Allelopathic Effects of Introduced Eucalyptus Gomphocephala Extracts on Germination and Seedling Growth of Native Ceratonia siliqua in Libya

2021 ◽  
pp. 117-124
Author(s):  
Mariam F. EL-Barghathi ◽  
Ali M. Elbakkosh ◽  
Nagma F. Ammosh

The present study aimed to investigate the allelopathic effects of leaf aqueous extracts of introduced Eucalyptus gomphocephala L. (donor species) were collected during different growing seasons at different concentrations (0, 25, 50, 75, and 100% v/v) on germination percentage, average germination time, plumule and radical length, dry weight of radical and plumule and seedling vigor index (SVI) of native Ceratonia siliqua L. (recipient species) seedlings under laboratory conditions. Results suggested that the germination percentage and all growth parameters of C. siliqua were significantly reduced gradually with the increase of aqueous extract concentration levels and the reduction was varied and could be extract concentration and growing season dependent. The highest phytotoxic effect on germination and seedling growth was exhibited by E. gomphocephala aqueous extract at 100% concentration, followed by 50% concentration. Generally, it is concluded that the allelopathic effect of introduced E. gomphoracephala trees on native Ceratonia siliqua trees has been weak or no effectiveness in some cases under laboratory conditions. Keywords: Eucalyptus gomphocephala; Introduced species; Libya; Allelopathy; Ceratonia siliqua

2021 ◽  
Vol 10 (2) ◽  
pp. 191-195
Author(s):  
Hana A. Al-Quhbi ◽  
Amna A.I. Saeed ◽  
Abdul Nasser Al-Gifri

Allelopathic effect of Aqueous decomposed leaf litter from four common trees and shrubs in Aden governorate, Yemen was investigated on the germination and early seedling growth of Cowpea, the test crop was subjected to four concentrations of 25, 50, 75 and 100% of the aqueous extract, while a control was maintained at 0% extract level. The study carried out in the laboratory of Botany at Faculty of Education, University of Aden. The Percentage of germination, Germination rate per plate, radicle length, plumule, (hypo and epicotyl lengths) observed. Data was recorded at 24 hours interval after germination for 15 days, the research revealed delayed germination rate per plate and a significant reduction in the radicle length and germination percentage (data was collected on percentage germination; plant height. Results obtained showed that significant reduction in the growth parameters considered at 100% and 75%, while at 50% and 25% the difference was not significant. From the result obtained, it can concluded that Conocarpus lancefolius and Thevetia peruviana possess allelopathic effect that inhibit the germination and early seedling growth of Cowpea, hence at 100% concentration.


2017 ◽  
Vol 23 (2) ◽  
Author(s):  
G. S. THAKUR

In this study the allelopathic effects of Parthenium hysterophorus on seed germination and seedling growth in Cajanus cajan (Pigeon pea) was investigated. The dried powdered leaves of Parthenium hysterophorus were soaked in distilled water for 24 hours to obtain aqueous extract of leaves and sterilized seeds were treated with 2%, 4%, 6%,8%, and 10% concentration of extract in triplicate. The germinated seeds were counted every day to observe germination index (G.I.) and mean germination time (MGT). It has been found that germination index (GI) were significantly decreased and MGT were delayed to germinate with increasing concentration. It has been observed that seed germination percentage, root length, shoot length and seedling vigor index were reduced at >2% as compared to control. The 10 % aqueous extract showed completely inhibitory effect on seed germination. The present investigation showed that the leaves aqueous extract of Parthenium hysterophorus had inhibiting effects on seed germination and seedling growth in Cajanus cajan (Pigeon pea).


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


Author(s):  
Gamze Kaya

The study aimed to evaluate the use of germination indices as a screening tool for salinity tolerance during germination and early seedling growth of pepper cultivars, and to distinguish the potential for genetic responses to salt tolerance. In the study, the seeds of seven pepper cultivars were germinated at increasing NaCl levels of 5, 10, 15 and 20 dS/m and distilled water as the control treatment for 14 days. Germination percentage (GP), mean germination time (MGT), germination index (GI), germination stress tolerance index (GSTI), seedling length (SL), seedling fresh weight (SFW) and vigor index (VI) were investigated. Results showed that germination percentage decreased with increasing NaCl levels while the highest germination percentage at 20 dS/m was 92% in BT Burdem with no significant reduction. Seedling growth of pepper cultivars was severely inhibited by increasing salinity stress. SFW was depressed depending on reduction in SL due to increasing NaCl. BT-Burli and BT İnce Sivri were the most tolerant cultivars to NaCl and they were used for genetic resources towards salinity. Seedling growth was much more sensitive to salinity than germination because of the highest percent reduction in seedling growth parameters. Among the parameters, GSTI gave the highest significant correlation coefficient with SL and SFW; indicating that it would be useful for estimating seedling growth. It was concluded that genotypic variation was observed among pepper cultivars for salinity tolerance and GSTI could be used for a predictor for salinity tolerance.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Eric B. Kouam ◽  
Simon M. Ndo ◽  
Marie S. Mandou ◽  
Asafor H. Chotangui ◽  
Christopher M. Tankou

AbstractThis study was carried out to determine effects of salinity on germination and seedling development of commercially important common bean genotypes in Cameroon. The seeds of eight genotypes were used for both trials. The germination experiments were carried out on petri dishes in the laboratory while early growth trials continued in plastic pots in the screenhouse. Both stages were setup using a randomized complete block design with three replications. Germination and early growth trials of the different genotypes were studied using distilled water as control or osmotic potentials of 50, 100, 150 and 200mM NaCl to study the effects of salinity on germination and seedling growth characteristics. Leaf concentrations of Na+ and K+ were determined. At the germination level, germination percentage, germination index and the coefficient of velocity of germination decreased with increasing salinity while the mean germination time and time to 50% germination increased with increasing level of salt. All the growth variables decreased with increasing salinity with the exception of the root length which was not affected by salinity. It was observed that increasing salinity induced a significant increase in leaf Na+ and substantial reduction in the accumulation of K+ in the leaves. For ions accumulation, germination variables and growth parameters, significant differences at 0.001 probability levels were found among salinity treatments, common bean genotypes and most of their interactions. Significant correlations were found between all germination variables and between most growth parameters. From the effect of salt application, the common bean genotypes namely KEBCB049, KEB-CB053 and Mac-33 were the most tolerant while KEB-CB055 and KEB-CB050 were the most sensitive. The results confirm that there is genotypic variation in salinity tolerance and that the most tolerant genotypes should be further explored in selection programs, with the aim that they should be promoted for cultivation in tropical zones affected by salinity.


Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 757-761 ◽  
Author(s):  
Nagi Reddy Achhireddy ◽  
Megh Singh

Allelopathic effects of lantana (Lantana camaraL. ♯3LANCA) residues (root, shoot), foliar leachates, and the soil (where lantana was grown) on milkweedvine (Morrenia odorataLindl. ♯3MONOD) seed germination and growth over a 30-day period were examined. Foliar leachates or the soil collected from the field where lantana had been growing had no effect on the final germination percentage or the seedling growth of milkweedvine. Incorporation of dried lantana shoot or root material into soil had no effect on the final percentage germination but caused significant reductions in milkweedvine growth over a 30-day test period. Roots were more inhibitory than shoots. Fifty percent of milkweedvine seedlings died within 15 days after germination at 1% (w/w) dried lantana root incorporation into the soil, and higher concentrations increased seedling death. Lantana roots incorporated into the soil produced foliar symptoms such as wilting and desiccation, whereas lantana shoots incorporated into the soil produced yellowing of the foliage of milkweedvine. Allelopathic activity of lantana residues was still strong even after decomposition of lantana residues for 4 weeks prior to the planting of milkweedvine seeds.


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.


2021 ◽  
Vol 27 (3) ◽  
pp. 321-330
Author(s):  
Bilal Ahmad Khan

Abstract Crop plants release biochemicals into surrounding environment that help in obtaining maximum yield of crop by acting bioherbicide at high concentration and plant growth hormone at low concentration. Therefore, this study was planned at Department of Agronomy in Weed Science Laboratory, University of Agriculture Faisalabad during Winter 2018 to evaluate the hermetic effects of Althaea officinalis L. (khatami) on vegetable crop Radish (Raphanus sativus) The experiments were laid out under completely randomized design (CRD) having three replications. The aqueous extracts of A. officinalis L. were used on radish different concentrations (2.5%, 5%, 10%, 20%, 40% and 80%). Data regarding seed germination and seedling growth (shoot length, root length, shoot fresh weight, root dry weigh) of radish were recorded using standard procedures. Results Reveals that the aqueous extract of A. officinalis at higher concentration (80%) act as bioherbicide and produced inhibitory effects on R. sativus result in Maximum time to 50% germination (4.68 days) and mean germination time (9.05 days) while minimum germination index (3.60), germination percentage (85.00%), shoot length (42.4 cm), root length (25.90 cm), shoot fresh weight (53.30 g) and root fresh weight (13.30 g). While at lower concentration (10%) it shows hermetic effect and produce maximum germination percentage (100.00%), shoot length (58.2 cm), root length (52.0 cm), shoot fresh weight (90.00g), root fresh weight (26.30 g) minimum time to complete 50% germination (3.36 days), germination index (6.00%) and mean germination time (5.73 days) growth. In A. officinalis among different phenolic compound minimum Syringic acid (0.60%) and maximum Quercetion (12.3%) compound was found. Therefore, it was concluded from this study that aqueous extract of officinalis can be used as growth promoter at lower concentration while at higher concentration for environmentally friendly control of weeds.


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