Dormancy, germination and seedling growth in bay laurel (Laurus nobilis)

The present study was conducted to assess the effects of polystimulins, gibberellic acid and duration of cold stratification on germination of bay laurel seeds and seedling growth. Seeds were treated with cold stratification at 4 degrees C for 30, 70 and 90 days; soaking in 500, 750, 1000 mg L-1 polystimulins (PS-A6 + PS-K) for 24 hours and then cold stratified for 70 days, or soaking in 500, 750, 1000 mg L-1 gibberellic acid (GA(3)) for 24 hours and then cold stratified for 70 days. The best results (94%) were recorded when seeds were pre-treated with 1000 mg L-1 PS-A6 + PS-K and then cold stratified for 70 days. This study also examined the effects of pre treatment on seedling growth. The greatest seedling height (223 mm) and root length (532 mm) were seen in seedlings produced from PS-treated seeds. Pre-sowing treatment changed the root/shoot ratio of seedlings positively and increased seedling survival. Polystimulin hormone application with cold stratification to seeds is recommended in nursery production of bay laurel seedlings.