Effect of warm, cold stratification and GA3 on breaking dormancy and characters germination seeds of Laurus nobilis. L in Shahat, Libya

Abstract

This research was conducted to study the effect of cold and warm stratification periods and gibberellic acid concentrations on dormancy breaking and characteristics germination of wild Bay laurel seeds in the archaeological area of Cyrene (Shahat), Al Jabal Al. Akhdar, Libya. The seeds were exposed to stratification periods of 20-40 days (cold - warm), the temperature of cold stratification was 6°C, seeds   put in a sterile sand while the warm stratification temperature was 22°C, the seeds were put in layers of moist cotton cloth inside a plastic bag and treated with gibberellic acid concentrations (without,500 and 1000 mg/L GA₃). Experiment was designed as a completely randomized block design with four replicates. The results revealed that 40 days of cold or warm stratification, with in a 500-mg/L gibberellic acid concentration, achieved the highest germination rate (95%) and improved germination characteristics such as the first day of germination and time spread of germination (17.25–19.00 days, respectively) in addition to germination speed and uniformity (10.42 seed/ day –1.88 day /seed) respectively. In contrast, 20 days of stratification for the both warm and cold without of gibberellic acid resulted of the lowest germination rate, the least speed and uniformity of the germination.