Wild Buckwheat (Polygonum convolvulus) Interference in Sugarbeet

2010 ◽  
Vol 24 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Dennis C. Odero ◽  
Abdel O. Mesbah ◽  
Stephen D. Miller ◽  
Andrew R. Kniss
Keyword(s):  
Yield Loss ◽  
Field Studies ◽  
Sucrose Content ◽  
Root Yield ◽  
Negative Effects ◽  
Wild Buckwheat ◽  
Weed Density ◽  
Polygonum Convolvulus ◽  
Negative Effect ◽  
Critical Timing

Field studies were conducted in Powell, WY in 2006 and 2007 to determine the influence of season-long interference of various wild buckwheat densities and duration of interference on sugarbeet. Percent sucrose content was not affected by wild buckwheat interference. Root and sucrose yield loss per hectare increased as wild buckwheat density increased. The estimated percent yield loss as wild buckwheat density approaches infinity was 64 and 61% for root and sucrose yield loss, respectively. The estimated percent yield loss per unit weed density at low weed densities was 6% for both root and sucrose yield loss. Greater durations of wild buckwheat interference had a negative effect on sugarbeet root yield. The critical timing of weed removal (CTWR) to avoid 5 and 10% root yield loss was 32 and 48 d after sugarbeet emergence (DAE), respectively. These results show that wild buckwheat is competitive with sugarbeet and should be managed appropriately to forestall any negative effects on sugarbeet root and sucrose yield.

Lanceleaf Sage (Salvia reflexa) Interference in Sugarbeet

2010 ◽  
Vol 24 (4) ◽  
pp. 557-561 ◽  
Author(s):  
Dennis C. Odero ◽  
Abdel O. Mesbah ◽  
Stephen D. Miller ◽  
Andrew R. Kniss
Keyword(s):  
Yield Loss ◽  
Maximum Yield ◽  
Field Studies ◽  
Control Measures ◽  
Root Yield ◽  
Rectangular Hyperbola ◽  
Weed Density ◽  
Negative Effect ◽  
Critical Timing ◽  
The Relationship

Field studies were conducted in Powell, WY, in 2006 and 2007 to determine the influence of season-long interference of various lanceleaf sage densities and durations of interference on sugarbeet. The rectangular hyperbola model with the asymptote (A) constrained to 100% maximum yield loss characterized the relationship between lanceleaf sage density and sugarbeet yield loss. The estimated parameterI(yield loss per unit weed density as density approaches zero) was 3% for both root and sucrose yield loss. Increasing duration of lanceleaf sage interference had a negative effect on sugarbeet root yield. The critical timing of weed removal to avoid 5 and 10% root yield loss was 37 and 52 d after sugarbeet emergence, respectively. Lanceleaf sage interference did not affect percentage of sucrose content. These results indicate that lanceleaf sage is not as competitive as other weeds but that appropriate control measures should be undertaken to minimize sugarbeet yield loss from interference.

Venice Mallow (Hibiscus trionum) Interference in Sugarbeet

2009 ◽  
Vol 23 (4) ◽  
pp. 581-585 ◽  
Author(s):  
Dennis C. Odero ◽  
Abdel O. Mesbah ◽  
Stephen D. Miller ◽  
Andrew R. Kniss
Keyword(s):  
Seed Bank ◽  
Yield Loss ◽  
Sucrose Concentration ◽  
Field Studies ◽  
Root Yield ◽  
Negative Effects ◽  
Rectangular Hyperbola ◽  
Weed Density ◽  
Hibiscus Trionum ◽  
Critical Timing

Field studies were conducted in Powell, WY, in 2006 and 2007 to determine the influence of season-long interference of various Venice mallow densities and duration of interference on sugarbeet. Sucrose concentration was not affected by Venice mallow interference. The effect of Venice mallow density on sugarbeet root and sucrose yield loss was described by the rectangular hyperbola model. Root and sucrose yield loss increased as Venice mallow density increased. The estimated asymptote,A(percent yield loss as density approaches infinity) was 61% for both root and sucrose yield loss, and the estimated parameter,I(percent yield loss per unit weed density as density approaches zero) was 6% for both root and sucrose yield loss. Sugarbeet root yield decreased as the duration of Venice mallow interference increased. The critical timing of weed removal to avoid 5 and 10% root yield loss was 30 and 43 d after sugarbeet emergence, respectively. Results show that Venice mallow is competitive with sugarbeet implying that it should be managed appropriately to reduce negative effects on yield and prevent seed bank replenishment and re-infestation in subsequent years.

Interference of Redstem Filaree (Erodium cicutarium) in Sugarbeet

Weed Science ◽  
2011 ◽  
Vol 59 (3) ◽  
pp. 310-313 ◽  
Author(s):  
Dennis C. Odero ◽  
Abdel O. Mesbah ◽  
Stephen D. Miller ◽  
Andrew R. Kniss
Keyword(s):  
Maximum Yield ◽  
Field Studies ◽  
Yield Reduction ◽  
Root Yield ◽  
Negative Effects ◽  
Rectangular Hyperbola ◽  
Weed Density ◽  
Erodium Cicutarium ◽  
Critical Timing ◽  
The Relationship

Redstem filaree is a troublesome weed for sugarbeet growers in northern Wyoming and southern Montana. Field studies were conducted in Powell, WY, in 2006 and 2008 to determine the influence of season-long interference of various redstem filaree densities and the duration of interference on sugarbeet. Root and sucrose yield decreased with increasing redstem filaree density. The rectangular hyperbola model with the asymptote (A) bounded at 100% maximum yield reduction characterized the relationship between redstem filaree density and sugarbeet yield reduction. The estimated parameterI(percent yield reduction per unit weed density as density approaches zero) was 5% for root and sucrose yield reduction. Sugarbeet root yield decreased as the duration of redstem filaree interference increased. The critical timing of redstem filaree removal to avoid 5 and 10% root yield reduction was estimated to be 25 and 32 d after sugarbeet emergence, respectively. Redstem filaree interference did not affect the sucrose content percentage. These results demonstrate that redstem filaree is competitive with sugarbeet and should be managed appropriately to reduce negative effects on yield.

Critical Timing of Fall Panicum (Panicum dichotomiflorum) Removal in Sugarcane

2016 ◽  
Vol 30 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Dennis C. Odero ◽  
Mathew Duchrow ◽  
Nikol Havranek
Keyword(s):  
Yield Loss ◽  
Field Studies ◽  
Maximum Amount ◽  
Annual Grass ◽  
Early Season ◽  
Negative Effect ◽  
Effect On Yield ◽  
Critical Timing ◽  
Panicum Dichotomiflorum ◽  
Grass Weed

Fall panicum is the most troublesome annual grass weed in sugarcane in Florida. The critical timing of fall panicum removal in sugarcane or the maximum amount of early season interference that sugarcane can tolerate before it suffers irrecoverable yield loss is not known. Field studies were conducted from 2012 to 2015 in Belle Glade, FL to determine the critical timing of fall panicum removal and season-long interference in sugarcane. The effect of season-long fall panicum interference and critical timing of removal based on 5 and 10% acceptable yield loss (AYL) levels were determined by fitting a log-logistic equation to percentage millable stalk, cane, and sugar yield loss data. Millable stalks, cane, and sucrose yield decreased as the duration of fall panicum interference increased. Season-long interference of fall panicum resulted in 34 to 60%, 34 to 62%, and 44 to 60% millable stalk, cane, and sucrose yield loss, respectively. The critical timing of fall panicum removal based on 5 and 10% AYL for millable stalks was 5 to 9 wk after sugarcane emergence (WAE). At 5 and 10% AYL, the critical timing of fall panicum removal ranged from 5 to 9 WAE and 6 to 8 WAE for cane and sucrose yield loss, respectively. These results show that fall panicum is competitive with sugarcane early in the season, demonstrating the need for timely early-season control to reduce negative effect on yield.

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.

Critical timing of Palmer amaranth (Amaranthus palmeri) removal in sweetpotato

2020 ◽  
Vol 34 (4) ◽  
pp. 547-551 ◽  
Author(s):  
Stephen C. Smith ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Sushila Chaudhari ◽  
Jonathan R. Schultheis ◽  
...  
Keyword(s):  
North Carolina ◽  
Logistic Model ◽  
Yield Loss ◽  
Relative Yield ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Marketable Yield ◽  
Yield Data ◽  
Critical Timing

AbstractPalmer amaranth is the most common and troublesome weed in North Carolina sweetpotato. Field studies were conducted in Clinton, NC, in 2016 and 2017 to determine the critical timing of Palmer amaranth removal in ‘Covington’ sweetpotato. Palmer amaranth was grown with sweetpotato from transplanting to 2, 3, 4, 5, 6, 7, 8, and 9 wk after transplanting (WAP) and maintained weed-free for the remainder of the season. Palmer amaranth height and shoot dry biomass increased as Palmer amaranth removal was delayed. Season-long competition by Palmer amaranth interference reduced marketable yields by 85% and 95% in 2016 and 2017, respectively. Sweetpotato yield loss displayed a strong inverse linear relationship with Palmer amaranth height. A 0.6% and 0.4% decrease in yield was observed for every centimeter of Palmer amaranth growth in 2016 and 2017, respectively. The critical timing for Palmer amaranth removal, based on 5% loss of marketable yield, was determined by fitting a log-logistic model to the relative yield data and was determined to be 2 WAP. These results show that Palmer amaranth is highly competitive with sweetpotato and should be managed as early as possible in the season. The requirement of an early critical timing of weed removal to prevent yield loss emphasizes the importance of early-season scouting and Palmer amaranth removal in sweetpotato fields. Any delay in removal can result in substantial yield reductions and fewer premium quality roots.

Value cocreation at its peak: the asymmetric relationship between coproduction and loyalty

2016 ◽  
Vol 27 (4) ◽  
pp. 563-590 ◽  
Author(s):  
Nicola E. Stokburger-Sauer ◽  
Ursula Scholl-Grissemann ◽  
Karin Teichmann ◽  
Martin Wetzels
Keyword(s):  
Customer Loyalty ◽  
Field Studies ◽  
Service Industries ◽  
Optimum Level ◽  
Negative Effects ◽  
Cross Sectional ◽  
Content Type ◽  
Negative Effect ◽  
Value Cocreation ◽  
Potential Benefits

Purpose – Coproduction, as one component of cocreation of value, offers many benefits to customers and management, but also requires customers to invest a considerable amount of effort and time. The purpose of this paper is to investigate the coproduction paradox of benefits and costs. Design/methodology/approach – One experimental study and two cross-sectional field studies across three service industries test the nonlinear relationship between level of coproduction and customer loyalty. Findings – Results show not only the optimum level but also the negative effects of increasing levels of coproduction on customer loyalty and, in turn, monetary expenditures. The negative effect can be partially offset by perceived process enjoyment (PE), such that consumers who enjoy the process exhibit increased loyalty after the optimum coproduction point. Customer self-efficacy (SE), however, further strengthens the inverted u-shaped relationship. Research limitations/implications – Further research should try to replicate the findings in more complex and less hedonic service settings (e.g. financial investments) because both PE and SE might be even more powerful here. Practical implications – Service managers need to determine the optimal degree to which customers want to engage in the creation of services and avoid overburdening them. Management should further explore opportunities to elicit feelings of fun and enjoyment through coproduction. Originality/value – Research usually highlights the potential benefits of coproduction for customers and companies and suggests a positive linear relationship between coproduction and success outcomes. This article instead shows that after an optimum level, the marginal benefits of coproduction for customer loyalty turn negative.

scholarly journals Interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri) and large crabgrass (Digitaria sanguinalis) in sweetpotato

Weed Science ◽  
2019 ◽  
Vol 67 (4) ◽  
pp. 426-432 ◽  
Author(s):  
Nicholas T. Basinger ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
David L. Jordan ◽  
Wesley J. Everman ◽  
...  
Keyword(s):  
Ipomoea Batatas ◽  
Yield Loss ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Digitaria Sanguinalis ◽  
Weed Density ◽  
Dry Biomass ◽  
Presence And Absence ◽  
Large Crabgrass

AbstractField studies were conducted in 2016 and 2017 in Clinton, NC, to determine the interspecific and intraspecific interference of Palmer amaranth (Amaranthus palmeri S. Watson) or large crabgrass [Digitaria sanguinalis (L.) Scop.] in ‘Covington’ sweetpotato [Ipomoea batatas (L.) Lam.]. Amaranthus palmeri and D. sanguinalis were established 1 d after sweetpotato transplanting and maintained season-long at 0, 1, 2, 4, 8 and 0, 1, 2, 4, 16 plants m−1 of row in the presence and absence of sweetpotato, respectively. Predicted yield loss for sweetpotato was 35% to 76% for D. sanguinalis at 1 to 16 plants m−1 of row and 50% to 79% for A. palmeri at 1 to 8 plants m−1 of row. Weed dry biomass per meter of row increased linearly with increasing weed density. Individual dry biomass of A. palmeri and D. sanguinalis was not affected by weed density when grown in the presence of sweetpotato. When grown without sweetpotato, individual weed dry biomass decreased 71% and 62% from 1 to 4 plants m−1 row for A. palmeri and D. sanguinalis, respectively. Individual weed dry biomass was not affected above 4 plants m−1 row to the highest densities of 8 and 16 plants m−1 row for A. palmeri and D. sanguinalis, respectively.

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.

Large crabgrass (Digitaria sanguinalis) and Palmer amaranth (Amaranthus palmeri) intraspecific and interspecific interference in soybean

Weed Science ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 649-656 ◽  
Author(s):  
Nicholas T. Basinger ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
David L. Jordan ◽  
Wesley J. Everman ◽  
...  
Keyword(s):  
Yield Loss ◽  
Maximum Yield ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Weed Species ◽  
Digitaria Sanguinalis ◽  
Weed Density ◽  
Loss Estimate ◽  
Large Crabgrass

AbstractField studies were conducted in 2016 and 2017 at Clinton, NC, to quantify the effects of season-long interference of large crabgrass [Digitaria sanguinalis (L.) Scop.] and Palmer amaranth (Amaranthus palmeri S. Watson) on ‘AG6536’ soybean [Glycine max (L.) Merr.]. Weed density treatments consisted of 0, 1, 2, 4, and 8 plants m−2 for A. palmeri and 0, 1, 2, 4, and 16 plants m−2 for D. sanguinalis with (interspecific interference) and without (intraspecific interference) soybean to determine the impacts on weed biomass, soybean biomass, and seed yield. Biomass per square meter increased with increasing weed density for both weed species with and without soybean present. Biomass per square meter of D. sanguinalis was 617% and 37% greater when grown without soybean than with soybean, for 1 and 16 plants m−2 respectively. Biomass per square meter of A. palmeri was 272% and 115% greater when grown without soybean than with soybean for 1 and 8 plants m−2, respectively. Biomass per plant for D. sanguinalis and A. palmeri grown without soybean was greatest at the 1 plant m−2 density. Biomass per plant of D. sanguinalis plants across measured densities was 33% to 83% greater when grown without soybean compared with biomass per plant when soybean was present for 1 and 16 plants m−2, respectively. Similarly, biomass per plant for A. palmeri was 56% to 74% greater when grown without soybean for 1 and 8 plants m−2, respectively. Biomass per plant of either weed species was not affected by weed density when grown with soybean due to interspecific competition with soybean. Yield loss for soybean grown with A. palmeri ranged from 14% to 37% for densities of 1 to 8 plants m−2, respectively, with a maximum yield loss estimate of 49%. Similarly, predicted loss for soybean grown with D. sanguinalis was 0 % to 37% for densities of 1 to 16 m−2 with a maximum yield loss estimate of 50%. Soybean biomass was not affected by weed species or density. Results from these studies indicate that A. palmeri is more competitive than D. sanguinalis at lower densities, but that similar yield loss can occur when densities greater than 4 plants m−2 of either weed are present.

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