GROWTH OF MAGNOLIA UNDER THREE IRRIGATION SYSTEMS IN A WOODY ORNAMENTAL NURSERY

Supplying ornamental plants for landscaping is a challenge and an opportunity for the large and competitive nursery industry. Offering better products with lower prices demands application of improved technologies and more efficient management of agricultural practices, including irrigation systems and water saving strategies. This paper reports the effects of three different irrigation systems on plant growth parameters of one-year-old magnolia plants (Magnolia grandiflora ‘D.D. Blanchard’), in 56.8-L plastic containers. The study was carried out in a commercial nursery in Florida, USA. Irrigation variables and plant growth parameters of magnolia were monitored during a period of 12 months. There were significant effects of irrigation systems on plant heights and growth indexes during the study. In both cases, the overhead sprinkler irrigation system produced smaller plants than microirrigation and ebb and flow systems. However, increases in both parameters on a percentage basis were similar for the overhead sprinkler and ebb and flow systems and highest for the microirrigation system. The results suggest that the water use efficiency of the microirrigation system may be higher than the other two systems. Clearly, irrigation system selection and management practices have important impacts on plant growth, and also on water savings. The potential of these irrigation systems, or a combination of their structures, according to the local conditions, should be considered when planning nurseries to grow magnolias and, probably, other container-grown woody ornamental plants.