Feasibility of using Licorice (Glycyrrhiza glabra L.) Root Residue as Growth Medium and Its Effect on Growth Indices and Nutrients Uptake in Soilless Culture of Strawberry

Licorice root pulp is an organic waste which may be used as a growth medium in soilless culture. A research was conducted in a completely randomized design with 8 replications to assess the efficiency of licorice root pulp as a growth medium for strawberry plant (Selva cv.) under greenhouse conditions for three months. In this experiment, four ratios (v/v) of perlite:licorice root pulp (75:25, 50:50, 25:75 and 0:100%) were compared with cocopeat:perlite (50:50) as control. Plant growth indices and fungal population of growth medium were significantly affected by the type of medium. Fruit yield and greenness index (SPAD) values were enhanced by the cocopeat-perlite mixture; but there were not significant differences with media comprising of 25 and 50 percent of pulp residue. Bulk density, water holding capacity and fungal population in the media containing 75 and 100 percent of licorice root pulp were higher than other culture media. In addition, plants grown on 75 and 100 percent of licorice root pulp had the lowest yield and SPAD values compared to other treatments. Licorice root pulp had higher contents of nutrients such as Mn, Cu, P, Fe and Zn, but, its K and Na concentrations were less than those in the cocopeat-perlite. Concentrations of Fe and Mn in the leaves were increased, while concentrations of P and Zn were decreased, by increasing the ratio of licorice root pulp in the culture medium.