2015 to determine the CPWC for smaller broadleaf weeds, using mungbean as a mimic weed. Mungbean was planted at densities of 1, 3, 6, 15, 30, and 60 plants m−2 with or after cotton emergence and added and removed at approximately 0, 150, 300, 450, 600, 750, and 900 degree days of crop growth (GDD). Mungbean competed strongly with cotton, with season-long interference; 60 mungbean plants m−2 resulted in an 84% reduction in cotton yield. A dynamic CPWC function was developed for densities of 1 to 60 mungbean plants m−2 using extended Gompertz and exponential curves including weed density as a covariate. Using a 1% yield-loss threshold, the CPWC defined by these curves extended for the full growing season of the crop at all weed densities. The minimum yield loss from a single weed control input was 35% at the highest weed density of 60 mungbean plants m−2. The relationship for the critical time of weed removal was further improved by substituting weed biomass for weed density in the relationship.

Mechanical Termination of Diverse Cover Crop Mixtures for Improved Weed Suppression in Organic Cropping Systems

Weed Science ◽  
2013 ◽  
Vol 61 (1) ◽  
pp. 162-170 ◽  
Author(s):  
Sam E. Wortman ◽  
Charles A. Francis ◽  
Mark A. Bernards ◽  
Erin E. Blankenship ◽  
John L. Lindquist
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Cover Crop ◽  
Relative Yield ◽  
Residue Management ◽  
Yield Reduction ◽  
Weed Biomass ◽  
Early Season ◽  
Species Mixture ◽  
Grass Weed

Cover crops can provide many benefits in agroecosystems, including the opportunity for improved weed control. However, the weed suppressive potential of cover crops may depend on the species (or mixture of species) chosen, and the method of cover crop termination and residue management. The objective of this study was to determine the effects of cover crop mixture and mechanical termination method on weed biomass and density, and relative crop yield in an organic cropping system. A field experiment was conducted from 2009 to 2011 near Mead, NE, where spring-sown mixtures of two, four, six, and eight cover crop species were included in a sunflower–soybean–corn crop rotation. Cover crops were planted in late March, terminated in late May using a field disk or sweep plow undercutter, and main crops were planted within 1 wk of termination. Terminating cover crops with the undercutter consistently reduced early-season grass weed biomass, whereas termination with the field disk typically stimulated grass weed biomass relative to a no cover crop control (NC). The effects of cover crop mixture were not evident in 2009, but the combination of the undercutter and the eight-species mixture reduced early-season weed biomass by 48% relative to the NC treatment in 2010. Cover crops provided less weed control in 2011, where only the combination of the undercutter and the two-species mixture reduced weed biomass (by 31%) relative to the NC treatment. Termination with the undercutter resulted in relative yield increases of 16.6 and 22.7% in corn and soybean, respectively. In contrast, termination with the field disk resulted in a relative yield reduction of 13.6% in soybean. The dominant influence of termination method highlights the importance of appropriate cover crop residue management in maximizing potential agronomic benefits associated with cover crops.

Sign in / Sign up

Export Citation Format

Share Document