Alteration of NO - 3, PO 3- 4 and SO 2- 4 Concentration on rose plants in response to greenhouse climate parameters and their concentration in the nutrient solution

Abstract

The objective of this work was to quantify temporal changes of NO - 3, PO 3- 4 and SO 2- 4 concentration on leaves, shoots and roots of rose plants during a short growing period, in response to air temperature, light intensity and the concentration of the above mentioned anions in the nutrient solution. For this reason rose plants (×Rosa hybrida 'Iceberg') were placed in a glasshouse during September 2004 and grown in nutrient solution according to the Deep Flow Technique (DFT). The plants were pruned in order to develop one main flower shoot. Measurements were performed during December 2004. The concentration of NO - 3, PO 3- 4 and SO 2- 4 (mg L -1) in the nutrient solution and in different plant parts (mg kg -1) as well as the fresh (fw) and dry (dw) weight of leaves, shoots and roots were measured every day, by destructive sampling of 6 plants each time, for a period of 28 days. In addition during the same period the greenhouse air temperature and the intensity of the incoming solar radiation were continually recorded. The concentration of NO - 3 and PO 3- 4 in leaves was significantly affected by i) the intensity of the incoming solar radiation and ii) the concentration of NO - 3 and PO 3- 4 in the nutrient solution. The concentration of NO - 3 and PO 3- 4 in shoots was affected by the above mentioned parameters and by the greenhouse air temperature. Alteration of NO - 3 concentration in the nutrient solution causes an instant alteration of NO - 3 concentration in leaves and a delayed alteration of NO - 3 concentration in shoots. In contrast, alteration of PO 3- 4 concentration in the nutrient solution causes a delayed alteration of PO 3- 4 concentration in both leaves and shoots. The concentration of NO - 3 and PO 3- 4 in roots and SO 2- 4 in shoots and roots was not strongly related to the above mentioned greenhouse climate parameters and the concentration of NO - 3, PO 3- 4 and SO 2- 4 in the nutrient solution.