Nanoparticles are gaining ever−wider application in plant production (for both agriculture and forestry), in the role of pesticides, as well as stimulators of plant growth and resistance. We sought to determine the efficacy of silver and copper nanoparticles (AgNPs and CuNPs respectively), used as seed dressings or subjected to foliar application, in affording protection from parasitic damping−off disease among soil−grown seedlings of Scots pine in a forest nursery. Experiments also assessed the influence of the nanoparticles on the growth of the plants potentially safeguarded in this way. Nanoparticles were used in seed soaking and foliar spraying at 50 ppm concentration. Pines treated with fungicides (Zaprawa Nasienna T 75 DS, Acrobat MZ 69 WG, Topsin M 500 SC, Gwarant 500 SC, Thiram Granuflo 80 WG and Signum 33 WG) or unprotected at all were used for comparison. In each treatment (AgNPs, CuNPs, fungicides or unprotected), seedlings were inventoried 6 weeks after the sowing and at the end of the growing season, while all individuals on 80 1−m−long segments of seed row were counted. At the end of the growing season, shoot length, root−collar diameter, root length and dry mass of shoots and roots were determined. The seedlings treated with nanoparticles had longer root systems of greater dry mass, but also only more weakly−developed above−ground parts (both height and dry mass being limited) in comparison with young Scots pines that had been fungicide−treated or were unprotected. It resulted in a significantly more favourable ratio between shoot and root masses, where nanoparticle treatment had been applied. The effectiveness of the protection extended to the germination and first−growth stages up to 6 weeks from the time of sowing was furthermore shown to be greatest where AgNPs had been applied, while at the season end there were comparable results among pines treated with either nanoparticles or fungicides. Our results thus indicate that nanoparticles limit damping−off disease in pine seedlings (AgNPs more effectively than CuNPs), with that effectiveness also proving comparable with that noted for the fungicides applied traditionally.
W artykule przeanalizowano koloidy srebra stabilizowane hydrolizatami skrobiowymi pod kątem właściwości bakteriobójczych, określając również ich wielkość oraz kształt. Zbadano także właściwości wytrzymałościowe zapraw cementowych z domieszkami analizowanych hydrolizatów skrobiowych, lignosulfonianów sodowych i ich połączenia z nanosrebrem. Koloidy srebra poddano analizie spektrofotometrycznej UV-vis w celu stwierdzenia obecności nanostruktur srebra. Określono również rozkład wielkości nanocząstek metodą nieinwazyjnego wstecznego rozproszenia światła oraz ich kształt za pomocą mikroskopii elektronowej (TEM). Otrzymane koloidy srebra podczas wykonania prób bakteriobójczych wykazały silną odporność na działanie tzw. bakterii bytowych. Połączenie wymienionych właściwości nanosrebra z właściwościami uplastyczniającymi plastyfikatorów daje możliwość wytwarzania zapraw cementowych i betonów odpornych na działanie mikroorganizmów o zwiększonej urabialności i wytrzymałości na ściskanie.
EN
The article analyzes silver colloids stabilized with starch hydrolysates for their bactericidal properties as well as determining the size and shape of investigated colloids. The strength properties of cement mortars with the admixtures of the analyzed starch hydrolysates, sodium lignosulfonates and their combination with nanosilver were also investigated. To determine the presence of silver nanostructures, colloidal silver were analyzed with UV-vis spectrophotometry. The particle size distribution and the shape of nanoparticles were analyzed by non-invasive backscattering light method and transmission electron microscopy (TEM), respectively. The resulting silver colloids showed strong resistance to domestic bacteria. The combination of the aforementioned properties of nanosilver with the plasticizing properties of plasticizers, provides the possibility of producing cement mortars and concretes resistant to microorganisms with significantly improved workability and compressive strength.
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