Japanese knotweed control with winter soil injection of chemicals targeting the rhizome system

Author(s):  
Misako Ito ◽  
Kanji Ito
Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 133
Author(s):  
Urška Jug ◽  
Katerina Naumoska ◽  
Irena Vovk

The antioxidant activities of Japanese knotweed rhizome bark extracts, prepared with eight different solvents or solvent mixtures (water, methanol, 80% methanol(aq), acetone, 70% acetone(aq), ethanol, 70% ethanol(aq), and 90% ethyl acetate(aq)), were determined using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay. Low half maximal inhibitory concentration (IC50) values (2.632–3.720 µg mL−1) for all the extracts were in the range of the IC50 value of the known antioxidant ascorbic acid at t0 (3.115 µg mL−1). Due to the highest extraction yield (~44%), 70% ethanol(aq) was selected for the preparation of the extract for further investigations. The IC50 value calculated for its antioxidant activity remained stable for at least 14 days, while the IC50 of ascorbic acid increased over time. The stability study showed that the container material was of great importance for the light-protected storage of the ascorbic acid(aq) solution in a refrigerator. Size exclusion–high-performance liquid chromatography (SEC-HPLC)–UV and reversed phase (RP)-HPLC-UV coupled with multistage mass spectrometry (MSn) were developed for fractionation of the 70% ethanol(aq) extract and for further compound identification, respectively. In the most potent antioxidant SEC fraction, determined using an on-line post-column SEC-HPLC-DPPH assay, epicatechin, resveratrol malonyl hexoside, and its in-source fragments (resveratrol and resveratrol acetyl hexoside) were tentatively identified by RP-HPLC-MSn. Moreover, epicatechin was additionally confirmed by two orthogonal methods, SEC-HPLC-UV and high-performance thin-layer chromatography (HPTLC) coupled with densitometry. Finally, the latter technique enabled the identification of (−)-epicatechin. (−)-Epicatechin demonstrated potent and stable time-dependent antioxidant activity (IC50 value ~1.5 µg mL−1) for at least 14 days.


Cellulose ◽  
2021 ◽  
Author(s):  
Nina Čuk ◽  
Martin Šala ◽  
Marija Gorjanc

Abstract The development of cellulose-based textiles that are functionalised with silver nanoparticles (AgNP), synthesised according to a green approach, and offer protection against ultraviolet (UV) radiation and pathogenic bacteria is very important today. In the present work we demonstrate the environmentally friendly approach to obtain such textile material by AgNP synthesis directly (in-situ) on cotton fabrics, using water extracts of plant food waste (green tea leaves, avocado seed and pomegranate peel) and alien invasive plants (Japanese knotweed rhizome, goldenrod flowers and staghorn sumac fruit) as reducing agents. The extracts were analysed for their total content of phenols and flavonoids and their antioxidant activity. The synthesised AgNP on cotton were round, of different size and amount depending on the reducing agent used. The highest amount of AgNP was found for samples where Japanese knotweed rhizome extract was used as reducing agent and the lowest where extracts of goldenrod flowers and green tea leaves were used. Regardless of the reducing agent used to form AgNP, all cotton samples showed excellent protection against E. coli and S. aureus bacteria and against UV radiation with UV protection factor values above 50. The best results for UV protection even after the twelve repetitive washing cycles were found for the sample functionalized with AgNP synthesised with an extract of the Japanese knotweed rhizome. Due to the presence of AgNP on cotton, the air permeability and thermal conductivity decreased. AgNP had no effect on the change in breaking strength or elongation of fabrics. Graphic abstract


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1232
Author(s):  
Rozalija Cvejić ◽  
Susanne Klages ◽  
Marina Pintar ◽  
Lara Resman ◽  
Ana Slatnar ◽  
...  

In this study, fermentation-based organic fertilizer (OF) was produced from the aboveground parts of Fallopia japonica (Houtt.) Ronse Decr. The quantity of N in OF (17.2 kg t−1 fresh lactic-fermented OF) was higher than average in cattle farmyard manure, but on a comparable level to solid poultry and rabbit manure. The OF was applied on a field to evaluate its effect on Chinese cabbage. The applied nutrients with OF N159 were 159, 44 and 121 kg ha−1 for N, P, and K, respectively. The applied nutrients with OF N317 were 317, 38, and 200 kg ha−1 for N, P, and K, respectively. The average mass of marketable Chinese cabbage (Brassica pekinensis Rupr.) single heads ranged from 253 g with N0 treatment to 602 g with N317 treatment. The nutrient recovery efficiency REN,P,K was 37, 20, and 50% for N317 and 55, 48, and 77% for N159. The OF was found to be a suitable alternative to farmyard manure. Additionally, OF produced from F. japonica could complement existing approaches to limit the spread of invasive species in cities. Further research should focus on perennial crop rotations and cropping patterns, different soil types, and a greater variety of crops and consider the possible retention of urban farmers using fertilizer from invasive plants.


2016 ◽  
Vol 40 (9) ◽  
pp. 8131-8140 ◽  
Author(s):  
Huaguo Chen ◽  
Qingfang Deng ◽  
Xiuhong Ji ◽  
Xin Zhou ◽  
Glen Kelly ◽  
...  

Glucose oxidase can completely convert resveratrol glycoside into resveratrol, and significantly increase the extraction yield of resveratrol in Japanese knotweed.


2015 ◽  
Vol 8 (2) ◽  
pp. 250-253 ◽  
Author(s):  
Brian P. Colleran ◽  
Katherine E. Goodall

The objective of this article is to extend the reported period in which flood-distributed knotweed propagules may be successfully managed using only manual labor. During a second round of early detection and rapid response (EDRR) management along the Green River in Guilford, VT, we collected and measured all Japanese knotweed propagules that had been distributed by flooding approximately 21 mo earlier, in August 2011, at a single site. Our data suggest that knotweed s.l. prioritizes the growth of new stems over new rhizomes at the start of a growing season. Because the limiting factor for successful removal of new knotweed s.l. plants by hand is the size of the rhizome system, our findings support extending the time frame for EDRR management of flood-distributed knotweed s.l. into the second spring after its initial dispersal. Additionally, in November 2013, surveys of our work sites found no new knotweed s.l. plants in locations accessible to work crews. In addition to validating our EDRR management techniques, this implies that knotweed s.l. fragment viability does not extend past the second spring following its dispersal.


1990 ◽  
Vol 68 (7) ◽  
pp. 1441-1448 ◽  
Author(s):  
John M. Bernard

The genus Carex is made up of about 2000 species of herbaceous perennials occurring in a wide range of habitats throughout the world but especially in north temperate and arctic regions. They are modular organisms that reproduce vegetatively by rhizomes or other means, some species forming extensive and long-lived clones, others tufts, clumps, or tussocks of various sizes. Most temperate and arctic species have shoots formed during the previous year, some emerging in autumn, others remaining below ground until spring. The maximum shoot life span for temperate species appears to be approximately 24 months but mortality is very high; sometimes 90% of shoots do not live for the whole 2-year life span. Snoots in arctic-alpine regions live longer, perhaps as long as 5–7 years, with lower mortality. Mortality is caused by differences in time of emergence, flowering, animal grazing, the age of the genet, and internal competition through the rhizome system.


2017 ◽  
Vol 54 (4) ◽  
pp. 651-654
Author(s):  
Florina Ardelean ◽  
Razvan Susan ◽  
Florin Borcan ◽  
Alina Moaca ◽  
Diana Simona Antal ◽  
...  

Polymer microstructures containing plant extracts are a novel technique used to increase the bioavailability of active agents with low aqueous solubility. Japanese knotweed (Reynoutria japonica) is an invasive plant with multiple biomedical properties. The aim of the present study was to obtain and characterize polyurethane microstructures used as a drug delivery system of a Japanese knotweed extract. The results indicate the obtaining of microstructures with an almost neutral pH, with sizes between 540 and 1134 nm, with a medium stability against the tendency to form clusters and a very good thermal stability. These first results present the potential of the obtained polyurethane microstructures as candidates for the transmembrane drug delivery of Japanese knotweed extracts, as a starting point for further bioactivity investigations.


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