Temporal changes of plant water potential and stomatal conductance of olive (cv memecik) tree under the deficit irrigation

This study was conducted in Bornova Olive Research Institute of the Ministry of Food, Agriculture and Livestock, in 2013. In this study, temporal change of the stomatal conductance(gs), plant water potential(YSP) and canopy-air temperature difference (Tc-Ta) under the deficit irrigation conditions was observed in Memecik cultivar. Also regression and correlation analysis between the stomatal conductance and plant water potential and some meteorological parameters was performed and the relationship between them were investigated. Irrigation treatments; K1: non-irrigated (rainfed), K2: soil water deficit in a 90 cm soil depth was refilled to field capacity for every 5 days, K3: application of the 33% of water given at K2, K4: 3 times application of the 50% of the soil water deficit in a 90 cm soil depth concerning 3 growing stages; seed hardening, fruit growth and oil accumulation, K5: 3 times application of the 25% of the soil water deficit in a 90 cm soil depth concerning 3 growing stages; seed hardening, fruit growth and oil accumulation. According to the treatment, the irrigation water requirement was varied between 0 to 813.9 mm and ETa is varied between 128 to 785 mm. The results of experiments showed that the difference of water potential between the treatment were statisticaly significant. It is also same for stomatal conductance and canopy-air temperature difference. In this study, the relationship between stomatal conductance and plant water potential were found a statistically significant. The correlation coefficient of the relationship was 0.708 and r2 was equal with 0.501. The correlation between meteorological data (such as wind speed, solar radiation, soil temperature and the vapor pressure deficit) and stomatal conductivity and plant water potential has seen to be weak or insignificant. This result is due to the influence of several parameters simultaneously under field conditions, individually the independent effect would not be explainable.