6 research outputs found
STANDORTSKUNDLICHE UND WALDBAULICHE UNTERSUCHUNGEN VON NATURNAHEN BUCHENWALDERNIM VORAS-GEBIRGE (NORDGRIECHENLAND)
No full textDormancy-Breaking Requirements and Germination for Seeds of Ostrya carpinifolia Scop.
No full textThe present research aims at investigating the combined effects of warm stratification (WS)+cold stratification (CS), and gibberellic acid (GA3)+cold stratification (CS) on breaking dormancy and germination in seeds of Ostrya carpinifolia. The seeds were subjected to WS (20-25 °C) for 0, 1 and 2 months and were subsequently cold stratified at 3-5 °C for 0, 1, 2, 3 and 4 months (1st experiment). A further amount of seeds was treated with 500, 1000 or 2000 ppm GA3 for 30 hours and then cold stratified at 3-5 °C for 0, 1, 2, 3 and 4 months (2nd experiment). No germination was observed in the seeds subjected to only WS (1 and 2 months) or CS for 1 month indicating that the seeds of O. carpinifolia are dormant. A 4-month stratification (1 month WS+3 month CS or 4 months CS) fully released dormancy and led to a high germination percentage (94.17 and 98.34% respectively) in a short time (7.12 and 7.00 days respectively). Warm stratification treatment prior to CS, was not required in order to break the seed dormancy of O. carpinifolia and also did not reduce the length of the (total) stratification period required for breaking seed dormancy. Gibberellic acid (GA3) application entirely replaced the CS period required for breaking seed dormancy. The germination of the seeds treated only with 2000 ppm GA3 (0 months of CS) was (94.17%) as high as the germination of the seeds subjected to 4 months of CS (98.34%). It is obvious that the seedcoat of O. carpinifolia seeds was permeable to GA3 and did not mechanically restrict embryo growth, thus, the seeds did not exhibit physical dormancy. Based on dormancy breaking requirements, the O. carpinifolia seeds displayed intermediate physiological dormancy
Effect of sowing date on seedling emergence of species with seeds enclosed in a stony endocarp
No full textEffect of Pretreatments on Seed Germination of Prunus mahaleb L.
No full textSexual propagation of Prunus mahaleb is difficult due to seed dormancy. To overcome dormancy and maximize germination, various pretreatments have been applied, including stratification (warm and cold), gibberellic acid (GA3), sulfuric acid scarification (AS), and endocarp removal. The results show that warm stratification (WS) prior to cold stratification (CS) does not improve seed germination and a long period of WS (3 months) is disastrous for germination. CS alone (up to 4 months) has been found to hasten and increase seed germination. Pretreatment of the seeds with exogenous GA3, during the CS period, has been observed to result in significantly higher seed germination. AS of seeds for 45 minutes prior to GA3 (1000 ppm for 24 hours) plus CS (up to 1 month) pretreatment has been considered to reduce the mechanical resistance of endocarp and improve germination. However, extended time of AS (180 minutes) prior to GA3 plus CS pretreatment has been found to harm the seeds. The removal of endocarp has been noted to significantly improve germination. Seeds without endocarp, which were pretreated with GA3 (1000 or 2000 ppm for 24 hours) and then cold stratified for 1 month, have been noted to exhibit the highest germination percentages
Site quality assessment for Pinus sylvestris L. in mixed forests of the central part of "Rhodope Mountains" in northeastern Greece
No full textIn this work, site index curves are developed for Pinus sylvestris in Greece, because of the ecological, social and economic importance of the species. Data from the forest of the Central Rhodope Mountains of north-eastern Greece are used. Thirty one dominant trees, which had the mean height of the 100 tallest trees per hectare were randomly selected and cut, in the 1990s. For each sampled tree a stem analysis was conducted. The selected height-age model for Pinus sylvestris was . The mean annual increment from stem analyses was equal to 0.212 m, corresponding to a base age of 68 years. The height estimation, calculated by the selected model, for a 68 year-old tree, is 23 m (SI23). Using the quadratic model as the guide curve for the development of anamorphic site index curves, we produced two more curves, SI20 and SI27. The main findings of this research are that Pinus sylvestris seems to grow faster in height in the productive site of the present study compared with that of Sweden, its growth is similar to that of the two most productive sites in forests in northwestern Spain, and it seems comparable to the fairly productive sites of northwestern Turkey
Effects of donor tree age, cutting collection time and K-IBA application on rooting ability of Taxus baccata L. stem cuttings: preliminary results
No full textThe present study investigates the effect of donor tree age (juvenile, adult), collection time (March, November) and the K-IBA (indole-3-butyric acid potassium salt; 0, 3, 6, 12 g L−1 K-IBA) application on rooting of T. baccata stem cuttings. Terminal hardwood leaf stem cuttings were collected of the year 2013 from individuals growing in their natural habitat in the Cholomontas mountains in the northern part of Greece. In cuttings taken from adult individuals, the application of K-IBA only significantly improved the rooting percentage. However, in cuttings taken from juvenile individuals, the collection time and K-IBA application as well as their interaction were statistically significant. In November collection, the cuttings treated with 12 g L−1 of K-IBA exhibited the highest rooting percentage (98.3%), while in March collection, the cuttings treated with 3 g L−1 of K-IBA exhibited higher rooting percentages (61.7%) than those of control (41.7%). In cuttings taken from juvenile individuals, the K-IBA application significantly improved the rooting of cuttings collected in November compared with those collected in March. The cuttings taken from juvenile individuals, exhibited significantly higher rooting percentages than those taken from adult individuals
