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Pruning Ficus trees in urban green spaces may lead to the accumulation and spread of their leaf litter on the understory vegetation. This study was conducted to evaluate the allelopathic effect of Ficus retusa L. leaf litter on the understory species in urban gardens. A field study showed that the plant cover and species richness of litter-affected plots were lower than those of litter-free areas. The litter-affected soils had substantially lower pH and higher electrical conductivity. In a greenhouse experiment, litter-affected soil significantly inhibited the emergence and growth of understory species selected for the purpose of this study: Melilotus indicus (L.) All., Trifolium resupinatum L. and Amaranthus viridis L. Osmotic potentials equivalent to those of the litter-affected soils did not affect emergence or growth of these species. A spectrophotometric analysis indicated that the litter-affected soils contained larger amounts of phenolics and flavonoids. An HPLC analysis revealed that the litter-affected soils contained higher concentrations of free phenolic and flavonoid allelochemicals. These results demonstrate that F. retusa leaf litter may reduce plant cover and species richness. The significant inhibition in both field and greenhouse experiments could be attributed to phenolic and flavonoid allelochemicals released from the tree litter, as the osmotic potential of the litter had no effect on the understory species. The allelopathic potential of F. retusa leaf litter plays at least a partial role in reducing urban vegetation. [ABSTRACT FROM AUTHOR]

Abstract Ficus retusa was used as reducing and stabilizing agent in the green synthesis of silver and gold nanoparticles with high dispersion stability and controllable size and shape. The controlling of reaction conditions i.e. contact time, extract quantity, metal concentration, and pH value enables the tuning of the particle size and size distribution of the metal nanoparticles. UV–visible spectroscopy was used to follow the spectral profile changes of the surface plasmon resonance of the metal nanoparticles due to different treatments. The surface plasmon resonance varies between 400 and 432 nm and between 522 and 554 nm for silver and gold nanoparticles, respectively, depending on the different reaction parameters. Atomic force and transmission electron microscopy results confirmed the success of preparation of spherical silver (15 nm) and gold (10–25 nm) nanoparticles with narrow size-distribution. Fourier transform infrared spectroscopy suggested the phenolic compounds play the key role in the reduction and stabilizing of metal ions. The colorimetric sensitivity of silver and gold nanoparticles to detect the presence of heavy metals in water was studied. Graphical abstract Ficus retusa-stabilized silver and gold nanoparticles. Unlabelled Image Highlights • Ficus retusa is used as reducing and stabilizing agent for synthesis of metal NPs. • The extract quantity, metal ion concentration, and pH value control the size and shape of NPs. • Phenolic compounds are responsible for the reduction and stabilization of NPs. • AgNPs exhibits excellent colorimetric sensing performances towards Fe3+ ions. [ABSTRACT FROM AUTHOR]

Synthesis of AgNPs was attempted using aqueous Ficus retusa leaf extract (FRLE). The effects of silver nitrate concentrations, FRLE volume, initial pH and temperature on synthesis were also studied. TEM revealed the size of AgNPs in range of 5-35 nm and crystal structure was confirmed by XRD. FTIR showed the capping of AgNPs by biomolecules of FRLE. Zeta potential of -39.1 indicates good stability of AgNPs. The AgNPs were evaluated for their antibacterial and high catalytic activity in enhancing decolourisation of eriochrome black T dye in presence of sodium borohydride (from 19.74 to 86.05%) and light source (from 41.96 to 80.11%). [ABSTRACT FROM AUTHOR]

Resistance to conventional fungicides causes poor disease control in agriculture. Natural products from plants have great potential as novel fungicide sources for controlling pathogenic fungi. In this study the antipathogenic activity of the leaf juices of 11 plant species (Chenopodium ambrosioides, Pulicaria vulgaris, Lavandula pubescens, Lavandula dentata, Ageratum conyzoides, Ficus retusa, Zizyphus nummularia, Acacia tortilis, Phragmanthera sp. Aff. Rufescens, Lawsonia alba and Olea europaea) were evaluated in vitro against three plant pathogenic fungi (Fusarium solani, Phytophthora spp. and Rhizoctonia solani). Plate assays showed that the leaf aqueous juices have antifungal activity against these fungi. The aqueous extracts of Pulicaria vulgaris, Lavandula dentata, Ageratum conyzoides, Ficus retusa, Zizyphus nummularia, Acacia tortilis, Phragmanthera sp. Aff. Rufescens (when associated with Acacia tortilis), Lawsonia alba and Olea europaea exhibited antifungal properties against Fusarium solani, Phytophthora spp. and Rhizoctonia solani with variable degrees. On the other hand, Chenopodium ambrosioides, Lavandula pubescens and Phragmanthera sp. Aff. Rufescens (when associated with Zizyphus nummularia) did not exhibit any fungitoxicity. All these observations suggest the possible exploitation of Chenopodium oil as a potential botanical fungitoxicant in ecofriendly control of post-harvest biodeterioration of food commodities from storage fungi. [ABSTRACT FROM AUTHOR]