Effects of cereal rye seeding rate on waterhemp (Amaranthus tuberculatus) emergence and soybean growth and yield

2021 ◽  
pp. 1-25
Author(s):  
Mandy Bish ◽  
Brian Dintelmann ◽  
Eric Oseland ◽  
Jacob Vaughn ◽  
Kevin Bradley

Abstract The evolution of herbicide-resistant weeds has resulted in the necessity to integrate non-chemical control methods with chemicals for effective management in crop production systems. In soybean, control of the pigweed species, particularly herbicide-resistant waterhemp and Palmer amaranth, have become predominant concerns. Cereal rye planted as a winter cover crop can effectively suppress early-season weed emergence in soybean, including waterhemp, when planted at a rate of 123 kg ha−1. The objectives of this study were to determine the effects of different cereal rye seeding rates (0, 34, 56, 79, 110, and 123 kg ha−1) on early-season waterhemp suppression and soybean growth and yield. Soybean was planted into fall-seeded cereal rye, which was terminated within four days of soybean planting. The experiment was conducted over the 2018, 2019, and 2020 growing seasons in Columbia, Missouri. Effects of cereal rye on early-season waterhemp suppression varied by year and were most consistent at 56 kg ha−1 or higher seeding rates. Linear regression analysis of cereal rye biomass, height, or stand at soybean planting showed inverse relationships with waterhemp emergence. No adverse effects to soybean growth or yield were observed at any of the cereal rye seeding rates relative to plots that lacked cereal rye cover. Result differences among the years suggest that the successfulness of cereal rye on suppression of early-season waterhemp emergence is likely influenced by the amount of waterhemp seed present in the soil seed bank.

1993 ◽  
Vol 3 (2) ◽  
pp. 211-214 ◽  
Author(s):  
Ronald D. Morse

Conservation tillage systems offer distinct advantages for crop production under erosive and droughty soil conditions. This report contains 4 years of data on the effects of in situ cereal rye and wheat mulches on yield of cabbage (Brassica oleracea L. var. capitata) grown under limited-irrigation, conservation-tillage systems. Three tillage systems were studied: conventional plow-disk (CT); strip tillage (ST) and no-tillage (NT). The summers of 1987 and 1990 were characterized by below-average total rain and periods of prolonged (45 days) of dry weather during head enlargement; cabbage yields were highest in the mulched ST and NT plots. In contrast, the 1988 and 1989 growing seasons were above average in total rain and there were no prolonged periods of dry weather. Cabbage yields were unaffected by tillage treatments in 1988, while, in 1989, yields with NT were 65% and 60% lower than with CT and ST, respectively. A combination of abundant rain, soil compaction, and delayed planting retarded plant growth in the 1989 NT plots, resulting in smaller, less-productive plants than in the tilled ST and CT plots. These data show that: 1) conservation tillage and particularly strip tillage systems are viable options for production of cabbage; and 2) rain-irrigation patterns, site selection, and planting dates are major determinants of the relative advantages of conservation tillage compared to conventional tillage systems.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1152
Author(s):  
Rebekah Waller ◽  
Murat Kacira ◽  
Esther Magadley ◽  
Meir Teitel ◽  
Ibrahim Yehia

Recognizing the growing interest in the application of organic photovoltaics (OPVs) with greenhouse crop production systems, in this study we used flexible, roll-to-roll printed, semi-transparent OPV arrays as a roof shade for a greenhouse hydroponic tomato production system during a spring and summer production season in the arid southwestern U.S. The wavelength-selective OPV arrays were installed in a contiguous area on a section of the greenhouse roof, decreasing the transmittance of all solar radiation wavelengths and photosynthetically active radiation (PAR) wavelengths (400–700 nm) to the OPV-shaded area by approximately 40% and 37%, respectively. Microclimate conditions and tomato crop growth and yield parameters were measured in both the OPV-shaded (‘OPV’) and non-OPV-shaded (‘Control’) sections of the greenhouse. The OPV shade stabilized the canopy temperature during midday periods with the highest solar radiation intensities, performing the function of a conventional shading method. Although delayed fruit development and ripening in the OPV section resulted in lower total yields compared to the Control section (24.6 kg m−2 and 27.7 kg m−2, respectively), after the fourth (of 10 total) harvests, the average weekly yield, fruit number, and fruit mass were not significantly different between the treatment (OPV-shaded) and control group. Light use efficiency (LUE), defined as the ratio of total fruit yield to accumulated PAR received by the plant canopy, was nearly twice as high as the Control section, with 21.4 g of fruit per mole of PAR for plants in the OPV-covered section compared to 10.1 g in the Control section. Overall, this study demonstrated that the use of semi-transparent OPVs as a seasonal shade element for greenhouse production in a high-light region is feasible. However, a higher transmission of PAR and greater OPV device efficiency and durability could make OPV shades more economically viable, providing a desirable solution for co-located greenhouse crop production and renewable energy generation in hot and high-light intensity regions.


Weed Science ◽  
2016 ◽  
Vol 64 (SP1) ◽  
pp. 570-584 ◽  
Author(s):  
Micheal D. K. Owen

Herbicides have been the principal means of weed control in developed countries for approximately 50 yr because they are the most cost-effective method. Such general use of herbicides has resulted in weed resistance to herbicides, which continues to be a growing problem. Within the past decade, the evolution of resistance to the once-dominant herbicide glyphosate has resulted in major concerns about the future ability to control weeds in many crop systems. Moreover, many weed species have evolved resistance to multiple mechanisms of herbicide action. Given the dearth of new herbicides with novel mechanisms of action, it appears inevitable that weed management programs will need to be supplemented by the use of tactics other than herbicides. However, the inclusion of more diversity for weed management also introduces complexity, cost, and time constraints to current crop production systems. This paper describes broadly the considerations, opportunities, and constraints of diverse weed management tactics to address the burgeoning problems with herbicide resistance.


Weed Science ◽  
2012 ◽  
Vol 60 (SP1) ◽  
pp. 31-62 ◽  
Author(s):  
Jason K. Norsworthy ◽  
Sarah M. Ward ◽  
David R. Shaw ◽  
Rick S. Llewellyn ◽  
Robert L. Nichols ◽  
...  

Herbicides are the foundation of weed control in commercial crop-production systems. However, herbicide-resistant (HR) weed populations are evolving rapidly as a natural response to selection pressure imposed by modern agricultural management activities. Mitigating the evolution of herbicide resistance depends on reducing selection through diversification of weed control techniques, minimizing the spread of resistance genes and genotypes via pollen or propagule dispersal, and eliminating additions of weed seed to the soil seedbank. Effective deployment of such a multifaceted approach will require shifting from the current concept of basing weed management on single-year economic thresholds.


HortScience ◽  
2020 ◽  
Vol 55 (3) ◽  
pp. 368-373
Author(s):  
Daljeet S. Dhaliwal ◽  
Martin M. Williams

Consumer demand for edamame [Glycine max (L.) Merr.], the vegetable version of soybean (Glycine max), has grown during the past decade in North America. Domestic production of edamame is on the rise; however, research to guide fundamental crop production practices, including knowledge useful for developing appropriate recommendations for crop seeding rate, is lacking. Field experiments near Urbana, IL, were used to quantify edamame response to plant density and determine the economically optimal plant density (EOPD) of machine-harvested edamame. Crop growth and yield responses to a range of plant densities (24,700 to 395,100 plants/ha) were quantified in four edamame cultivars (AGS 292, BeSweet 292, Gardensoy 42, and Midori Giant) across 2 years. Plots were harvested with the Oxbo BH100, a fresh market bean harvester. In general, as plant density increased, branch number and the ratio of pod mass to vegetative mass decreased, while plant height and leaf area index increased. Recovery, the percent of marketable pods in the machine-harvested sample, varied among cultivars from 86% to 95%. Results identified the EOPD for machine-harvested edamame ranged from 87,000 to 120,000 plants/ha. When considering the effect of plant density on plant morphology, as well as seeding cost, harvester efficiency, recovery, and marketable pod yield, edamame EOPDs are considerably lower than seeding rates of up to 344,200 seeds/ha recommended in recent publications.


Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 138-147 ◽  
Author(s):  
Bharat M. Upadhyay ◽  
Elwin G. Smith ◽  
G. W. Clayton ◽  
K. N. Harker ◽  
R. E. Blackshaw

Integrated weed management (IWM) decision strategies in herbicide-resistant canola-production systems were assessed for net returns and relative risk. Data from two field experiments conducted during 1998 to 2000 at two locations in Alberta, Canada, were evaluated. A herbicide-based experiment included combinations of herbicide system (glufosinate-, glyphosate-, and imazethapyr-resistant canola varieties), herbicide rate (50 and 100% of recommended dose), and time of weed removal (two-, four-, and six-leaf stages of canola). A seed-based experiment included canola variety (hybrid and open-pollinated), seeding rate (100, 150, and 200 seeds m−2), and time of weed removal (two-, four-, and six-leaf stages of canola). For the herbicide-based experiment, strategies with glyphosate were profitable at Lacombe, but both imazethapyr and glyphosate strategies were profitable at Lethbridge. Weed control at the four-leaf stage was at least as profitable as the two-leaf stage at both sites. For the seed-based experiment, the hybrid was more profitable than the open-pollinated cultivar, seed rates of 100 and 150 seeds m−2were more profitable than 200 seeds m−2, and weed control at the two- and four-leaf stages was more profitable than at the six-leaf stage. When risk of returns and statistical significance was considered, several strategies were included in the risk-efficient set for risk-averse and risk-neutral attitudes at each location. However, the glyphosate-resistant cultivar, the 50% herbicide rate, and weed control at four-leaf stage were more frequent in the risk-efficient IWM strategy set. The open-pollinated cultivar, 200 seeds m−2rate, and weed control at the six-leaf stage were less frequent in the set. The risk-efficient sets of IWM strategies were consistent across a range of canola prices.


Weed Science ◽  
2017 ◽  
Vol 65 (6) ◽  
pp. 699-709 ◽  
Author(s):  
Nick T. Harre ◽  
Haozhen Nie ◽  
Renae R. Robertson ◽  
William G. Johnson ◽  
Stephen C. Weller ◽  
...  

Giant ragweed is a highly competitive weed that continually threatens crop production systems due to evolved resistance to acetolactate synthase–inhibiting herbicides (ALS-R) and glyphosate (GR). Two biotypes of GR giant ragweed exist and are differentiated by their response to glyphosate, termed here as rapid response (RR) and non–rapid response (NRR). A comparison of data from surveys of Indiana crop fields done in 2006 and 2014 showed that GR giant ragweed has spread from 15% to 39% of Indiana counties and the NRR biotype is the most prevalent. A TaqMan®single-nucleotide polymorphism genotyping assay was developed to identify ALS-R populations and revealed 47% of GR populations to be ALS-R as well. The magnitude of glyphosate resistance for NRR populations was 4.6 and 5.9 based on GR50and LD50estimates, respectively. For RR populations, these values were 7.8 to 9.2 for GR50estimates and 19.3 to 22.3 for LD50estimates. A novel use of the Imaging-PAM fluorometer was developed to discriminate RR plants by assessing photosystem II quantum yield across the entire leaf surface. H2O2generation in leaves of glyphosate-treated plants was also measured by 3,3′-diaminobenzidine staining and quantified using imagery analysis software. Results show photo-oxidative stress of mature leaves is far greater and occurs more rapidly following glyphosate treatment in RR plants compared with NRR and glyphosate-susceptible plants and is positively associated with glyphosate dose. These results suggest that under continued glyphosate selection pressure, the RR biotype may surpass the NRR biotype as the predominant form of GR giant ragweed in Indiana due to a higher level of glyphosate resistance. Moreover, the differential photo-oxidative stress patterns in response to glyphosate provide evidence of different mechanisms of resistance present in RR and NRR biotypes.


Weed Science ◽  
2012 ◽  
Vol 60 (SP1) ◽  
pp. 2-30 ◽  
Author(s):  
William K. Vencill ◽  
Robert L. Nichols ◽  
Theodore M. Webster ◽  
John K. Soteres ◽  
Carol Mallory-Smith ◽  
...  

Development of herbicide-resistant crops has resulted in significant changes to agronomic practices, one of which is the adoption of effective, simple, low-risk, crop-production systems with less dependency on tillage and lower energy requirements. Overall, the changes have had a positive environmental effect by reducing soil erosion, the fuel use for tillage, and the number of herbicides with groundwater advisories as well as a slight reduction in the overall environmental impact quotient of herbicide use. However, herbicides exert a high selection pressure on weed populations, and density and diversity of weed communities change over time in response to herbicides and other control practices imposed on them. Repeated and intensive use of herbicides with the same mechanisms of action (MOA; the mechanism in the plant that the herbicide detrimentally affects so that the plant succumbs to the herbicide; e.g., inhibition of an enzyme that is vital to plant growth or the inability of a plant to metabolize the herbicide before it has done damage) can rapidly select for shifts to tolerant, difficult-to-control weeds and the evolution of herbicide-resistant weeds, especially in the absence of the concurrent use of herbicides with different mechanisms of action or the use of mechanical or cultural practices or both.


2019 ◽  
Vol 33 (2) ◽  
pp. 312-320 ◽  
Author(s):  
Derek M. Whalen ◽  
Mandy D. Bish ◽  
Bryan G. Young ◽  
Aaron G. Hager ◽  
Shawn P. Conley ◽  
...  

AbstractIn recent years, the use of cover crops has increased in U.S. crop production systems. An important aspect of successful cover crop establishment is the preceding crop and herbicide program, because some herbicides have the potential to persist in the soil for several months. Few studies have been conducted to evaluate the sensitivity of cover crops to common residual herbicides used in soybean production. The same field experiment was conducted in 2016 in Arkansas, Illinois, Indiana, Missouri, Tennessee, and Wisconsin, and repeated in Arkansas, Illinois, Indiana, Mississippi, and Missouri in 2017 to evaluate the potential of residual soybean herbicides to carryover and reduce cover crop establishment. Herbicides applied during the soybean growing season included acetochlor; acetochlor plus fomesafen; chlorimuron plus thifensulfuron; fomesafen; fomesafen plus S-metolachlor followed by acetochlor; imazethapyr; pyroxasulfone; S-metolachlor; S-metolachlor plus fomesafen; sulfentrazone plus S-metolachlor; sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor; and sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor followed by acetochlor. Across all herbicide treatments, the sensitivity of cover crops to herbicide residues in the fall, from greatest to least, was forage radish = turnip > annual ryegrass = winter oat = triticale > cereal rye = Austrian winter pea = hairy vetch = wheat > crimson clover. Fomesafen (applied 21 and 42 days after planting [(DAP]); chlorimuron plus thifensulfuron and pyroxasulfone applied 42 DAP; sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor; and sulfentrazone plus S-metolachlor followed by fomesafen plus S-metolachlor followed by acetochlor caused the highest visual ground cover reduction to cover crop species at the fall rating. Study results indicate cover crops are most at risk when following herbicide applications in soybean containing certain active ingredients such as fomesafen, but overall there is a fairly low risk of cover crop injury from residual soybean herbicides applied in the previous soybean crop.


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