A RAPID PSYCHROMETRIC METHOD FOR DETERMINING THE LEAF WATER POTENTIALIN ALMOND AND LEMON TREES

Equilibration times for determining the leaf water potential (PSI(w)) of almond and lemon trees measured psychrometrically were obtained and found to be very long. The psychrometric dewpoint readings for leaves in a wide range of leaf water potential determined 5 minutes after th e sample had been introduced into the psychrometer chamber were found to be linearly related to the values obtained when temperature and vap our pressure had reached steady state. This allowed the water potentia l to be obtained in a much shorter time than usual. The water potentia ls obtained by the proposed method showed a good correlation with xyle m pressure potential (PSI(x) values obtained by a pressure chamber).