Influence of Fertigation in ‘Manzanilla de Sevilla’ Olive Oil Quality

Abstract

<jats:p>We report the results of a study carried out in a ‘Manzanilla de Sevilla’ olive orchard near Seville, Spain, where the influence of different fertigation treatments on oil chemical composition was considered. Four treatments were established: control (no fertilizer) and T200, T400, and T600 in which each tree, respectively, received 200, 400, or 600 g N per irrigation season of a 4N–1P–3K complex fertilizer applied daily from 1999 to 2003. Results shown here correspond to the last 2 years of the experiment, 2002 and 2003. Fruits were sampled at the beginning of ripeness at the “green” stage. Fruit water content increased with the amount of fertilizer, probably because of the increase of potassium in the pulp. Oil content was unaffected by the treatments, but oil yield increased with the fertilizer dose in 2003 as a result of the number of fruits per tree. Polyphenol content, which is related to antioxidant oil capacity, K<jats:sub>225</jats:sub> (bitterness), and oxidative stability were lower in the oils made from trees receiving greater fertilizer doses. The monounsaturated fatty acid content, in particular oleic acid, decreased with increasing amounts of applied fertilizers, whereas polyunsaturated fatty acids, in particular linoleic acid, increased with it.</jats:p>

Plant-soil interactions in a fertigated ‘Manzanilla de Sevilla’ olive orchard

“…This could have accounted for the observed increase in canopy volume, flower quantity, fruit number per tree and fruit weight with the amount of fertilizer. These conclusions are further evidence to confirm those reported in the two related papers made with the same experimental design (Morales-Sillero et al 2007, 2008. For these growing conditions and when the fruits are used for oil production, then T400 (460 g N per tree, the 400 g of the treatment plus the 60 g supplied by the irrigation water) could be the most adequate treatment; if the fruits are for table olive production, the T600 treatment (660 g N per tree, the 600 g of the treatment plus the 60 g supplied by the irrigation water) could be the most appropriate for the producer, but there is a risk of leaching losses and the possibility of groundwater contamination.…”

“…They found that the greater fruit yield of the fertigation treatment with respect to the control, irrigated without fertilizer, resulted from an increase in fruit number but not in fruit weight. The increase in fruit weight recorded in this work could have been due, at least in part, to increased fruit K concentration: results obtained by Morales-Sillero et al (2007) from a research carried out in the same orchard, suggested that the accumulation of K induced osmotic adjustment in the fruit cells, which enhance water accumulation, leading to an increase in fruit weight.…”

“…This justified a set of experiments in which we started with the purpose of studying the effects of increasing doses of a 4N-1P-3K fertilizer applied by fertigation in a 'Manzanilla de Sevilla' olive orchard. In a first approach, Morales-Sillero et al (2007) found that oil yield increased significantly with the amount of fertilizer; oil quality, however, was negatively affected. The polyphenol content, K 225 (bitterness) and oxidative stability were lower in the oil from trees receiving higher fertilizer doses (T400 and T600).…”

Conserving Open Natural Pollination Safeguards Jatropha Oil Yield and Oil Quality

“…[37], Prunus amygdalus Batsch [38], Brassica napus L. [39], Nigella sativa Linn. [40] and Olea europaea L. [41][42][43]. J. curcas can reproduce through self-and cross-pollination and is pollinated by insects [44] but which pollinators [45] and which pollination mode yields the highest oil quantity and best oil quality has not been studied yet.…”

Influence of the harvesting year and fertilizer on the fatty acid composition and some physicochemical properties of linseed (Linum usitatissimum L.)

“…Suitable rate of the fertilizers should be used for the highest protein and oil contents of oilseed (Kumar et al 2006). Morales-Sillero et al (2007) reported that oil content of olive is unaffected but fatty acid composition is affected by the N fertilization treatment. Fertilizer treatments accelerate oil fruit ripening, increase oil contents and change the fatty acid composition of the oil fruits.…”