Application of Na ₂ SiO ₃ Improves Maize Germination Under Salt and pH Stress: An Optimization Using Response Surface Methodology

Forage maize cultivated in El Minea (Algeria) is affected by salt and pH stress concomitantly. Two forage maize varieties TWC‐352 and MAS‐55.N as well as three factors with five levels were studied: Na 2 SiO 3 (0, 1, 3.5, 6, and 7 mM), NaCl (0, 25, 87.5, 150, and 175 mM) and pH (4, 5, 7, 9 and 9.8). Different factors combinations were carried out using the Response Surface Method (RSM). The results show that the Na 2 SiO 3 supply is an efficient improvement strategy in the case of the tolerant variety MAS‐55.N whether it is under stress or not. On the other hand, for the sensitive variety TWC‐352, the efficiency is observed only in the event of saline‐pH stress; in the absence of stress, the supply of Na 2 SiO 3 inhibited the germination. Na 2 SiO 3 is particularly effective during simultaneous NaCl–pH alkaline stress. By exploiting the derivative of the trendline curves of the evolution of the Na 2 SiO 3 –NaCl and Na 2 SiO 3 –pH interaction coefficients, theoretical frequency supply was determined and then successfully confirmed by experimentation. Our results showed that three applications on 1‐day alteration improved germination by 10% and the vigor index by 100% in the MAS‐55.N in soil‐2 stress conditions.