A Physiological Study of Developing Pods and Leaves Honey Mesquite

Abstract

Photosynthetic and respiratory rates of developing pods and fully expanded leaves of mesquite were assayed during 1972 to determine whether current photosynthesis was sufficient to supply the demands of the developing pods or whether reserve carbohydrates from the roots were required. Net photosynthetic rates of developing pods were very low when expressed as a function of dry weight, whereas the rates of CO2 evolution were high, suggesting a very active metabolic rate. Leaf photosynthetic rates were comparable to reported rates for other tree species. From the data collected, it was concluded that current photosynthate could not supply the amount of organic matter needed for pod development on trees possessing heavy fruiting loads, and reserve carbohydrates would be needed during the period of maximum rate of dry matter accumulation by the pods.