Competitive interactions of tomato (Lycopersicon esculentum) and nutsedges (Cyperusspp.)

Weed Science ◽  
1997 ◽  
Vol 45 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Bielinski M. Santos ◽  
Thomas A. Bewick ◽  
William M. Stall ◽  
Donn G. Shilling
Keyword(s):  
Lycopersicon Esculentum ◽  
Relative Yield ◽  
Dry Weight ◽  
Competitive Interactions ◽  
Population Densities ◽  
Replacement Series ◽  
Purple Nutsedge ◽  
Yield Analysis ◽  
Yellow Nutsedge

Replacement series experiments were conducted under greenhouse conditions to evaluate effects of population densities and proportions on the intraspecific and interspecific interference of either purple nutsedge or yellow nutsedge with tomato cv. Sunny, under nonlimiting conditions of water and nutrients. When grown with either nutsedge species for 40 d, tomato dry weight per plant increased and dry weight per plant of nutsedge decreased as their relative proportions decreased in mixture. Relative yield analysis indicated tomato is a stronger competitor than either nutsedge species. Both nutsedges appeared to be weak interspecific competitors but strong intraspecific competitors. Attenuated light on a purple nutsedge canopy showed that tomato additions can reduce light received by the weed compared to pure nutsedge stands.

The Evidence for Reduced Glyphosate Efficacy on Acetolactate Synthase–Inhibiting Herbicide-Resistant Yellow Nutsedge (Cyperus esculentus)

Weed Science ◽  
2016 ◽  
Vol 64 (3) ◽  
pp. 389-398
Author(s):  
Parsa Tehranchian ◽  
Jason K. Norsworthy ◽  
Matheus Palhano ◽  
Nicholas E. Korres ◽  
Scott McElroy ◽  
...  
Keyword(s):  
Amino Acid ◽  
Production Systems ◽  
Acetolactate Synthase ◽  
Dry Weight ◽  
Cross Resistance ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Epsps Gene ◽  
Treated Leaf ◽  
Als Inhibitors

A yellow nutsedge biotype (Res) from an Arkansas rice field has evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides. TheResbiotype previously exhibited cross-resistance to ALS inhibitors from four chemical families (imidazolinone, pyrimidinyl benzoate, sulfonylurea, and triazolopyrimidine). Experiments were conducted to evaluate alternative herbicides (i.e., glyphosate, bentazon, propanil, quinclorac, and 2,4-D) currently labeled in Arkansas rice–soybean production systems. Based on the percentage of aboveground dry weight reduction, control of the yellow nutsedge biotypes with the labeled rate of bentazon, propanil, quinclorac, and 2,4-D was < 44%. Glyphosate (867 g ae ha−1) resulted in 68 and > 94% control of theResand susceptible yellow nutsedge biotypes, respectively, at 28 d after treatment. Dose-response studies were conducted to estimate the efficacy of glyphosate on theResbiotype, three susceptible yellow nutsedge biotypes, and purple nutsedge. Based on the dry weights, theResbiotype was ≥ 5- and ≥ 1.3-fold less responsive to glyphosate compared to the susceptible biotypes and purple nutsedge, respectively. Differences in absorption and translocation of radiolabeled glyphosate were observed among the yellow nutsedge biotypes and purple nutsedge. The susceptible biotype had less14C-glyphosate radioactivity in the tissues above the treated leaf and greater radioactivity in tissues below the treated leaf compared to theResbiotype and purple nutsedge. Reduced translocation of glyphosate in tissues below the treated leaf of theResbiotype could be a reason for the lower glyphosate efficacy in theResbiotype. No amino acid substitution that would correspond to glyphosate resistance was found in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene of theResbiotype. However, an amino acid (serine) addition was detected in the EPSPS gene of theResbiotype; albeit, it is not believed that this addition contributes to lower efficacy of glyphosate in this biotype.

Toxicity of Imazethapyr to Purple (Cyperus rotundus) and Yellow Nutsedges (C. esculentus)

1993 ◽  
Vol 7 (4) ◽  
pp. 900-905 ◽  
Author(s):  
John S. Richburg ◽  
John W. Wilcut ◽  
Glenn R. Wehtje
Keyword(s):  
Dry Weight ◽  
Cyperus Rotundus ◽  
Purple Nutsedge ◽  
Soil Application ◽  
Yellow Nutsedge ◽  
Shoot Dry Weight ◽  
Shoot Number ◽  
Root Tuber ◽  
Tuber Treatment

Greenhouse studies were conducted to determine the response of purple and yellow nutsedges to selective soil placement of 5 cm of soil treated with imazethapyr above and/or below the nutsedge tubers. Early postemergence (EPOST) or postemergence (POST) imazethapyr treatments at 71 g ai/ha as a foliar, soil, or foliar + soil application was also evaluated. Imazethapyr placement above or below the nutsedge tuber generally increased shoot number, shoot dry weight (SW), shoot regrowth dry weight (SRW), and root tuber dry weight (RTW) production in both species, 28 and 42 days after treatment (DAT) compared with the control. However, the 5-cm above + 5-cm below tuber treatment at 14, 28, and 42 DAT reduced purple nutsedge shoot number, SW, SRW, and RTW to 19, 7, 14, and 26% of the control, respectively. Yellow nutsedge shoot number was 103% of the control with the 5-cm above + 5-cm below tuber treatment 42 DAT. The 5-cm above + 5-cm below tuber treatment reduced yellow nutsedge SW, SRW, and RTW to 43, 44, and 23% of the control, respectively, 28 and 42 DAT. EPOST and POST foliar + soil and soil-only applications reduced SW 28 d after treatment (DAT) to 13% or less of the control for both species. SRWs of both species were ≤ 53% of the control 42 DAT for the soil-only application. The foliar-only treatment was the least effective in SW, SRW, and RTW reductions.

Sweet Potato Allelopathic Substance Inhibits Growth of Purple Nutsedge (Cyperus rotundus)

1995 ◽  
Vol 9 (2) ◽  
pp. 277-280 ◽  
Author(s):  
J. K. Peterson ◽  
H. F. Harrison
Keyword(s):  
Sweet Potato ◽  
Root Length ◽  
Shoot Growth ◽  
Dry Weight ◽  
Cyperus Rotundus ◽  
Root Number ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Shoot Dry Weight ◽  
Allelopathic Substance

The allelopathic influence of sweet potato cultivar ‘Regal’ on purple nutsedge was compared to the influence on yellow nutsedge under controlled conditions. Purple nutsedge shoot dry weight, total shoot length and tuber numbers were significantly lower than the controls (47, 36, and 19% inhibition, respectively). The influence on the same parameters for yellow nutsedge (35, 21, and 43% inhibition, respectively) were not significantly different from purple nutsedge. Sweet potato shoot dry weight was inhibited by purple and yellow nutsedge by 42% and 45%, respectively. The major allelopathic substance from ‘Regal’ root periderm tissue was isolated and tested in vitro on the two sedges. The I50's for shoot growth, root number, and root length were 118, 62, and 44 μg/ml, respectively, for yellow nutsedge. The I50's for root number and root length were 91 and 85 μg/ml, respectively, for purple nutsedge and the I50for shoot growth could not be calculated.

Competitive Interactions of Wheat (Triticum aestivum) and Wild Oats (Avena fatua) Grown at Different Densities

Weed Science ◽  
1989 ◽  
Vol 37 (4) ◽  
pp. 538-543 ◽  
Author(s):  
David W. Cudney ◽  
Lowell S. Jordan ◽  
Jodie S. Holt ◽  
John S. Reints
Keyword(s):  
Relative Density ◽  
Plant Density ◽  
Wheat Yield ◽  
Dry Weight ◽  
Field Studies ◽  
Competitive Interactions ◽  
Plant Responses ◽  
Replacement Series ◽  
Area Index ◽  
Wild Oats

Competitive interactions of wheat and wild oats in relation to variations in plant density of both species were investigated in field studies under irrigation and added fertilizer. Competition studies included comparisons by both additive and replacement series. The additive series was used to study plant responses to competition under fixed density of wheat and increasing density of wild oats. The replacement series was used to study plant responses to competition under constant total plant density with differing proportions of wheat and wild oats. On a per plant basis, shoot dry weight and leaf area index of wild oats were less than those of wheat at anthesis. However, the replacement series experiment indicated that wheat and wild oats were equivalent in competitiveness. Relative density of wild oats gave a better regression fit for wheat yield than did absolute wild oats density (r2values of 0.83 and 0.61, respectively). Yield of wheat grain was linearly proportional to relative density of wild oats.

Tomato (Lycopersicon esculentum) Cultivar and Weed Sensitivity to DPX-E9636

1995 ◽  
Vol 9 (3) ◽  
pp. 499-503 ◽  
Author(s):  
Thomas A. Bewick ◽  
Kenneth Smith ◽  
William M. Stall ◽  
Steven M. Olson
Keyword(s):  
Lycopersicon Esculentum ◽  
Dry Weight ◽  
Field Conditions ◽  
Yellow Nutsedge ◽  
Greenhouse Experiments ◽  
Black Nightshade ◽  
Application Method ◽  
American Black ◽  
Tomato Cultivars

Sensitivity of 49 tomato cultivars and four weeds to DPX-E9636 was determined in greenhouse experiments. Cultivar tolerance varied from completely tolerant to intolerant. The most efficacious application method in greenhouse experiments was early POST for the weeds tested (yellow nutsedge, prostrate eclipta, and paraquat-resistant and -sensitive American black nightshade). Paraquat-resistant American black nightshade was 123 times more sensitive to DPX-E9636 than the paraquat-sensitive biotype. Under field conditions and at 0, 36, or 72 g ai/ha applied one week after transplanting, tomato cultivars showed no response to DPX-E9636 in visual vigor ratings 3 wk treatment, or in shoot fresh or dry weight 4 wk after treatment.

Influence of pyrithiobac sodium on purple (Cyperus rotundus) and yellow nutsedge (C. esculentus)

Weed Science ◽  
1998 ◽  
Vol 46 (1) ◽  
pp. 111-115 ◽  
Author(s):  
John W. Wilcut
Keyword(s):  
Dry Weight ◽  
Cyperus Rotundus ◽  
Purple Nutsedge ◽  
Treated Soil ◽  
Yellow Nutsedge ◽  
Shoot Number ◽  
Root Tuber ◽  
Selective Placement

Greenhouse studies were conducted to determine purple and yellow nutsedge response to selective placement of a 5-cm layer of pyrithiobac sodium-treated soil above, below, or above and below nutsedge tubers. Pyrithiobac sodium at 36 or 72 g ae ha−1applied postemergence as foliar, soil, or foliar and soil treatments also was evaluated. Pyrithiobac sodium applied above, below, or above and below nutsedge tubers reduced yellow and purple nutsedge shoot number, shoot regrowth, and root-tuber dry weight at least 90%. Foliar-only treatment of pyrithiobac sodium was less effective at reducing emerged purple and yellow nutsedge numbers than application to soil only or to foliage and soil. Best reduction in yellow and purple nutsedge growth with pyrithiobac sodium was obtained with soil-incorporated treatments.

Effects of Purple Nutsedge (Cyperus rotundus) on Tomato (Lycopersicon esculentum) and Bell Pepper (Capsicum annuum) Vegetative Growth and Fruit Yield

1997 ◽  
Vol 11 (4) ◽  
pp. 672-676 ◽  
Author(s):  
Jose P. Morales-Payan ◽  
Bielinski M. Santos ◽  
William M. Stall ◽  
Thomas A. Bewick
Keyword(s):  
Dry Weight ◽  
Fruit Yield ◽  
Cyperus Rotundus ◽  
Bell Pepper ◽  
Initial Population ◽  
Yield Losses ◽  
Population Densities ◽  
Purple Nutsedge ◽  
Shoot Dry Weight ◽  
Percentage Unit

Additive series experiments were conducted under greenhouse conditions to determine the effect of season-long interference of different initial population densities of purple nutsedge on the shoot dry weight and fruit yield of tomato and bell pepper. Purple nutsedge densities up to 200 plants/m2linearly reduced shoot dry weight at flowering and fruit yield of both crops as weed density increased. Both variables were directly correlated, and for each percentage unit of tomato shoot dry weight loss at flowering, fruit yield was reduced 1.24 units, whereas for bell pepper this relationship was 1 to 2.01. Total shoot and tuber biomass of purple nutsedge increased as density increased. The presence of either crop caused a decline in the total shoot dry weight accumulation of purple nutsedge, with tomato producing a higher degree of loss than bell pepper to the weed. Fruit yield losses due to purple nutsedge interference reached 44% for tomato and 32% for bell pepper.

Toxicity of AC 263,222 to Purple (Cyperus rotundus) and Yellow Nutsedge (C.esculentus)

Weed Science ◽  
1994 ◽  
Vol 42 (3) ◽  
pp. 398-402 ◽  
Author(s):  
John S. Richburg ◽  
John W. Wilcut ◽  
Glenn R. Wehtje
Keyword(s):  
Dry Weight ◽  
Cyperus Rotundus ◽  
Purple Nutsedge ◽  
Yellow Nutsedge ◽  
Root Dry Weight ◽  
Shoot Dry Weight ◽  
Shoot Number ◽  
Root Tuber ◽  
Ac 263,222 ◽  
Selective Placement

Greenhouse studies were conducted to determine the response of purple and yellow nutsedge to selective placement of 5 cm of soil treated with AC 263,222 above and/or below nutsedge tubers. AC 263,222 applied early POST (EPOST) or POST at 71 g ai ha-1as a foliar, soil, or foliar + soil application also was evaluated. AC 263,222 applied below nutsedge tubers did not reduce purple or yellow nutsedge shoot number, shoot dry weight, shoot regrowth dry weight, or root-tuber dry weight. However, when it was applied above purple nutsedge tubers, shoot dry weight was reduced; and when it was applied above yellow nutsedge tubers, shoot dry weight and root dry weight were reduced. AC 263,222 applied 5 cm above + 5 cm below purple nutsedge tubers reduced shoot number, shoot dry weight, shoot regrowth dry weight, and root dry weight to 9, 4, 10, and 16% of the control, respectively, in purple nutsedge and to 23, 16, 9, and 15% of the control, respectively, in yellow nutsedge. AC 263,222 applied EPOST or POST reduced shoot dry weight, shoot regrowth dry weight, and root dry weight of purple nutsedge to less than or equal to 11, 7, and 27% of the control, respectively, and to less than or equal to 10, 16, and 29% of the control, respectively, for yellow nutsedge with no differences between application methods. The foliar and soil activity of AC 263,222 for purple and yellow nutsedge control provides an advantage over currently registered peanut herbicides.

Does Resistance to Propanil or Clomazone Alter the Growth and Competitive Abilities of Barnyardgrass (Echinochloa crus-galli)?

Weed Science ◽  
2011 ◽  
Vol 59 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Muthukumar V. Bagavathiannan ◽  
Jason K. Norsworthy ◽  
Prashant Jha ◽  
Kenneth Smith
Keyword(s):  
Production Systems ◽  
Management Strategies ◽  
Relative Yield ◽  
Dry Weight ◽  
Replacement Series ◽  
Shoot Dry Weight ◽  
Randomized Design ◽  
Number Of Leaves ◽  
Competitive Abilities ◽  
Pressure Resistance

Barnyardgrass biotypes resistant (R) to propanil (PR) or clomazone (CR) have been confirmed in rice production systems in Arkansas. However, it is not clear whether resistance to these herbicides impose any fitness cost on theRbiotypes compared to susceptible barnyardgrass (S). The overall objective of this experiment was to determine if the growth and competitiveness of barnyardgrass is altered by resistance to propanil or clomazone and to establish a competitive hierarchy among theS,PR, andCRbiotypes. A replacement series study was conducted in a greenhouse using five proportions ofSandRbiotypes (0 : 100, 25 : 75, 50 : 50, 75 : 25, and 100 : 0). The study was carried out in a completely randomized design (CRD) with four replications. The variables, including plant height, number of tillers, number of leaves, and shoot dry weight, were used for quantifying the differences in competitive abilities. Replacement series indices were calculated to explore the competitiveness. Expected (He) and observed (Ho) values for relative yield (RY) and relative yield total (RYT) were compared for number of tillers, number of leaves, and shoot dry weight for each biotype comparison. Other replacement series indices including competitive ratio (CR), relative crowding coefficient (RCC), and aggressiveness index (AI) also were calculated for these variables. The results showed that there were no major differences among theSandRbiotypes for these variables, indicating that in the absence of selection pressure, resistance to propanil or clomazone does not influence the growth and competitiveness of barnyardgrass. The findings will be useful for predicting the dynamics of resistant populations in the absence of herbicide selection and for designing suitable management strategies.

scholarly journals Effect of Purple Nutsedge (Cyperus rotundus) Population Densities on the Growth of Transplants of Three Papaya (Carica papaya) Cultivars

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 431E-431
Author(s):  
J.P. Morales-Payan ◽  
W.M. Stall
Keyword(s):  
Carica Papaya ◽  
Dry Weight ◽  
Cyperus Rotundus ◽  
Initial Population ◽  
Santo Domingo ◽  
Population Densities ◽  
Purple Nutsedge ◽  
Shoot Dry Weight ◽  
Weight Losses ◽  
Significant Difference

Nursery experiments were conducted in Santo Domingo, Dominican Republic, to determine the effect of increasing population densities of purple nutsedge (Cyperus rotundus) on the growth of papaya (Carica papaya) transplants. Seeds of `Sunrise Solo', `Red Lady', and `Cartagena Ombligua' were separately sown in plastic 12 × 15-cm containers filled with a 1:1 mixture of sand and loamy soil. Viable purple nutsedge tubers were planted 5 cm apart from the papaya seeds. The purple nutsedge initial population densities were 0, 1, 2, 4, and 6 tubers per container. The crop and the weed were sown the same day and allowed to interfere during 6 weeks. Purple nutsedge density had a significant effect on the height, leaf area, and shoot dry weight of the three papaya cultivars. There was no significant difference in the response of the three papaya cultivars to purple nutsedge densities. In general, as purple nutsedge density increased, papaya growth decreased. Nutsedge interference caused papaya shoot dry weight losses of 15% at the density of one plant per container and 73% at six plants per container.

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