scholarly journals Allelopathic Effects of Ludwigia decurrens and L. adscendens subsp. diffusa on Germination, Seedling Growth and Yield of Corchorus olitorious L.

2010 ◽  
Vol 2 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Ayobola A. Moninuola SAKPERE ◽  
Matthew OZIEGBE ◽  
Idowu Arinola BILESANMI

This study examined the allelopathic effect of Ludwigia decurrens and L. adscendens exudates on germination, seedling growth (hypocotyl and radicle elongation), seedling mortality, vegetative growth and reproductive yield of Corchorus olitorious. Ludwigia decurrens, L. adscedens exudates and tap water (control) were applied to seeds of Corchorus olitorious over a period of 15 days and to 3 weeks old seedling for a period of 4 weeks. Ludwigia exudates had no inhibitory effect on the germination percentage of C. olitorious, but the exudates from the two Ludwigia spp. induced mortality rate of the 15 day old seedlings (control: 5.00%, L. decurrens: 17.50%, L. adscendens: 26.88%) and a significant decrease in seedling elongation (hypocotyl and radicle length) of C. olitorious. For the vegetative growth experiment, results showed that the stem length, stem fresh weight and leaf area of C. olitorious were significantly inhibited during week 6 (P

2020 ◽  
pp. 1450-1455
Author(s):  
Ramida Krumsri ◽  
Hisashi Kato Noguchi ◽  
Thanatsan Poonpaiboonpipat

The allelopathic effect of Sphenoclea zeylanica Gaertn., a broadleaf paddy weed that hinders rice production in Thailand, was investigated. Different parts of S. zeylanica were used to determine their inhibitory effect on seed germination, and shoot and root length of rice in a laboratory. Aqueous extracts of leaves and stems had an inhibitory effect on rice germination and seedling growth more than 50% that of control at concentrations higher than 50 g L-1, whereas all concentrations of root extracts had no effect on rice seeds. At the concentration of 100 g L-1, leaf and stem extracts completely (100%) inhibited rice seed germination. The inhibitory effect was increased with increasing concentrations. Additionally, leaf extracts contained higher total phenolics (7.36 mg GE g-1 DW) and total flavonoids (254.19 µg QE g-1 DW) than extracts of other parts. In glasshouse conditions, soil incorporation with dried whole plant residue had a significant inhibitory effect on rice emergence, seedling height, and dry weight when compared with extracted residue at an equal concentration. The decomposition of S. zeylanica in the soil was also evaluated regarding rice seedling growth. The maximum inhibition was achieved 1-3 days after the application of plant residues. At the 30th day, the inhibition disappeared, suggesting that residue decomposition in the soil has been finished. These results support that S. zeylanica has an allelopathic effect on paddy fields, which may cause a reduction in rice growth and yield.


2018 ◽  
Vol 10 (3) ◽  
pp. 881-885 ◽  
Author(s):  
Pravin Rawat ◽  
S S Narkhede ◽  
A D Rane ◽  
V M Mhaiske ◽  
V V Dalvi

The present study was conducted to assess allelopathic effect of Dendrocalamus stocksii (Munro.) on the growth and yield of ground nut (Arachis hypogaea). Bamboo leaf leachate was prepared by soaking the dry leaves in tap water for 24 hours in a ratio of 1:10 w/v.  Using prepared leachate as stock solution the leachate of various concentrations viz., control (0%), 25, 50 and 75 and 100 per cent were prepared by adding tap water accordingly. The results revealed the concentration-dependent significant (p=0.05) inhibitory effect of bamboo leaf leachates on the germination, radicle and plumule length of groundnut in laboratory condition. The leaf leachate of 100% concentration reduced down the germination percentage (56%), radicle length (3.00 cm) and plumule length (5.36 cm) as compared to control treatment where the germination percentage (86.66%), radicle length (5.02 cm) and plumule length (12.08 cm) were maximum. Similarly, the allelopathic effect of leaf leachate on transplanted seedlings of groundnut in prepared beds inside the poly house were significantly (p=0.05) inhibitory for the test seed weight and straw yield/ha. Minimum test seed weight (430.33 g) was recorded in the treatment of 25 % concentration as compared to control (601.33 g) and straw yield per hectare in the treatment of 100 % concentration (2421.1 kg/ha) as compared to control (4729.4 kg/ha). However, the non- significant effect of leaf leachate was observed on other yield parameters i.e., number of tillers per plant, number of pods / plant, test seed weight, seed yield per plant, number of seeds per pod and grain yield per ha. Finally, it is concluded that the harmful effect of leaf leachates of Dendrocalamus stocksii is more prominent in early stage of germination, emergence of radicle and plumule etc., rather than after transplanting; it is recommended to avoid the effect of these allelochemicals in early growth stage in field condition.


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.


2021 ◽  
Vol 27 (1) ◽  
pp. 1-12
Author(s):  
Bilal Ahmad Khan ◽  
Saima Anwar ◽  
Rizwan Maqbool Maqbool ◽  
Muhammad Mohsin Amin ◽  
Muhammad Mansoor Javaid ◽  
...  

ABSTRACT Aqueous extracts of plants are used to control weeds and having no hazards to environment and are inexpensive. Present study was undertaken to investigate the effect of aqueous extracts of Sonchus oleraceus L. on the Oryza punctata L. emergence and initial seedling growth. It consists of aqueous extract of leaves, stem and fruit of S. oleraceus at varying concentrations 0.25, 0.50, 1, 2, 4 and 8 % (w/v) along with a distilled water control. The allelochemicals present in the aqueous extracts showed stimulatory, inhibitory and hormetic responses depending upon the concentration and the plant part. Results directed that maximum mean emergence time (5.26 days) and minimum germination index (1.67), germination percentage (40%), seedling fresh weight (59 g) and dry weight (8 g) of O. punctata were examined with 8% aqueous extract of S. oleraceus fruit. However, 4% aqueous extract of S. oleraceus fruit produced minimum root length (5.71). On the basis this experiment it was concluded that 8% aqueous extract of S. oleraceus fruit can be used for controlling O. punctata weed. Keywords: Aqueous extract, environment, allelochamicals, hermetic response, stimulatory ABSTRACT Aqueous extracts of plants are used to control weeds and having no hazards to environment and are inexpensive. Present study was undertaken to investigate the effect of aqueous extracts of Sonchus oleraceus L. on the Oryza punctata L. emergence and initial seedling growth. It consists of aqueous extract of leaves, stem and fruit of S. oleraceus at varying concentrations 0.25, 0.50, 1, 2, 4 and 8 % (w/v) along with a distilled water control. The allelochemicals present in the aqueous extracts showed stimulatory, inhibitory and hormetic responses depending upon the concentration and the plant part. Results directed that maximum mean emergence time (5.26 days) and minimum germination index (1.67), germination percentage (40%), seedling fresh weight (59 g) and dry weight (8 g) of O. punctata were examined with 8% aqueous extract of S. oleraceus fruit. However, 4% aqueous extract of S. oleraceus fruit produced minimum root length (5.71). On the basis this experiment it was concluded that 8% aqueous extract of S. oleraceus fruit can be used for controlling O. punctata weed. Keywords: Aqueous extract, environment, allelochamicals, hermetic response, stimulatory ABSTRACT Aqueous extracts of plants are used to control weeds and having no hazards to environment and are inexpensive. Present study was undertaken to investigate the effect of aqueous extracts of Sonchus oleraceus L. on the Oryza punctata L. emergence and initial seedling growth. It consists of aqueous extract of leaves, stem and fruit of S. oleraceus at varying concentrations 0.25, 0.50, 1, 2, 4 and 8 % (w/v) along with a distilled water control. The allelochemicals present in the aqueous extracts showed stimulatory, inhibitory and hormetic responses depending upon the concentration and the plant part. Results directed that maximum mean emergence time (5.26 days) and minimum germination index (1.67), germination percentage (40%), seedling fresh weight (59 g) and dry weight (8 g) of O. punctata were examined with 8% aqueous extract of S. oleraceus fruit. However, 4% aqueous extract of S. oleraceus fruit produced minimum root length (5.71). On the basis this experiment it was concluded that 8% aqueous extract of S. oleraceus fruit can be used for controlling O. punctata weed. Keywords: Aqueous extract, environment, allelochamicals, hermetic response, stimulatory


2018 ◽  
Vol 111 (2) ◽  
pp. 293
Author(s):  
Seyed Nader MOUSAVIAN ◽  
Hamdollah ESKANDARI

<p>A laboratory factorial (2 × 5) experiment was carried out based on completely randomized block in four replications to evaluate the effect of plant species and concentration of their allelopathic extracts on seed germination and seedling growth of purslane weed (<em>Portulaca oleraceae</em> L.). The first factor studied was plant species (<em>Artemisia sieberi </em>and <em>Salvia syriaca</em>) and the second one the concentration percentage of plant ethanol extract (0.0, 5 %, 10 %, 15 % and 20 %). The effect of <em>Artemisia </em>on<em> </em>germination reduction of purslane<em> </em>was stronger compared to <em>Salvia.</em> The results indicated that higher extract concentration led to decreased germination percentage, germination speed and seedling growth indices of purslane including leaf length, leaf number, leaf width, leaf dry mass, stem mass and stem length. The effect of <em>Artemisia </em>was higher than that of <em>Salvia</em>. In a complementary experiment, the effect plant residues of <em>Artemisia </em>and <em>Salvia </em>(0.0, 1, 2, 3 and 4 g kg<sup>-1</sup> soil) were evaluated in a factorial experiment base on completely randomized block design with three replications. The results of field experiment showed that plant residues significantly (P ≤ 0.01) reduced capsule number per plant, seed number per capsule, seed production and shoot dry mass, while its effect on 1000-seed mass was not substantial. The effect of plant species and the interaction of plant species and their allelopathic extracts concentration had no major impact on the above-mentioned properties. The increase in plant residues in soil, led to the reduction of growth and seed production of purslane induced by plant number per unit area and capsule per plant. <em>Artemisia sieberi </em>Bess<em>. </em>and<em> Salvia syriaca </em>L.<em> </em>residues can be successfully used for non-chemical control of purslane weed.</p>


2005 ◽  
pp. 74-77
Author(s):  
István Dávid ◽  
László Radócz

Cockleburs are noxious weeds in Hungary, where they are widespread in row crops, especially in maize, sunflower and sugarbeet. A low density population of these weeds may be harmful because of their large competitive ability, fast growth in early phenological stages, allelopathy, and persistant sprouting.Allelopathy of Xanthium italicum Mor. was examined during the growing season in 2004. Root and shoot samples were collected at 4 or 5 leaves stage (in the end of May and in the beginning of June) and before flowering (in the beginning of July) before and after rain. Extracts were made in tap water. The test plant was Beta vulgaris L.; its germination, root and shoot growth were evaluated at the 6th and 10th days after treatment.Most of extracts inhibited the germination of sugar beet. In these experiments the phenological stage of the donor plant determined slightly the effectiveness of the extracts on sugar beet. Generally, significant differences existed between treatments only in cases of concentrated extracts.Rainfall can modify the inhibitory effect of extracts (especially shoot extracts). Shoot extracts of young plants inhibited stronger germination and growth after rain than before rain. Density of cockleburs influenced the effect of extracts, as well. Generally, differences between the efficacy of extracts was larger after rain.The results supported the hypothesis that the phenological stage and some environmental factors can modify allelopathy of cockleburs.


2018 ◽  
Vol 69 ◽  
pp. 1-11 ◽  
Author(s):  
Nuurismaan Hassan ◽  
Md. Kamrul Hasan ◽  
Md. Obaidullah Shaddam ◽  
Mohammad Sohidul Islam ◽  
Celaleddin Barutçular ◽  
...  

A pot experiment was carried out at the Laboratory of Department of Agronomy, Hajee Mohamad Danesh Science and Technology University (HSTU), Bangladesh during 2016 to evaluate the response of maize varieties at germination and seedling growth stages under salt stress. The seeds of the BARI (Bangladesh Agricultural Research Institute) developed four maize varietiesviz.Barnali, Khoi Vutta, Mohor and BARI Maize 5 were placed in plastic pots (each of 25 cm length and 12 cm width) on sand bed irrigated with tap water (control), 100 and 200 mM NaCl salt solutions. It was replicated in thrice with completely randomized design (CRD). Salinity stress significantly affected the germination characters and seedling growth parameters of maize varieties. The germination percentages (GP) and germination rate (GR) reduced significantly with increasing salinity, and the variety Khoi Vutta showed the highest GP and GR followed by Barnali and Mohor showed the lowest GP and GR followed by BARI maize 5. Under high salinity level, seedling growths characteristics like shoot and root lengths, fresh and dry weight of shoot and roots reduced remarkably in the variety Mohor indicating salt susceptible while the minimum reduction of the aforementioned traits was observed in the variety Khoi Vutta demonstrating high salt tolerant variety. The studied varieties can be ranked on the basis of salt tolerance as Khoi Vutta > Barnali > BARI Maize 5 > Mohor from the experiment.


2016 ◽  
Vol 34 (4) ◽  
pp. 639-648 ◽  
Author(s):  
A.P.P. OLIVEIRA ◽  
S.R. PEREIRA ◽  
A.C.S. CÂNDIDO ◽  
V.A. LAURA ◽  
M.T.L.P. PERES

ABSTRACT Tree establishment in pasture areas can be inhibited, at least in part, by exotic grasses allelopathy and this can represent an important limitation by changing the patterns of both germination and seedling growth of tree species. This study aims to evaluate the allelopathic potential of Urochloa brizantha and U. decumbens on germination, growth and metabolism of Guazuma ulmifolia seedlings. We performed bioassays evaluating the effect of the crude ethanol extract and semipurified fractions (hexane fraction, ethyl acetate fraction and ethanol-water fraction) of U. brizantha and U. decumbens using completely randomized design, with four concentrations (0, 250, 500, 1,000 mg L-1) and four replications. The variables analyzed were germination percentage, mean germination time, shoot and root growth, catalase and peroxidase activity, chlorophyll content and root respiration. The results showed that both grasses have an inhibitory effect on G. ulmifolia metabolism, affecting both germination and seedlings growth and inducting metabolic defense. Thus, these results show that the grass species evaluated have the potential to restrict the re-introduction of G. ulmifolia in pasture areas due to interference competition.


Author(s):  
Amit Kumar Tiwari ◽  
Prawal P.S. Verma ◽  
Dipender Kumar ◽  
Sonveer Singh ◽  
Rakesh Kumar ◽  
...  

Background: Sarpagandha is an indigenous medicinal herb of Indian continent. It has many medicinal properties. Due to increasing demand of Sarpagandha, its exploitation is increasing continuously but for lack of cultivation, this plant has been listed in endangered category. Commercially, it is propagated through seeds but the main barrier of seed propagation is its irregular and low germination. Hence, the current study was undertaken to study the effect of growing media and seed treatment methods on seed germination and seedling growth of Sarpagandha to eliminate the inhibitory effect of the hard stony endocarp.Methods: Seed germination and seedling growth experiments of Sarpagandha were carried out with following different seed treatments, T1 (Control), T2 (Water soaking for 24 hours), T3 (water soaking for 48 hours), T4 (Water soaking for 24 hours + cotton cloth wrapping for 24 hours), T5 (GA3 200 ppm), T6 (FYM treatment for 24 hours), T7 (FYM treatment for 48 hours), T8 (Hot water treatment) and T9 (Cow dung treatment for 24 hours). Experiment was laid out in CRD. The data recorded on the various parameters were analyzed at 5% level of significance by using ANOVA.Result: Results indicated highest germination percentage (51), lowest mortality percent (49), minimum days for initiation of germination (23), minimum days taken for germination completion (33), highest speed of germination (3.77), maximum vigour index (1441.44), highest root (11.27 cm) and highest shoot length (17 cm) in T5 (GA3 200 ppm) followed by T3 (water soaking for 48 hours). Indicating, T5 (GA3 200 ppm) to be best seed treatment for higher germination and subsequent seedling growth of Sarpagandha (Rauvolfia serpentine L.).


Author(s):  
Nadia A. Hamed ◽  
M. Salah ◽  
M. F. Ahmed ◽  
Tahsin Shoala

Aims: The objective of this study is evaluate the effects of both pre-sowing gamma irradiation at low dose of 0 or 20 Gy and the soaking part of radiated seeds in zinc nanoparticles (Zn NPs) solutions at rate 0, 500, 1000 and 2000 ppm on behavior and physiological changes of sour orange seedling. Study Design: The design of the study is Two-Way Randomized Blocks. Place and Duration of Study: The present study was carried out during two successive seasons of 2016-2017 and 2017-2018 on sour orange rootstock (Citrus aurantium) grown at the experimental farm of the  Horticulture Institute, Giza , Egypt. Methodology: Eight different treatments were used as follow: 1) Control, 2) Gamma radiation at 0 Gy + soaking in Zn NPs at 500 ppm. 3) Gamma radiation at 0 Gy + soaking in Zn NPs at 1000 ppm. 4) Gamma radiation at 0 Gy + soaking in Zn NPs at 2000 ppm. 5) Gamma radiation at 20 Gy + soaking in tap water Zn NPs at 0 ppm. 6) Gamma radiation at 20 Gy + soaking in Zn NPs at 500 ppm. 7) Gamma radiation at 20 Gy + soaking in Zn NPs at 1000 ppm. 8) Gamma radiation at 20 Gy + soaking in Zn NPs at 2000 ppm. Results: Transmission electron microscope (TEM) images showed multiple shapes and uniform distribution of Zn NPs through the polymer network and the mean size of Zn NPs ranging is 40.9 nm. Generally, the results reveal that, 20 Gy combined with 1000ppm Zn NPs treatment increased seed germination percentage and stem length. While, 20 Gy plus 500 ppm Zn NPs treatment increased stem diameter and plant pigments concentration. Protein analysis of sour orange seedling treated with gamma radiation and then Zn NPs showed that, protein groups pattern (10-20 KD) enhanced with gamma rays 20 gray alone or with Zn NPs at 500 or 1000 ppm, while the protein groups pattern above 60 KD disappeared. Conclusion: Using gamma irradiation and then soaking part of irradiated seeds in Zn NPs solutions had significant effects on vegetative growth and root characters as well as some chemical properties of sour orange leaves. In addition, there are variable differences in the protein pattern between treated and untreated sour orange seedlings with gamma radiation and / or Zn NPs. Although, 20 Gy + 500 ppm Zn NPs treatment increased stem diameter, which is the main characteristic for the success of grafting process, the obtained results showed changes in proteins and it possible the gene structure had been changed due to this treatment.


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