Seed and seedling characteristics in central black sea populations of Quercus petraea, Q. robur and Q. cerris species

In this psesent study, in order to investigate the seed biology of Q. cerris, Q. petraea and Q. robur, it was aimed to determine seed morphological and physiological characteristics, to investigate the effect of radicle pruning in pre-germination applications, to develop seed storage techniques, to establish new quality classes by determining seedling characters, and to evaluate afforestation performance according to the new seedling quality classes. Seeds of three different oak species were collected from Sinop, Samsun and Vezirköprü populations. The critical moisture content of the seeds varied between 28-31% in Q. cerris, 31-36% in Q. petraea and 32-37% in Q. robur. Radicle cutting on pre-germinated seeds of all three oak species increased the number of main roots by 1.5 to 2 times and had a positive effect on all morphological traits in general. Oak seeds were treated with thermotherapy before storage and then stored at +2°C for 24 months. The lowest germination percentage was 54% at the end of 24 months in Q. cerris. In Q. petraea, the germination percentage in the Sinop population was 60% in the 20th month, while it decreased to 68% in the Samsun population in the 8th month. In Q. robur, the lowest germination percentage was 56% at the end of 24 months. Seeds from seven populations of Q. cerris, Q. petraea and Q. robur were grown for two years in three different nurseries. Morphological characteristics and quality parameters of the seedlings were evaluated. In addition, new seedling quality class values of seedlings in 1+0 and 2+0 age groups for all three oak species were determined based on seedling height and root collar diameter. In the evaluations, it was determined that Kunduz nursery had the highest distribution rate of 1st class seedlings in all three oak species. The 2+0-year-old seedlings of Q. cerris, Q. petraea and Q. robur were monitored for one vegetation period after they were planted in the afforestation area according to their quality classes and it was found the determined that the survival percentage of the seedlings was no directly related to the quality classes of the seedlings. Determining the target seedling concept in oak species will be possible not only by considering the seed, seedling and afforestation processes independently from each other, but also by evaluating these components with a holistic and detailed approach at the regional level.