The results showed that there are no significant difference within the stomatic distribution of outer epidermis of young and aged stem and aged leaf sheath in three plants ; but there are significant or very significant difference within apex , middle and base of young and aged leaves .
Under high fertilizer condition , the soil water was consumed largely during the early period , therefore , the crop suffered severe drought stress during the procreation stage , and the net photosynthetic rate ( pn ) , transpiration rate ( tr ) and stomatic conductance ( gs ) of potato declined greatly .
