Response of stomatal resistance against water stress at different growth stages in four potato cultivars

Plant response to water-stress is controlled by plant water status. In particular, water potential (w)has been promoted as the determinant of physiological response to water-stress because of its physicalbasis, its ease of measurement, and its suitability for modeling. Maximum reduction in RWC (28%) wasobserved when water stress was imposed at tuber enlargement stage (T₃) whereas minimum reduction(12%) in relative water content (RWC) of leaf was observed when water stress was imposed at tuberinitiation stage (T₂). High stomatal resistance in plants is considered advantageous in water economyand drought resistance. In present study highest increase of stomatal resistance (278% and 256%) wasobserved in cultivar Desiree when water stress was imposed at tuber initiation stage (T₂) and tuberenlargement stage (T₃). Higher stomatal resistance in Desiree indicated its strategy for waterconservation under water stress situations.