Summary:

Irrigation of ornamental plants nurseries because of the diversity of species grown there, requires considerable water supplies. The using of inappropriate intensity of irrigation in relation to water needs of plants is the cause of the deterioration of their quality and requires a significant investment of work related to control of their growth. Suitable irrigation enables the control of plant growth and development and also the reduction of water resources used and the costs associated with the labour. As a consequence, it may affect significantly the improvement of the competitiveness of the nursery and the reduction of the environment hazard caused by unreasonably high use of natural water resources. Regulated Deficit Irrigation (RDI) is a method consists in limitation or in complete cessation of irrigation during the appropriate plant development phase, in a way that it does not cause damage, deterioration of quality, flowering, crop yield and post-harvest stability. The periodic water deficit applied at the appropriate time and with suitable intensity allows to control plant growth and development, and also reduces water using during their growing significantly. This method has proved to be effective in reducing water using and improving yield in many species of fruit plants. The potential application of RDI to ornamental shrubs growing has received less attention. However, in recent years conducted experiments have demonstrated the positive impact of the use of controlled deficit irrigation in the cultivation of this group of plants. This paper discusses the physiological basis of resistance of trees and shrubs on deficit irrigation, and the potential use of Regulated Deficit Irrigation method (RDI) in nursery production