Surface sterilization of English oak (Quercus robur L.) acorns using wet water steam
Effective and environmentally friendly methods of protection to reduce seed contamination from fungi are constantly sought. The use of thermal impulses of 100 °C wet water steam to reduce fungal contamination has not been sufficiently investigated, and the potential of this physical approach has not been estimated.The aim of the study was to investigate what impact 100 °C wet water steam with different time durations had on acorn contamination with fungi, acorn germination and biometric indicators of English oak (Quercus robur) seedlings during the first year of growth. Different treatment durations with wet water steam were used: 2, 4, 6, 8, 10, 12 and 14 s.Research showed that 6 seconds impact of wet steam on the surface of the oak acorn destroyed Alternaria spp., 8 seconds impact destroyed Penicillium spp. and 14 seconds impact destroyed Mucor spp. Using 14 seconds water steam treatment Penicillium, Alternaria and Mucor spp. fungi were eliminated.Wet water steam treatment for 2 - 4 seconds not only stimulated the acorns germination by 4.0 - 7.6%, but also had positive influence on the root collar diameter of seedlings. Wet water steam treatment for 2 - 12 seconds had a positive effect on the root development of oak seedlings, however, high temperature environment had a suppressive effect on the oak seedling height.
Keywords: biological control, wet water steam, fungi, oak acorns, seedling production