Phytotoxic Activity ofOcimum tenuiflorumExtracts on Germination and Seedling Growth of Different Plant Species

Phytotoxic activity ofOcimum tenuiflorum(Lamiaceae) plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), Italian ryegrass (Lolium multiflorum), barnyard grass (Echinochloa crus-galli), and timothy (Phleum pratense) at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL−1reduced significantly the total germination percent (GP), germination index (GI), germination energy (GE), speed of emergence (SE), seedling vigour index (SVI), and coefficient of the rate of germination (CRG) of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T50) and mean germination time (MGT) were increased at the same or higher than this concentration. The increasing trend ofT50and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species byO. tenuiflorumplant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL−1. TheI50values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL−1. Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest thatO. tenuiflorumplant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds.

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Study of the allelopathic activity of Garcinia pedunculata Roxb

Plant Omics ◽

10.21475/poj.12.01.19.pt1773 ◽

2019 ◽

pp. 31-36 ◽

Cited By ~ 3

Author(s):

Md. Mahfuzur Rob ◽

Hisashi Kato- Noguchi

Keyword(s):

Root Growth ◽

Weed Control ◽

Dry Weight ◽

Phleum Pratense ◽

Italian Ryegrass ◽

Allelopathic Potential ◽

Barnyard Grass ◽

Allelopathic Activity ◽

Shoot And Root Growth ◽

Test Plants

The allelopathic properties of plants can be used as an alternative weed control method to reduce the use of synthetic herbicides. Accordingly, the present study was carried out to determine the allelopathic activity of Garcinia pedunculata. Six different concentrations of aqueous methanol extracts of G. pedunculata fruit were prepared and used to determine their effect on the growth of eight test plants: alfalfa (Medicago sativa L.), cress (Lepidum sativum L.), lettuce (Lactuca sativa L.), rapeseed (Brassica napus L.), barnyard grass (Echinochloa crus-galli (L.) P. Beauv.), foxtail fescue (Vulpia myuros (L.) C.C. Gmel.), Italian ryegrass (Lolium multiflorum Lam.), and timothy (Phleum pratense L.). The test plants were grown in Petri dishes and after 48 h incubation, the length of the roots and shoots of the seedlings was measured and compared with control seedlings. Experiments were carried out in a completely randomized design (CRD). Analysis of variance (ANOVA) of the data was performed using the SPSS statistical package, and the I50 values were measured from a regression equation. The extracts at each concentration significantly inhibited the shoot and root growth of all the test plants, except the concentration of 0.001 g dry weight equivalent extract/mL, compared with control. At a concentration of 0.3 g of dry weight equivalent extract/mL, the shoot and root growth of all the tested plants were completely inhibited, except the shoot growth of barnyard grass. The degree of inhibition increased in line with increased extract concentration. The shoots of alfalfa and the roots of barnyard grass were determined to be the most susceptible to the G. pedunculata extract based on the concentration of extract resulting in 50% (I50) growth inhibition of the test plants. These results suggest that G. pedunculata may have allelopathic potential and may possess allelochemicals. From our study, we can conclude that G. pedunculata could be developed as an eco-friendly weed control option.

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Influence of BAS-145138 on the Activity of Sulfonylurea and Imidazolinone Herbicides

Zeitschrift für Naturforschung C ◽

10.1515/znc-1991-11-1202 ◽

1991 ◽

Vol 46 (11-12) ◽

pp. 939-944

Author(s):

Robert M. Devlin ◽

Irena I. Zbiec

Keyword(s):

Root Growth ◽

Dry Weight ◽

Sulfonylurea Herbicides ◽

Fresh Weight ◽

Phytotoxic Activity ◽

Phytotoxic Effects ◽

Shoot And Root Growth ◽

Imidazolinone Herbicides

This study demonstrates that corn can be partially safened by BAS-145138 against sulfonylurea and imidazolinone herbicides. The corn seeds were impregnated with BAS-145138 by soaking the seeds for 6 h in solutions of the safener. BAS-145138 had no effect on corn growth. However, corn shoot and root growth in length, fresh weight, and dry weight was partially protected by BAS-145138 from the phytotoxic effects of the sulfonylurea herbicides thiameturon and CGA -136872. Similar protection was given to corn against the phytotoxic activity of the imidazolinone herbicides imazapyr, imazaquin, and imazethapyr. This study suggests that corn could be safened with BAS-145138 against the phytotoxic effects of residual amounts of sulfonylurea and imidazolinone herbicides found in fields where wheat/corn or soybean/corn rotations take place.

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Determination of allelopathic properties of Acacia catechu (L.f.) Willd.

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha48412104 ◽

2020 ◽

Vol 48 (4) ◽

pp. 2050-2059

Author(s):

Kawsar HOSSEN ◽

Hisashi KATO-NOGUCHI

Keyword(s):

Root Growth ◽

Shoot Growth ◽

Dry Weight ◽

Italian Ryegrass ◽

Potential Candidate ◽

Dependent Manner ◽

Allelopathic Potential ◽

Barnyard Grass ◽

Acacia Catechu ◽

Test Plants

Plants possessing allelopathic potential could be used as a source of bio-herbicide to help decrease the use of synthetic herbicides. Acacia catechu (L.f.) Willd., a deciduous tree from the Mimosaceae family, has been reported to have medicinal properties. However, there have been no reports on the allelopathy of this tree. Therefore, the leaf extracts of A. catechu were examined for allelopathic potential using six concentrations: 0.001, 0.003, 0.01, 0.03, 0.1, and 0.3 g dry weight equivalent extract mL-1. The aqueous methanol extracts of A. catechu significantly suppressed the seedling growth of six test plants such as alfalfa, cress, lettuce, barnyard grass, Italian ryegrass, and timothy. The extracts inhibited the six test plants in a concentration-dependent manner. The shoot and root growth of all the test plant species were completely inhibited from the concentration of 0.3 g of dry weight equivalent extract mL-1, except the shoot growth of barnyard grass. Concentrations needed for 50% growth inhibition (I50 values) ranged from 0.004 to 0.043 g dry weight equivalent extract mL-1 for shoot growth, and 0.003 to 0.019 g dry weight equivalent extract mL-1 for root growth. Moreover, the I50 values indicated that the root growth of all the test plants was more susceptible to the A. catechu extracts than the shoot growth. The inhibitory effects of the extracts of A. catechu suggest that the extracts may contain allelopathic potential and, therefore, may be a potential candidate for the isolation and characterization of allelochemicals to develop an ecofriendly bio-herbicide.

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Influence of BAS-145138 on the Activity of Sulfonylurea and Imidazolinone Herbicides

Zeitschrift für Naturforschung C ◽

10.1515/znc-1991-9-1037 ◽

1991 ◽

Vol 46 (9-10) ◽

pp. 939-944 ◽

Cited By ~ 3

Author(s):

Robert M. Devlin ◽

Irena I. Zbiec

Keyword(s):

Root Growth ◽

Dry Weight ◽

Sulfonylurea Herbicides ◽

Fresh Weight ◽

Phytotoxic Activity ◽

Phytotoxic Effects ◽

Shoot And Root Growth ◽

Imidazolinone Herbicides

AbstractThis study demonstrates that corn can be partially safened by BAS-145138 against sulfonylurea and imidazolinone herbicides. The corn seeds were impregnated with BAS-145138 by soaking the seeds for 6 h in solutions of the safener. BAS-145138 had no effect on corn growth. However, corn shoot and root growth in length, fresh weight, and dry weight was partially protected by BAS-145138 from the phytotoxic effects of the sulfonylurea herbicides thiameturon and CGA -136872. Similar protection was given to corn against the phytotoxic activity of the imidazolinone herbicides imazapyr, imazaquin, and imazethapyr. This study suggests that corn could be safened with BAS-145138 against the phytotoxic effects of residual amounts of sulfonylurea and imidazolinone herbicides found in rotations take place.

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Phytotoxic Activity and Identification of Phytotoxic Substances from Schumannianthus dichotomus

Plants ◽

10.3390/plants9010102 ◽

2020 ◽

Vol 9 (1) ◽

pp. 102 ◽

Cited By ~ 5

Author(s):

Md. Mahfuzur Rob ◽

Kawsar Hossen ◽

Arihiro Iwasaki ◽

Kiyotake Suenaga ◽

Hisashi Kato-Noguchi

Keyword(s):

Root Growth ◽

Syringic Acid ◽

Italian Ryegrass ◽

Dependent Manner ◽

Leaf Extracts ◽

Concentration Dependent Manner ◽

Crop Fields ◽

Phytotoxic Activity ◽

Shoot And Root Growth ◽

Methyl Syringate

The phytotoxic potential of plants and their constituents against other plants is being increasingly investigated as a possible alternative to synthetic herbicides to control weeds in crop fields. In this study, we explored the phytotoxicity and phytotoxic substances of Schumannianthus dichotomus, a perennial wetland shrub native to Bangladesh, India, and Myanmar. Leaf extracts of S. dichotomus exerted strong phytotoxicity against two dicot species, alfalfa and cress, and two monocot species, barnyard grass and Italian ryegrass. A bioassay-driven purification process yielded two phenolic derivatives, syringic acid and methyl syringate. Both constituents significantly inhibited the growth of cress and Italian ryegrass in a concentration-dependent manner. The concentrations required for 50% growth inhibition (I50 value) of the shoot and root growth of cress were 75.8 and 61.3 μM, respectively, for syringic acid, compared with 43.2 and 31.5 μM, respectively, for methyl syringate. Similarly, to suppress the shoot and root growth of Italian rye grass, a greater amount of syringic acid (I50 = 213.7 and 175.9 μM) was needed than methyl syringate (I50 = 140.4 to 130.8 μM). Methyl syringate showed higher phytotoxic potential than syringic acid, and cress showed higher sensitivity to both substances. This study is the first to report on the phytotoxic potential of S. dichotomus and to identify phytotoxic substances from this plant material.

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Genetic variation for rate of establishment in caucasian clover

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1998.60.2282 ◽

1998 ◽

pp. 213-217

Author(s):

K.H. Widdup ◽

T.L. Knight ◽

C.J. Waters

Keyword(s):

Genetic Variation ◽

Root Growth ◽

Seedling Growth ◽

White Clover ◽

Seedling Emergence ◽

Red Clover ◽

Dry Weight ◽

Cool Season ◽

Trifolium Ambiguum ◽

Root Dry Weight

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum

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Phytotoxic Activity of Parthenium Against Wheat and Canola Differ With Plant Parts and Bioassays Techniques

Planta Daninha ◽

10.1590/s0100-83582016340100002 ◽

2016 ◽

Vol 34 (1) ◽

pp. 11-24 ◽

Cited By ~ 2

Author(s):

A. KHALIQ ◽

F ASLAM ◽

A MATLOOB ◽

A JAVAID ◽

A TANVEER ◽

...

Keyword(s):

Seedling Growth ◽

Filter Paper ◽

Leaf Extracts ◽

Invasive Weed ◽

Test Species ◽

Chlorophyll Contents ◽

Phenolic Contents ◽

Plant Parts ◽

Phytotoxic Activity ◽

Whole Plant

Phytotoxic effects of invasive weed Parthenium hysterophorus were studied by using whole plant, leaf and root aqueous extracts at 0, 2.5, 5.0, 7.5 and 10% (w/v) concentrations against germination and early seedling growth of wheat and canola. Studies were carried out both in Petri plates with filter paper as substratum placed in controlled conditions and soil-filled plastic pots placed in open environments. Pronounced variation was noted for phytotoxic activity of different plant parts of parthenium, aqueous extract concentrations, test species, and bioassay techniques. Aqueous parthenium extracts either inhibited or delayed the germination and suppressed seedling growth of test species over control. For both test species, all the germination attributes were suppressed to a greater extent in Petri plates than in plastic pots. Leaf extracts were more suppressive to germination of test species than whole plant and root extracts. Increasing extract concentration beyond 2.5% caused significant reduction in seedling dry biomass of both test species. Aqueous parthenium extract diminished chlorophyll contents of wheat and canola by 32-63% and 29 69%, respectively. Nevertheless, an increase of 9-172% and 22-60% in phenolic contents of wheat and canola was recorded. Canola appeared to be more susceptible than wheat at all extract concentrations. Present study concluded that bioassays conducted under controlled condition using filter paper as substratum may be misleading due to over estimation of allelopathic response and variation in potential of receiver and donor species. Furthermore, it implies that threshold concentrations of allelochemicals for test species in Petri plates are rarely reached under field conditions.

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Allelopathic potential of Artemisia campestris ssp. caudata on Lake Huron sand dunes

Canadian Journal of Botany ◽

10.1139/b97-902 ◽

1997 ◽

Vol 75 (11) ◽

pp. 1903-1912 ◽

Cited By ~ 5

Author(s):

Kyeong W. Yun ◽

M. A. Maun

Keyword(s):

Seed Germination ◽

Seedling Growth ◽

Mycorrhizal Fungi ◽

Sand Dune ◽

Sand Dunes ◽

Dry Weight ◽

Fungal Colonization ◽

Test Species ◽

Allelopathic Potential ◽

Artemisia Campestris

Greenhouse studies were conducted to test allelopathic effects of Artemisia campestris ssp. caudata on seed germination and seedling growth of several sand-dune species and colonization by mycorrhizal fungi. The aqueous extracts of A. campestris showed no inhibitory effect on seed germination, seedling elongation, or dry-weight growth of plants at lower concentrations (10 and 50%), but 100% concentration of the extracts caused varying degrees of inhibition depending on the test species. The mixing of dry leaves of seedlings of A. campestris to the sand showed severe inhibition of Elymus canadensis seedlings. The percent germination of test species in soil from the rhizosphere of A. campestris was significantly lower than that of the control. The leaf area and dry weight were also lower but the differences were not significant. The aqueous extract inhibited mycorrhizal fungal colonization in roots of three sand-dune grasses. Key words: allelopathy, Artemisia campestris ssp. caudata, seed germination, seedling growth, mycorrhizal fungi.

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Phytotoxic effects of Cerbera manghas L. leaf extracts on seedling elongation of four monocot and four dicot test species

Acta Agrobotanica ◽

10.5586/aa.1720 ◽

2017 ◽

Vol 70 (3) ◽

Cited By ~ 3

Author(s):

Ichsan Nurul Bari ◽

Hisashi Kato-Noguchi

Keyword(s):

Weed Management ◽

Dry Weight ◽

Phleum Pratense ◽

Italian Ryegrass ◽

Lepidium Sativum ◽

Leaf Extracts ◽

Isolation And Identification ◽

Test Species ◽

Phytotoxic Effects ◽

Cerbera Manghas

Exploration of allelochemicals with phytotoxic effects is intended to minimize a current dependency on synthetic herbicides in weed management. Several allelochemicals from the tropical tree Cerbera manghas (sea mango) have been reported as termiticides and bactericides. The present study investigated possible phytotoxic effects of C. manghas leaf extracts under laboratory conditions. Four monocots: barnyard grass (Echinochloa crus-galli), foxtail fescue (Vulpia myuros), Italian ryegrass (Lolium multiflorum), and timothy (Phleum pratense) and four dicots: alfalfa (Medicago sativa), garden cress (Lepidium sativum), lettuce (Lactuca sativa), and rapeseed (Brassica napus) were used as test species. Elongation of both shoots and roots of seedlings was measured to assess any phytotoxic effects. The results showed that the sensitivities of shoots and roots were different between the test species, and the inhibition of seedling elongation significantly increased with increasing concentration of leaf extracts of C. manghas for all the test species. The IC50 (50% inhibitory concentration) values showed that 8.50–32.30 and 4.26–34.67 mg dry weight equivalent extract mL−1 of C. manghas inhibited seedling elongation by 50%, for shoots and roots respectively. Isolation and identification of the phytotoxic substances from C. manghas are suggested for future investigation.

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Myrislignan, a Growth Inhibitor from the Roots of Citronella grass

Natural Product Communications ◽

10.1177/1934578x1701200719 ◽

2017 ◽

Vol 12 (7) ◽

pp. 1934578X1701200 ◽

Cited By ~ 2

Author(s):

Prapaipit Suwitchayanon ◽

Kiyotake Suenaga ◽

Arihiro Iwasaki ◽

Hisashi Kato-Noguchi

Keyword(s):

Root Growth ◽

Growth Inhibition ◽

Seedling Growth ◽

Growth Inhibitor ◽

Root Extracts ◽

Phytotoxic Activity ◽

Cymbopogon Nardus ◽

Phytotoxic Effect ◽

Phytotoxic Compound ◽

Citronella Grass

A phytotoxic compound was isolated from the root extracts of Cymbopogon nardus by bioassay-guided purification and characterized to be myrislignan. Myrislignan significantly inhibited seedling growth of cress at a concentration greater than 100 μM (p < 0.05). The concentrations required for 50% growth inhibition of myrislignan on hypocotyl and root growth of cress were 429 μM and 517 μM, respectively. The inhibition on seedling growth indicated that myrislignan had a phytotoxic activity and may contribute to the phytotoxic effect of C. nardus.

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