The Effect of Temperature on Photosynthesis of Ryegrass and White Clover Leaves

The rate of photosynthesis of leaves of perennial ryegrass (Lolium perenne L.) and white clover (Trifollum pratense L.) grown at different temperatures was measured at a range of temperatures. There was a small effect of the temperature at which a leaf had grown on its photosynthetic rate, but a large effect of measurement temperature, especially in bright light, where photosynthetic rates at 15°C were about twice those at 5°C. It appears that temperature could affect sward photosynthesis in the field. Ryegrass and clover had similar photosynthetic rates which responded similarly to temperature.