Growth Of Purple Nutsedge Research Articles

Efficacy of Some Herbicides on Growth, Tuber Production and Viability of Purple Nut-sedge (Cyperus rotundus L.)*

An experiment was conducted at the Sugarcane ResearchCenter, Guneid, during 2004/05 and 2005/06 seasons to evaluate theefficacy of some foliar herbicides on the growth of purple nutsedge(Cyperus rotundus L.) and to assess the effect of the treatments on theproduction and viability of tubers. The products tested were Krismat 75WG (Trifloxysulfuron-sodium+ametryn) at three rates (1.79, 2.38 and2.98 kg product ha-1 ) and Envoke 75 WG (Trifloxysulfuron-sodium) atthree rates (0.025, 0.030 and 0.035 kg product ha-1 ). Ametryn (Gesapax50 FW) + Atrazine (Gesaprim 50 FW) were used at the recommendedrates (3.81 L + 3.81 L product/ha), as a control. The results showed thatstatistically significant control of purple nut-edge was attained by allchemical treatments compared with the untreated check. Envoke 75 WGat 0.035 kg product/ha and the standard mixture of Gesapax + Gesaprimat its recommended rate significantly (P=0.05) reduced the number ofpurple nut-sedge compared with the untreated check. Gesapax +Gesaprim gave the lowest number of green leaves per plant. Envoke 75WG and Krismat 75 WG showed consistent reductions in tuberproduction and sprouting. Therefore, their successive application maylead to persistence and continuous reduction in the population density ofpurple nut-sedge in the fields of sugarcane.

The potential of Cosmos sulphureus flower extract as a bioherbicide for Cyperus rotundus

Abstract. Respatie. D. W, Yudono P, Purwantoro A, Trisyono Y.A. 2019. The potential of Cosmos sulphureus flower extract as a bioherbicide for Cyperus rotundus. Biodiversitas 20: 3568-3574. Cosmos (Cosmos sulphureus Cav.) flower is recognized as natural source of bioherbicide compounds for several weeds. The purple nutsedge (Cyperus rotundus L.) is an important weed, and this research was aimed to determine the effects of cosmos flower extract on this weed. Dried cosmos flowers were threshed and extracted using maceration method with 70% alcohol. The experiment was conducted in the greenhouse using a completely randomized design (CRD) with three replications. Purple nutsedge tubers were planted in polybags and treated with cosmos flower extract applicated once to three times with 300 mL polybag-1 at the concentration of 40%. Different levels of inhibitions on purple nutsedge growth were observed at 30 and 60 days after sowing (DAS) due to the presence of gallic acid in the extract. Growth parameters for purple nutsedge were analyzed using Analysis of Variance (ANOVA) and followed by Least Significant Differences (LSD) at α=0.05. Significant reductions in the number of mother shoots, daughter shoots, and roots, length of mother leaves, length of rhizomes, root, and total leaf area of the purple nutsedge treated with the cosmos flower extract at 30 DAS compared to those in the control. A significant reduction was also observed in foliage dry weight, underground organs dry weight, and total dry weight of purple nutsedge. The three application times yielded maximum inhibition. In addition, these treatments reduced N, P, and K content, chlorophyll content, and photosynthesis rates at 30 DAS. These results suggest that cosmos flower extract has the potential for controlling purple nutsedge.

Competitive Performance of Purple Nutsedge (<i>Cyperus rotundus</i> L.) and Onion (<i>Allium cepa</i> L.) as Affected by Different Sources of Nitrogen

Experiments were conducted in Yala 2010 and Maha 2010/11 to determine the effects of N sources and purple nutsedge ( Cyperus rotundus L.) densities on purple nutsedge growth and its interference with onion ( Allium cepa L.) as organic amendments can promote weed management. A 3×4 factorial design with four replicates per treatment was adopted. The treatments were three different purple nutsedge densities (0, 20, 40 plants/m 2 ) with four N sources i.e. cattle manure, gliricidia ( Gliricidia sepium ) leaves, improved compost and inorganic fertilizer (urea). Onion (variety Vethalan ) and purple nutsedge were allowed to grow together for 12 week. The results of the two experiments were combined as the treatment by season interaction was not significant (p>0.05). Onion bulb yield was significantly affected by purple nutsedge density and N source. No significant (p>0.05) effect of N sources on purple nutsedge biomass was observed at a density of 20 plants/m 2 whereas at 40 plants/m 2 , the effects were significant. Onion N concentration was high when grown with improved compost, whereas N concentration in purple nutsedge was low in this treatment. Purple nutsedge tuber weight and tuber number were significantly (p Tropical Agricultural Research Vol. 23 (4): 290 – 299 (2012) DOI: http://dx.doi.org/10.4038/tar.v23i4.4864

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

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.

Influence of native endomycorrhiza, soil flooding and nurse plant on mycorrhizal status and growth of purple nutsedge ( Cyperus rotundus L.)

A study was made to investigate the effects of native endomycorrhizal fungi, soil flooding and nurse plant (onion) on the mycorrhizal status, growth and phosphorus (P) uptake of purple nutsedge ( Cyperus rotundus L.). Above ground (AG) and below ground (BG) dry weight of mycorrhizal purple nutsedge plants were significantly lower than the non-mycorrhizal plants, but ratios of BG:AG dry weight were the same except when grown with onion. Mycorrhizal infection was characterized by vesicles and hyphae, both intraradical and extramatrical, but lacked arbuscules. Percentage root colonization of purple nutsedge and onion was significantly higher when the two grew together, but plants growing alone had less infection. Flooding of soil inhibited mycorrhizal formation in purple nutsedge, and mycorrhizal infected plants produced smaller tubers than uninfected plants. AG tissue P concentration was lower in mycorrhizal purple nutsedge but BG P concentration had no significant variations between infected and uninfected plants. P utilization efficiency (PUE) was similar for mycorrhizal and non-mycorrhizal purple nutsedge. Plants in flooded soil had the maximum AG and BG dry weights, tuber dry weight and P content, but had lower AG:BG dry weight ratio and PUE.

Sprouting and Growth of Purple Nutsedge, Cyperus rotundus, in Relation to pH and Aeration

AbstractThe results of experiments on the sprouting and growth of purple nutsedge (Cyperus rotundus L.) in relation to pH and aeration are described. All pH levels between 2.2 to 9.0 allowed high sprouting percentage but the sprouted tubers did not survive at pH below 3 and survival beyond pH 7 was very poor. Post‐sprouting growth of nutsedge was optimal at pH 4.Pre‐sprouting aeration of tubers stimulated early sprouting and produced vigorous shoots, whereas submersion of the tubers was inhibitory. Continuous aeration of the submerged tubers substantially removed the inhibitory influence on sprouting but the shoots remained weak. Seedlings grown in constantly aerated nutrient solution showed significantly better growth than in a non‐aerated one.

Seasonal Development of Yellow and Purple Nutsedges(Cyperus esculentusandC. rotundus)in Illinois

Yellow nutsedge(Cyperus esculentusL.) and purple nutsedge(C. rotundusL.) were grown in clay pots in the field to investigate the effect of sunlight intensity, planting date, and harvesting date on growth and development. Reducing the length of the growing season by delayed planting or early harvesting reduced the growth (dry matter accumulation) and tuber production of both species. Purple nutsedge growth (dry matter accumulation) was linearly reduced at 30 and 73% shade, but yellow nutsedge growth at 30% shade was not different from that at full sunlight. Tuber production in both species began about August 1, with slight delays in the initiation of tuber growth as planting date was delayed. At the end of the growing season a significant number of tubers were formed in both species even at the latest planting date under 73% shade.

Effect of Light and Temperature on Growth of Purple Nutsedge

Purple nutsedge (Cyperus rotundusL.) from single tubers was grown for 3 months at 24, 32, and 40 C and 9, 13, and 19 klux illumination. Growth in number and dry weight of shoots, bulbs, and tubers were determined at monthly intervals. Maximum growth for all portions of the plant occurred after 3 months at 32 C and 19 klux illumination. Minimum growth occurred at 40 C and 9 klux illumination. Growth at 24 C was not significantly affected by increased illumination above 9 klux.