scholarly journals Allelopathic Effect of Artemisia Dubia Extracts on Seed Germination and Seedling Growth of Some Weeds and Winter Crops

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

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.


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.


2020 ◽  
pp. 69-76
Author(s):  
Bhawna Negi ◽  
S.S Bargali ◽  
Kiran Bargali ◽  
Kavita Khatri

Ageratum conyzoides L. is an invasive weed that has severely infested cultivated lands and interferes with the growth of crops. In this study aqueous extracts of 50 and 100% concentration were prepared from fresh and air dried plant parts (Leaves and roots) of A. conyzoides and their allelopathic effect was observed on seed germination and seedling growth of two rice varieties namely Sava and Geru. In Sava variety, a significant reduction in seed germination, seedling length and dry weight was recorded under dry leaf extract while under fresh leaf extract seed germination and seedling length was increased at 50% concentration as compared to control. In Geru variety both fresh and dry leaf extracts resulted in decreased seed germination and seedling growth with increasing concentration. Similar patterns were recorded for fresh and dry root extracts. The inhibitory effect of leaf extracts was more pronounced than root extract and overall dry aqueous extracts of leaf and root were more inhibitory than fresh aqueous extracts. Among varieties, Sava was least affected as compared to the Geru. This study indicated that A. conyzoides exert allelopathic effect towards rice crop by releasing water soluble phytochemicals.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 742 ◽  
Author(s):  
Ming-Tung Hsueh ◽  
Chihhao Fan ◽  
Wen-Lian Chang

Bidens pilosa L. var. radiata Sch. Bip. (BPr) had been found capable of excluding Cyperus rotundus L. (CR) from its vegetation in fallow fields. Both allelopathy and competition of BPr were able to limit the growth of CR, but this has not been extensively investigated. To verify the two effects of BPr on CR management, density-dependent experiments and interspecies competitions with the application of activated carbon were conducted. The effects of BPr soil and its residues on the reproduction of CR were also evaluated. The results showed that the residues of BPr reduced the growth (54–61% of control) and tuber number (58–71% of control) of CR in the 3 plants pot−1 treatment but not in higher density treatments. In the interspecies competition, BPr exhibited an allelopathic but not competitive effect on CR when activated carbon was absent. CR tuber sprouting was significantly suppressed when sowed in the BPr soil. Likewise, BPr residue mulch inhibited the CR plant density by 87% as compared to natural-occurring CR residue mulch in the field. This study revealed that BPr might have potential for use as a cover plant and allelopathic mulch to control CR in the agroecosystem.


Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 535
Author(s):  
Deng Wang ◽  
Jingzhong Chen ◽  
Xue Xiong ◽  
Shu Wang ◽  
Jiming Liu

We examined allelopathic effects and underlying mechanisms of Cinnamomum migao on its associated species Liquidambar formosana. We assessed effects of aqueous extracts of C. migao pericarp, leaf, and rhizosphere soil at different concentrations on seed germination, seedling growth, and physiology of L. formosana. All extracts inhibited L. formosana seed germination, with obvious inhibition at high concentrations (50 mg mL−1). All extracts promoted the height and ground diameter of seedlings, with the highest promotion achieved with aqueous leaf extract at a concentration of 1 mg mL−1 and aqueous pericarp and rhizosphere soil extracts at a concentration of 5 mg mL−1. All extracts promoted soluble protein accumulation in L. formosana seedlings, with the highest accumulation achieved with aqueous pericarp extracts. Aqueous leaf extract promoted soluble starch accumulation. Aqueous pericarp extract at concentrations of >10 mg mL−1 significantly increased soluble sugar content. Aqueous leaf and rhizosphere soil extracts at concentrations of >5 mg mL−1 increased proline accumulation. All extracts at concentrations of >1 mg mL−1 significantly increased malondialdehyde content. Aqueous pericarp and rhizosphere soil extracts at concentrations of 10 and 0.5 mg mL−1, respectively, promoted superoxide dismutase activity. Activities of soil urease, polyphenol oxidase, and catalase were significantly increased when the concentration of aqueous pericarp and leaf extracts exceeded 5 mg mL−1, and the activity of soil acid phosphatase significantly increased when the concentration of all extracts were 5 mg mL−1. According to the synthetic allelopathic index, the low- and medium-concentration extracts all showed a promoting effect, whereas high concentrations exhibited obvious inhibitory effects; furthermore, the comprehensive effect value of leaf water extraction was higher than that of the pericarp and rhizosphere soil. Thus, allelopathy can affect the long-term co-existence of C. migao and L. formosana.


2013 ◽  
Vol 5 (1) ◽  
pp. 37-40 ◽  
Author(s):  
Oinam Ibetombi Devi ◽  
Biman Kumar Dutta ◽  
P. Choudhury

In present study the allelopathic effect of aqueous leaf extracts of Clerodendrum viscosum, Ageratum conyzoides and Parthenium hysterophorus was observed on the seed germination of Chickpea in vitro (Cicer arietinum.L.).Seed germination was found to be inhibited in all the leaf extract concentrations used i.e. 2%,4%,6%,8% and 10%. However higher inhibition was observed in the 10% leaf extract of the test plants (i.e. Cl. viscosum, Ag. conyzoides and P. hysterophorus). In compare to all allelopathic plants extracts more inhibition was found in P. hysterophorus leaf extract followed by Cl. viscosum and Ag. conyzoides. Higher inhibition of radical and plumule growth of the Chickpea seeds was found with the increase in concentration of the leaf extracts used. Percentage of germination of Chickpea seeds was found to be low in 10% concentration whereas in untreated seeds it was found to be more.


Author(s):  
MBB Das ◽  
BD Acharya ◽  
M Saquib ◽  
MK Chettri

A study was conducted to investigate the effects of invasive weed Ageratina adenophora on the seed germination and seedling growth of Triticum aestivum, Brassica campestris and on weeds Ageratum conyzoides, Bidens pilosa, Galinsoga parviflora and Cyperus rotundus. The aqueous extracts of Ageratina plant’s part root, stem and leaf; and compost extract of Ageratina on different concentrations (control, 1, 2.5, 5 and 10%) were used to determine its effect on the seed germination, shoot and root length of Triticum aestivum, Brassica campestris and some common weed seeds under laboratory condition. The compost of A. adenophora at different doses viz. 0, 10, 20, 40 and 50g compost/kg soil was also applied to study the effect on the seed germination and seedling growth of B. campestris and T. aestivum and some weed seeds. The aqueous and compost extracts of Ageratina caused significant reduction in the seed germination and seedling length (shoot and root) which increased progressively on increasing the concentration of invasive plant's extract. The stem and leaf extracts of A. adenophora have more inhibitory effect on the germination percentage of winter crops as compared to root extract on the test crop seeds under study. In the compost of A. adenophora, the weeds showed more reduction in comparison to the crop plants B. campestris and T. aestivum. J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(2): 11-20


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