Development of a Nutrient Solution for Potato (Solanum tuberosum L.) Seed Tuber Production in a Closed Hydroponic System

수경재배용 감자 배양액 개발

To develop a nutrient solution for a closed hydroponic system in potato (Solanum tuberosum L.) 'Atlantic' and 'Superior' potatoes were grown with the nutrient solutions whose strengths were 0.25, 0.5, 1.0, and 1.5 of the concentration of the nutrient solution developed by the National Horticultural Experiment Station in Japan. The best results in potato growth and yield were obtained with 0.5 and 1.0 strength nutrient solutions, and nutrient compositions for potato were determined based on the 1.0 strength nutrient solution; $14.4me{\cdot}L^{-1}\;N,\;4.2me{\cdot}L^{-1}\;P,\;7.5me{\cdot}L^{-1}\;K,\;5.5me{\cdot}L^{-1}\;Ca$, and $3.5me{\cdot}L^{-1}\;Mg$ for stolon growth stage and $14.8me{\cdot}L^{-1}\;N,\;4.0me{\cdot}L^{-1}\;P,\;8.5me{\cdot}L^{-1}\;K,\;6.5me{\cdot}L^{-1}\;Ca$, and $3.0me{\cdot}L^{-1}\;Mg$ for tuber growth stage. To examine the suitability of the nutrient solutions developed for potato, the strengths of 1.0 (PS 1.0S), 0.75 (PS 0.75S), or 0.5 (PS 0.5S) were compared with half-strength of Japanese Horticultural Experiment Station' solution (JH 0.5S). Changes in pH, EC, and mineral concentrations in nutrient solutions depended more on solution strength and growth stage than on the type of nutrient solution. However, most elements in solution remained constant with plant age in PS 0.75S solution during stolon growth stage, and in PS 0.5S solution during tuber growth stage. The greatest growth and tuber yield was obtained in the standard strength solution (PS 1.0S), and potato solution developed in this experiment was recommended for hydroponic culture of potato in a closed system.

감자 수경재배에 적합한 배양액을 개발하고자 일본원시 표준액을 0.25, 0.5, 1.0 및 1.5배액 농도로 하여 재배하였을때, 생육과 수량이 0.5~1.0배액에서 가장 좋았기 때문에 감자의 양분흡수 특성에 적합한 농도로 판단하였다. 그러므로 표준액(1.0배액)에서의 양분흡수 특성에 따라 조성한 새로운 배양액의 이온조성은 복지 생장기에는 $14.4me{\cdot}L^{-1}\;N,\;4.2me{\cdot}L^{-1}\;P,\;7.5me{\cdot}L^{-1}\;Ca,\;3.5me{\cdot}$L^{-1}\;Mg$이며, 괴경 비대기는 $14.8me{\cdot}L^{-1}\;N,\;4.0me{\cdot}L^{-1}\;P,\;8.5me{\cdot}L^{-1}\;K,\;6.5me{\cdot}L^{-1}\;Ca$, and $3.0me{\cdot}L^{-1}\;Mg$이었다. 감자 수경재배용으로 개발된 배양액인 감자액의 적합성을 검정하고자 기존의 배양액인 일본원시액과 비교하였다. 배양액의 pH, EC 및 무기성분의 농도변화는 배양액의 종류보다는 주로 배양액의 농도와 생육단계에 의해 영향을 받았지만, 복지 생장기에는 감자액 0.75배액에서, 괴경 비대기에는 감자액 0.5배액에서 안정적이었다. 생육과 수량도 감자 표준액에서 가장 높았기 때문에 본 실험에서 개발된 배양액은 기존의 일본원시액보다 감자 수경재배에 더 적합하다고 할 수 있다.