The optimal level of oxygen in rhizosphere and the differences in the accompanying physioecological adaptations with the different levels of oxygen in aeroponics were investigated in order to establish an ideal system of soilless culture. The levels of oxygen of rootzone were regulated four levels, which were 10, 20, 30 and 40%. The level of oxygen was controlled by liqufied oxygen gas. The tomato cultivar ´Seokwang´ which was bred for forcing culture were served for this experiment.
1. The growth of top parts were better in the 20% and 30% plots than in the 10% or 40% plot.
2. The root growths were similar among the 10%, 20% and 30% plots, while those were better than in the 40% plot.
3. The photosynthetic activity were almost double in the 20`% and 30% level of oxygen than in the 10% or 40%, but the leaf and root respirations were less affected by the level of oxygen of rootzone.
4. The chlorophyll contents in the 10%, 20% and 30% plots were 2.88∼2.92㎎/g, while it in the 40% plot was 2.19㎎/g.
5. CGR in the 20% and 30% plots which were 2.47 and 2. 96g/㎡/day, respectively, were about 1.8 times greater than those in the 10% or 40% plot, but NAR in the 40% plot was higher than those in the 10%. 20% and 30% plots. However, RGR, SLA, LAR and T/R ratio did not significantly differ among the treatments. While LAI and root number/root length ratio were significantly differed by the different level of oxygen of rootzone.
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