The contribution of nano-zinc to alleviate salinity stress on cotton plants.

To investigate the effect of nano-zinc fertilizer on growth, yield and mineral status of cotton plants grown under salt stress, a pot experiment was set up in the greenhouse of the National Research Centre. The treatments were as follows: (I) diluted seawater: 10% (S1), 20% (S2) and tap water as a control (S0), (II) 100 ppm (NZn1), 200 ppm (NZn2) nano-zinc and distilled water as a control (NZn0). Irrigation with 10 and 20% seawater decreased dry weight (DW) of leaves by 11.53 and 43.22%, while decreases in bolls were 15.50 and 71.65%, respectively. Except for root DW and top/root ratio, the measured growth parameters were increased as nano-zinc concentration increased. As for the interaction between treatments, the highest DW of stem, leaves and bolls resulted from the addition of NZn2 under normal condition, followed by NZn2 x S1 and the next was NZn2 x S2. The foliar application of 200 ppm nano-Zn led to mitigating the adverse effect of salinity and confirmed that diluted seawater could be used in the irrigation of cotton plant. However, phosphorus fertilizer should be added with nano-Zn application to avoid P/Zn imbalance. Some elements' status and their ratios were recorded.