Diurnal and seasonal changes in the diffusion resistance of potato leaves and their differences between the adaxial and abaxial leaf surfaces and between three leaf positions on the stem.

摘要

Field measurements of the diffusion resistance (DR) of adaxial and abaxial leaf surfaces at three leaf positions of the main stem were recorded during the growing seasons of 1993 and 1994 using 2 potato cultivars with different root mass. DR was about 2- to 5-times higher for the adaxial leaf surface than the abaxial leaf surface, and higher in lower leaves throughout the growing season. DR of both leaf surfaces were lowest in the morning, increased in the afternoon and were highest in the evening.After rainfall, DR was low on all leaf surfaces regardless of leaf age. DR was higher in the warmer 1994 season than the cooler 1993 season. There was no correlation between root mass and leaf DR.