AMELIORATIVE EFFECTS OF NANO SILICA AND SOME GROWTH STIMULANTS ON WATER RELATIONS, BIOCHEMICAL AND PRODUCTIVITY OF WHEAT UNDER SALINE SOIL CONDITIONS.

Salinity inferiorly affects physiological and biochemical processes of wheat plants making grain yield economically drops. Ameliorative effects of some growth stimulants (control, humic acid, tocopherol, nano-silica and nitric oxide) on two wheat cultivars (Sakha 95 and Misr3) under saline soil conditions were investigated in this work. The experiment was conducted during 2019/2020 and 2020/2021seasons using split-plot design. Results disclosed that although Sakha 95 recorded higher value of grain yield than Misr 3 but there were insignificant differences between the two cultivars in almost all studied traits, except for relative water content, malondialdehyde content and catalase activity, where Misr 3 significantly superior Sakha 95 in these traits. Nano-silica or nitric oxide significantly affected water relations traits of the two studied cultivars, where the two treatments gave the lowest values of transpiration rate and the highest values of both stomata resistance and relative water content in both seasons. The two treatments also gave the highest activity of catalase and peroxidase enzymes and the lowest values of malondealdehyde. The highest increase in chlorophyll pigments (a and b) and yield as well as its attributes were obtained from spraying nano silica. It could be recommended that cultivation of Sakha 95 or Misr 3 treated with nano-silica or Sakha 95 with spraying any of the other studied stimulant substances (nitric oxide or humic acid or tocopherol) to obtain high productivity under saline soil conditions. [ABSTRACT FROM AUTHOR]