Relationships between LeafWater Potential, Stress-Degree-Day and Available Water Depletion in Almond Tree under Salinity Stress

Almond (Prunus dulcis) is an important horticultural crop in Iran especially in East Azarbaijan province. Due to the scarcity of water resources and increase in their salinity during the recent years, also economic importance of this crop in the area, studying the salinity effect on almond water relations seems crucial for irrigation scheduling. This investigation aimed to evaluate the salinity effects on some water stress indicators that can be used for irrigation scheduling in almond orchards. The study was conducted during 2014 based on randomized complete block design with three replications on a loamy sand soil at horticultural station of the State Agricultural Research Center. Treatments comprised three irrigation salinity levels viz. 2 (T1), 4 (T2), and 5 (T3) dS m-1. Air temperature (Ta) and relative humidity were taken from the meteorological site. Canopy temperature (Tc) leaf water potential (LWP) and volumetric soil water content (WC) at three depths (0-20, 0-40, and 0-70 cm) were measured at midday (12-14) during the growing season using infrared thermometer, pressure chamber and TDR respectively. Results indicated that salinity has significant effect (p