Expansion of leaf area per plant in field bean (Vicia faba L.) as related to daily maximum temperature.
Relative rate of increase of leaf area per plant was measured in field beans during May-Aug. 1966. In the early stages of growth, until LAI reached about 3, this rate was closely related to daily maximum air temp. Published data on other temperate crops indicated that this relationship may be general up to the point at which LAI has about half of its final value. The regression equation relating the rate of leaf-area increase with maximum temp. in field beans was very similar to that for other crops and showed a Q10 of 2.1. Using this regression it was calculated that a temp. difference of 2.5°C in spring would change the time taken to reach LAI 2 by about 4 days, and that later sowing in a given year could shorten this time by up to 23 days.-R.B.