Optimizing carbon dioxide enrichment with environmental management to improve photosynthesis, water use efficiency and yield in cucumbers: a meta-analysis study.

Despite the ongoing increase in atmospheric carbon dioxide concentrations, these levels remain well below the optimal threshold for cucumber growth and development. To address the challenges posed by climate change to agricultural production, carbon dioxide enrichment (eCO2) has been widely used to meet the global demand for vegetables. However, the effects of eCO2 and environmental factors on cucumbers remain unclear. In this study, we conducted a meta-analysis of 73 studies to analyse the responses of cucumber photosynthesis, biomass accumulation and yield to eCO2. Our findings revealed that eCO2 significantly increased the net photosynthetic rate by 56.31%, water-use efficiency by 121.11%, biomass by 27.75% and yield by 21.98%. The optimal eCO2 concentration for cucumber production was found to be 800-1200 ppm. Combined application with high light intensity, a suitable temperature, humidity and fertiliser was found to have a synergistic effect. Our findings support the regulation of greenhouse environments for cucumber cultivation in the context of climate change, promoting the green and sustainable development of the cucumber industry.