Influence of Physico.Chemical Properties of Root Substrates on the Growth of 'Maehyang' Strawberry Daughter Plants Produced by Bag Culture of Stock Plants

Abstract

ABSTRACTThis research was conducted to determine the influence of physiological and chemical properties of root substrates on the growth of the daughter plants of ‘Maehyang’ strawberry produced by bag culture. The daughter plants produced by stock plants during bag culture were individually separated and grown in 10-cm diameter plastic pots containing six different formulations of root substrates: a) 50% peatmoss plus 50% vermiculite (5:5 by volume, A), b) 70% peatmoss plus 30% perlite (7:3, B), c) 70% coir dust plus 30% perlite (7:3, C), d) mixture of 35% coir dust, 35% peatmoss, and 30% perlite (3.5:3.5:3.0, D), e) mixture of 20% rice hull, 70% coir dust, and 10% perlite (2:7:1, E), and f ) 30% rice hull plus 70% coir dust (30:70, F). The container capacity and air filled porosity of the growing medium varied g reatly among the six substrate formulations evaluated. The substrates E and F had less container capacity and higher air-holding spaces than the rest of the formulations. Therefore, these two formulations (E and F) may cause a problem in water management during the production of healthy daughter plants. The substrate formulations A, B, and D retained higher nitrogen (N) concentrations than other formulations containing coir dus t or rice hull. The substrate formulations E and F which contained rice hull had lower N, phosphorus (P), and potassium(K) concentrations than other substrate formulations containing coi r. The quality of the daughter plants grown in all six different substrate formulations was good with the crown diameters at aro und 10 mm. Fresh weights of the daughter plants grown in substrate formulations A, C, and D were higher than those obtained from B, E, and F. Dry weights of the daughter plants showed a similar trend. The daughter plants having high fresh and dry weights and increased crown diameter are in demand by the industry. For this reason, the substrate formulations A, C and D can readily be used as potting mixes during the productio n of ‘Maehyang’ strawberry transplants utilizing the bag culture system.Key words:air space, container capacity, crown diameter, dry weight, fresh weight