Role of bulk and Nanosized SiO2 to overcome salt stress during Fenugreek germination (Trigonella foenum- graceum L.).

The effects of bulk and Nanosized SiO2 on seed germination and seedling growth indices of fenugreek under salinity stress were studied in the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013. The experimental treatments included 4 levels of salinity stress (0, 50, 100 and 150 mM), 2 concentrations of bulk (50 and 100 ppm), 2 concentrations of nanosized SiO2 (50 and 100 ppm), and control (without any SiO2 types). Seedling growth attributes significantly improved when bulk and nanosized SiO2 concentrations applied singly or with different levels of salt stress. However, they significantly declined with salt application. The adverse effects of salt on shoot, root and seedling lengths were alleviated by application of 50 ppm nanosized SiO2 treatment. Under salt stress condition, addition of 50 and 100 ppm nanosized SiO2 to fenugreek seeds increased shoot, root and seedling dry weights as compared to bulk SiO2 concentrations and control treatments, though 50 ppm nanosized SiO2 was more effective than 100 ppm nanosized SiO2 application. It was concluded that nanosized SiO2 improves growth attributes of fenugreek and mitigate adverse effects of salt stress.

Phytotoxicity and stimulatory impacts of nanosized and bulk titanium dioxide on fennel (Foeniculum vulgare Mill).

The objective of the this study was to compare concentrations of nanosized TiO2 at 0, 5, 20, 40, 60 and 80 mg L(-1) with bulk TiO2 for phytotoxic and stimulatory effects on fennel seed germination and early growth stage. After 14 d of seed incubation, germination percentage highly improved following exposure to 60 ppm nanosized TiO2. Similar positive effects occurred in terms of shoot dry weight and germination rate. Application of bulk TiO2 particles in 40 ppm concentration greatly decreased shoot biomass up to 50% compared to the control. Application of 40 ppm nanosized TiO2 treatment improved mean germination time by 31.8% in comparison to the untreated control. In addition, low and intermediate concentrations of nanosized TiO2 enhanced indices such as germination value, vigor index and mean daily germination. In general, there was a considerable response by fennel seed to nanosized TiO2 presenting the possibility of a new approach to overcome problems with seed germination in some plant species, particularly medicinal plants.

Effects silver nanoparticles and magnetic field on growth of fodder maize (Zea mays L.).

Two experiments were done in 2008 and 2009 to study the effects of magnetic field and silver nanoparticles on fodder maize (Zea mays L.). These experiments were done with seven treatments based on a randomized complete block design in four replications. The treatments were as follows: magnetic field and silver nanoparticles + Kemira fertilizer (T1), magnetic field and silver nanoparticles + Humax fertilizer (T2), magnetic field and silver nanoparticles (T3), Kemira fertilizer (T4), Librel fertilizer (T5), Humax fertilizer (T6), and a control (T7). Results showed that fresh yield was higher in treatments T3 and T4. Treatments T3 and T4 had increased maize fresh yields of 35 and 17.5 % in comparison to the control, respectively. The dry matter yield of those plants exposed to magnetic field and silver nanoparticles was significantly higher than that from any of the other treatments. Magnetic field and silver nanoparticle treatments (T3 and T1) showed higher percentages for ears, and the lowest percentages were found in treatments T7 and T5. In general, the soil conditions for crop growth were more favorable in 2009 than in 2008, which caused the maize to respond better to treatments tested in the study; therefore, treatments had more significant effects on studied traits in 2008 than in 2009.

Impact of bulk and nanosized titanium dioxide (TiO2) on wheat seed germination and seedling growth.

The impacts of different concentrations of bulk and nanosized TiO(2) on seed germination and seedling growth of wheat were studied in a randomized completely design with four replications in the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2011. The experimental treatments included five concentrations of bulk (1, 2, 10, 100, and 500 ppm), five concentrations of nanosized TiO(2) (1, 2, 10, 100, and 500 ppm), and control (without any TiO(2)). Results indicated that among the wheat germination indices, only mean germination time was affected by treatments. The lowest and the highest mean germination time (0.89 vs. 1.35 days) were obtained in 10 ppm concentration of nanosized TiO(2) and control treatments, respectively. In addition, shoot length, seedling length, and root dry matters were affected by bulk and nanosized TiO(2) concentrations, significantly. Shoot and seedling lengths at 2 and 10 ppm concentrations of nanosized TiO(2) were higher than those of the untreated control and bulk TiO(2) at 2 and 10 ppm concentrations. Employing nanosized TiO(2) in suitable concentration could promote the seed germination of wheat in comparison to bulk TiO(2) but in high concentrations had inhibitory or any effect on wheat.