Effects of Light and Dark Conditions on Root Development of Black Mulberry (Morus nigra L.) Hardwood Cuttings

This study was carried out to determine the root development of black mulberry hardwood cuttings kept in light and dark conditions. The experiment was carried out in the polyethylene greenhouse of Tokat Gaziosmanpaşa University Research and Application Center, in 2021. As material, hardwood cuttings prepared from one-year-old branches of black mulberry trees were used. The cuttings were divided into 3 different groups and planted in rooting beds containing perlite with bottom heating (22±2 °C). First group of cuttings were planted into beds as soon as taken from tree (control), the second group of cuttings were plantend after the cuttings were kept under daylight conditions for 5 days (in the open) and third group cuttings were planted after the cuttings were kept in the dark conditions (in the dark) for 5 days in both conditions soaked in water. All cuttings were dipped in 6000 ppm IBA (indole-3-butyric acid) hormone for 5 seconds just before planting. The experiment is with 3 replications and there are 15 cuttings in each replication. After keeping 90 days in the rooting environment, the cuttings were removed; root number (root/stem), root length (cm), root diameter (mm), decay rate (%), rooting rate (%) and callus formation rate (%) parameters were investigated. As a result of the study, there was no statistical difference between the different conditions in the investigated parameters. The data obtained varied between the following values; rooting rate between 68.89% - 93.33%, decay rate between 24.4% - 55.5%, callus formation rate between 68.8% - 88.8%, number of roots 8.8 - 13.5 root/stem, root length 6.5 - 7.4 cm and root diameter between 1.02 - 1.16 mm.