Venice Mallow Competition in Soybeans

Weed Science ◽  
1973 ◽  
Vol 21 (2) ◽  
pp. 89-94 ◽  
Author(s):  
B. J. Eaton ◽  
K. C. Feltner ◽  
O. G. Russ
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Seed Yield ◽  
Soybean Seed ◽  
Late Summer ◽  
Growing Season ◽  
Yield Component ◽  
Weed Competition ◽  
Soybean Plant ◽  
Hibiscus Trionum

Competition studies were conducted with soybeansGlycine max.(L.) Merr. ‘Clark 63’ and Venice mallow (Hibiscus trionumL.). One Venice mallow per 7.5 cm of soybean row reduced soybean seed yield 632 kg/ha after 85 days competition. Thirty to 40-cm weed bands in and between soybean rows reduced yields 270 to 651 kg/ha with 35 to 40 days of competition. A natural stand of 215 Venice mallow plants per square meter reduced soybean yield 454 kg/ha after 30 days of competition, and competition up to 110 days reduced yield as much as 1490 kg/ha. Weed competition affected the number of pods per soybean plant more than any other seed-yield component, and soybean height was reduced. Soybean yields were reduced more when soil moisture was abundant early in the growing season and limited in late summer than when moisture was limited early in the growing season and above average until soybeans matured.

Interference Between Soybeans (Glycine max) and Common Cocklebur (Xanthium strumarium) Under Indiana Field Conditions

Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 753-760 ◽  
Author(s):  
William T. Henry ◽  
Thomas T. Bauman
Keyword(s):  
Spatial Distribution ◽  
Regression Analysis ◽  
Glycine Max ◽  
Seed Yield ◽  
Soybean Seed ◽  
Growing Season ◽  
Field Conditions ◽  
Xanthium Strumarium ◽  
Soybean Yield ◽  
Over Time

The effects of interference between soybeans and common cocklebur were investigated. Common cocklebur interference reduced soybean growth at each of four sample dates during the growing season. The area of interference surrounding individual common cocklebur plants within the soybean row fluctuated over time with respect to intensity and spatial distribution. Soybean growth was significantly reduced up to 10 cm away from individual cocklebur plants at 6 weeks after planting (WAP), 30 cm at 8 WAP, 20 to 30 cm at 10 WAP, and 40 cm at 12 WAP. The maximum possible distance of cocklebur influence, determined by regression analysis, also varied during the growing season. When areas of interference from adjacent cocklebur plants overlapped, the cumulative influence was found to be additive, especially late in the growing season. Soybean interference caused a 50 to 90% reduction in the size of common cocklebur plants grown within the soybean row compared to plants grown without interference. At harvest, soybean yield was reduced up to 40 to 50 cm within the row from individual cocklebur plants. The maximum distance of interference on one side of individual cocklebur plants was 75 cm. One cocklebur plant reduced soybean yield 16.0% within 1.5 m of soybean row as the result of full-season interference. Interference of common cocklebur plants spaced 60 cm apart within the row overlapped and caused an additive reduction in soybean seed yield. Across all cocklebur treatments, there was a consistent ratio of approximately 1 kg/ha loss in soybean seed yield for each 4 kg/ha of cocklebur herbage produced.

Interactions Between Soybean (Glycine max) Cultivars and Selected Weeds

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 770-774 ◽  
Author(s):  
David W. Monks ◽  
Lawrence R. Oliver
Keyword(s):  
Glycine Max ◽  
Seed Yield ◽  
Soybean Seed ◽  
Growing Season ◽  
Field Studies ◽  
Palmer Amaranth ◽  
The Other ◽  
Weed Species ◽  
Competitive Effects ◽  
Soybean Cultivars

Competition of weeds was characterized by determining the distance down the soybean row that a weed affects soybean biomass and yield. Field studies were conducted for 2 yr to compare competitive effects of common cocklebur, johnsongrass, Palmer amaranth, sicklepod, and tall morningglory on ‘Forrest’ and ‘Centennial’ soybeans. The weeds did not significantly reduce soybean biomass for 6 weeks after emergence. Palmer amaranth, common cocklebur, and tall morningglory had the greatest biomass by 6 weeks after emergence. However, only competition from common cocklebur and Palmer amaranth measurably reduced soybean biomass during the growing season. Biomass of Forrest and Centennial soybeans was reduced when these cultivars were growing within 12.5 and 50 cm of common cocklebur, respectively. Johnsongrass, sicklepod, and tall morningglory grew more slowly than the other weeds and had no measurable competitive effects on soybean biomass. Soybean competition reduced biomass of all weeds 90 to 97%. Soybean cultivar influenced the level and duration of competitiveness depending on the weed species present. Biomass of both soybean cultivars was reduced when they were growing within 50 cm of Palmer amaranth. Soybean seed yield was reduced when soybeans were growing within 25 cm of common cocklebur and Palmer amaranth and also when they were growing within 12.5 cm of tall morningglory. Sicklepod had no effect on soybean seed yield.

Competition of Velvetleaf, Prickly Sida, and Venice Mallow in Soybeans

Weed Science ◽  
1976 ◽  
Vol 24 (2) ◽  
pp. 224-228 ◽  
Author(s):  
B. J. Eaton ◽  
O. G. Russ ◽  
K. C. Feltner
Keyword(s):  
Glycine Max ◽  
Yield Components ◽  
Soybean Seed ◽  
Abutilon Theophrasti ◽  
Weed Competition ◽  
Soybean Yield ◽  
Hibiscus Trionum ◽  
Sida Spinosa ◽  
Prickly Sida ◽  
Seed Yields

Weed competition in soybeans [Glycine max(L.) Merr. ‘Clark 63′] with planted stands of velvetleaf (Abutilon theophrastiMedic.), prickly sida (Sida spinosaL.), and Venice mallow (Hibiscus trionumL.) is reported. Weeds were planted 0, 10, 20, 30, and 40 days after soybeans and competed until soybeans matured. Soybean seed yields were reduced 720, 250, and 230 kg/ha by velvetleaf, Venice mallow, and prickly sida, respectively. Weeds that emerged with soybeans reduced yields 1,010 kg/ha. Weeds planted 10 days later reduced yields 480 kg/ha, but weeds planted 20 to 40 days after soybeans did not significantly reduced yield. Soybean yields were reduced regardless of weed placement in or between soybean rows. Weed competition reduced numbers of soybean pods per plant more than other soybean-yield components.

The SCREENING OF HERBICIDES FOR EFFECTIVE CONTROL OF WEEDS IN SOYBEAN (Glycine max L.)

2020 ◽  
Vol 27 (2) ◽  
pp. 251-266
Author(s):  
Muhammad Ehsan Safdar ◽  
Muhammad Ather Nadeem ◽  
Abdul Rehman ◽  
Amjed Ali ◽  
Nasir Iqbal ◽  
...  
Keyword(s):  
Seed Yield ◽  
Soybean Seed ◽  
Dry Weight ◽  
Yield Component ◽  
Effective Control ◽  
College Of Agriculture ◽  
Glycine Max L ◽  
Relationship Of ◽  
Moderate Relationship ◽  
100 Seed Weight

Little is known about best herbicidal weed option for weed eradication in soybean in agro-climatic circumstances of Sargodha, Punjab, Pakistan. A two year field study was accomplished at College of Agriculture experimental site Sargodha in spring seasons of 2018 and 2019 to evaluate the efficacy of different herbicides adjacent to major weeds present in soybean. The study consisted of 8 herbicide treatments including two pre-emergence herbicides (pendimethalin at 489.1 g a.i. ha-1, pendimethalin + S-metolachlor at 731.1 g a.i. ha-1) which are applied immediately after sowing and six post-emergence herbicides (oxyfluorfen at 237.1 g a.i. ha-1, metribuzin at 518.7 g a.i. ha-1, quizalofop-p-ethyl at 148.2 g a.i. ha-1, acetochlor at 741 g a.i. ha-1, halosulfuron at 37 g a.i. ha-1and topramezone at 21.5 g a.iha-1) which were used 25 days subsequent to sowing. In contrast to control, all herbicides have shown significant decline in weed density (up to 94%) and dry weight (up to 88%); and caused significant increases in plant height (up to 85%), pod bearing branches (up to 77%), number of pods per plant (up to 83%), 100-seed weight (up to 37%) and seed yield (up to 160%) of soybean. Among herbicides, topramezone at 21.5 g a.i ha-1 gave significantly the highest (1234 and 1272 kg ha-1 in the year 2018 and 2019) seed yield of soybean and HEIs (1.28 and 1.03 in year 2018 and 2019, respectively). However, oxyfluorfen at 237.1 g a.i. ha-1, pendimethalin + S-metolachlor at 731.1 g a.i. ha-1, pendimethalin at 489.1 g a.i. ha-1, quizalofop-p-ethyl at 148.2 g a.i.ha-1 followed it. The regression analysis depicted a significant negative moderate relationship of soybean seed yield with weed dry weight (R2 = 0.7074), and pods per plant (R2 = 0.7012) was proved to be the main yield component responsible for higher yield of soybean.

scholarly journals Using Canopy Measurements to Predict Soybean Seed Yield

2021 ◽  
Vol 13 (16) ◽  
pp. 3260
Author(s):  
Peder K. Schmitz ◽  
Hans J. Kandel
Keyword(s):  
Seed Yield ◽  
Prediction Models ◽  
Plant Density ◽  
Soybean Seed ◽  
Canopy Cover ◽  
Growing Season ◽  
Practical Method ◽  
Coefficient Of Determination ◽  
Planting Dates ◽  
The Individual

Predicting soybean [Glycine max (L.) Merr.] seed yield is of interest for crop producers to make important agronomic and economic decisions. Evaluating the soybean canopy across a range of common agronomic practices, using canopy measurements, provides a large inference for soybean producers. The individual and synergistic relationships between fractional green canopy cover (FGCC), photosynthetically active radiation (PAR) interception, and a normalized difference vegetative index (NDVI) measurements taken throughout the growing season to predict soybean seed yield in North Dakota, USA, were investigated in 12 environments. Canopy measurements were evaluated across early and late planting dates, 407,000 and 457,000 seeds ha−1 seeding rates, 0.5 and 0.8 relative maturities, and 30.5 and 61 cm row spacings. The single best yield predictor was an NDVI measurement at R5 (beginning of seed development) with a coefficient of determination of 0.65 followed by an FGCC measurement at R5 (R2 = 0.52). Stepwise and Lasso multiple regression methods were used to select the best prediction models using the canopy measurements explaining 69% and 67% of the variation in yield, respectively. Including plant density, which can be easily measured by a producer, with an individual canopy measurement did not improve the explanation in yield. Using FGCC to estimate yield across the growing season explained a range of 49% to 56% of yield variation, and a single FGCC measurement at R5 (R2 = 0.52) being the most efficient and practical method for a soybean producer to estimate yield.

Wild Oat (Avena fatua) Competition in Soybean (Glycine max)

Weed Science ◽  
1981 ◽  
Vol 29 (4) ◽  
pp. 410-414 ◽  
Author(s):  
Duane P. Rathmann ◽  
Stephen D. Miller
Keyword(s):  
Glycine Max ◽  
Seed Yield ◽  
Seed Weight ◽  
Soybean Seed ◽  
Avena Fatua ◽  
Wild Oat ◽  
Soybean Yield

The effects of various densities and durations of wild oat (Avena fatuaL.) competition in soybean [Glycine max(L.) Merr. ‘Evans’] were determined in the field during a 2-yr period. Season-long competition by densities of 1, 3,9, and 30 wild oat plants/m of row reduced soybean seed yield an average of 6, 17, 32, and 51%, respectively. An infestation of 30 wild oat plants/m of row did not reduce soybean yield if the period of competition was limited to 4 weeks after crop emergence; however, yields were reduced 29, 50, 63, 58, and 63% when wild oat competed for 5, 6, 7, and 8 weeks, or season long, respectively. Wild oat competition reduced soybean pods per plant and seeds per plant more than seeds per pod or seed weight.

Effect of Imazaquin and Chlorimuron Plus Metribuzin on Sicklepod (Cassia obtusifolia) Interference in Soybean (Glycine max)

1991 ◽  
Vol 5 (1) ◽  
pp. 206-210 ◽  
Author(s):  
David R. Shaw ◽  
Marshall B. Wixson ◽  
Clyde A. Smith
Keyword(s):  
Glycine Max ◽  
Seed Yield ◽  
Dry Matter ◽  
Soybean Seed ◽  
Cassia Obtusifolia ◽  
Soybean Yield ◽  
Herbicide Treatment ◽  
Herbicide Treatments ◽  
Herbicide Use

Three experiments evaluated sicklepod interference with soybean with and without preplant incorporated applications of chlorimuron plus metribuzin or imazaquin. Sicklepod density, weed-free period, and weedy period were examined. In the absence of herbicides, soybean seed yield was reduced with 2 sicklepod plants row m-1, whereas 8 plants row m-1were necessary to reduce yield when herbicides were used. Herbicide use also increased soybean yield at higher sicklepod densities. Chlorimuron plus metribuzin reduced sicklepod dry matter at 8 plants row m-1. To maintain soybean yield, a weed-free period of 4 wk after emergence was required, regardless of treatment. Both herbicide treatments resulted in increased soybean yield at the zero and two wk weed-free periods; however, they did not affect soybean yield when the weed-free period was 4 wk or more. Imazaquin reduced sicklepod density when plots were left weedy full-season, and further reductions were noted with chlorimuron plus metribuzin. A sicklepod weedy interval of 8 wk reduced soybean yield when untreated, but either herbicide treatment extended that interval to 16 wk.

Soybean (Glycine max) and Rotational Crop Response to PPI Chlorimuron, Clomazone, Imazaquin, and Imazethapyr

1994 ◽  
Vol 8 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Ronald F. Krausz ◽  
George Kapusta ◽  
Joseph L. Matthews
Keyword(s):  
Glycine Max ◽  
Seed Yield ◽  
Wheat Yield ◽  
Soybean Seed ◽  
Field Studies ◽  
Corn Yield ◽  
Crop Response ◽  
Crop Tolerance ◽  
Height Reduction ◽  
Rotational Crop

Field studies were conducted from 1989 to 1992 to evaluate soybean and rotational crop tolerance to PPI applications of chlorimuron (23 to 140 g ai/ha), clomazone (560 to 3360 g/ha), imazaquin (70 to 420 g/ha), and imazethapyr (53 to 310 g/ha). Soybean injury was evident only in 1989. Soybean height reduction 45 d after application increased linearly with increasing rates of chlorimuron, imazaquin, and imazethapyr. Chlorimuron at 140 g/ha and imazaquin at 420 g/ha reduced soybean height 120 d after planting. None of the herbicides influenced soybean density. Chlorimuron and imazaquin reduced soybean seed yield linearly as rates increased. None of the herbicides reduced subsequent wheat yield. Corn height reduction increased as the rate of imazaquin and imazethapyr increased. Imazethapyr and imazaquin caused 2 to 40% and 1 to 12% height reduction at 30 d after planting, respectively. Imazethapyr at 310 g/ha applied the previous year reduced corn height at 120 d after planting. There were no differences in corn density. Imazaquin and imazethapyr at 420 and 310 g/ha, respectively, applied the previous year reduced corn yield.

Joint Effects of Acifluorfen Applications and Soybean Thrips (Sericothrips variabilis) Feeding on Soybean (Glycine max)

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 667-670 ◽  
Author(s):  
Randy M. Huckaba ◽  
Harold D. Coble ◽  
John W. Van Duyn
Keyword(s):  
Glycine Max ◽  
Seed Yield ◽  
Sodium Salt ◽  
Growth Parameters ◽  
Soybean Seed ◽  
Field Studies ◽  
Interactive Effects ◽  
Root Weight ◽  
Shoot Weight ◽  
Soybean Thrips

Field studies were conducted during 1983 and 1984 to determine the single and interactive effects of trifluralin, soybean thrips, and the sodium salt of acifluorfen on soybean. Increased soybean injury was observed in 1983 when acifluorfen at 0.6 kg ai/ha was applied to soybeans infested with soybean thrips versus plants where soybean thrips were controlled. Soybean injury measured by percent defoliation and visual injury ratings was reduced when thrips were controlled versus soybeans where thrips were not controlled with carbaryl at 0.9 kg ai/ha in 1983. Soybean thrips alone did not reduce soybean seed yield in this study. Acifluorfen reduced soybean photosynthetic rate, shoot weight, root weight, and seed yield. Trifluralin had no effect on soybean growth parameters measured in this study.

Interrelations of Tillage and Weed Control for Soybean (Glycine max) Production

Weed Science ◽  
1987 ◽  
Vol 35 (6) ◽  
pp. 830-836 ◽  
Author(s):  
Charles L. Webber ◽  
Harold D. Kerr ◽  
Maurice R. Gebhardt
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Weed Control ◽  
Foliar Application ◽  
Soybean Seed ◽  
Conventional Tillage ◽  
No Tillage ◽  
Herbicide Application ◽  
Weed Growth ◽  
Soybean Plants

A 3-yr (1982, 1983, and 1984) study was conducted to determine the relationship between tillage and six weed control treatments for soybean [Glycine max(L.) Merr. ‘Williams 79′] production on silt loam (Udollic and Mollic Ochraqualfs). Conventional tillage consisted of spring moldboard plowing and secondary tillage with a combination tool just before planting. No-tillage consisted of a foliar application of glyphosate [N-(phosphonomethyl)glycine] at the time of planting. Weed control treatments included combinations of no weed control with and without soybean plants, preemergence herbicide application only, postemergence herbicide application only, and combined preemergence and postemergence applications with and without additional handweeding. In 1982, a year of above-normal seasonal rainfall, conventional tillage had significantly greater soybean grain yields than no-tillage for all weed control treatments except the preemergence-only treatment. Yields within tillage systems and between weed control treatments in 1982 were not significantly different because adequate rainfall reduced the effect of weed competition for soil moisture. Soybean seed yields in 1983 and 1984 in no-tillage were equal to or significantly greater than those of conventional tillage. No-tillage treatments had greater soil moisture conservation and soil moisture availability resulting in less plant water stress during podfilling in periods of drought in 1983 and 1984. In all 3 yr, conventional tillage had significantly greater early weed growth than no-tillage in the treatments with and without soybean plants where no preemergence or postemergence herbicides were used. Comparing treatments with and without soybean plants indicated an average increase of 36 and 38% weed control for no-tillage and conventional tillage, respectively.

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