Evaluation of propagation methods by seeds and cuttings in some hawthorn taxons (Crataegus microphylla, C. orientalis and C. azarolus var. pontica)

This study was carried out to develop an efficient seed treatment that facilitates rapid and enhanced germination of Crataegus microphylla, C. orientalis and C. azarolus var. pontica and determine the effect of growth hormons on rooting in the three species that are native to Artvin Province. The methods applied to remove seed dormancy were determined in combination with sulphuric acid scarification, warm and cold stratification pretreatments. IBA hormone application was performed at the six concentration ratios for softwood and semi-hardwood cuttings of three Crataegus taxons to investigate the root primordium formation. The overall results indicated that the Crataegus seeds possess a deep physical dormancy and physiological dormancy. Pretreatments improved seed germination in the Crataegus species, and germination response varied significantly across the treatments. The methods that yielded the best germination for each species were as follows: C. microphylla; pretreated with 2 hours sulphuric acid scarification followed by 8 or 12 weeks of warm stratification+16 weeks of cold stratification (>39%), C. orientalis; pretreated with 1 hour sulphuric acid scarification followed by 8 weeks of warm stratification+16 weeks cold stratification (39.5%) and pretreated with 2 hours sulphuric acid scarification followed by 12 weeks of warm stratification+12 weeks cold stratification (36.5%), and C. azarolus var. pontica; pretreated with 1 hour sulphuric acid scarification followed by 8 weeks of warm stratification+16 weeks cold stratification (58.5%). Semi-hardwood stem cuttings resulted more root primodium formation compared to softwood stem cuttings in the species. The methods that yielded the best root primordium formation for each species were as follows: C. microphylla; IBA at 5000 ppm applied to semi-hardwood stem cuttings (23.3%), C. orientalis; IBA at 3000 and 5000 ppm applied to semi-hardwood stem cuttings (43.3% and 41.1%, respectively), C. azorolus var. pontica; IBA at 5000 ppm applied to semi-hardwood stem cuttings (26.7%). Key words: Hawthorn, stem cutting, seed dormancy, IBA, stratification, root primordium