scholarly journals Allelopathic Effect of Leaf Extract of Two Wild Plants on Seed Germination, Shoot and Root Lengths of Two Weed Species; Portulacaoleracea and Chenopodium murale

2018 ◽  
Vol 15 (4) ◽  
pp. 929-935 ◽  
Author(s):  
Nadi Awad Al-Harbi

The present study aims to evaluate the effect of leaf extract of Rhanterium epapposum and Salsola imbricata at various concentrations (20%, 40%, and 60%) on the germination and shoot and root lengths of two weed species; Portulaca oleracea and Chenopodium murale. The present study findings proved that the inhibitory effect of seed germination and shoot and root lengths of the studied species was largely dependent on the concentration of R. epapposum and S.imbricata leaf extract. The results showed that the highest allelopathic effect on the germination of the seeds of C.murale by leaf extract of R. epapposum and S. imbricata especially at concentration of 40% and 60% . While the lowest effect was of the leaf extract of S.imbricata. However the concentration of 60% was higher on the germination of the seeds C. murale and P. oleracea. Results also showed that the root and shoot lengths of C. murael was more sensitive to allelochemicals of R. epapposum leaf extract compared to S.imbricata leaf extract. However, the root and shoot lengths of P. oleracea was more sensitive to allelochemicals of S. imbricata leaf extract compared to R.epapposum leaf extract. Hence, the present findings recommended using the R. epapposum leaf extract and S. imbricata leaf extract as a tool for weed management especially C. murale and P. oleracea.

Author(s):  
Weihong Sun ◽  
Guofeng Yang ◽  
Lili Cong ◽  
Juan Sun ◽  
Lichao Ma

Background: Plant allelopathy refers to the release of chemicals from plants or microorganisms into the environment, may have direct or indirect, beneficial or harmful effects on other plants or microorganisms. When plants grow in an unfavorable environment,more allelochemicals will be secreted and the expression of allelopathic effects will increase, giving plants a certain competitive advantage. Hairy vetch is one of the most promising allelopathic crops and the aqueous extract of hairy vetch has an inhibitory effect on the root length and seedling height of grass crops. The current study aimed to study the allelopathic effect of hairy vetch on alfalfa, and exploring an ecological method to remove the root system of alfalfa.Methods: In this experiment, the allelopathic effects of the seeds, stems and leaves, roots extracts and root exudates (0, 3, 6, 9 and 12 mg·mL-1) on the seed germination and seedling growth of alfalfa were evaluated. And the main allelopathic substances from the stem and leaf extract were isolated and identified using high performance liquid chromatography- mass spectrometry (HPLC-MS).Result: The results showed that all of the extracts can inhibit alfalfa seed germination and seedling growth and stem and leaf extract had the strongest inhibitory effect, especially for inhibiting the root growth. A main allelochemical substance, o-coumaric acid, was screened out and the root length of alfalfa was completely inhibited at 1.6 mg·mL-1 of o-coumaric acid. The findings of these experiments show hairy vetch has strong allelopathic effect on alfalfa and o-coumaric acid is a chemical growth inhibitor.


Author(s):  
Satyajit Oraon ◽  
Subrata Mondal

The present study reveals the allelopathic effect of aqueous leaf extracts of Putranjiva roxburghii Wall. on seed germination and early growth stages of an economically important plant chickpea (Cicer arietinum L.). Aqueous leaf extracts at 0, 5, 10, 15, 25, 35, 50, 75 and 100% concentrations were applied to determine their effect on seed germination and early growth stages under laboratory conditions. Laboratory-based experiments with three replicates were used to arrange treatments accordingly. After 5 days of incubation the rate of seed germination, radicle length and hypocotyls length etc. of chickpea seeds were observed after treatment with aqueous leaf extracts. Highest inhibitory effect was noticed in 100% of aqueous leaf extract. Results indicated that the inhibitory effect was proportional to the concentration of the extracts. The water soluble leaf extracts contain allelochemicals, which inhibit the seed germination and reduced the early growth of chickpea.


2016 ◽  
Vol 6 (3) ◽  
pp. 95-100
Author(s):  
Nadi Awwad Al Harbi

The aim of the present study was to investigate the potentials for utilization of Artemisia herba-alba and Anthemis arvensis shoot aqueous extract at different concentrations (1%, 3%, and 5%) to suppress the germination and growth of Panicum turgidum and Portulaca oleracea (weeds of crop fields) in Petri dish experiment. Results indicated that the degree of inhibition on seed germination and growth of the recipient species was largely dependent on the concentration of A. herba-alba and A.arvensis shoot aqueous extract. The aqueous extract of A.herba-alba showed the highest allelopathic effect on the germination of the seeds of P. turgidum, (10%,10% and 0%) while the effect of A. arvensis shoot aqueous extract was greater on the germination of the seeds P. oleracea (40%,0% and 0%). Percentage germination of the two selected crop species Triticum aestivum and Hordeum vulgare also de-creased as the A.herba-alba and A.arvensis shoot aqueous extract concentra-tion increased from 1% to 5% (90%,80% and 70%),(40%,40% and 20%). But the inhibition percentage was largely less than that of weed species. The results also showed that H.vulgare was more sensitive than T. aestivum and responds more strongly to the increase of concentration of A. herba-alba shoot aqueous extract . Results also showed that the radicle length of almost all tested species was more sensitive to allelochemicals from A.herba-alba and A.arvensis shoot aqueous extract than plumule length. Therefore, A. herba-alba and A. arvensis shoot aqueous extract may offer promises for their usefulness as a tool for weed management.


Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 312-320 ◽  
Author(s):  
Heino B. Papenfus ◽  
Manoj G. Kulkarni ◽  
Martin Pošta ◽  
Jeffrey F. Finnie ◽  
Johannes Van Staden

Weeds pose a great problem to farmers worldwide, and controlling weeds demands a high input cost for herbicides and labor. Because of current environmental regulations, a limited number of herbicides are commercially available (with limited modes of action) to control weeds. Smoke water and the biologically active compounds isolated from smoke affect seed germination in a significant way. Smoke water (SW) and karrikinolide (KAR1, the germination stimulant isolated from smoke) have been tested extensively for their ability to promote seed germination in a vast array of plant species. In addition to KAR1, a germination inhibitor, trimethylbutenolide (TMB), was also isolated from plant-derived smoke. The effects of SW, KAR1, and TMB were tested on five major weed species of South Africa: fleabane, hairy wild lettuce, bugweed, spilanthes, and fameflower. Seeds of these weed species were subjected to 16/8 h light/dark conditions or to constant dark conditions at constant temperatures of 20, 25, 30 C and alternating 30/20 C. SW and KAR1significantly increased germination, whereas TMB significantly inhibited germination of these weed species. Furthermore, TMB treatment reduced the amylase activity of the tested weed seeds compared with the water control. These results indicate the possibility of manipulating germination of certain weed seeds by SW, KAR1, and TMB. Thus, smoke and smoke-isolated compounds could potentially be used in new weed management strategies.


2017 ◽  
Vol 5 (3) ◽  
pp. 387-395
Author(s):  
Raj Kumar Nagar ◽  
Dinesh Kumar Jain

A field experiment was conducted to analyze the types of flora, intensity, cover and effects on yields of coriander. Pooled analysis of data indicated that Goose foot (Chenopodium murale L.), Corn spurry (Spergula arvensis L.) among dicots and Purple nutsedge (Cyperus rotundus L.) among monocots were found most dominant weeds at all stages of crop growth. Of the total eight weed species reported dicot weeds were found most dominating weed species and comprises 78-80 percent of total weed density throughout crop cycle. All weed management practices significantly reduced the density of monocot and dicot weeds and improved the yield (seed and biological yield) of crop as compared to control. Two hand weeding at 30 and 45 DAS resulted in maximum reduction in total weed density and gave the highest seed (15.84 q/ha) and biological yield (41.11 q/ha) of coriander. However, seed and biological yields was obtained at par by pendimethalin 1.0 kg/ha + one hand weeding at 45 DAS. This treatment also resulted in favorably lowest weed competition index as compared to rest of other practices. Balanced fertilization with N+P+K+S also improved monocot and dicot weed density but the effect was not significant over N+P and N+P+K fertilization. N+P+K+S fertilization significantly enhanced crop seed and biological yields over N+P (1.86 q/ha and 4.36 q/ha, respectively) and N+P+K application (0.94 q/ha and 2.20 q/ha, respectively). Weed management and balanced fertilization practices also found to have significant interaction effect on seed and biological yield of coriander.


CORD ◽  
2020 ◽  
Vol 36 ◽  
pp. 41-46
Author(s):  
S.H.S. Senarathne ◽  
S. S. Udumann

Vernonia zeylanica (L.) belongs to the family Asteraceae, is one of the major endemic weed species present in coconut (Cocos nucifera L.) plantations of the tropics, which propagates very easily.  There is a possibility that this plant could also possess allelopathic effects, but this has not been scientifically tested.  Thus, a study was carried out to determine the seed germination of V. zeylanica under soil moisture stress conditions, shoot propagation methods and possible allopathic effects of this species, on selected species in bioassay tests.  Germination of V. zeylanica seeds was not observed at higher osmotic potential (-0.9 MPa).  The highest sprouting percentage of this species were obtained with soft wood cuttings.  The aqueous leaf extract was highly phytotoxic, and it significantly reduced germination and seedling growth of all bioassay species tested. Full strength (33.3 g L-1) aqueous extracts of leaves significantly reduced the germination percentage, root and hypocotyl growth rates of all species tested.  The inhibitory effects were often dependent on concentration.  However, the degree of inhibition varied among the test plant species.  The seedling emergences of all four tested plants were severally inhibited when planted in V. zeylanica contaminated soil.  The results indicated that incorporated aqueous leaf extract of V. zeylanica and its rhizosphere contaminated soil can suppress seed germination, seedling growth and seedling emergence of certain plant species indicating a possible allelopathic effect.


2015 ◽  
Vol 21 ◽  
pp. 23-30
Author(s):  
Baby Babita Das Mallik ◽  
BD Acharya ◽  
M Saquib ◽  
MK Chettri

Allelopathic effects of aqueous extract of different plant parts (root, stem and leaf) of Artemisia dubia on seed germination and seedling growth of two winter crops (Triticum aestivum and Brassica campestries, and some associated weeds (Bidens pilosa, Ageratum conyzoides, Galinsoga parviflora and Cyperus rotundus) have been investigated in the present study. Extracts of root, stem and leaves of Artemisia dubia showed significant reduction in germination and seedling growth of test crops and weeds. Germination of crop and weed seeds and growth of shoot and root were reduced significantly in test treatments in comparison to the control. The seed germination, shoot length and root length were low at higher concentration. Complete inhibition of seed germination of Ageratum conyzoides, Galinsoga parviflora and Cyperus rotundus at 5 and 10% leaf extract of A.dubia was observed. Allelopathic effects were more pronounced with leaf extract than root or stem extract in most cases.The result indicated difference in allelopathic effect on crop seed and weed seed at higher concentrations. ECOPRINT 21: 23-30, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11901


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