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.

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.

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.

Toxicity, Absorption, and Translocation of Soil-Applied Chlorimuron in Yellow and Purple Nutsedge (Cyperus esculentusandC. rotundus)

Weed Science ◽  
1989 ◽  
Vol 37 (2) ◽  
pp. 147-151 ◽  
Author(s):  
Krishna N. Reddy ◽  
Leo E. Bendixen
Keyword(s):  
Laboratory Experiments ◽  
Shoot Growth ◽  
Dry Weight ◽  
Purple Nutsedge ◽  
Treated Soil ◽  
Yellow Nutsedge ◽  
Shoot Dry Weight ◽  
C Distribution ◽  
Tuber Sprouting ◽  
Shoot Emergence

The activity of soil-applied chlorimuron in yellow and purple nutsedge was studied in greenhouse and laboratory experiments. Soil-applied chlorimuron decreased tuber sprouting by 80% in yellow nutsedge and by 30% in purple nutsedge at 60 g ai/ha. Chlorimuron decreased shoot emergence by 53 to 83% and shoot growth by 85 to 99% in both species at rates as low as 10 g/ha. Previous exposure of tubers to chlorimuron-treated soil reduced tuber resprouting by 20 to 25% in herbicide-free soil at 60 g/ha in both species. There was no rate response in shoot emergence from tubers previously exposed to chlorimuron, but shoot dry weight decreased by 60 to 81% in both species at 60 g/ha. At 12 h after application, 47% of the total14C applied to the shoot in yellow nutsedge and 32% of that applied in purple nutsedge were absorbed. However, less than 1% of the total14C applied was translocated out of the shoot and into the roots and tuber in either species. In both species, 1.3% of the14C applied to the roots and tuber was absorbed and 0.1% was translocated out of the roots and tuber into the shoot at 12 h after application. The pattern of root- and tuber-absorbed14C distribution indicated that the14C absorbed by the tuber remained in the tuber and that absorbed by the roots was translocated to the shoots.

Effect of MON-12037 on Purple (Cyperus rotundus) and Yellow (Cyperus esculentus) Nutsedge

1995 ◽  
Vol 9 (1) ◽  
pp. 148-152 ◽  
Author(s):  
William K. Vencill ◽  
John S. Richburg ◽  
John W. Wilcut ◽  
Larry R. Hawf
Keyword(s):  
Dry Weight ◽  
Soil Treatment ◽  
Cyperus Rotundus ◽  
Cyperus Esculentus ◽  
Purple Nutsedge ◽  
Soil Application ◽  
Yellow Nutsedge ◽  
Shoot Dry Weight ◽  
Shoot Number ◽  
Root Tuber

Greenhouse studies were conducted to determine the response of purple and yellow nutsedge to selective soil placement of 5 cm of soil treated with MON-12037 above and/or below the nutsedge tubers. MON-12037 at 53 g/ai ha applied as a foliar, soil, or foliar + soil application also were evaluated. MON-12037 placement above, below, or above + below the nutsedge tuber decreased shoot number, shoot dry weight, shoot regrowth dry weight, and root-tuber dry weight production in both species, 30 and 60 d after treatment. MON-12037 applied as a foliar, soil, and foliar + soil treatment was effective in reducing purple nutsedge shoot regrowth dry weight to less than 5% of the non-treated control. Yellow nutsedge shoot regrowth dry weight from the foliar + soil and soil-only applications was less than 1% of the non-treated control.

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.

scholarly journals Genetic Variability in Root and Shoot Growth Characteristics of Peanut1,2

1982 ◽  
Vol 9 (2) ◽  
pp. 68-72 ◽  
Author(s):  
D. L. Ketring ◽  
W. R. Jordan ◽  
O. D. Smith ◽  
C. E. Simpson
Keyword(s):  
Root Growth ◽  
Leaf Area ◽  
Root Length ◽  
Shoot Growth ◽  
Primary Root ◽  
Positive Association ◽  
Dry Weight ◽  
Root Parameters ◽  
Shoot Dry Weight ◽  
Highly Correlated

Abstract The shape and extent of root systems influence the rate and pattern of nutrient and water uptake from the soil. In dicotyledons such as peanut (Arachis hypogaea L.), the primary root and its laterals constitute the main root system. Rooting trait differences in some crops have been associated with drought tolerance. Our objective in this study was to determine if variation in root length and number occurs among peanut genotypes. In one test, shoot and root growth of 23 genotypes (12 spanish and 11 virginia types) were compared in the greenhouse at 55 days after planting using clear acrylic tubes 7.5 cm in diameter and 2.2 m in length. Shoot dry weight, leaf area, tap root length, and root number at 1 m depth ranged for spanish-type entries from 1.23 to 2.65 g, 214 to 409 cm2, 95.0 to 186.8 cm, and 1.0 to 3.1, respectively. Similarly, ranges for virginia-type entries were 1.35 to 3.23 g, 135 to 460 cm2, 122.4 to 192.6 cm, and 1.0 to 7.1. Correlations between shoot and root parameters indicated strong positive association between aerial and subterranean growth. However, the relationship of leaf area to root length was stronger for virginia- than for spanish-type entries. Root length and numbers were highly correlated for spanish, but not for virginia entries. In other tests that included two each of virginia-, spanish-, and valencia-type entries, similar results were found for plants at 34 and 47 days after planting. Significant differences in both root (length and numbers) and shoot growth (dry weight and leaf area) were found among the genotypes tested. Inherent differences in root growth rate were evident at early stages of seedling growth. The results from this sample of peanut germplasm indicate that there is considerable diversity in root growth and there is high shoot/root growth association.

Root and shoot development in Corymbia calophylla and Banksia brownii after the application of the fungicide phosphite

2002 ◽  
Vol 50 (2) ◽  
pp. 155 ◽  
Author(s):  
S. R. Barrett ◽  
B. L. Shearer ◽  
G. E. St J. Hardy
Keyword(s):  
Root Development ◽  
Root Length ◽  
Native Species ◽  
Shoot Growth ◽  
Foliar Application ◽  
Leaf Size ◽  
Dry Weight ◽  
Shoot Development ◽  
Shoot Dry Weight ◽  
Growth Abnormalities

The effects of low-volume foliar application (24, 48, 96 kg ha–1) of phosphite on root and shoot development in Corymbia calophylla Lindley and Banksia brownii ex R.Br. were investigated in a glasshouse study. Shoot growth, root and shoot dry weight and root length were not significantly reduced by phosphite application in C. calophylla 2 weeks and 4 months after phosphite application. Shoot growth, shoot dry weight and root length were not significantly reduced in the non-mycorrhizal B. brownii. However, in plants treated with 24 and 96 kg ha–1, root dry weight was significantly reduced 4 months but not 2 weeks after spray. A discoloration of the root stele was also observed in phosphite-treated plants of this species. At 2 weeks after spray, root concentrations of phosphite in C. calophylla were up to five times higher than shoot concentrations. At 4 months after application, growth abnormalities were observed in B. brownii and these included spindly new shoot growth with rosetted foliage of reduced leaf size. The results of this study, which assessed one mycorrhizal and one non-mycorrhizal native species, suggest that species may vary in their response to phosphite in terms of root development and phosphite applied at rates of 24 kg ha–1 or higher may result in reduced root growth, particularly in non-mycorrhizal species. Further studies on root development in a wider range of species are needed to validate these findings.

Influence of purple nutsedge(Cyperus rotundus)density and nitrogen rate on radish(Raphanus sativus)yield

Weed Science ◽  
1998 ◽  
Vol 46 (6) ◽  
pp. 661-664 ◽  
Author(s):  
Bielinski M. Santos ◽  
Jose P. Morales-Payan ◽  
William M. Stall ◽  
Thomas A. Bewick
Keyword(s):  
Field Experiments ◽  
Dry Weight ◽  
Field Studies ◽  
Cyperus Rotundus ◽  
Shoot Biomass ◽  
Purple Nutsedge ◽  
Shoot Dry Weight ◽  
Radish Root ◽  
Negative Effect ◽  
Nitrogen Rates

Greenhouse and field experiments were conducted to determine the effects of nitrogen (N) supply and purple nutsedge population densities on the yield of radish. In the greenhouse studies, additive series with purple nutsedge densities of 0, 50, 100, 200 or 350 plants m−2were established. Nitrogen rates of 0, 110, 220, or 330 kg ha−1were provided to the potting medium. A significant density by N interaction was found for radish fresh weight. Within a given nutsedge density, radish yield decreased as N rate increased. In field studies, additive series of 0, 50, 100, 150, or 200 nutsedge plants m−2were established the same day radish was sown. Nitrogen rates were 100 or 200 kg ha−1. Marketable radish yield losses and nutsedge shoot dry weight and height were determined 30 d after seeding the crop. Nutsedge densities and N rates interactively influenced radish root yield. Radish yield loss reached 100% at nutsedge densities of 75 and 125 plants m−2at 200 and 100 kg N ha−1, respectively. Purple nutsedge produced larger shoot biomass as N increased from 100 to 200 kg ha−1. Results of both greenhouse and field studies showed that as N increased, the negative effect of the weed on the crop was enhanced.

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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