Net photosynthesis
The rate at which a leaf gains carbon through photosynthesis after subtracting carbon released by respiration and photorespiration.
Gross photosynthesis is the total carbon fixed by photosynthetic reactions. Net photosynthesis subtracts carbon returned through respiration and, in C3 plants, photorespiration Photorespiration A carbon-recycling pathway initiated when Rubisco reacts with oxygen instead of carbon dioxide, consuming energy and releasing some previously fixed carbon. . The remainder represents the leaf's net carbon gain under the measured conditions.
Gas-exchange instruments commonly report net carbon dioxide assimilation per unit leaf area and time. Light, carbon dioxide, temperature, water status, nutrition, leaf age, and stomatal behavior can all affect the result.
Higher net photosynthesis can support growth, but it does not translate directly into flower yield. The plant must also allocate the additional carbon among leaves, stems, roots, flowers, storage, and maintenance.