Rhizogenesis and gas exchange in dogwood stem cuttings as affected by two biostimulators

The UE-imposed restrictions on the manufacture and use of plant protection chemicals necessitate screening for new substances that are more environmentally friendly. Biopreparations may constitute such a group; therefore, studies on their efficiency in the production of plant material are needed. This study evaluated the effects of two biostimulators on rhizogenesis and the gas exchange rate (respiration, photosynthesis, transpiration) of stem cuttings of dogwood (Cornus alba) as compared to conventional treatments with a rooting powder containing 2% auxin IBA and with aqueous IBA solution. Both biopreparations enhanced rhizogenesis; their efficiency varied depending on the cultivar, biostimulator applied, and the number of treatments. There was no relationship between rhizogenesis and physiological parameters tested. The experiments demonstrated that at least some biopreparations have potential in commercial production but their effectiveness may be different in different species and under different conditions.