RAPID WATERING TO ACHIEVE PARTIAL SATURATION OF ROOT MEDIUM ON FLOODED FLOORS

Sub-irrigation for production of potted ornamental plants combats the waste of water and fertilizer in traditional overhead watering systems used in greenhouses.
However, current ebb and flow watering systems for flooded floors operate slowly.
The root medium takes up water to near saturation during each watering cycle.
There is no ability to restrict the water provided to the plants.
We have examined a system to rapidly deliver and remove water.
Less water is absorbed by the root medium and little if any water drains out of the pots.
This improves plant quality and prevents spread of disease.
We examined several parameters that vary between this partial saturation ebb and flow watering on a flooded floor compared to full saturation watering.
Plants took up 20 to 30% less water and fertilizer.
Biomass until flower development and bloom, and stem height, were also reduced by 10 to 20% under partial saturation.
In one experiment with Poinsettia, inoculation of some plants with Pythium resulted in wilting of 20 of 240 non-inoculated plants grown under full saturation.
No plants were affected under partial saturation.
Postharvest quality of leaves and flowers in a controlled environment were similar under the two watering regimes.

International Symposium on High Technology for Greenhouse Systems: GreenSys2009

M.P.N. Gent, W. Elmer, R. McAvoy

ebb and flow, growth, moisture content, water use

https://doi.org/10.17660/ActaHortic.2011.893.121