scholarly journals Allelopathic Behaviour of Cyperus Rotundus L. On Both CHORCHORUS OLITORIUS (BROAD LEAVED WEED) AND ECHINOCHLOA CRUS-GALLI (GRASSY WEED) ASSOCIATED WITH SOYBEAN

2010 ◽  
Vol 50 (3) ◽  
pp. 274-279 ◽  
Author(s):  
Kowthar El-Rokiek ◽  
Samia El-Din ◽  
Faida Sharara

Allelopathic Behaviour ofCyperus RotundusL. On BothCHORCHORUS OLITORIUS(BROAD LEAVED WEED) ANDECHINOCHLOA CRUS-GALLI(GRASSY WEED) ASSOCIATED WITH SOYBEANPurple nutsedge (Cyperus rotundus) foliage and tubers were tested for allelopathic potential against the following weeds; juteChorchorus olitorius(broad leaved weed), and barnyard grassEchinochloa crus-galli(grassy weed) associated with soybean. In the greenhouse, during 2008 and 2009, foliage and tubers ofC. rotunduswere mixed with soil surface at 20, 40, 60 and 80 g/kg.C. rotundusnegatively affected those of jute and barnyard grass particularly at 80 g. Jute was more susceptible to allelopathy byC. rotundusthan barnyard grass. Inhibition in weed dry matter was higher with tuber than foliage residues. Tuber residues reduced the dry weight of jute and barnyard grass by 85.96% of the control and by 58.28% with 80 g, respectively. On the other hand, soybean growth and yield showed a high significant increase compared with unweeded pots. A high-performance liquid chromatography analysis showed thatC. rotundusfoliage contained the following phenolic acids: caffeic, ferulic, coumaric, benzoic, vanelic, chlorogenic and cinnamic. Tubers contained hydroxybenzoic, caffeic, ferulic, vanelic and chlorogenic.

2015 ◽  
Vol 33 (2) ◽  
pp. 165-173 ◽  
Author(s):  
R.S.O. Lima ◽  
E.C.R. Machado ◽  
A.P.P. Silva ◽  
B.S. Marques ◽  
M.F. Gonçalves ◽  
...  

This work was carried out with the objective of elaborating mathematical models to predict growth and development of purple nutsedge (Cyperus rotundus) based on days or accumulated thermal units (growing degree days). Thus, two independent trials were developed, the first with a decreasing photoperiod (March to July) and the second with an increasing photoperiod (August to November). In each trial, ten assessments of plant growth and development were performed, quantifying total dry matter and the species phenology. After that, phenology was fit to first degree equations, considering individual trials or their grouping. In the same way, the total dry matter was fit to logistic-type models. In all regressions four temporal scales possibilities were assessed for the x axis: accumulated days or growing degree days (GDD) with base temperatures (Tb) of 10, 12 and 15 oC. For both photoperiod conditions, growth and development of purple nutsedge were adequately fit to prediction mathematical models based on accumulated thermal units, highlighting Tb = 12 oC. Considering GDD calculated with Tb = 12 oC, purple nutsedge phenology may be predicted by y = 0.113x, while species growth may be predicted by y = 37.678/(1+(x/509.353)-7.047).


1987 ◽  
Vol 1 (3) ◽  
pp. 217-220 ◽  
Author(s):  
Gamini Siriwardana ◽  
Roy K. Nishimoto

The upper 30 cm of soil in a field infested with purple nutsedge (Cyperus rotundusL. #3CYPRO) contained 4900 to 5100 corms and tubers/m26 weeks after soil rotovation and irrigation. The upper 4, 8, 12 and 16 cm of soil had 45, 79, 95 and 99%, respectively, of the corms and tubers. Lower depths of soil contained larger tubers with higher percent dry matter than the shallow depths. Of the total number of corms and tubers, 51% were from the parent population. At 6 weeks, only 15% of the total tuber and corm population were not connected to aerial parts. Tubers from the parent population had a higher fresh weight than those from the new population. Parent tubers occurred singly or in chains of up to eight tubers.


2010 ◽  
pp. 132-140 ◽  
Author(s):  
MA Islam ◽  
MH Reza ◽  
SMAHM Kamal ◽  
MA Wazed ◽  
KM Islam

An experiment was conducted with a local cultivar of garlic to study the effects of planting date and gibberellic acid on the growth and yield of garlic at the field laboratory of the Department of Crop Botany, Bangladesh Agricultural University, Mymensingh during November 2001 to April 2002. Early planting influenced the plant height, leaf number, bulb diameter and total dry matter. With the delay in planting time starting from November 7, the yield was chronologically reduced in later plantings. Significantly the highest bulb yield (2.67 t/ha) was recorded when planting was done on November 7 and lowest yield (0.92 t/ha) was obtained from December 22 planted crop. Bulb yield was higher in control plants than those of GA3 treated plants. The interaction effects of planting date and different concentrations of GA3 differed significantly in respect of plant height, number of leaves, bulb diameter and dry weight of roots, leaves and bulbs and yield of garlic.


2018 ◽  
Vol 45 (3) ◽  
pp. 249
Author(s):  
Solikin ,

Dioscorea is potentially used as staple food to support food security. The research was aimed to determine the effect of stake length and time of  stem twining  on  the growth of Dioscorea sansibarensis Pax. The experiment was conducted  in  Purwodadi Botanic Garden from December 2014 until May 2015 using split plot randomized block design consisted of two factors, i.e. the stake length and time of stem twining. The stake length was the main plot consisted of 150 cm, 100 cm and 50 cm above soil surface and without stake (control). The time of stem twining as subplots, i.e. stem twined early, twined at the time of 4 leaves stage, and twined at 8 leaves stage. Each combination of the treatments was replicated three times. The results showed that there was significant effect on the stake length  and the time of stem twining treatments on the plant growth and yield. The stake  length of 150 cm treatment produced the highest fresh tuber and total plant dry weight, i.e., 257.24 g and 132.77 g per plant, respectively. On the contrary, the plant without stake produced the lowest fresh tuber and  total dry weight of plant, i.e., 112.10 g and 48.65 g per plant, respectively.<br /><br />Keywords: biomass,leaf area, photosyntesis, tuber weight


2008 ◽  
Vol 59 (2) ◽  
pp. 183 ◽  
Author(s):  
Alexa N. Seal ◽  
James E. Pratley ◽  
Terry Haig

Several weeds of rice in Australia have developed resistance to the main herbicide available for their control. Allelopathy is one phenomenon that could be incorporated into an integrated weed-management system as a supplement or alternative to synthetic herbicides. Several rice cultivars were screened both in the laboratory and the field for allelopathic potential against a major rice weed, Damasonium minus. Results from the laboratory bioassay showed that there were significant differences among cultivars in their ability to inhibit D. minus root growth. D. minus root lengths ranged from 2.0% (cv. Hungarian #1) to 32.6% (cv. Rexmont) that of the control. In the field study, significant differences existed in the D. minus dry matter grown in association with different cultivars, ranging from 4.6% (cv. Tono Brea) to 72.2% (cv. Rexmont) that of the control. Comparison between laboratory and field results indicated a strong relationship between performance in the field and in the laboratory (r2 = 0.713). Those cultivars ranked as allelopathic in the bioassay tended to have associated lower D. minus dry weight in the field. Eight of the top 10 allelopathic cultivars in the bioassay were among the top 10 suppressive cultivars in the field trial. This important finding indicates that at least some of the variation in field performance of cultivars may be predicted by their performance in bioassays.


Weed Science ◽  
1983 ◽  
Vol 31 (2) ◽  
pp. 200-207 ◽  
Author(s):  
C. Dennis Elmore ◽  
Michael A. Brown ◽  
Elizabeth P. Flint

Early weed and crop interference was examined in a greenhouse pot experiment combining aspects of additive, substitutive, and diallel designs. Cotton (Gossypium hirsutumL. 'Stoneville 213′) and four weeds {purple nutsedge (Cyperus rotundusL.), large crabgrass [Digitaria sanguinalis(L.) Scop.], velvetleaf (Abutilon theophrastiMedic.) and prickly sida (Sida spinosaL.)} were grown singly and in all possible combinations of pairs including reciprocals for 5 weeks in 10-cm plastic pots. After 5 weeks large crabgrass was the tallest species in all combinations except when grown with purple nutsedge. Purple nutsedge, however, had more leaf area and greater dry weight than all other species. Height, leaf area, and dry weight were lowest in prickly sida. Mean relative yields in mixtures (a measure of competitive ability) were 1.90, 1.15, 1.13, 0.86, and 0.41 for purple nutsedge, large crabgrass, cotton, velvetleaf, and prickly sida, respectively, when grown with the other four species as associates. Conversely, purple nutsedge and cotton as associates depressed mean relative yields of competing species to 0.59 and 0.94. Large crabgrass, velvetleaf, and prickly sida as associates increased mean relative yields of competing species to 1.17, 1.18, and 1.55, respectively. Analysis of these data and replacement-series diagrams indicated that purple nutsedge was the most competitive, prickly sida the least, and the other species were intermediate and approximately equivalent in competitive ability.


Weed Science ◽  
1997 ◽  
Vol 45 (3) ◽  
pp. 382-387 ◽  
Author(s):  
Glenn R. Wehtje ◽  
Robert H. Walker ◽  
Timothy L. Grey ◽  
H. Gary Hancock

A series of greenhouse studies examined the effectiveness of PRE- and POST-applied sulfentrazone in controlling purple and yellow nutsedge as influenced by selective tissue exposure. In addition,14C-sulfentrazone was utilized to contrast absorption and translocation resulting from these exposures. Consistent control with preemergence applications to germinating tubers was obtained with a combined root and shoot zone exposure. Yellow nutsedge was more susceptible than purple nutsedge. Performance of the separate root and shoot zone exposure was soil pH- and nutsedge-species dependent. POST-foliar applications to established nutsedge were more effective when sulfentrazone was allowed to contact the soil surface.14C-sulfentrazone was readily absorbed by the roots and translocated to the foliage of both species in hydroponic culture.


Weed Science ◽  
1978 ◽  
Vol 26 (2) ◽  
pp. 127-131 ◽  
Author(s):  
D. J. Rincon ◽  
G. F. Warren

Five thiocarbamate herbicides, butylate(S-ethyl diisobutylthiocarbamate), EPTC(S-ethyl dipropylthiocarbamate), molinate(S-ethyl-hexahydro-1H-azepine-1-carbothioate), pebulate(S-propyl butylethyl-thiocarbamate), and vernolate(S-propyl dipropylthiocarbamate) were used in the greenhouse at doses of 0.5 to 5 kg/ha incorporated 6 cm deep in a silt loam. Purple nutsedge(Cyperus rotundusL.) tubers were planted 5 cm deep. Three and 9 weeks after treatments were applied, nutsedge plants were harvested. EPTC also was used at doses of 0.25 to 10 kg/ha and plants were harvested every 2 days up to 20 days and every 3 weeks up to 24 weeks. The most effective reduction in the number of sprouts above ground was given by butylate, EPTC, and vernolate followed by pebulate and molinate. Persistence was directly related to level of initial activity. No effect was observed on the number of tubers which sprouted. However, all the thiocarbamates stimulated the number of sprouts produced per nondormant tuber. These sprouts were abnormal and did not reach the soil surface. Treated tubers produced approximately twice as many sprouts as controls. The number of rhizomes produced from the basal bulb was reduced with all the thiocarbamates used, even 24 weeks after treatment for the higher doses.


1970 ◽  
Vol 34 (1) ◽  
pp. 67-73
Author(s):  
M SH Islam ◽  
MSU Bhuiya ◽  
AR Gomosta ◽  
AR Sarkar ◽  
MM Hussain

Pot experiments were conducted during T. aman 2001 and 2002 (wet season) at Bangladesh Rice Research Institute (BRRI) in net house. Hybrid variety Sonarbangla-1 and inbred modern variety BRRI dhan-31 were used in both the seasons and BRRI hybrid dhan-l was used in 2002. The main objective of the experiments was to compare the growth and yield behaviour of hybrid and inbred rice varieties under controlled condition. In 2001, BRRI dhan-3l had about 10-15% higher plant height, very similar tillers/plant, 15-25% higher leaf area at all days after transplanting (DAT) compared to Sonarbangla-1. Sonarbangla- 1 had about 40% higher dry matter production at 25 DAT but had very similar dry matter production at 50 and 75 DAT, 4-11% higher rooting depth at all DATs, about 22% higher root dry weight at 25 DAT, but 5-10% lower root dry weight at 50 and 75 DAT compared to BRRI dhan-31. The photosynthetic rate was higher (20 μ mol m-2/sec-1) in BRRI dhan-3l at 35 DAT (maximum tillering stage) but at 65 DAT, Sonarbangla-l had higher photosynthetic rate of 19.5 μ mol m-2 sec-1. BRRI dhan-3l had higher panicles/plant than Sonarbangla-1, but Sonarbangla-1 had higher number of grains/panicle, 1000-grain weight and grain yield than BRRI dhan-31. In 2002, BRRI dhan-31 had the highest plant height at 25 DAT, but at 75 DAT, BRRI hybrid dhan-l had the highest plant height. Sonarbangla-1 had the largest leaf area at 25 and 50 DAT followed by BRRI dhan-31, but at 75 DAT, BRRI dhan-31 had the largest leaf area. The highest shoot dry matter was observed in BRRI dhan-31 followed by Sonarbangla-1 at all DATs. Sonarbangla-1 had the highest rooting depth and root dry weight at all DATs. BRRI dhan-31 gave the highest number of panicles/plant followed by Sonarbangla-I, BRRI hybrid dhan-l had the highest grains/panicle followed by BRRI dhan-31 and Sonarbangla-I had the highest 1000-grain weight followed by BRRI dhan-31. The highest amount of grains/plant (34.6 g) was obtained from BRRI dhan-31. Key Words: Shoot dry matter; root dry weight; leaf area; photosynthesis; grain yield. DOI: 10.3329/bjar.v34i1.5755Bangladesh J. Agril. Res. 34(1) : 67-73, March 2009


2001 ◽  
Vol 81 (4) ◽  
pp. 815-819 ◽  
Author(s):  
I. M. Chung ◽  
J. K. Ahn ◽  
S. J. Yun

Experiments were conducted to identify allelochemicals from rice (Oryza sativa L.) straw extracts of four rice cultivars (Gin shun, Kasawala mundara, Philippine 2 and Juma 10), and to test their biological activity on barnyard grass (Echinochloa crus-galli P. Beauv. var. oryzicola Ohwi). High performance liquid chromatography (HPLC) analysis showed that the concentration and composition of allelopathic compounds depended on the cultivar. Among the compounds identified were p-hydroxybenzoic acid at 6.87 mg g–1 in Gin shun, p-coumaric acid at 0.34 mg g–1 in Kasawala mundara, ferulic acid at 0.05 mg g–1 in Philippine 2, and p-hydroxybenzoic acid at 6.34 mg g–1 in Juma 10. Preliminary identification by HPLC analysis resulted in peaks with retention times near those of standards, including p-hydroxybenzoic acid m/z = 138). This was confirmed with electron impact/mass spectra. In a bioassay with nine known allelochemicals and their mixtures, p-hydroxybenzoic acid (10–3 M) showed the greatest inhibitory effect on barnyard grass seed germination, seedling length, and dry weight. This suggests that this compound may be a key factor in rice allelopathy on barnyard grass. Key words: Allelopathic compound, rice, barnyard grass, bioassay


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