Growth and water use efficiency of potted Murraya paniculata as affected by irrigation system and container size

Irrigation system and pot size can affect the growth and development of containerized ornamental crops. A greenhouse experiment was carried out from November 2011 till July 2012, in order to determine the influence of two irrigation systems (closed drip-irrigation or subirrigation) and two pot sizes (∅14 or 18 cm) on growth, chlorophyll content, leaf gas exchanges and water use efficiency (WUE) of potted Murraya paniculata. Subirrigation offered promising potential for M. paniculata when compared to drip-irrigation given the similar growth and the higher WUE. Lower variation of the electrical conductivity in the subirrigation in comparison to drip-irrigation represents a crucial aspect for the simplification of the nutrient solution management. Increasing the pot size from 14 to 18-cm diameter yielded plants with 156%, 30%, 43%, and 138% more shoot biomass, height, leaf number and area, respectively. Best performance of plants grown in 18 cm-pots was attributed to higher net photosynthesis and SPAD index (by 35% and 16%, respectively), suggesting that suitable manipulation of container volume and switching from drip-irrigation to subirrigation will yield high quality potted M. paniculata and improve WUE.