Soybean Yield Loss Potential Associated with Early-Season Weed Competition across 64 Site-Years

Weed Science ◽  
2013 ◽  
Vol 61 (3) ◽  
pp. 500-507 ◽  
Author(s):  
Nathanael D. Fickett ◽  
Chris M. Boerboom ◽  
David E. Stoltenberg
Keyword(s):  
Yield Loss ◽  
Average Density ◽  
Yield Potential ◽  
Weed Competition ◽  
Growth Stages ◽  
Average Height ◽  
Weed Species ◽  
Potential Yield ◽  
Early Season ◽  
On Farm

Glyphosate applied POST can provide a high level of efficacy on many weed species in soybean, but delayed application beyond optimal weed growth stages might fail to fully protect yield potential. Further, we do not have a good understanding of the extent to which delayed glyphosate application and its associated yield loss is occurring on-farm. Our goal was to characterize on-farm weed communities in glyphosate-resistant soybean just prior to glyphosate application and estimate potential yield loss associated with early-season soybean-weed competition. In field surveys conducted across 64 site-yr in southern Wisconsin in 2008 and 2009, common lambsquarters, velvetleaf, dandelion,Polygonumspp., andAmaranthusspp. were the five most abundant broadleaf weed species across site-years, present in 92, 69, 64, 42, and 50% of all fields, respectively, at average densities of 14, 5, 5, 14, and 10 plants m−2, respectively. Average height of these species was 21 cm or less at or near the time of glyphosate application. Grass and sedge species occurred in 95% of fields at an average density of 41 plants m−2and height of 21 cm. The mean and median values of total weed density across site-years were 101 and 41 plants m−2, with heights of 19 and 17 cm, respectively. Recommended height for treatment is 15 cm. Glyphosate application occurred on average at V3 to V4 soybean growth stage, which is later than V2 soybean typically targeted to protect yield. Average yield loss predicted by WeedSOFT® was 5% with a mean economic loss of $47 ha−1. Predicted yield loss was greater than 5% on one-fourth of the site-years, all of which were treated at V4 soybean or later. The maximum predicted yield loss was 27%. These results suggest that glyphosate was applied at weed height and soybean growth stages that were greater than optimal to protect yield in many fields across southern Wisconsin. A soil-residual herbicide applied PRE, or a more timely POST application of glyphosate would alleviate the majority of these losses.

Predicted Corn Yield Loss Due to Weed Competition Prior to Postemergence Herbicide Application on Wisconsin Farms

2013 ◽  
Vol 27 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Nathanael D. Fickett ◽  
Chris M. Boerboom ◽  
David E. Stoltenberg
Keyword(s):  
Weed Management ◽  
Yield Loss ◽  
Economic Loss ◽  
The United States ◽  
Yield Potential ◽  
Weed Competition ◽  
Corn Yield ◽  
Herbicide Application ◽  
Weed Species ◽  
Early Season

Approximately 50% of the genetically modified herbicide-resistant corn hectares in the United States are treated only with POST-applied herbicides for weed management. Although a high degree of efficacy can be obtained with POST-applied herbicides, delayed timing of application may result in substantial corn yield loss. Our goal was to characterize on-farm corn–weed communities prior to POST herbicide application and estimate potential corn-yield loss associated with early-season corn–weed competition. In 2008 and 2009, field surveys were conducted across 95 site-years in southern Wisconsin and recorded weed species, density, and height in addition to crop height, growth stage, and row spacing. WeedSOFT® was used to predict corn yield loss. Common lambsquarters, velvetleaf, dandelion, common ragweed, andAmaranthusspecies were the five most abundant broadleaf weed species across site-years, present in 92, 86, 59, 45, and 44% of all fields, respectively, at mean densities of 19, 3, 3, 4, and 3 plants m−2, respectively. Mean plant heights among these species were 17 cm or less. Grass and sedge species occurred in 96% of fields at a mean density of 25 plants m−2and height of 7 cm. The mean and median of total weed density across site-years were 96 and 52 plants m−2, with heights of 14 and 13 cm, respectively. Mean predicted corn yield loss was 4.5% with a mean economic loss of $62 ha−1. However, predicted yield loss was greater than 5% on one-third of the site-years, with a maximum of 26%. These results indicate that delayed application of POST herbicides has led to corn yield loss due to early-season weed-crop competition on a substantial number of fields across southern Wisconsin, and suggest that management tactics need to be improved to protect corn yield potential fully.

The critical weed-free period in glyphosate-resistant soybean in Ontario is similar to previous estimates using glyphosate-susceptible soybean

2019 ◽  
Vol 99 (4) ◽  
pp. 437-443
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Amit J. Jhala ◽  
Peter H. Sikkema
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Weed Species ◽  
Weed Biomass ◽  
Weed Density ◽  
Weed Interference ◽  
Beginning Of Flowering ◽  
Minimal Reduction

A study consisting of 13 field experiments was conducted during 2014–2016 in southwestern Ontario and southcentral Nebraska (Clay Center) to determine the effect of late-emerging weeds on the yield of glyphosate-resistant soybean. Soybean was maintained weed-free with glyphosate (900 g ae ha−1) up to the VC (cotyledon), V1 (first trifoliate), V2 (second trifoliate), V3 (third trifoliate), V4 (fourth trifoliate), and R1 (beginning of flowering) growth stages, after which weeds were allowed to naturally infest the soybean plots. The total weed density was reduced to 24%, 63%, 67%, 72%, 76%, and 92% in Environment 1 (Exeter, Harrow, and Ridgetown) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 soybean growth stages, respectively. The total weed biomass was reduced by 33%, 82%, 95%, 97%, 97%, and 100% in Environment 1 (Exeter, Harrow, and Ridgetown) and 28%, 100%, 100%, 100%, 100%, and 100% in Environment 2 (Clay Center) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 stages, respectively. The critical weed-free periods for a 2.5%, 5%, and 10% yield loss in soybean were the V1–V2, VC–V1, and VC–V1 soybean stages in Environment 1 (Exeter, Harrow, and Ridgetown) and V2–V3, V2–V3, and V1–V2 soybean stages in Environment 2 (Clay Center), respectively. For the weed species evaluated, there was a minimal reduction in weed biomass (5% or less) when soybean was maintained weed-free beyond the V3 soybean growth stage. These results shows that soybean must be maintained weed-free up to the V3 growth stage to minimize yield loss due to weed interference.

scholarly journals Effect of Application Timing on Winter Wheat Response to Metribuzin

2017 ◽  
Vol 31 (1) ◽  
pp. 94-99 ◽  
Author(s):  
Mark J. VanGessel ◽  
Quintin R. Johnson ◽  
Barbara A. Scott
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Early Spring ◽  
Growth Stages ◽  
Wheat Cultivars ◽  
Weed Species ◽  
Application Timing ◽  
Herbicide Resistant ◽  
Stage 4 ◽  
Stage 1

Metribuzin will control many problematic weed species in winter wheat in the mid-Atlantic states, including herbicide-resistant biotypes, but it has not been recommended due to crop safety concerns. In a three-year trial, metribuzin was applied at 105 or 210 g ai ha−1to wheat at the PRE, 2-leaf (Feekes stage 1 to 2), early spring (Feekes stage 3 to 4), and late spring (Feekes stage 4 to 6) growth stages using wheat cultivars sensitive to metribuzin. Early spring applications had the least amount of injury, and injury at this timing was transient and yield was not reduced. Yield loss was observed with the other application timings in at least one out of three years. Rainfall shortly after application appears to increase the risk of wheat injury.

scholarly journals Practices and constraints of tomato production among smallholder farmers in Uganda

2021 ◽  
Vol 21 (02) ◽  
pp. 17560-17580
Author(s):  
G Ddamulira ◽  
◽  
O Isaac ◽  
M Kiryowa ◽  
R Akullo ◽  
...  
Keyword(s):  
Viral Infections ◽  
Market Access ◽  
Smallholder Farmers ◽  
Cropping System ◽  
Production Costs ◽  
Yield Potential ◽  
Potential Yield ◽  
Tomato Production ◽  
Tomato Yield ◽  
On Farm

Tomato(Solanum esculentum)is one of the most promising vegetables whose production is being intensified in Uganda. However, tomato yields remain low due to several constraints. The study aimed at identifying production and marketing practices, and constraints affecting tomato productivity in major tomato growing areas of Uganda. A survey was conducted in eight major tomato producing districts using a questionnaire to guide interviews for 240 farmers and 16 key informants. The data were analyzed using SPSS software. Results revealed that tomato production in Uganda is dominated by males who grow them on 0.68 acres of land on average. Mosttomatofarmers (78.4%) use mono cropping system with varietiesAsilla F1 (35.3%), Tengeru97(21.1%), Rambo (18.1%), NovelaF1(17.7%) and Riogrande (10.3%) dominating. The choice of tomato varieties used by farmers mainly depend on yield potential, pest and disease tolerance and market preference attributes such as long shelf life. In the study area, tomato is mainly fertilized using foliar fertilizers, followed by Diammonium phosphate and cattle manure. The key pests affecting tomato include caterpillars, thrips, worms and whitefly, while bacterial wilt, blight, leaf spots and viral infections are the major diseases. Majority (95.7%) of farmers use chemical sprays(pesticides and fungicides)and 4.3% of farmers used other control methods. The other methods of pest and disease control included rogueing, hand picking, ash, organic extracts, urine and frequent weeding. Average tomato yield was 4,846.3 kg/acre lower than the potential yield of 6000kg/acre. Thirty five percent of farmers market their tomato individually on-farm, 32.8% sell in rural markets, while 32.2% send to the nearest urban markets. The study revealed intensive chemical use accounting for 20% of the production costs, high seed costs (11%) and drought (10%) as the major production constraints impeding tomato production; and price fluctuations, low prices, high transport costs, post-harvest loss on farm, and poor market access as the major marketing constraints. The research findings will aid in the development of new market-oriented, highly productive tomato varieties with improved access to seed and designing initiatives to address production and marketing constraints, which will eventually enhance tomato production.

scholarly journals Performance of Sorghum Recombinant Inbred Lines (RIL) developed for rain-fed areas of Sudan

2015 ◽  
Vol 60 (4) ◽  
pp. 395-406
Author(s):  
El Hassan ◽  
Yasir Gamar ◽  
Ibrahim Elzein ◽  
Asma Ali ◽  
Tareg Ahmed
Keyword(s):  
Grain Yield ◽  
Grain Quality ◽  
Recombinant Inbred Lines ◽  
Block Design ◽  
Inbred Lines ◽  
Yield Potential ◽  
High Yield ◽  
Growth Stages ◽  
Potential Yield ◽  
Wide Range

Sorghum (Sorghum bicolor (L) Moench) is the most widely produced and consumed cereal crop in Sudan. However, productivity is low since the crop is produced in favorable and unfavorable environments where the crop suffers from drought stresses at different growth stages. In the present study, six sorghum inbred lines developed by local breeding program and two commercial checks were evaluated for grain yield potential, yield stability, some important agronomic characters and grain quality properties. Series variety trials were conducted at Elobeid and Suki, Damazin areas of Sudan, during three consecutive rainy seasons. The selected locations represent low, medium and high rainfall areas of Sudan. The trial was laid out in a randomized complete block design. The results revealed that mean squares of genotypes, seasons, locations, location x season, location x genotypes, season x genotypes and season x location x genotype interactions were highly significant (P=0.01) for grain yield. The sorghum genotypes Edo 34-23-4, Edo 26-18 and Edo 16-dwarf produced substantially higher grain yields than commercial checks and the trial mean. Their percentage yield increase ranged from 5% to 75% over commercial checks. The stability analysis revealed that the above mentioned Edo-genotypes had high yield potentials and were stable across a wide range of agricultural conditions. Moreover, the same Edo-lines showed early maturing compared to selected commercial checks and also the Edo-lines possessed good food grains and were market preferred and acceptable for making quality kisra (fermented sorghum pancake-like flatbread). The Edo developed lines also possess the acceptable grain quality in addition to moderate physical grain characteristics such as protein content, fat acidity and moisture content.

scholarly journals Interference of Broadleaf Buttonweed and White-Eye in Soybean

2020 ◽  
Vol 38 ◽  
Author(s):  
F. DIESEL ◽  
M.M. TREZZI ◽  
M. GALLON ◽  
P.H.F. MIZERSKI ◽  
S.C. BATISTEL ◽  
...  
Keyword(s):  
Grain Yield ◽  
Yield Loss ◽  
Block Design ◽  
Grain Weight ◽  
Weed Competition ◽  
Yield Losses ◽  
Weed Species ◽  
Randomized Block Design ◽  
Crop Weed Competition ◽  
1000 Grain Weight

ABSTRACT: Weed species is one of the factors contributing to grain yield losses due to crop-weed competition. Two of the most common weeds of soybean fields in Brazil are from the Rubiaceae family: Borreria latifolia and Richardia brasiliensis. This study aimed to evaluate the effects of B. latifolia and R. brasiliensis on plant development, yield components, and soybean productivity. Two assays were conducted in a randomized block design with four replications, using a two-level factorial design, in which the first factor consisted of the species B. latifolia and R. brasiliensis and the second factor consisted of the densities 0, 2, 4, 6, 8, 10, and 12 plants m-2. Plant height, leaf area and total chlorophyll in the V6 and R5 stages, number of pods per plant, number of grains per pod, 1000-grain weight, and grain yield loss were evaluated in both cultivars. Grain yield of both soybean cultivars was negatively affected by the interference with B. latifolia and R. brasiliensis. The species B. latifolia was more competitive with soybean when compared to R. brasiliensis, causing higher reductions for all variables. Each B. latifolia plant per square meter is able to reduce the yield of soybean by 3 a 4.4%, while each R.brasiliensis plant reduces yield by 2 a 2.6%. For both species, the reduction in soybean yield due to competition was caused by a decrease in the number of pods per plant, number of grains per pod, and 1000-grain weight.

Competitiveness with Weeds of Soybean Cultivars with Different Maturity and Canopy Width Characteristics

2007 ◽  
Vol 21 (4) ◽  
pp. 1082-1088 ◽  
Author(s):  
Dawn E. Nordby ◽  
Dustin L. Alderks ◽  
Emerson D. Nafziger
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Growth Stage ◽  
Competitive Ability ◽  
Field Studies ◽  
Yield Potential ◽  
Weed Competition ◽  
Early Season ◽  
Soybean Cultivars ◽  
Maturity Date

Field studies were conducted in 2005 at five locations throughout Illinois to determine the effect of maturity date and canopy width characteristics of selected glyphosate-resistant soybean cultivars on competitive ability against weeds. Natural weed populations at all sites were allowed to compete with the soybean cultivars until the V1, V3, V5, or V7 growth stage and then removed with an application of glyphosate. Light-interception readings, weed control ratings, and soybean yield were all measured to compare cultivars. Cultivars of later maturities tended to withstand early season weed competition better and attained higher yields when weeds were removed at later timings than those of earlier maturity. Although canopy width differed moderately among cultivars in some cases, canopy width had no effect on the ability of soybeans to compete with weeds. Thus, choosing soybean cultivars of later maturity might provide more flexibility in weed management and might reduce losses due to weeds, but that benefit needs to be balanced with yield potential.

Influence of Early-Season Yield Loss Predictions from WeedSOFT®and Soybean Row Spacing on Weed Seed Production from a Mixed-Weed Community

2004 ◽  
Vol 18 (2) ◽  
pp. 412-418 ◽  
Author(s):  
Andrew A. Schmidt ◽  
William G. Johnson
Keyword(s):  
Seed Production ◽  
Crop Yield ◽  
Weed Management ◽  
Yield Potential ◽  
Management Decision ◽  
Yield Reduction ◽  
Weed Seed ◽  
Weed Species ◽  
Early Season ◽  
Giant Foxtail

Seed production from weeds that are missed by herbicide application can affect future weed populations and management decisions. It may be possible to expand the utility of computerized weed management decision aids to include an estimate of weed seed production resulting from selected treatments based on crop yield potential. Field studies were conducted in soybean near Columbia, MO, to determine whether weed control recommendations based on crop yield potential from a computerized weed management decision aid influence weed seed production in two soybean row spacings. At approximately 28 d after planting, weed densities and heights were entered into WeedSOFT®to generate a list of treatments ranked by predicted crop yields. Treatments included: (1) highest predicted crop yield in a glyphosate-resistant system, (2) highest predicted crop yield in a nonglyphosate-resistant system, (3) a 10% yield reduction, (4) a 20% yield reduction, and (5) an untreated control. These treatments were applied to soybean grown in 38- and 76-cm rows. Treatments that provided 90% or higher control of an individual species at 22 d after treatment usually produced less seed than untreated checks. Weed seed production based on early-season herbicide efficacy showed a linear relationship and was relatively predictable (r2≥ 0.52) for the predominant weed species. For less dominant weed species, weed seed production was not strongly correlated (r2≤ 0.27) to early-season herbicide efficacy but apparently influenced by control of other weed species. Narrow row spacing reduced giant foxtail biomass both years but did not reduce common ragweed and ivyleaf morningglory biomass. Narrow rows did not decrease giant foxtail, common ragweed, and ivyleaf morningglory seed production.

Sweetpotato Tolerance to Thifensulfuron Applied Postemergence

2007 ◽  
Vol 21 (4) ◽  
pp. 928-931 ◽  
Author(s):  
Andrew W. MacRae ◽  
David W. Monks ◽  
Roger B. Batts ◽  
Allan C. Thornton
Keyword(s):  
Yield Loss ◽  
Total Yield ◽  
Yield Reduction ◽  
Weed Species ◽  
Potential Yield ◽  
Optimal Amount ◽  
Crop Maturity

An experiment was conducted at two locations in 2003 and 2004 to determine the timing and rate of thifensulfuron that is safe to use on sweetpotato. Thifensulfuron was applied 1, 2, and 4 wk after transplanting (WAP) in 2003 and 4, 6, and 8 WAP in 2004. Within each timing, thifensulfuron treatments were 1.1, 2.1, 3.2, 4.3, and 8.5 g ai/ha plus a weed-free control. The 1 and 2 WAP timings of thifensulfuron reduced the yield of number 1 roots greater than 25%. The 4, 6, and 8 WAP timings had less than 15% reduction in yield, with the 6 WAP timing reducing number 1 roots and total yield 10% or less. When 4.3 g/ha of thifensulfuron was applied 4 WAP, total yield was reduced 13%. The 6 and 8 WAP timings had little yield reduction, with no rate response observed. Application of 4.3 g/ha of thifensulfuron at 6 WAP would allow for control of problematic weed species while limiting potential yield loss. Yield loss from a 4 WAP application of thifensulfuron may in fact be a delay in crop maturity that could be recovered if the sweetpotato harvest was delayed to allow for the optimal amount of number 1 grade roots to be produced.

scholarly journals Pollinator Habitat Establishment after Organic and No-till Seedbed Preparation Methods

HortScience ◽  
2017 ◽  
Vol 52 (10) ◽  
pp. 1349-1355 ◽  
Author(s):  
Gina M. Angelella ◽  
Megan E. O’Rourke
Keyword(s):  
Large Degree ◽  
Schizachyrium Scoparium ◽  
Weed Competition ◽  
Eastern Shore ◽  
Weed Species ◽  
Preparation Methods ◽  
Monarda Fistulosa ◽  
No Till ◽  
Seedbed Preparation ◽  
On Farm

Establishing on-farm pollinator habitat can mitigate native pollinator and pollination ecosystem service declines, and federal programs are available to provide technical and financial assistance to farmers interested in habitat installation. Although sufficient seedbed preparation to limit weed competition is thought to be the most important step toward achieving good pollinator habitat establishment, preparation recommendations vary and studies have not investigated seedbed preparation techniques in the context of the U.S. Department of Agriculture (USDA) Farm Bill programs for pollinator conservation. To address this, we assessed the effects of two seedbed preparation methods, conventional inversion tillage and no-till with herbicide, on wildflower establishment and weed competition during the first year after planting. Experiments were conducted in Blacksburg, VA, and were replicated in 2015 and 2016. In addition, we tracked seedbed preparation methods and pollinator habitat establishment on seven farms located on the Eastern Shore of Virginia and Maryland in 2016. The wildflower mix consisted of nine species of forbs and two species of grasses: the forbs were black-eyed Susan (Rudbeckia hirta L.), partridge pea [Chamaecrista fasciculata (Michx.) Greene], plains coreopsis (Coreopsis tinctoria Nutt.), lanceleaf coreopsis (Coreopsis lanceolata L.), purple coneflower [Echinacea purpurea (L.) Moench], narrowleaf mountain mint (Pycnanthemum tenuifolium Schrad.), wild bergamot (Monarda fistulosa L.), Maximilian sunflower (Helianthus maximiliani Schrad.), and showy tickseed [Bidens aristosa (Michx.) Britton] or Indian blanket (Gaillardia pulchella Foug.); the grasses were splitbeard bluestem (Andropogon ternarius Michx.) and little bluestem [Schizachyrium scoparium (Michx.) Nash]. In the experiments, wildflower establishment was greater after no-till with herbicide than after tillage preparation (2015: P = 0.09; 2016: P = 0.002). Predominating weed species varied by study, with more common lambsquarters (Chenopodium album L.) and hairy galinsoga [Galinsoga ciliata (Raf.) S.F. Blake] growth after tillage treatments, and more hairy vetch (Vicia villosa Roth) growth after no-till preparation. On-farm pollinator habitat establishment on the Eastern Shore was highly variable, but more wildflower forbs established after tillage-plus-herbicide than tillage-only seedbed preparations (P = 0.01). Across sites, we found a large degree of site-specific variation in wildflower establishment and predominant weed species.

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