Germination Indices and Seedling Growth Parameters in Maize under Salinity Stress with Varying Concentrations of Giberellic Acid (GA)

Salinity stress is one of the factors limiting seed emergence and seedling development in sunflower at New halfa scheme in East of Sudan. A study of two factors pots experiment was conducted during winter season of 2019 to evaluate germination indices and seedling growth characters of maize seeds under salinity stress with varying concentrations of synthetic growth regulator namely (GA3). The experiment was laid out according RCBD with three replications. Treatments consisted of five levels of salinity (0, 0.5, 1.0, 1.5 and 2% ) designated as Na0, Na0.5, Na1.0 ,Na1.5 and Na2.0, and four levels of GA3 were (0, 50,75 and 100 p.pm) designated as G0, G50, G75 and G100, respectively,. The studied parameters include germination indices; daily germination (MDG), daily germination speed (DGS), final germination percentage (FGP), mean emergence time (MET), mean Energy of germination (EE), emergence index (EI), coefficient of uniformity of emergence (CUE) and vigour index (SVI). Also, seedling fresh and dry weight, shoot length and root length were measured, and the shoot/root ratio was calculated. The negative effects of salinity stress significantly decreased germination indices and seedlings growth characters in a dose dependent manner. The results showed that, application of GA3 at medium levels concentration (specify those doses) increased all studied parameters. In conclusion, application of high Ga3 levels enhanced all germination indices and seedlings growth characters while high salinity levels reduced these traits of maize seeds. Such result has made the base for further study that should be conducted in different seasons with different growth regulators involving different parameters of other crops.