Influence of Different Rates of Irrigation to Olive Trees on Fruits Yield, Quality and Sensory Attributes of Olive Oil Output.

   An experiment was carried out in olive farm in Wady-El Natron, El Behera governorate, Egypt, to study the influence of deficit rate in different amounts of  irrigation water, 96, 64 and 32 liter water / tree per hr.( at rates 80, 53.3 and 26.6 %, respectively) are given to olive trees (Coratina and Dolce vars.), and its compared with 120 liter water / tree per hr. (at rate 100%) as a control on the chemical composition, promological parameters of olive fruits (fruit characteristics) and fruits yield and also on the quality parameters, fatty acids composition, natural antioxidant contents, stability and organoleptic characteristics (sensory attributes) of the extracted oils from olive fruits. The results showed that:-
The fruit characteristics of olive trees (Coratina and Dolce vars.) were affected by different amounts of irrigation water whereas, 100- fruit weight, fruit weight, pulp weight and pulp/stone ratio showed statistical variation at a significance level of 5% according to the level of irrigation water applied, generally these parameters gradually decreased with lowering amount water during irrigation for two varieties. Values of FFA, PV, K232, K270 and Δk of olive fruits oil decreased gradually by decreasing the amounts of irrigation water are given to olive trees in both two varieties. Oils from the 32 liter water / tree treatment had higher contents of oleic acid, total polyphenols and O-diphenol, higher oleic / linoleic and TUSFA / TSFA ratios and the highest oxidative stability, despite their lower total tocopherols, carotonids and chlorophyll contents compared with other treatments. Gradual reducing amount of irrigation water caused gradually an increase in fruitiness, bitterness and pungency in virgin olive oils in both two varieties.