Improving seed germination and seedling growth of true seed shallot (TSS) using plant growth regulator seed priming

Seeding is the most important and quite challenging stage in seed/TSS cultivation. Plant growth regulator (PGR) seed priming has the potential to enhance the quality of TSS seedlings. The research had been conducted in the greenhouse of Agriculture Faculty, UGM, from February to April 2020. The factorial treatments of shallot cultivars (Tuk-Tuk, Lokananta and Sanren) and seed treatments (soaking seed with GA3 100 ppm and NAA 50 ppm for 12 hours and untreated seeds as control) were assigned in the RCBD with four replications. Each experimental unit was consisted of 728 seeds per cultivar. Both treated and untreated seeds were sown in soil blocks. The data were analyzed using ANOVA and continued with Tukey HSD procedure at α=0.05. The results showed that PGR priming on seeds significantly increased the germination percentage, plant height, leaf number, leaf area, and hypothetical vigor index of the three cultivars at six weeks after sowing. However, there was no significant difference in the fresh weight and dry weight of seedlings. This research implied that soaking seeds in GA3 100 ppm and NAA 50 ppm for 12 hours could improve seed germination and TSS seedling growth. Additional fertilizers are perhaps needed in soil blocks to increase the effect of hormones on the seedlings.