Holzfasersubstrat zur kultur von pelargonium-zonale-hybriden - Biophysikalische und pflanzenbauliche untersuchung

Wood fibre and peat substrates were compared by different watering strategies on a Pelargonium hortorum culture. Mass growth and morphogenesis of plants depended on amount of water supply and nutrient solution. It was possible to divide into two groups: the vegetative growth in wood fibre was as strong as in peat substrate if watered and therefore fertilized more often (at -60hPa). By watering less (at -90hPa) a clearly reduced mass growth in both wood fibre and wood fibre/peat mixture substrates was noticed. An early flowering effect was noticed by both of the wood fibre treatments and a distinct zonation of leaves of plants in wood fibre watered at the -90hPa variation was shown. The strongest root growth was noticed by the wood fibre (-60hPa), especially at the bottom of the pot. Gas exchange measurements showed a higher evaporation and faster increase of soil moisture tension in peat, but a higher CO₂ exchange rate in wood fibre. The capacity for water uptake depended on the degree of substrate humidity. Compared with peat there was a faster water uptake of wood fibre with increasing dryness of the substrate. Typical for wood fibre at intermittent irrigation was the formation of a dry closing layer at the substrate surface.