Response of photosynthetic characteristics and yield of grape to different CO concentrations in a greenhouse.

Due to the enclosed environment of greenhouse grape production, the supply of CO required for photosynthesis is often insufficient, leading to photosynthetic downregulation and reduced yield. Currently, the optimal CO concentration for grape production in greenhouses is unknown, and the precise control of actual CO levels remains a challenge. This study aims to investigate the effects of different CO concentrations on the photosynthetic characteristics and yield of grapes, to validate the feasibility of a CO gas irrigation system, and to identify the optimal CO concentration for greenhouse grape production.