THE EFFECT OF HORMONE, STRATIFICATION PERIOD AND CULTIVAR ON SEEDS GERMINATION OF BLUEBERRY

Abstract

This work aimed to evaluate hormones, stratification periods and cultivars on seed germination of blueberry. The experiment was carried out at the company Frutplan Mudas Ltda. in Pelotas/RS from December 2005 to July 2006. Seeds were used from fruits of three open pollinated cultivars 'Bluegem', 'Powderblue' and 'Bluebelle'. After extraction the seeds were immersed into solutions with the hormones gibberellins and promalin (0, 100, 200 or 300 mg/L) with different stratification periods (0, 30, 60 or 90 days). The percentage of emerged and dead seedlings and the emergence velocity index (EVI) were measured weekly from the emergence of the first seedling until the establishment of the stand. There was interaction between treatments. The seeds from fruits of 'Bluebelle' showed the higher percentages of dead seedlings (7.10%). In regard to the hormones used, the higher percentage of germination was effectuated by 200 mg/L of gibberellin, while poor results were obtained with 200 and 100 mg/L of Promalin. Promalin, in these concentrations, also resulted in higher percentages of dead seedlings (16.34 and 10.51%, respectively). The non-stratification was the better period for seeds germination and dead seedlings percentage (65.25 and 8.71%, respectively). For EVI, the utilization of 100 mg/L of Promalin and 200 mg/L of gibberellin showed the better results. The higher period of stratification the higher percentage of germination and post-germinated dead seedlings, where without stratification (zero days) the number of dead seedlings increased. Similar results were verified for EVI with inverse effect to stratification period, where the increase of stratification period decreased the EVI. Therefore, seeds from fruits of 'Bluebelle' showed high germination percentage. The higher EVI may not be a good indicative for presenting following higher percentage of dead seedlings.