Abstract
Tomato seedlings were grown in a Wet-sheet culture (WSC), where roots developed in the wet atmosphere, or in a Deep flow technique (DFT), where roots were submerged in the solution.
Differences in water and nitrate absorption between tomato roots in the WSC and DFT were compared at four-root temperatures; 17, 27, 33 and 45°C. Root dry weight in the WSC was larger than in the DFT, whereas whole plant weights in the both systems were equal. Water absorption rates on whole root were almost equal in the both systems at all temperature. On the other hand, nitrate absorption was greater in the WSC than the DFT at 45°C, but no significant differences were observed at other temperatures. Root respiration in the DFT showed an increase as the root temperature increased from 17°C to 33°C, but decreased at 45°C. We suggested that roots in the wet atmosphere would be more tolerant to supraoptimal temperature than those in the solution, in part because of keeping with its activity.
