Romero-Trigueros Cristina, Vivaldi Gaetano Alessandro, Nicolás Emilio Nicolás, Paduano Antonello, Salcedo Francisco Pedrero, Camposeo Salvatore
Dipartimento di Scienze Agro-Ambientali e Territoriali, Università degli Studi di Bari Aldo Moro, Bari, Italy.
Department of Irrigation, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Murcia, Spain.
Front Plant Sci. 2019 Oct 9;10:1243. doi: 10.3389/fpls.2019.01243. eCollection 2019.
The 70% worldwide surface of olive orchards is irrigated. The evaluation of non-conventional water resources and water-saving techniques has gained importance during the last decades in arid and semiarid environments. This study evaluated the effects of irrigation with two water sources: low-cost water DEsalination and SEnsoR Technology (DESERT) desalinated water (DW) EC ∼1 dS m) and reclaimed water (RW) (EC ∼ 3 dS m) combined with two irrigation strategies: full irrigation (FI) (100% of ET) and regulated deficit irrigation (RDI, 50% of ET) on fruit yield, ripening indices, and oil yield and quality of olive trees cv Arbosana planted in Mediterranean conditions. Our results showed that RW without water restrictions increased the fruit yield by 35% due to a slight increase in the fruit weight and, mainly, to a greater fruit set than the control trees; although this did not result in a higher oil yield (g tree) since the oil content per fruit dry weight was reduced. The RDI strategy did not decrease the fruit yield despite the fact that olive weight tended to decrease, and it increased the oil yield by ∼14.5%. The combination of both stresses (RW and RDI) neither decreased the fruit yield; however, it significantly reduced oil yield (25% less in 2018) since oil content per fruit dry weight was strongly reduced (40%) compared to control trees. Both RDI treatments, regardless water source, determined acidity levels in olive paste lower than in FI treatments; however, it reduced oil extractability and fatty yield. The finding about oil quality indicated that olive exposure to RW, regardless of the water amount, decreased oil quality mainly due to the reduction of oleic acid and the increase of C18:2/C18:3 ratio and peroxides; on the contrary, both RW and RDI improved the total polyphenols. In all cases, the parameters met the legislation. In short, with appropriate management, RW and RDI have great potential to manage oil olive production; nevertheless, studies subjected to long-term use of these techniques should be experienced to ensure the sustainability of oil yields and quality.
全球70%的橄榄园采用灌溉方式。在过去几十年里，干旱和半干旱地区对非常规水资源和节水技术的评估变得愈发重要。本研究评估了两种水源灌溉的效果：低成本海水淡化与传感技术（DESERT）淡化水（DW，电导率约1 dS/m）和再生水（RW，电导率约3 dS/m），并结合两种灌溉策略：充分灌溉（FI，100%蒸发散量）和调亏灌溉（RDI，50%蒸发散量），对种植于地中海环境下的阿尔博萨纳（Arbosana）品种橄榄树的果实产量、成熟指数、油产量和品质的影响。我们的结果表明，不受水限制的再生水使果实产量提高了35%，这是由于果实重量略有增加，主要是由于坐果率高于对照树；尽管由于每个果实干重的含油量降低，这并没有导致更高的油产量（每棵树的克数）。尽管橄榄重量有下降趋势，但RDI策略并未降低果实产量，且油产量提高了约14.5%。两种胁迫（RW和RDI）的组合也未降低果实产量；然而，由于每个果实干重的含油量与对照树相比大幅降低（40%），它显著降低了油产量（2018年减少25%）。两种RDI处理，无论水源如何，都使橄榄酱中的酸度水平低于FI处理；然而，它降低了油的提取率和脂肪酸产量。关于油品质的研究结果表明，橄榄接触再生水，无论水量多少，都会降低油品质，主要是由于油酸减少以及C18:2/C18:3比例和过氧化物增加；相反，RW和RDI都提高了总多酚含量。在所有情况下，各项参数均符合法规要求。简而言之，通过适当管理，RW和RDI在油橄榄生产管理方面具有巨大潜力；然而，应进行长期使用这些技术的研究，以确保油产量和品质的可持续性。
