Time of Removal of Crownbeard (Verbesina encelioides) on Peanut Yield

2005 ◽  
Vol 19 (2) ◽  
pp. 380-384 ◽  
Author(s):  
Rodney L. Farris ◽  
Cody J. Gray ◽  
Don S. Murray ◽  
Laval M. Verhalen
Keyword(s):  
Natural Population ◽  
Field Experiments ◽  
Yield Reduction ◽  
Weed Density ◽  
Weed Interference ◽  
Weed Growth ◽  
Poor Predictor ◽  
Verbesina Encelioides ◽  
Shell Peanut ◽  
Weed Removal

Field experiments were conducted in southwestern Oklahoma near Colony in 2000 and near Ft. Cobb in 2001 to quantify the effect of time of removal of a natural population of crownbeard on peanut yield. Weed densities and dry weed weights were measured at eight weed-removal times, and in-shell peanut yields were determined at harvest. Crownbeard was removed at 0 (the weed-free check), 4, 6, 8, 10, 12, 14, and 16 wk (full season) after crop emergence (WAE). Weed density was a poor predictor for dry weed weight and peanut yield; however, dry weed weight and time of removal were good predictors for peanut yield. Weed growth was minimal up to 4 WAE and increased linearly after that time. For each week of weed growth, a 0.52 kg/plot increase in dry weed weight was measured. Peanut yield decreased linearly because of crownbeard competition. For each kilogram per plot increase in dry weed weight, a 129 kg/ha or 5.1% peanut yield reduction took place. For each week of weed interference, a 75 kg/ha or 2.8% peanut yield reduction occurred. Crownbeard removal by or before 4 WAE will minimize losses in peanut yield because of interference.

LAMB’S-QUARTERS INTERFERENCE WITH DIRECT SEEDED BROCCOLI

1990 ◽  
Vol 70 (4) ◽  
pp. 1215-1221 ◽  
Author(s):  
IRIS BITTERLICH ◽  
MAHESH K. UPADHYAYA
Keyword(s):  
Brassica Oleracea ◽  
Field Experiments ◽  
Chenopodium Album ◽  
Total Yield ◽  
Growth And Yield ◽  
Marketable Yield ◽  
Weed Density ◽  
Weed Interference ◽  
Lamb’S Quarters ◽  
Cole Crop

Field experiments were conducted in 1987 and 1988 to study the effect of lamb’s-quarters (Chenopodium album L.) interference on broccoli (Brassica oleracea L. var. botrytis ’Emperor’) growth and yield. Broccoli growth was initially affected by weed interference at 28–36 d after seeding. Generally, the negative effect of weed interference on broccoli growth increased with increasing weed density and time after seeding. Interference by 15 lamb’s-quarters plants m−2 reduced the biomass of broccoli plants by 71–73% compared to the weed-free control at 57–58 d after seeding. Weed density-crop yield relationship curves showed that one lamb’s-quarters plant m−2 decreased total yield by 18–20% and marketable yield by 22–37%. Lamb’s-quarters reduced the total yield per plot by decreasing the average head weight of broccoli. The number of heads per plot was not affected. Weed interference also reduced the weight of heads classified as marketable (> 10 cm across). However, in 1987 more heads failed to reach a marketable size which resulted in a much smaller marketable yield than in 1988.Key words: Brassica oleracea var. botrytis, broccoli, Chenopodium album L., weed density, weed interference, cole crop

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.

Influence of Crownbeard (Verbesina encelioides) Densities on Peanut (Arachis hypogaea) Yield

2006 ◽  
Vol 20 (3) ◽  
pp. 627-632 ◽  
Author(s):  
Rodney L. Farris ◽  
Don S. Murray
Keyword(s):  
Arachis Hypogaea ◽  
Good Predictor ◽  
Field Experiments ◽  
Yield Loss ◽  
Research Station ◽  
Weed Biomass ◽  
Weed Density ◽  
Verbesina Encelioides

Field experiments were conducted at the Caddo Research Station near Ft. Cobb, OK and at the Agronomy Research Station near Perkins, OK to measure the effects of seven crownbeard (Verbesina encelioides) densities on peanut (Arachis hypogaea) yield. The seven densities evaluated were 0 (the weed-free check), 0.2, 0.4, 0.8, 1.6, 2.4, and 3.2 weeds/m of row. Data collected consisted of dry weed biomass and peanut yields. Correlation between weed density and dry weed biomass, dry weed biomass and peanut yield (kg/ha), dry weed biomass and peanut yield loss (percentage of check), weed density and peanut yield (kg/ha), and weed density and peanut yield loss (percentage of check) were evaluated. For each weed/m of row, dry weed biomass increased by 0.34 kg/m row. Dry weed biomass was a good predictor of peanut yield. For each kilogram of dry weed biomass/ m row, a 1900-kg/ha or 46.3% reduction in peanut yield occurred. Weed density was also a good predictor of peanut yield. A 559-kg/ha reduction or 16% increase in peanut yield loss occurred for each weed/m row. Peanut yield was reduced approximately 50% when crownbeard density increased to 3.2 weeds/m row.

Effects of competition with weeds on the growth, development and yield of sorghum

1993 ◽  
Vol 120 (2) ◽  
pp. 187-196 ◽  
Author(s):  
A. P. Everaarts
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Canopy Structure ◽  
Ground Cover ◽  
Stem Length ◽  
Yield Reduction ◽  
Area Index ◽  
Weed Growth ◽  
Competition For Light ◽  
Number Of Leaves

SUMMARYIn two field experiments in Suriname, competition between weeds and sorghum (Sorghum bicolor(L.) Moench) was studied in the rainy seasons of 1982 and 1983. The crop was kept either weed-free or without weed control for each of six different periods of time from planting. Observations made at the end of each period allowed an analysis to be made of the growth and development of a crop with and without weed control.Due to the crop canopy structure and fertilizer placement near the row, weed growth was concentrated in the rows. Starting atc.20–30 days after planting, competition with weeds reduced ground-cover and leaf area index of the crop. Competition reduced growth rates, leading to lower yields. Plant population density was not affected, but competition reduced the number of leaves present. Stem length initially increased with competition in one season, but was retarded in another. Competition for nutrients was strong and was found as early as 15 days after planting. Nitrogen was the element most competed for initially. Competition for water occurred, but competition for light seemed unlikely. About 20 weed-free days after planting were necessary to avoid yield losses and around 30 weed-free days to attain negligible weed growth at harvest. Yield reduction was mainly due to a decrease in number of grains per panicle. Competition during floret establishment (c.30–40 days after planting) should be avoided.

Soybean response to weed interference and defoliation

Weed Science ◽  
1999 ◽  
Vol 47 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Charles F. Grymes ◽  
James L. Griffin ◽  
David J. Boethel ◽  
B. Rogers Leonard ◽  
David L. Jordan ◽  
...  
Keyword(s):  
Seed Development ◽  
Field Experiments ◽  
Dry Weight ◽  
Yield Reduction ◽  
Growth Stages ◽  
Lower Yield ◽  
Full Bloom ◽  
Soybean Yield ◽  
Weed Interference ◽  
Hemp Sesbania

Field experiments were conducted in Louisiana over 2 yr to evaluate the influence of full-season interference from johnsongrass, common cocklebur, or hemp sesbania at densities of 2.5, 0.5, and 2.0 plants m–1of row, respectively, and simulated insect defoliation of soybean on weed and soybean growth. Defoliation at R2 (full bloom) and R5 (beginning seed development) soybean growth stages was accomplished by removal of zero, one, or two leaflets per soybean trifoliate, which approximated 0, 33, and 66% defoliation, respectively. Height and dry weight of all weeds were not affected by soybean defoliation level or defoliation stage. Soybean height 3 wk after defoliation at R5 was not influenced by weed interference, soybean defoliation level, or defoliation stage in either year. Averaged across soybean defoliation levels and stages in 1994, johnsongrass, common cocklebur, and hemp sesbania reduced soybean yields 30, 15, and 14%, respectively. In 1995, johnsongrass reduced soybean yield 35%. As soybean defoliation level increased, a linear decrease in soybean yield was observed. Averaged across weeds and soybean defoliation stages, 33 and 66% defoliation reduced soybean yield 6 and 20% in 1994 and 12 and 33% in 1995, respectively. Defoliation at R5 resulted in 10% lower yield than defoliation at R2 in one of two years. Yield reduction due to combinations of weeds and soybean defoliation was additive.

scholarly journals Common lambsquarters (Chenopodium album) interference with corn across the northcentral United States

Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 1034-1038 ◽  
Author(s):  
David W. Fischer ◽  
R. Gordon Harvey ◽  
Thomas T. Bauman ◽  
Sam Phillips ◽  
Stephen E. Hart ◽  
...  
Keyword(s):  
United States ◽  
Field Experiments ◽  
Yield Loss ◽  
Management Decision ◽  
Yield Reduction ◽  
Model Parameters ◽  
Corn Yield ◽  
Data Set ◽  
Common Lambsquarters ◽  
Weed Density

Variation in crop–weed interference relationships has been shown for a number of crop–weed mixtures and may have an important influence on weed management decision-making. Field experiments were conducted at seven locations over 2 yr to evaluate variation in common lambsquarters interference in field corn and whether a single set of model parameters could be used to estimate corn grain yield loss throughout the northcentral United States. Two coefficients (IandA) of a rectangular hyperbola were estimated for each data set using nonlinear regression analysis. TheIcoefficient represents corn yield loss as weed density approaches zero, andArepresents maximum percent yield loss. Estimates of both coefficients varied between years at Wisconsin, andIvaried between years at Michigan. When locations with similar sample variances were combined, estimates of bothIandAvaried. Common lambsquarters interference caused the greatest corn yield reduction in Michigan (100%) and had the least effect in Minnesota, Nebraska, and Indiana (0% yield loss). Variation inIandAparameters resulted in variation in estimates of a single-year economic threshold (0.32 to 4.17 plants m−1of row). Results of this study fail to support the use of a common yield loss–weed density function for all locations.

scholarly journals The effect of the period of weed interference on the growth and yield of soybean (Glycine max L. Merrill)

2020 ◽  
Vol 65 (3) ◽  
pp. 225-237
Author(s):  
Olumide Daramola ◽  
Olusegun Adeyemi ◽  
Joseph Adigun ◽  
Christopher Adejuyigbe ◽  
Patience Olorunmaiye
Keyword(s):  
Detrimental Effect ◽  
Field Trials ◽  
Yield Component ◽  
Growth And Yield ◽  
Yield Reduction ◽  
Weed Interference ◽  
Weed Growth ◽  
Weed Infestation ◽  
Glycine Max L ◽  
Cropping Seasons

Field trials were conducted to evaluate the effect of different periods of weed interference on weed infestation, growth and yield of soybean in 2016-2017 cropping seasons. In both years, soybean grain yields ranged from 888- 1148 kg ha -1 in plots where weeds were allowed to grow until harvest to 2103- 2389 kg ha -1 in plots where weeds were controlled until harvest, indicating a 52- 58% yield loss with uncontrolled weed growth. Weed interference until 3 weeks after sowing (WAS) had no detrimental effect on soybean growth and yield provided the weeds were subsequently removed. However, further delay in weed removal until 6 WAS or longer depressed soybean growth and resulted in irrevocable yield reduction, with the number of pods per plant being the most affected yield component. For optimum growth and yield, it was only necessary to keep the crop weed-free between 3 and 6 WAS.

scholarly journals Influence of Nitrogen Rate, Seeding Rate, and Weed Removal Timing on Weed Interference in Barley and Effect of Nitrogen on Weed Response to Herbicides

Weed Science ◽  
2016 ◽  
Vol 65 (1) ◽  
pp. 189-201 ◽  
Author(s):  
Vipan Kumar ◽  
Prashant Jha
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Agricultural Research ◽  
Integrated Weed Management ◽  
Barley Plant ◽  
Wild Oat ◽  
Seeding Rate ◽  
Weed Interference ◽  
Green Foxtail ◽  
Weed Removal

Field experiments were conducted at the Montana State University Southern Agricultural Research Center, Huntley, MT, in 2011 through 2013 to determine the effect of nitrogen (N) rate, seeding rate, and weed removal timing on weed interference in barley. A delay in weed removal timing from the 3- to 4-leaf (LF) stage to the 8- to 10-LF stage of barley resulted in up to 3.5-fold increase in total weed biomass and 10% reduction in barley biomass, and this was unaffected by a N rate that ranged from 56 (low) to 168 (high) kg ha−1. The effect of N rate on barley biomass was more pronounced when weed removal was delayed from the 3- to 4-LF stage to the 8- to 10-LF stage of barley and in nontreated plots. Increasing the barley seeding rate from 38 to 152 kg ha−1increased the barley plant density by 50%, biomass by 13%, and grain yield by 29%, averaged over N rates and weed removal timing. On the basis of 5 and 10% levels of acceptable yield loss, the addition of ≥112 kg N ha−1delayed the critical timing of weed removal by at least 1.3 wk in barley, compared with the 56 kg N ha−1rate. A medium or high N rate prevented reduction in barley grain quality (plumpness and test weight) observed when the seeding rate was increased from 38 to 76 or 152 kg ha−1at the low N rate. In a separate greenhouse study, the effect of N rate on the effectiveness of various herbicides for controlling wild oat, green foxtail, kochia, or Russian thistle was investigated. Results highlighted that wild oat or green foxtail grown under 56 kg N ha−1(low N) soil required 1.4 to 2.6 times higher doses of clodinafop, fenoxaprop, flucarbazone, glyphosate, glufosinate, pinoxaden, or tralkoxydim for 50% reduction in shoot dry weights (GR50) compared with plants grown under 168 kg N ha−1(high N). Similarly, a reduced efficacy of thifensulfuron methyl + tribenuron methyl, metsulfuron methyl, or bromoxynil+pyrasulfotole was observed (evident from the GR50values) for kochia or Russian thistle grown under low- vs. high-N soil. Information gained from this research will aid in developing cost-effective, integrated weed management (IWM) strategies in cereals and in educating growers on the importance of fertilizer N management as a component of IWM programs.

Smooth Pigweed (Amaranthus hybridusL.) and Livid Amaranth (Amaranthus lividus) Interference with Cucumber (Cucumis sativus)

2006 ◽  
Vol 20 (1) ◽  
pp. 227-231 ◽  
Author(s):  
Adrian D. Berry ◽  
William M. Stall ◽  
B. Rathinasabapathi ◽  
Gregory E. Macdonald ◽  
R. Charudattan
Keyword(s):  
Dry Weight ◽  
Field Studies ◽  
Fruit Yield ◽  
Yield Reduction ◽  
Cucumber Plant ◽  
Weed Density ◽  
Weed Interference ◽  
Shoot Dry Weight ◽  
Cucumber Fruit ◽  
Smooth Pigweed

Field studies were conducted to determine the effect of season-long interference of smooth pigweed or livid amaranth on the shoot dry weight and fruit yield of cucumber. Smooth pigweed or livid amaranth densities as low as 1 to 2 weeds per m2caused a 10% yield reduction in cucumber. The biological threshold of smooth pigweed or livid amaranth with cucumber is between 6 to 8 weeds per m2. Consequently, weed interference resulted in a reduction in cucumber fruit yield. Smooth pigweed, livid amaranth, and cucumber plant dry weight decreased as weed density increased. Evaluation of smooth pigweed, livid amaranth, and cucumber mean dry weights in interspecific competition studies indicated that cucumber reduced the dry weight of both species of amaranths.

scholarly journals EFFECTS OF DURATION OF HEMP-NETTLE (Galeopsis tetrahit) INTERFERENCE IN OATS (Avena sativa) AND ALFALFA (Medicago sativa)

1990 ◽  
Vol 70 (3) ◽  
pp. 809-816
Author(s):  
ANNE LÉGÈRE ◽  
JEAN-MARC DESCHÊNES
Keyword(s):  
Medicago Sativa ◽  
Avena Sativa ◽  
Field Experiments ◽  
Early Spring ◽  
Residual Effects ◽  
Yield Reduction ◽  
Quebec City ◽  
Negative Effects ◽  
Weed Interference ◽  
Spring Planting

Effects of duration of common hemp-nettle (Galeopsis tetrahit L.) interference on oat (Avena sativa L.) yields, and alfalfa (Medicago sativa L.) yields during the year of establishment were measured in field experiments conducted in the Québec City area. Hemp-nettle growth was reduced in oats compared to that in alfalfa. Effects of duration of hemp-nettle interference on oat yields were significant in one out of two years. A 35% yield reduction was measured in oats after 12 wk of interference following an early spring planting (late April). First-cut alfalfa yields decreased as duration of hemp-nettle interference increased. Residual effects of hemp-nettle interference were also measured on second-cut alfalfa yields even though hemp-nettle had been absent from alfalfa stands throughout the regrowth period. Although early spring planting is generally recommended for alfalfa in the eastern Québec region, this practice appeared unsuitable for sites heavily infested with hemp-nettle, considering the early germination of the weed and its negative effects on crop yield.Key words: Hemp-nettle, Galeopsis tetrahit, weed competition, weed interference

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