Combined Application of Supplemental Lighting and Solid CO2 Generators to Improve the Growth, Yield, and Profitability of Winter Greenhouse Cucumber Cultivation

To enhance the productivity of greenhouse cucumbers during periods of low solar radiation, we evaluated the effects of the simultaneous application of supplemental lighting and CO 2 enrichment using solid CO 2 generators on growth, fruit quality, and yield outcomes.The study period was 75 days and plants were in a plastic greenhouse divided into ambient (control) and buffer zones along with a zone with simultaneous supplemental lighting and solid CO 2 generators (SL+sCO 2 ).When female flowers began to bloom, light-emitting diodes (LED) with a red:blue ratio of 5:5 were used for supplemental lighting, and solid CO 2 generators were used to increase CO 2 concentrations.Supplemental lighting was provided for 4 h immediately after sunrise at a light intensity level of 150 µmol•m -2 •s -1 .The use of solid CO 2 generators increased CO 2 concentrations by an average of 217 ± 67 µmol•mol -1 compared with the control.SL+sCO 2 significantly increased the plant height, number of leaves, number of nodes, and SPAD values compared with the control.The overall number of female flowers was higher in the SL+sCO 2 case than in the control, and SL+sCO 2 exhibited significantly greater fruit widths as well as fresh and dry weights.The yield of SL+sCO 2 was 18% higher than that of the control.An economic analysis revealed that SL+sCO 2 generated additional net income of 4,796,415 KRW•10 a -1 , with the income ratio increasing by 21% over the control.These results suggest that the simultaneous application of supplemental LED lighting and solid CO 2 generators effectively improves fruit quality, yield, and farm income outcomes during winter greenhouse cucumber cultivation while also providing practical insights for overcoming low-radiation constraints.