Rooting medium temperature and carbohydrates affected oleander rooting

Winter rooting capacity of semihardwood oleander (Nerium oleander L.) cuttings is reduced compared to other seasons. In this work the temperature regime was increased to different levels (¿18°C, ¿25°C, ¿32°C) to improve winter rooting. Starch and main soluble carbohydrates (glucose, fructose and sucrose) were analysed at rooting days 0, 19 and 60, due to their participation in the rooting process. Higher temperatures increased the percentage of rooting and some of the root growth parameters measured in the experiment (root length, root dry weight, etc.). The Basal Root Distribution Index was reduced with increasing temperature, in such that the distribution of roots in the basal section was more homogeneous than at lower temperatures. The temperature regime did not significantly affect carbohydrate mobilization, but initial starch level and the reduction in overall carbohydrates were significantly related to final rooting values, meaning that they participated in the rooting of cuttings of this species native to the southeast of Spain.