scholarly journals Allelopathy of Dahlstedtia araripensis on Calotropis procera and Zea mays

2019 ◽  
Vol 11 (14) ◽  
pp. 32
Author(s):  
Viviane Bezerra da Silva ◽  
José Weverton Almeida Bezerra ◽  
Mariana Ferreira da Cruz ◽  
Cícero dos Santos Leandro ◽  
José Fábio de Oliveira Sousa ◽  
...  
Keyword(s):  
Zea Mays ◽  
Experimental Design ◽  
Secondary Metabolites ◽  
Stem Bark ◽  
Calotropis Procera ◽  
Control Group ◽  
Distilled Water ◽  
Allelopathic Activity ◽  
Root Necrosis ◽  
Germination And Growth

Studies related to the allelopathic properties of plants have aroused great interest, since species that have compounds with allelopathic activity can be used as bioherbicides in the control of weeds. In this way, the aim of this study was to evaluate the allelopathic action of Dahlstedtia araripensis on the germination and growth of Calotropis procera and Zea mays. The bioassays were prepared using two 50 g portions of leaves, stem bark and D. araripensis roots, and each part of the plant received a hot treatment (1 L of distilled water at 100 °C) and one part cold (1 L of distilled water at 25 °C). The experimental design consisted of six treatments and the control group. The variables analyzed were: Index of Emergency Speed (IES), germinability, length and occurrence of necrotic radicles. The results indicated that the extracts interfered negatively on the germinability of the seeds, mainly on those of C. procera, since all extracts significantly inhibited its germination. In the seeds of C. procera and Z. mays there was delay in IES. The results indicated that the cold and hot extracts of the distinct parts of D. araripensis affected the development of the seedlings, besides promoting root necrosis. The observed effects may be due to the presence of secondary metabolites detected in the different extracts of D. araripensis. However, further research is required to prove the performance of such compounds, as well as their isolation, for future use asnatural herbicides.

scholarly journals Allelopathic effects of Androstachys johnsonii Prain on germination and growth of Zea mays L. and Vigna subterranea (L.) Verdc.

2022 ◽  
Vol 27 ◽  
pp. 945-958
Author(s):  
Mokgaetji Georginah Mokganya ◽  
Hadzhi Maanda Ligavha-Mbelengwa
Keyword(s):  
Zea Mays ◽  
Rural Communities ◽  
Zea Mays L ◽  
Germination Rate ◽  
Stem Bark ◽  
Vigna Subterranea ◽  
Allelopathic Effects ◽  
Germination And Growth ◽  
Androstachys Johnsonii Prain ◽  
Traditional Crops

Allelopathic effects of the donor plants are mostly regarded as harmful to target plants such as traditional crops. Traditional crops play pivotal role as staple food for rural communities and hence ensuring food security. Study of the allelopathic effects of Androstachys johnsonii Prain on the germination and growth of Zea mays L. and Vigna subterranea (L.) Verdc was conducted. Different plant leachates concentrations of 0.675%, 1.25%, 2.5% and 5% were prepared through serial dilutions. Germination bioassays were arranged in a complete randomized setup of three replicates for each treatment for seven days. Germination rates were calculated, radicle and hypocotyl lengths were also measured. Germination rates of Z. mays L. and V. subterranea (L.) Verdc. ranged from 50 - 100% and 18 - 76%, respectively. Significant differences of P< 0.005 were noticed from the germination rates of V. subterranea (L.) Verdc subjected to high concentrations of different extracts used. Statistically there was no significant differences between germination rates of Z. mays L. treated with all concentrations of leaf leachates against germination rates of the seeds treated with distilled water. Outstandingly, the germination rate and early growth of Z. mays L. were promoted by less concentrated extracts of leaf, root, stem bark and soil which then suggest future use of allelochemicals from Androstachys johnsonii Prain for promotion of maize plant productions. Based on the beneficial attributes of allelochemicals from Androstachys johnsonii on the germination and growth of Z. mays L., planting of Androstachys johnsonii Prain in maize fields is highly recommended.

scholarly journals Pengaruh Antibakteri Ekstrak Kulit Batang Matoa (Pometia pinnata) terhadap Bakteri Staphylococcus aureus secara In vitro

Jurnal MIPA ◽  
2013 ◽  
Vol 2 (2) ◽  
pp. 128 ◽  
Author(s):  
Mercy Ngajow ◽  
Jemmy Abidjulu ◽  
Vanda S. Kamu
Keyword(s):  
Staphylococcus Aureus ◽  
Secondary Metabolites ◽  
Antibacterial Effect ◽  
Inhibition Zone ◽  
Stem Bark ◽  
Positive Control ◽  
Negative Control ◽  
Bark Extract ◽  
Distilled Water

Telah dilakukan penelitian secara kualitatif terhadap pengaruh antibakteri dari ekstrak kulit batang matoa (Pometia pinnata. Spp.) terhadap bakteri Gram positif Staphylococcus aureus . Sebelum dilakukan uji antibakteri, sampel yang telah diekstrak secara maserasi diuji fitokimia terlebih dahulu untuk menentukan kandungan metabolit sekunder yang telah diketahui berperan sebagai agen antibakteri. Setelah dilakukan uji fitokimia, ekstrak diuji aktivitas antibakterinya terhadap bakteri Staphylococcus aureus dengan menggunakan teknik difusi agar dengan cara sumuran. Ekstrak dilarutkan pada aquades steril dengan perbandingan 2 g ekstrak pada 2 mL air. Untuk kontrol positif, digunakan ciprofloxacin dan aquades steril sebagai kontrol negatif. Hasil penelitian ini menunjukkan bahwa ekstrak kulit batang matoa memiliki aktivitas antibakteri setelah diinkubasi selama 24 jam pada 37 OC. Dari 3 kali pengulangan dengan masing – masing 3 sumuran, didapat zona hambat masing – masing 16.84 mm, 12.5 mm dan 14.5 mm dengan kontrol positif 29.67 mm serta kontrol negatif 0 mm. Hasil yang diperoleh didukung oleh keberadaan metabolit sekunder hasil uji fitokimia yaitu tanin, flavonoid, terpenoid dan saponin.A qualitative study has done  of the antibacterial effect of matoa (Pometia pinnata) stem bark extract against Gram-positive bacteria Staphylococcus aureus . Before the antibacterial test , samples were extracted by maceration and then  phytochemical  tested to measuring the content of secondary metabolites  that have been known to act as an antibacterial agent . After being tested of phytochemical , extracts were tested the antibacterial effect  against Staphylococcus aureus using agar diffusion technique. Extract was dissolved in sterile distilled water with a ratio of 2 g of extract in 2 mL of water . For the positive control , use of ciprofloxacin and sterile distilled water as a negative control . Results of this study indicate that matoa bark extract has antibacterial effect after incubation for 24 h at 37OC . Of 3 times with each repetition - each 3 wells, the inhibition zone obtained - each 16.84 mm , 12.5 mm and 14.5 mm with 29.67 mm of positive control and a negative control by 0 mm . The results are supported by the presence of secondary metabolites by phytochemical test such as tannins , flavonoids , terpenoids and saponins.

scholarly journals Acute and Subacute Toxicological Study of the Aqueous Extract of the Stem Bark of Khaya Grandifoliola (Meliaceae) in Wistar Rats

2020 ◽  
Vol 5 (1) ◽  
pp. 106-111
Author(s):  
Désirée Sandrine Essama Mbida ◽  
Gustave Lebeau Ndji Otto ◽  
George Enow-Orock Enonchong ◽  
Perfusion Amang ◽  
Paul Vernyuy Tan
Keyword(s):  
Wistar Rats ◽  
Water Extract ◽  
Stem Bark ◽  
Control Group ◽  
Distilled Water ◽  
Oral Gavage ◽  
Toxicity Assay ◽  
Toxicological Study ◽  
High Doses ◽  
Hematological And Biochemical Parameters

This study was carried out to investigate the possible toxic effects of the water extract from Khaya grandifoliola stem bark in Wistar rats. The acute assay used 9 females distributed into 3 groups of 3 rats each. A control group received distilled water and the two test groups received by oral gavage a unique dose of the extract at 2000 mg/kg. In subacute assay, 60 rats both sexes were distributed into 6 groups of 10 rats each (5 males and 5 females) and received the extract by oral gavage for 28 days consecutively. The tests groups received extract at 250, 500 and 1000 mg/kg. The controls and satellite test groups received respectively distilled water and extract at the dose of 1000 mg/kg. Some anthropometrical, hematological and biochemical parameters were measured and histological sections of some organs were realized. LD50 was superior at 2000 mg/kg in acute assay. In subacute toxicity assay, Khaya grandifoliola stimulated the haematopoetic and immune function, showed a significant decrease of alanine transaminase, aspartate transaminase and hypocholesterolaemic effects. Histopathology showed the presence of disturbances at the dose of 1000 mg/kg especially. K. grandifoliola stem bark could possess moderate toxicity at high doses and adequate caution should be exercised in its use in ethnomedicine.

scholarly journals Cordia oncocalyx (Allemão) Baill. (Boraginaceae) Chemical Composition and Alelopathic Effect Against Weeds

2018 ◽  
Vol 10 (12) ◽  
pp. 262
Author(s):  
Danúbio Lopes da Silva ◽  
Marcos Aurélio Figueiredo dos Santos ◽  
Jose Weverton Almeida Bezerra ◽  
Cícero dos Santos Leandro ◽  
Maria Daniele Pereira Rodrigues ◽  
...  
Keyword(s):  
Chemical Compounds ◽  
Bark Extract ◽  
Calotropis Procera ◽  
Control Group ◽  
Allelopathic Effect ◽  
Distilled Water ◽  
Weed Species ◽  
Donor Plant ◽  
Allelopathic Potential ◽  
Cold Infusion

Through secondary metabolism, plants produce chemical compounds which when released into the environment can have effects on other species, such effect is called allelopathy. In this research we evaluated the Cordia oncocalyx (Boraginaceae) allelopathic potential against two weed species, Cenchrus echinatus and Calotropis procera, as well as quantified its phenolic compounds using HPLC-DAD. The experimental design was completely randomized with six treatments and one control group (distilled water). Each treatment consisted of four replicates with 25 seeds each, totaling 100 seeds per treatment. The variables analyzed were: germinating potential, germination velocity and seedling development. The hot and cold infusion extracts were prepared with 50 g of each of the three parts of the donor plant (bark, leaves and roots) immersed in 500 ml of distilled water at 100 &deg;C (hot infusion) and 25 &deg;C (cold infusion). The experiments were mounted in Petri dishes having substrate filter paper embedded in 3 mL of the extracts (treatments) and conducted in a germination chamber. Hot and cold infusion extracts of the C. oncocalyx leaves, barks and roots presented allelopathic activity on C. echinatus and C. procera germination and development, with the hot bark extract promoting such effect with a greater intensity. The allelopathic effect observed may be due to the presence of allelochemicals such as caffeic acid, quercentin and kaempferol present in C. oncocalyx leaves, barks and roots.

scholarly journals Phenolic Composition and Allelopathy of Libidibia ferrea Mart. ex Tul. in Weeds

2019 ◽  
Vol 11 (2) ◽  
pp. 109 ◽  
Author(s):  
Cícero dos Santos Leandro ◽  
José Weverton Almeida Bezerra ◽  
Maria Daniele Pereira Rodrigues ◽  
Ana Karolina Fernandes Silva ◽  
Danúbio Lopes da Silva ◽  
...  
Keyword(s):  
High Performance ◽  
Seedling Development ◽  
Bark Extract ◽  
Calotropis Procera ◽  
Control Group ◽  
Phenolic Composition ◽  
Weed Species ◽  
Allelopathic Potential ◽  
Root Extracts ◽  
Allelopathic Activity

Considering the need to produce effective bioherbicides to control weeds and thus reduce the contamination of environments through the use of agrochemicals in control of these plants, the scientific community has been studying the allelopathic activity of several species of Caatinga, once studies indicate that some species of this biome presentind to have activity allelopathic about other plants. On this, the present study aimed to evaluate the allelopathic potential and phenolic composition of extracts of Libidibia ferrea Mart. ex Tul. on seed germination and seedling development of Calotropis procera (Aiton) WT Aiton. and Cenchrus echinatus L. For the allelopathy test, leaf, bark and root extracts, both hot (100 &deg;C) and cold (25 &deg;C), were used, followed by a control group (distilled H2O). Phytochemical prospecting was performed by High Performance Liquid Chromatography (HPLC). The results showed that the hot L. ferrea bark extract has allelopathic activity on C. procera and C. echinatus, which was observed in all parameters analyzed. The phytochemical results showed that L. ferrea extracts present several phenolic compounds which are possibly responsible for the results observed against the two weed species studied, with standing out Gallic acid, Catechin, Caffeic acid, Ellagic acid, and Quercetin. It is therefore necessary to isolate these compounds in view of a potential future use for L. ferrea extracts in the production of a bioherbicide.

scholarly journals Influence of Phenology and Post-Harvest Processing of Vegetal Material on the Allelopathy of Annoni Grass (Eragrostis plana) Extracts

2019 ◽  
Vol 37 ◽  
Author(s):  
S.M. SCHEFFER-BASSO ◽  
F. Jr. R. FIORENTIN ◽  
A. FAVARETTO
Keyword(s):  
White Clover ◽  
Plant Material ◽  
Allelopathic Effect ◽  
Distilled Water ◽  
Aqueous Extracts ◽  
Phenological Stage ◽  
Post Harvest ◽  
Allelopathic Activity ◽  
Germination And Growth ◽  
Growth Of Seedlings

ABSTRACT: The phenological stage, post-harvest processing and quantity of material can interfere in the allelopathic activity of extracts. The objective of this study is to test the allelopathic effect of aqueous extracts of the leaves of Annoni grass (Eragrostis plana), an invader of natural pastures. Twelve extracts were prepared by combining the phenological stage of the plants when harvesting the leaves (vegetative; flowering), post-harvest processing before extraction (fresh; dry at 40 oC), and the amount of plant material (5, 15, and 25 g 100 mL-1 distilled water). Two bioassays were conducted in a germination chamber, with evaluation of germination and growth of seedlings of lettuce (Lactuca sativa) and white clover (Trifolium repens). The extracts with higher allelopathic activity were further developed with 15 and 25 g of dried leaves and harvested in plants at the vegetative stage. Germination was attributed to being the greatest contribution to the divergence between the extracts. White clover was more sensitive to extracts, for which 50% to 67% of the extracts were effectively allelopathic (≥50% inhibition); in lettuce, between 8% and 58% of the extracts exhibited this potential. The phenological stage was the factor with a greater individual effect on the allelopathic activity on lettuce and white clover seedlings, and on lettuce germination. The post-harvest processing responded by the greater variation on germination and germination speed index of white clover. The sensitivity of the white clover to extracts of Annoni grass suggests a compromise of its establishment in pastures with the presence of the invader.

A Pilot Study on the Efficacy of Volunteer Mentorship for Young Adults With Self-Harm Behaviors Using a Quasi-Experimental Design

Crisis ◽  
2016 ◽  
Vol 37 (6) ◽  
pp. 415-426 ◽  
Author(s):  
Yik-Wa Law ◽  
Paul S. F. Yip ◽  
Carmen C. S. Lai ◽  
Chi Leung Kwok ◽  
Paul W. C. Wong ◽  
...  
Keyword(s):  
Experimental Design ◽  
Suicide Ideation ◽  
Intervention Group ◽  
Well Being ◽  
Control Group ◽  
Treatment As Usual ◽  
Prevention Services ◽  
Quasi Experimental ◽  
Self Harm ◽  
Volunteer Support

Abstract. Background: Studies have shown that postdischarge care for self-harm patients is effective in reducing repeated suicidal behaviors. Little is known about whether volunteer support can help reduce self-harm repetition and improve psychosocial well-being. Aim: This study investigated the efficacy of volunteer support in preventing repetition of self-harm. Method: This study used a quasi-experimental design by assigning self-harm patients admitted to the emergency departments to an intervention group with volunteer support and treatment as usual (TAU) for 9 months and to a control group of TAU. Outcome measures include repetition of self-harm, suicidal ideation, hopelessness, and level of depressive and anxiety symptoms. Results: A total of 74 cases were recruited (38 participants; 36 controls). There were no significant differences in age, gender, and clinical condition between the two groups at the baseline. The intervention group showed significant improvements in hopelessness and depressive symptoms. However, the number of cases of suicide ideation and of repetition of self-harm episodes was similar for both groups at the postintervention period. Conclusion: Postdischarge care provided by volunteers showed significant improvement in hopelessness and depression. Volunteers have been commonly involved in suicide prevention services. Further research using rigorous methods is recommended for improving service quality in the long term.

PROGRAM BIMBINGAN UNTUK MENINGKATKAN MOTIVASI BELAJAR SISWA

2017 ◽  
Vol 17 (1) ◽  
pp. 55
Author(s):  
Ismaniar Ismaniar Ismaniar
Keyword(s):  
Experimental Design ◽  
Quantitative Research ◽  
Sampling Technique ◽  
Learning Motivation ◽  
Control Group ◽  
Research Approach ◽  
Purposive Sampling ◽  
Guidance Program ◽  
Quasi Experimental ◽  
11Th Grade

The present study is aimed at developing effective guidance program for increasing student’s learning motivation. The present study applies quantitative research approach with nonequivalent pre-posttest control group quasi-experimental design, and nonrandom-purposive sampling technique. The data were collected using inventory, interview, and documentary study. The study comes up with the main finding that the tested guidance program is proven to be effective for increasing learning motivation students of 11th grade at SMA Kartika XIX-2 Bandung.

The Effect of Applying POSSE (Predict- Organize-Search-Summarize-Evaluate) on the Students’ Reading Comprehension

2013 ◽  
Vol 2 (1) ◽  
Author(s):  
Eka Rejeki Maha ◽  
Berlin Sibarani
Keyword(s):  
Reading Comprehension ◽  
Experimental Design ◽  
Null Hypothesis ◽  
Alternative Hypothesis ◽  
Choice Test ◽  
Control Group ◽  
Multiple Choice Test ◽  
Level Of Significance ◽  
And Control ◽  
Experimental Group

This study was aimed at finding out The Effect of Applying POSSE (Predict-Organize-Search-Summarize-Evaluate) Strategy on the Students’ Reading Comprehension. This study used the experimental design. The population of this study was the students of SMA Negeri 2 Medan. There were sixty students taken as the sample of the research. This study was conducted with two randomized groups namely experimental and control group. The experimental group was taught by applying POSSE strategy while control group was taught without applying POSSE strategy. The instrument of collecting the data was multiple choice test which consists of 40 items. To obtain the reliability of the test, the researcher used Kuder-Richardson (KR-21). The calculation shows the reliability was 0.81(high). The data were analyzed by using t-test. The calculation shows that t-observed (4.76) is higher than t-table (2.00) at the level of significance (α) 0.05 with the degree of freedom (df) 58. Therefore, the null hypothesis (Ho) is rejected and alternative hypothesis (Ha) is accepted. It means that there was a significant effect of applying POSSE strategy on the students’ reading comprehension. Keywords: POSSE Strategy, Reading Comprehension.

THE EFFECT OF RAP (READ, ASK, PARAPHRASE) STRATEGY ON STUDENTS’ READING COMPREHENSION IN READING ANALYTICAL EXPOSITION TEXT

2015 ◽  
Vol 4 (3) ◽  
Author(s):  
Veronika N. And Lince Sihombing
Keyword(s):  
Reading Comprehension ◽  
Experimental Design ◽  
T Test ◽  
Control Group ◽  
Multiple Choice Tests ◽  
Choice Tests ◽  
Second Year ◽  
Level Of Significance ◽  
And Control ◽  
Experimental Group

This study focused on finding out the effect of applying RAP (Read, Ask,Paraphrase) Strategy on students’ reading comprehension in reading analyticalexposition text. This study was conducted in experimental design. The populationof this research was the second year of students in SMA Swasta Katolik BudiMurni 2 Medan. There were seventy students of the second year senior highschool students as the sample of the research. This study was conducted with tworandomized groups namely Experimental Group and Control Group. Theexperimental group was taught by applying RAP Strategy, while the control groupwas taught by applying conventional strategy. The instrument of collecting thedata was multiple choice tests which consisted of 25 items. The data wereanalyzed by using t-test formula. The calculation shown that t-observed (5.36)was higher than t-table (1.994) at the level of significance (α) 0.05 with the degreeof freedom (df) 68. It means that there was a significant effect of applying RAPStrategy on students’ reading comprehension in reading analytical exposition text.

Sign in / Sign up

Export Citation Format

Share Document