3712:
Modeling Actual Evapotranspiration of Viburnum Odoratissimum, During Production From Rooted Cuttings to Market Size Plants in 11.4 L Containers

Tuesday, August 3, 2010: 8:30 AM
Springs K & L
Richard C. Beeson , University of Florida, Apopka, FL
Rooted cuttings of Viburnum odoratissimum were grown outdoors to market size in 11.4-L containers.  Actual evapotranspiration (ETA) of nine plants was determined daily, along with evaporation from three control containers shaded by plastic foliage to mimic plant growth. The first 60 days after transplanting, substrate evaporation accounted for most of ETA.  Substrate evaporation was generally constant the first 160 days before declining, but still remained around 160 mL/day through harvest at market size.  ETA increased with growth and generally followed variations in reference evapotranspiration (ETo).  Mean ETA during most of the production cycle was less than 600 mL/day (11.8 mm based on upper container surface area).  With the spring growth flush, mean ETA reached 1.3 L/day as plants achieved market size.  Mean cumulative ETA to produce 90% of measured plants to market size was 155 L or 3.1 m depth per plant based on container surface area.  Water need indices, similar to crop coefficients, were highly correlated with percent canopy closure.  This correlation offers a straight forward method to model shrub irrigation requirements based on plant size, spacing and ETo.