Interference and Seed Production by Common Lambsquarters (Chenopodium album) in Soybeans (Glycine max)

Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 113-118 ◽  
Author(s):  
S. Kent Harrison

Multiple regression and response surface plots were used to analyze the effects of common lambsquarters population density and interference duration on weed growth and soybean seed yield. Under favorable growing conditions in 1986, weed biomass production at all population densities and interference durations was four to five times that produced in 1987, under less favorable conditions. However, there was no significant treatment by year interaction for soybean seed yield reduction by common lambsquarters, and production of each kg/ha weed biomass resulted in an average soybean yield reduction of 0.26 kg/ha. Utilizing 5% yield loss as an arbitrary threshold level, the regression equation predicted a common lambsquarters density threshold of 2 plants/m of row for 5 weeks of interference after crop emergence and 1 plant/m of row for 7 weeks. Seed production by individual common lambsquarters plants was highly correlated (r=0.92) with weed dry weight, and seed production ranged from 30 000 to 176 000 seeds/plant.

Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 685-691 ◽  
Author(s):  
Andrew M. Westhoven ◽  
Greg R. Kruger ◽  
Corey K. Gerber ◽  
Jeff M. Stachler ◽  
Mark M. Loux ◽  
...  

Biotypes of common lambsquarters with tolerance to glyphosate have been identified in a number of states, but little is known about their fitness characteristics. Field and greenhouse studies were conducted to characterize the response of selected glyphosate-tolerant common lambsquarters biotypes to glyphosate, and also their biological and reproductive characteristics. In a greenhouse dose-response study, GR50and GR90values for four tolerant biotypes ranged from 1.48 to 3.22 and 8.73 to 18.7 kg ae ha−1, respectively, compared to 0.57 and 2.39 kg ae ha−1, respectively, for a glyphosate-sensitive biotype. In a field dose-response study, the GR50and GR90values were 0.06 and 0.48 kg ae ha−1, respectively, for a tolerant biotype, compared to 0.036 and 0.19 kg ae ha−1, respectively, for the sensitive biotype. The growth rate, time until flowering, and seed production of eight tolerant and two sensitive biotypes was evaluated in a field study. The tolerant biotypes grew taller, amassed more leaf area and dry weight, and advanced through growth stages more rapidly than sensitive biotypes during the early portion of the growing season. The tolerant biotypes were taller than sensitive biotypes at 6 and 10 wk after transplanting, but had lower dry weight at maturity. Tolerant biotypes initiated flower primordia approximately 6 to 8 wk after transplanting, whereas sensitive biotypes required 12 wk. However, no apparent fitness penalties were observed in glyphosate-tolerant biotypes based on seed-production estimates.


Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 358-364 ◽  
Author(s):  
Teresa M. Crook ◽  
Karen A. Renner

Field studies were conducted in 1987 and 1988 to evaluate the control and competitiveness of common lambsquarters in soybeans when present at four densities and when removed at four time intervals. Common lambsquarters were removed by hand or treated with a postemergence herbicide application of bentazon plus acifluorfen. Common lambsquarters could remain 10 weeks following soybean emergence before a 20% soybean yield reduction occurred when weeds were removed by hand. When treatment was attempted with postemergence herbicides, a 20% yield reduction occurred in 1987 if application was not made prior to 5 weeks after emergence. In 1988, all postemergence herbicide applications failed to control lambsquarters due to drought conditions. The postemergence herbicide's degree of control was reflected in the number of remaining lambsquarters plants. Common lambsquarters seed production and germination was not influenced by postemergence herbicide application. There was a strong correlation between dry weight of uncontrolled common lambsquarters plants and seed produced per plant.


Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 654-657 ◽  
Author(s):  
Janet L. Shurtleff ◽  
Harold D. Coble

Field experiments were conducted in 1979, 1980, and 1981 to determine the level of interference five broadleaf weed species exert on soybean [Glycine max(L.) Merr.]. Weed species studied were common cocklebur (Xanthium pensylvanicumWallr. ♯ XANST), common ragweed (Ambrosia artemesiifoliaL. ♯ AMBEL), common lambsquarters (Chenopodium albumL. ♯ CHEAL), sicklepod (Cassia obtusifoliaL. ♯ CASOB), and redroot pigweed (Amaranthus retroflexusL. ♯ AMARE). The following soybean seed yield reductions were observed with a density of 16 weeds/10-m row: redroot pigweed 22%, common lambsquarters 15%, common ragweed 12%, and sicklepod 5%, respectively. At a density of 8 weeds/10-m row, common cocklebur reduced soybean yield 11%. No single weed growth parameter predicted soybean seed yield reduction for all weed species. Soybean height was reduced by sicklepod competition; was not affected by competition from common lambsquarters, common ragweed, or common cocklebur; and was increased in the presence of redroot pigweed at 12 weeks after planting, when measured 30 cm from the weeds. Leaf area of soybean was higher at greater distances from the weed for all weed species. The range of soybean leaf area reductions occasioned by proximity to individual weed species corresponded fairly well with differences in soybean yield reduction.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 574
Author(s):  
Yun-Yin Feng ◽  
Jin He ◽  
Yi Jin ◽  
Feng-Min Li

Both water stress and P deficit limit soybean seed yield, but the effects of water regimes and P application rates, their interaction on P status, acquisition, and partitioning, and their roles in yield performance have not been well-studied. Two soybean genotypes (Huangsedadou (HD) and Zhonghuang 30 (ZH)) with contrasting seed yield and root dry weight (DW) were used to investigate the P status, P acquisition, P partitioning, and yield formation under two water regimes (well-watered (WW) and cyclic water stress (WS)) and three P rates (0 (P0), 60 (P60), and 120 (P120) mg P kg−1 dry soil). The results show that increased P and water supply increased the seed yield, shoot and root DW and P concentrations and accumulations in different organs. Cultivar ZH had a significantly higher seed yield than HD at P60 and P120 under WS and at P0 under WW, but a lower seed yield at P60 and P120 under WW. Cultivar ZH had a significantly higher P harvest index and P acquisition efficiency, but a significantly lower shoot and root DW than HD. The interaction between water treatments and P rates had significant effects on leaf and stem P concentration. Cultivar ZH had significantly lower P partitioning to leaves and stems but significantly higher P partitioning to seeds than HD. The seed yield was positively correlated with leaf and seed P accumulations and P acquisition efficiency under WS. We conclude that (1) adequate water supply improved the P mobilization from leaves and stems at maturity, which may have improved the seed yield; and (2) the high P acquisition efficiency is coordination to high P partition to seeds to produce a high seed yield under water- and P-limited conditions.


Weed Science ◽  
1998 ◽  
Vol 46 (5) ◽  
pp. 587-594 ◽  
Author(s):  
Kelly A. Nelson ◽  
Karen A. Renner ◽  
Donald Penner

Field and greenhouse experiments were conducted in 1995 and 1996 to determine soybean injury and weed control differences from imazamox and imazethapyr applied postemergence with a nonionic surfactant or methylated seed oil and with selected tank mixtures. Soybean injury from imazamox at 35 g ai ha−1plus either a methylated seed oil or nonionic surfactant was equal to injury from imazethapyr at 70 g ai ha−1in the greenhouse and field. Imazamox provided greater common lambsquarters control than imazethapyr in the field in 1995 and in the greenhouse. Thifensulfuron tank mixed with imazethapyr increased common lambsquarters control, while soybean response increased when thifensulfuron was tank mixed with imazamox. Common ragweed dry weight was reduced 61 to 64% from 35 g ha−1imazamox and 70 g ha−1imazethapyr in the field; however, imazamox provided greater common ragweed control than imazethapyr in the greenhouse. Tank mixtures of lactofen with imazamox or imazethapyr increased common ragweed control and resulted in greater soybean seed yield in 1996 than when imazamox and imazethapyr were applied alone; however, lactofen antagonized giant foxtail control with imazamox and imazethapyr, and antagonized common lambsquarters control with imazamox. Giant foxtail control in the greenhouse was antagonized more when acifluorfen, fomesafen, and lactofen were tank mixed with 35 g ha−1imazethapyr than with 35 g ha−1imazamox. Giant foxtail control with imazamox or imazethapyr applied alone or with diphenyl ether herbicides increased when 28% urea ammonium nitrate was added with nonionic surfactant compared with nonionic surfactant only. Imazethapyr antagonized giant foxtail control by clethodim in the field and was more antagonistic than imazamox in the greenhouse. A methylated seed oil improved common ragweed control by imazethapyr at 70 g ha−1and imazamox at 18 and 35 g ha−1, while common lambsquarters and velvetleaf control increased when a methylated seed oil was included with 18 g ha−1imazethapyr compared to nonionic surfactant in the greenhouse.


2020 ◽  
Vol 27 (2) ◽  
pp. 251-266
Author(s):  
Muhammad Ehsan Safdar ◽  
Muhammad Ather Nadeem ◽  
Abdul Rehman ◽  
Amjed Ali ◽  
Nasir Iqbal ◽  
...  

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.


Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 609-614 ◽  
Author(s):  
Corné Kempenaar ◽  
Petra J. F. M. Horsten ◽  
Piet C. Scheepens

Control of common lambsquarters by the use ofAscochyta caldinaas a postemergence mycoherbicide was studied in corn and sugar beet, in 1992 or 1993. The weed was planted at determined positions in the crops. Plots were treated with suspensions ofA. caulinaspores, and wetness duration's were varied to create different levels of disease development. Application ofA. caulinaresulted in necrosis development on, and mortality of common lambsquarters. Average severities of leaf necrosis 1 wk after treatment ranged from 0.01 to 0.75. Average proportions of dead plants 3 wk after treatment ranged from 0.00 to 0.65. Necrosis development and mortality were affected by wetness duration in two experiments. Sublethally diseased plants showed reduced growth. Maximum dry matter was affected by crop and by necrosis development. Numbers of fruits per plant showed a positive, almost linear relationship with plant dry matter weight. Seed weight was less affected by necrosis than number of fruits per plant. Competitiveness of common lambsquarters was reduced after infection byA. caulina.Crop dry matter weight showed a positive relationship with the level of common lambsquarters control. In corn, yield reduction by competition was prevented by application of A.caulina, but not in sugar beet.


2014 ◽  
Vol 6 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Mehdi PARSA ◽  
Akbar ALIVERDI ◽  
Hossein HAMMAMI

Crop-rhizobium symbiosis can be influenced by leaching of herbicides which is unavoidable after their application. Due to an adjuvant which might help to develop the low-use-rate of herbicide, an experiment was carried out to compare the impact of the recommended rate (1200 g active ingredient ha-1) and the optimized rate (282.15 g active ingredient ha-1) of pyridate on the biological properties of eight chickpea cultivars inoculated with Mesorhizobium mediterraneum, grown in pots. Based on the required rate of herbicide to give 95% control of common lambsquarters (Chenopodium album L.) value, the efficacy of pyridate improved up to 3.87-fold by adding methylated rapeseed oil to spray solution. The ‘Desi’ cultivar had significantly higher nodulation than ‘Kabuli’ cultivar. In general, toxicity of the recommended rate was higher than the optimized rate. With the exception of root dry weight, all of the measured parameters were significantly affected by the recommended rate of pyridate in varying degrees. The symbiotic properties of chickpea cultivars were affected more than 10% at the recommended dose. The reduced nodulation ranged from 29% to 73% among cultivars exposed to pyridate at the recommended dose. The ‘Desi’ cultivar was more sensitive than the ‘Kabuli’ to the recommended rate of pyridate. We may conclude that effective low-use-rate of pyridate via applying of activator adjuvants should be noted.


2020 ◽  
pp. 41-44
Author(s):  
R. Hutianskyi

Goal. of my study was to investigate the combined effect of pesticides, including seed dressers, post-emergence herbicides, fungicides, biologicals, and plant growth regulators on weediness and soybean yield in the Eastern Forest-Steppe of Ukraine. Methods. Field, analytical and statistical. Results. The weeds in the soybean crops were represented by 15 species. Cockspur (Echinochloa crusgalli (L.) Roem et Schult.), yellow foxtail (Setaria glaua (L.) Beauv.), lamb’s quarters (Chenopodium album L.) and redroot pigweed (Amaranthus retroflexus L.) dominated in the soybean crops. In the controls, the dominant position in the soybean crops (in terms of the wet weight of weeds) was occupied by biennial and annual dicotyledonous weeds (56—57% of the total wet weight of weeds). Annual gramineous weeds (37—42%) and perennial dicotyledonous weeds (2—6%) ranked the second and third most spread species. Pre-sowing treatment of seeds increased the competitiveness of soybean plants against weeds. Herbicide composition Tabezon (2.0 l/ ha) + Formula (6 g/ ha) + surfactant Trend 90 (0.2 l/ ha) (primordial leaves) + Lemur (1.5 l/ ha) (biternate/ triternate leaves) significantly reduced the total number of weeds in the soybean crops by 89% and their wet weight by 97%. There was no evidence of significant effects of post-emergence combinations of herbicides with chemical or biological pesticides on the effectiveness of weed control in the soybean crops. Analyzing the soybean seed yield, I revealed that application of herbicides alone in the crops was the most justified. Conclusions. Increased competitiveness of soybean plants against weeds on pre-sowing seed treatment has been demonstrated. There was no evidence of significant effects of post-emergence combinations of herbicides with chemical and biological pesticides on the weed control effectiveness. Monoapplication of herbicides was the most justified.


Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 128-133 ◽  
Author(s):  
E. E. Schweizer

Interference within a mixture of equal densities of common lambsquarters (Chenopodium albumL.), kochia [Kochia scoparia(L.) Schrad.], and redroot pigweed (Amaranthus retroflexusL.) in sugarbeets (Beta vulgarisL. ‘Mono Hy D2’) was determined in a 3-yr field study. Yield of sugarbeet roots and sucrose per hectare decreased as intensity of competition from equal populations of these three weeds increased. At densities of 6, 12, 18, and 24 broadleaf weeds per 30 m of row, root yields were reduced 13, 24, 33, and 39%, respectively. Sucrose yields were reduced similarly. Fewer than three weeds per 30 m of row did not significantly reduce root yield. Reduction in root yield (Y) of sugarbeets caused by specific densities (X) of the three broadleaf weeds was predicted by using the linear equation Y = 1.64 + 1.88 X. The actual reductions in yield were always less than the predicted reductions when this equation was tested against 36 weed control systems because the competitive ability of broadleaf weeds that were treated with herbicides, but not killed, was suppressed during the growing season. By harvest, broadleaf weeds present in weed-control-system plots weighed an average of 75 to 85% less than broadleaf weeds present in nontreated plots.


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