CHRYSANTHEMUM CULTIVATION IN A SOILLESS EBB/FLOW SYSTEM: INTERACTION OF NaCl, MINERAL NUTRITION AND IRRIGATION FREQUENCY

To study whether adverse consequences of NaCl in the root environment were influenced by irrigation frequency a trial was conducted using soilless ebb-and-flow irrigation with chrysanthemum.
Three treatments with different NaCl concentrations (0, 6 and 12 mmol/l) were applied at an equal electrical conductivity (EC 2.0 dS/m) of the nutrient solution in combination with two irrigation frequencies (1 and 3 times/hour).

A high NaCl concentration reduced growth.
In particular stem weight was reduced, inducing an increased leaf/stem ratio (g/g fresh weight). Both internode length and stem diameter were related with the reduction in stem weight.
An increase in the ebb-and flow irrigation frequency partly could prevent growth reduction.
Analysis of dried leaf material showed that the growth reduction was probably caused by decreased nutrient uptake, as leaf concentrations of NO₃, N-total, K, Mg and P were decreased.

Growth was decreased below a nutrient-EC of 1.2 dS/m at the high irrigation frequency.
At the lower frequency growth reduction occurred below 1.8 dS/m.

International Symposium on Growing Media & Plant Nutrition in Horticulture

M.G. Warmenhoven, R. Baas

https://doi.org/10.17660/ActaHortic.1995.401.48