Abstract
The present study was undertaken to evaluate the physiological characteristics of strawberry plants‘Nyoho’ affected by the nutrient concentration and NH4-N ratio to the total N. The treatment was combined two levels of nutrient concentration (EC 0.9, 1.7 mS/cm) and three levels of NH4-N ratios (10%, 20%, 30%) .
The higher fresh weights were observed in plants with the low nutrient concentration of 30% NH4-N ratio, and with the high concentration of 20% NH4-N ratio. The greater total fruit yield was obtained in plants with the low nutrient concentration of 30% NH4-N ratio as compared with the other plots. The distribution of 13C-assimilates to the root decreased in the high nutrient concentration. In the case of the low nutrient concentration, the distribution of assimilates decreased in the terminal cluster and increased in the lateral cluster at the ratio of 30% NH4-N. The decrease in C-N ratio was observed in plants with the high concentration of 20% or 30% NH4-N ratio. The potassium content in the root increased in plants with higher nutrient concentration and/or higher NH4-N ratios. The esculin oxidized in the root increased with increasing NH4-N ratios in the nutrient solution.
It is concluded that the better plant growth and higher yield were obtained in the plants grown with the low nutrient concentration of 30% NH4-N ratio. This may be due to increased translocation of assimilates to the root, increased phosphorus and potassium contents in the root, and increased respiration rates in the root.
