The, Effect Effect of Gibberellic Acid (GA3) and Stratification on Seed Germination and Seedling Growth of Grape (Vitis vinifera L.)

Abstract

  The research was carried out at the lath-house of the college of Agricultural Engineering Sciences, Salahaddin University-Erbil for the period from  August 2020  to  February 2021 using grape (Vitis vinifera L.) cv. Rash-meri seeds to study the effect of (GA3 concentration and stratification period) on germination and seedling vigor to obtain  good and healthy seedlings within a relatively short time. The seeds were soaked in 3 concentrations of GA3, which are (500, 100, 1500 mg. l^-1), in addition to the control (0 mg. l^-1) for 24 hours, then treated seeds were stratified for (1, 2 and 3 months) at 5±1oC. Complete Randomized Design (C.R.D) was used as a factorial experiment as three replications with 25 seeds for each treatment. The SAS statistical tool (SAS 2003) was used to perform an analysis of variance (ANOVA) on the obtained data, when significant differences were found, the means were correctly separated, and mean values were assessed at the p<0.05 level of significance using Duncan's Multiple Range Test. The results showed that there were significant differences in the germination percent and seedling growth, with the increase in GA3 concentration, the differences increased significantly compared with control, the concentration (1500mg.l^-1) gave the highest increase in all studied traits (Seed germination%, Stem length (cm), Stem diameter (mm), Root length (cm), Vigor index, shoot and root  dry weight(g), Total dry weight (g) and quality index. With increasing stratification period differences increased significantly, the highest values were recorded in seeds stratified for (3 months). As for the interaction effect of 2 studied factors, the treatment that exceeded the other was (1500 mg.l^-1) GA3 and (2 and 3 months) stratification period compared with seeds not treated with GA3.