Olive mill wastewater spreading effects on productivity and oil quality of adult chemlali olive (Olea europaea L.) in the South of Tunisia

In the present work, olive-crop yields and olive oil physico-chemical quality were studied after three and six years of olive mill wastewater (OMW) spreading at three levels (50, 100 and 200 m3 ha-1 year-1). Olive yield showed improvements with OMW level. Insignificant difference in oil content and oil quality indices of the control and treatments amended by OMW was observed. Moreover, olive oil acidic composition showed invariability after all OMW rates application. However, the extracted oils from the three-treated olive plots presented the higher tocopherol values. OMW spreading at different rates influenced significantly the oil total phenol contents. While -sitosterol, campesterol and stigmasterol contents showed increases after six successive spreading with a high percentage in the 100 OMW m3 ha-1 treatment, cholesterol and -7-stigmastenol contents didn’t exhibit any significant difference between the experimented treatments. After OMW treatment, the olive oil quality was that of virgin extra category. * Corresponding Author: Emna Ammar  [email protected] International Journal of Agronomy and Agricultural Research (IJAAR) ISSN: 2223-7054 (Print) 2225-3610 (Online) http://www.innspub.net Vol. 6, No. 6, p. 56-67, 2015 International Journal of Agronomy and Agricultural Research (IJAAR) ISSN: 2223-7054 (Print) 2225-3610 (Online) http://www.innspub.net Vol. 5, No. 1, p. 14-22, 2014