Determination of Daily Amount of N and K Required in Various Growth Stages and Establishment of Diagnostic Criteria Using Petiole Sap Analysis in the Semi-Forcing Culture of Cucumber

This study was conducted to determine the daily application rate and amount of N and K with fertigation during different growth stages in semi-forcing culture of cucumber plants (Cucumis sativus L. cv. Eunseongbaekdadagi). The diagnostic criteria for N and K also investigated based on petiole sap analysis. The dry weight increased slowly until 30 days after transplanting. The highest dry weights were observed at 60 days after planting, then it decreased. As the plant grew, the contents of N and K in the petiole sap and fruit of cucumber decreased. The daily uptake of N and K were highly correlated with the growing days. The $NO_3$ concentrations in petiole sap were in the range from 3,500 to 4,500 mgㆍ$L^{-1}$ in the early growth stage, but those were in the range from 2,000 to 3,000 mgㆍ$L^{-1}$ after then. However, K concentration in petiole sap were in the rang from 5,000 to 7,000 mgㆍ$L^{-1}$ The fluctuation in petiole sap concentration of K was severe in the monthly fertigation and moderate in the daily fertigation. The fertigation by petiole sap diagnosis forced EC of soil to be low and yield to increase compared to the control.

반촉성 관비재배 오이의 생육단계별 시비관리를 위한 일일시비량 및 엽병즙액의 농도 기준 설정