Nanoscience technology is leading to the development of a
range of inexpensive applications for enhanced plant growth.
Applications of nanomaterial can promote earlier plant germination
and improve plant production. To our knowledge, this work
is the first publication related to the effects of bulk and nanosized
TiO2 particles in fennel (F. vulgare). Fennel seeds have naturally
weak germination (about 54%) contributing to some problems for
its cultivation. Surprisingly, using TiO2 nanoparticles promoted
fennel seed germination percentage, while seed germination percentages
decreased following exposure to concentrations of bulk
TiO2 particles compared to the control group. Exposure of fennel
seeds to 40 ppm nanosized TiO2 obtained the lowest mean germination
time but higher concentrations did not improve mean germination
time. Low and intermediate concentrations of nanosized
TiO2 improved seedling growth indices but higher concentration
(80 ppm) had an inhibitory effect on seed and seedling. Application
of bulk TiO2 reduced some traits in the study such as germination
rate, GMD, GV and vigor index compared to nanosized TiO2 and the
control. Nanomaterial can improve plant germination in certain
plants but can have adverse affects on others. In such cases, nanomaterial
can be applied under controlled conditions (such as in
greenhouse-grown plants) to promote germination in plants of
interest. Nevertheless, on the basis of these results it is highly recommended
that the influence of low dose nanomaterial be assessed
in order to encourage seed germination and seedling
growth of different medicinal and aromatic plant species. Although
this study demonstrated the potential of nanomaterial for agricultural
application, further exploration and research is needed to elucidate
and expand these possibilities.