scholarly journals Allelopathic Interference of Leaf Powder and Aqueous Extracts of Hostile Weed: Parthenium hysterophorus (Asteraceae)

2016 ◽  
Vol 4 (3) ◽  
pp. 86-93 ◽  
Author(s):  
Tauseef Anwar ◽  
Shahida Khalid ◽  
Maimona Saeed ◽  
Roomina Mazhar ◽  
Huma Qureshi ◽  
...  
Keyword(s):  
Parthenium Hysterophorus ◽  
Aqueous Extracts ◽  
Leaf Powder ◽  
Allelopathic Interference

Phytotoxic evaluation of Phragmites australis: an investigation of aqueous extracts of different organs

2012 ◽  
Vol 63 (9) ◽  
pp. 777 ◽  
Author(s):  
Md N. Uddin ◽  
Domenico Caridi ◽  
Randall W. Robinson
Keyword(s):  
Phragmites Australis ◽  
Invasive Plants ◽  
Aerobic Condition ◽  
Water Soluble ◽  
Aqueous Extracts ◽  
Soluble Phenolics ◽  
Leaf Leachate ◽  
Allelopathic Interference ◽  
The Stability ◽  
Germination Bioassays

Phragmites australis is one of the most widespread and invasive plants on earth. Allelopathic interference has been considered as a possible way associated with its invasiveness in wetlands. A series of ecologically realistic experiments was conducted to explore allelochemical phytotoxicity of Phragmites. Germination bioassays using aqueous extracts of different organs (leaf, stem, root and rhizome) of Phragmites were tested with model seeds (Lactuca sativa and Raphanus sativus) and associated plant species (Juncus pallidus and Rumex conglomeratus). These studies showed that leaf and rhizome extracts exhibited strong inhibition on germination, biometric and physiological parameters (all P ≤ 0.001). Dose–response studies confirmed LC50 (4.68% and 11.25%) of Lactuca for leaf and rhizome extracts respectively. Root growth of Juncus and Rumex was inhibited by 75% and 30%, respectively, in leaf leachate-incorporated soil. Chlorophyll content and maximum quantum yield (Fv/Fm) were significantly reduced with leaf and rhizome leachates. The stability and quantity of water-soluble phenolics in anaerobic versus aerobic condition may influence phytotoxic effects to other species. Phragmites organs can be ranked in order of allelopathic potentiality as follows: leaf > rhizome > root > stem. The present study highlighted the potential impacts of allelochemicals on plant recruitment in wetlands invaded by Phragmites.

scholarly journals Oleuropein Degradation Kinetics in Olive Leaf and Its Aqueous Extracts

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1963
Author(s):  
María Esther Martínez-Navarro ◽  
Cristina Cebrián-Tarancón ◽  
José Oliva ◽  
María Rosario Salinas ◽  
Gonzalo L. Alonso
Keyword(s):  
Degradation Kinetics ◽  
Aqueous Extracts ◽  
Olive Leaf ◽  
First Order ◽  
Degradation Reactions ◽  
First Order Kinetics ◽  
Leaf Powder ◽  
The Stability ◽  
Multiple Health ◽  
By Products

Although olives leaves are currently considered a waste material from oil mills, they have great potential to be transformed into by-products due to their high oleuropein content. Oleuropein is a glycoside precursor of hydroxytyrosol, which is the phenolic compound with the highest antioxidant capacity in nature and which is associated with multiple health benefits. For this reason, the demand for oleuropein is growing in the pharmaceutical, cosmetic and food sectors. The objective of this study is to determine the stability of oleuropein in olive leaves from oil mills in solid and aqueous forms under different conditions of temperature, relative humidity and lighting. The results indicate that the degradation of oleuropein conforms well to first-order kinetics. The rate constants at the temperatures tested in the aqueous extracts indicate activation energies from RTl to 80 °C and from 7 °C to 14 °C, as the degradation reactions were different in these ranges. Furthermore, olive leaf powder stored at any temperature with an RH ≥ 57% showed greater stability after six months, which is an encouraging result for the storage and transformation of this waste in oil mills.

scholarly journals Aqueous extracts and oil of neem combined with neonicotinoid insecticides against Bemisia tabaci biotype B in melon

2007 ◽  
Vol 37 (6) ◽  
pp. 1798-1800
Author(s):  
Maria Santana de Araújo Trindade ◽  
Adalberto Hipólito de Sousa ◽  
Patrício Borges Maracajá ◽  
Rui Sales Júnior ◽  
Wilson Galdino de Andrade
Keyword(s):  
Experimental Design ◽  
Bemisia Tabaci ◽  
Chemical Treatment ◽  
Leaf Extract ◽  
Aqueous Extracts ◽  
Neem Oil ◽  
Neonicotinoid Insecticides ◽  
Leaf Powder ◽  
Biotype B ◽  
Bemisia Tabaci Biotype B

This research was aimed at evaluating nymph population density of whitefly (Bemisia tabaci biotype B) in melon plants after treatment with neem-dry-leaf aqueous extracts and neem-oil ( A. Juss.) applied alternately with neonicotinoid insecticides under field conditions. The experimental design was a randomized block, with 6 treatments and 4 replications. The treatments were control (only water); neem-dry-leaf extract at 5% (neem-dry-leaf powder 50g L-1 of water); neem oil (5.0mL L-1 water); chemicals insecticides imidacloprid (30g 25L-1 of water) and acetamiprid (5g 20L-1 of water); neem-dry-leaf extract at 5% weekly alternated with imidacloprid (30g 25L-1 of water) and acetamiprid (5g 20L-1 of water); neem oil (5.0mL L-1 of water) weekly alternated with imidacloprid (30g 25L-1 of water) and acetamiprid (5g20 L-1 of water). The efficiency of treatments was compared through of the number of nymphs recorded in leaves of melon with 35, and 50 days after planting. The less number of nymphs was registered when the neem oil was applied alternatively with the chemical treatment with efficiency of 28.58 and 7.85% in the first and second evaluations, respectively. However, the nymphs incidence was higher when the neem oil and the chemical treatment were applied separately.

scholarly journals Invasive vs. Invasive, Parthenium hysterophorus as a Bio-Control Agent against Invasive Mealybugs

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 936
Author(s):  
Taswar Ahsan ◽  
Bingxue Li ◽  
Yuanhua Wu
Keyword(s):  
Mortality Rate ◽  
Aqueous Extract ◽  
Large Scale ◽  
Control Agent ◽  
Parthenium Hysterophorus ◽  
High Dose ◽  
Contact Method ◽  
Aqueous Extracts ◽  
Dalbergia Sissoo ◽  
Residual Method

Parthenium hysterophorus has an antagonistic potential against mealybugs, which are hosted on wild Dalbergia sissoo. In the current study, an aqueous extract of Parthenium was evaluated against mealybugs on Dalbergia sissoo. A serial dose of 12.5, 25, 50, 100, 200, and 500 µg/mL of aqueous extract was prepared from all parts of the Parthenium plant. After 72 h at high doses, 200 µg/mL and 500 µg/mL aqueous extracts had high mortality of 76.67% and 73.33% via the residual method, respectively. Meanwhile at same dose after 72 h, the contact method had higher mortality percentages of 80% and 80% at 200 µg/mL and 500 µg/mL, respectively. After 48 h at a high dose (200 µg/mL and 500 µg/mL), the mortality of the mealybugs was highest via the contact method. The results show a mortality of 73.33% with both doses. Meanwhile the same doses, via the contact method, after 48 h had a 63.33% mortality rate. After 24 h via the contact method, at 200 µg/mL and 500 µg/mL the mortality of mealybug was 70% with both doses, whereas via the mortality rate via the residual method at 200 µg/mL and 500 µg/mL doses was 56.67% and 66.67%, respectively. These results indicate that Parthenium is a strong bio-control agent against mealybugs. Aqueous extracts could lead to a cost effective and environmentally friendly insecticidal for sustainable use in large scale forestry.

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