Effects of Different Auxin Concentrations on Growth of Autumn Olive (Elaeagnus umbellata Thunb.) Saplings

Autumn olive (Elaeagnus umbellata Thunb.) is a versatile plant used for numerous purposes in nature, distinguished by its medicinal and ecological benefits. Its ability to adapt and grow in challenging environmental conditions, improve soil, and survive with minimal water makes it a critical species, particularly in combating climate change. While this highly important plant can be propagated from seed, studies on its vegetative propagation are limited. The success of vegetative propagation is not solely a dependent on obtaining rooted cuttings; it depends on the production of high-quality saplings from these cuttings. Therefore, data on the effects of saplings grown from rooted cuttings on long-term growth performance are important to demonstrate the success of the application. This study was conducted to determine the optimal Indole-3-Butyric Acid (IBA) concentration for the growth of surviving individuals obtained from rooted cuttings at different time intervals (June 19, 2023, and December 8, 2023) over a period of one and a half years. For this purpose, the effects of different concentrations of Indole-3-Butyric Acid [IBA (1000 ppm, 5000 ppm, and 8000 ppm)] on the root collar diameter and sapling height in Elaeagnus umbellata saplings propagated from cuttings were investigated. A control group was also created without hormone application. It was found that IBA application improved the growth of E. umbellata saplings, but the first year of measurements were not sufficient to assess growth performance. Among the hormone concentrations tested over the long term, a dose of 5000 ppm IBA was found to be more effective on growth (p<0.05). The success of vegetative propagation depends on obtaining high-quality saplings that meet the desired standards. Therefore, to achieve long-term results, the rooting and sapling production processes must be considered.