Abstract
Establishment of cashew trees often fails due to drought damage at the seedling stage although cashew is an important cash crop in Indonesia. To determine whether the ability to maintain water transport in xylem, which is often responsible for plant adaptation to drought, is a suitable parameter for early evaluation of drought resistance at the seedling stage, differences in xylem vulnerability to dysfunction and the relationship to xylem vessel diameter were examined in ten high-yielding strains in cashew. The xylem vulnerability was evaluated by the applied pressure which induced 50% loss of stem hydraulic conductivity (P50) . Variation in the P50 value from 0.32 MPa for Wonogiri to 1.50 MPa for A3-1 was recorded among the strains. However, since there was no difference in the mean vessel diameter, the use of the vessel diameter was not suitable for the evaluation of xylem vulnerability. Since a strain such as A3-1 may maintain the water continuity in the xylem under drought conditions, it was suggested that the plant ability to maintain the water continuity in the xylem would be a suitable parameter for the early evaluation of drought resistance at the seedling stage in cashew.
