Influence of nano-silica and humic acid on physiological characteristics of Bermuda grass (Cynodon dactylon L.) under salinity stress

This research was conducted to evaluate the effects of water salinity and nano-silica (NS) and humic acid (HA) on Bermuda grass. The study was carried out under greenhouse and exterior space conditions in a completely randomized design with factorial arrangements. Treatments included 4 water salinity levels (0, 5, 7 and 9 dS/m) and 4 level of NS (0, 1, 2 and 3 mm/l) as well as 4 level of HA (0, 50, 100 and 150 mg/l). Results indicated a decrease in chlorophyll content, and increase in proline, malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) and electrolyte leakage (EL) with increasing levels of salinity. The chlorophyll content in greenhouse and exterior space also increased with increasing levels of NS and HA, while proline in two environments, with increasing levels of NS and HA decreased. EL with increasing levels of NS fluctuated, but with increasing levels of HA, it decreased in two environments. With increasing levels of NS, CAT in both environments was eventually decreased after the oscillation, but there was no particular trend in HA levels. With increasing levels of NS and HA, MDA in the greenhouse decreased and in the exterior space – it increased. Finally, by increasing levels of NS and HA, SOD did not show any change in the greenhouse condition, but in the exterior space, the SOD was decreased.