Response of Mature Olive Trees - Switching from Conventional to Drip irrigation

Response of Mature Olive Trees - Switching from Conventional to Drip irrigation

• 1.
  Response of matureolive trees to switching from conventional to drip irrigation in dry area of Morocco- Assessment of fruit and oil quality and composition Abderaouf El Antari(1,*), Lhassane Sikaoui(1), Abdelaziz Bouizgaren(1), Mohammed Karrou(2), Hakim Boulal(2), Mohammed Idrissi(1), Yamna Ouguas(1), Vinay Nangia(3), Theib Oweis(3) (1) INRA, CRRA Marrakech, BP 533 Morocco (2) ICARDA, Rabat, Morocco (3) ICARDA, Amman, Jordan
• 2.
  In Morocco, thearea of irrigated olive trees increased in the last decades to reach 35% of a total of around one million hectares. Most of this irrigated area is cultivated under traditional inefficient surface irrigation system. To overcome this inefficiency of water use, new saving irrigation methods such as drip irrigation have been promoted by the Government.
• 3.
  The objective ofthis research is to study the response of mature olive trees to switching from conventional to drip irrigation.
• 4.
  For this purpose:  A trial was conducted in a 36-years old irrigated olive orchard (var. Picholine marocaine) at the Tessaout experiment station of INRA Marrakech characterized by a hot and dry summer Mediterranean climate.  Five treatments are tested : T1= Flood irrigation (farmer’s use) T2= Minimum tillage with drip irrigation (100% x ETc) T3= Minimum tillage with drip irrigation (70% x ETc) T4= Deep tillage with drip irrigation (100% x ETc) T5= Deep tillage with drip irrigation (70% x ETc)
• 5.
  Estimated fruit yieldunder the five studied treatments.
• 6.
  Olive average weightunder the five studied treatments.
• 7.
  Maturity index ofolives under the five studied treatments Treatments Maturity index T1 (Flood irrigation) 2.2 b T2 (Min Till 100 % ETc) 3.04 a T3 (Min Till 70 % ETc) 2.87 a T4 (Deep till 100 % ETc ) 2.94 a T5 (Deep till 70 % ETc ) 2.69 a
• 8.
  Oil yield (Kg/Ha)of olives under studied treatments Treatments Maturity index Oil yield (Kg/Ha) T1 (Flood irrigation) 2.2 b 1244,0 T2 (Min Till 100 % ETc) 3.04 a 1531,4 T3 (Min Till 70 % ETc) 2.87 a 1607,0
• 9.
  Treatments Viscosity (%) Colorindex L* a* b* T1 (Flood irrigation) 3.27 ab 69.79 -6.58 46.77 T2 (Min Till 100 % ETc) 3.44 ab 54.68 -3.02 28.19 T3 (Min Till 70 % ETc) 3.82 b 59.82 0.14 15.02 T4 (Deep till 100 % ETc ) 3.72 ab 38.62 -0.03 23.75 T5 (Deep till 70 % ETc ) 3.16 a 36.23 0.18 21.94 Viscosity and color index of olive oils obtained under studied treatments.
• 10.
  Treatments E232 E270 Oil bitterness Totalpoly-phenols (ppm) T1 (Flood irrigation) 1.41 0.106 0.900 292.46 T2 (Min Till 100 % ETc) 1.56 0.091 0.540 236.96 T3 (Min Till 70 % ETc) 1.60 0.103 0.510 222.83 T4 (Deep till 100 % ETc ) 1.54 0.087 0.464 183.80 T5 (Deep till 70 % ETc ) 1.43 0.092 0.554 201.97 Specific extinction, bitterness and total poly-phenols of olive oils obtained under studied treatments.
• 11.
  Treatments C16:0 C16:1 C18:0C18:1 C18:2 C18:3 Mono/Poly T1 (Flood irrigation) 9.83 0.57 2.62 74.05 11.31 0.97 6.10 T2 (Min Till 100 % ETc) 9.85 0.57 2.83 73.38 11.82 0.95 5.87 T3 (Min Till 70 % ETc) 10.14 0.62 2.47 73.78 11.33 1.00 6.13 T4 (Deep till 100 % ETc ) 9.86 0.57 1.81 75.02 11.10 0.99 6.29 T5 (Deep till 70 % ETc ) 9.77 0.57 2.21 75.67 10.11 0.98 6.91 Mayor fatty acids content of olive oils obtained under studied treatments
• 12.
  Sensoriel profils ofpositif attributs under deficit and full irrigation
• 13.
  Specific aromatic profilsunder deficit and full irrigation
• 14.
  Hedonic test The organolepticquality of extracted olive oils was tested by 60 farmers in a hedonic test : 80% of participants had appreciated and prefered oil produced under deficit irrigation.
• 15.
  Conclusion 1/2  highestolive fruit yield and fruit olive weight were obtained under deep tillage and deficit irrigation.  maturity index was shown no significant effect between minimum and deep tillage, and between full and deficit irrigation  olive oils from the various treatments were quite viscous and the higher values were obtained under minimum tillage with deficit drip irrigation (T3).  No significant effect of oil color index was noted between studied treatments  The specific extinction values indicated that olive oils obtained under all studied treatments had a high potential stability
• 16.
  Conclusion 2/2  thehigh values of total phenols content and bitterness were obtained with flood irrigation treatment (T1).  The composition of the total fatty acids of olive oils did not show significant differences among studied treatments.  sensory evaluation of olive oil indicated that under deficit irrigation (70% x ETc), the expression of sensorial positive attributes was more intense and the specific aromas were clear with a good expression, harmony and complexity of attributes.  80% of participants in hedonic test had appreciated and preferred oil produced under deficit irrigation
• 17.
  Thank you