10 research outputs found
Effects of long term irrigation with treated wastewater on leaf mineral element contents and oil quality in Olive cv. Chemlali
No full textWater is one of the most limiting factors in agriculture, particularly in arid areas such as Tunisia. Olives are the most important tree fruit in the country and are cultivated over 1.6 million hectares. An olive grove of cv. Chemlali was irrigated either by using treated wastewater (TWW) or fresh water (FW) from 2002 to 2012. The aim of this 10-year study was to investigate the effects of irrigation with TWW on both quality parameters (i.e. K232, total phenols, free fatty acids, etc.) and content of mineral elements in the leaves. Data obtained indicated no effects of the irrigation on parameters such as oil content and K270, either by using TWW or FW, and significant effects only after 10Â years on free acidity and K232. Instead, palmitoleic and stearic acid contents significantly decreased after 10Â years of irrigation with TWW with respect to FW irrigation. TWW irrigation also increased the content of total phenols, chlorophyll, and minor and major nutrients in the leaves
Chemlali olive trees in an irrigated grove: Effects of tree age on virgin olive oil quality and mineral nutrient distribution in roots, leaves and fruits
No full textIntroduction. The effects of tree age on the quality of olive oil are not very clear. Data on the mineral element content in different plant organs of cv. Chemlali are also very scarce, and the correlation between tree age and mineral content is still unclear. Materials and methods. A two-year study was conducted on irrigated 'Chemlali' olive trees of two different ages (12 years old vs. 24 years old) in order to verify possible effects on either the nutritional balance in different plant organs (leaves, roots, fruits) or the virgin olive oil (VOO) quality. Results and discussion. The 24-year-old trees showed a higher mineral concentration with respect to 12-year-old trees in roots and fruits, whereas the opposite was reported for the leaves. Total phenols and induction time values were significantly lower in VOO from 24-year-old trees. Palmitic, palmitoleic, stearic and linoleic acid concentrations were higher in VOO of 24-year-old trees. Conclusion. These results can be useful in order to discriminate the characteristics of VOO obtained from trees of different ages and the mineral content data can be used for the optimization of the fertilization schedules with respect to the olive tree age for more sustainable management of olive groves
Irrigation with treated wastewater affected the minor components of virgin olive oil from cv. Chemlali in Tunisia
No full textWater limitation for agriculture is a problem
in many countries and irrigation with treated wastewater
(TWW) can be a tool to face the decreasing availability
of water for important domestic crops such as olive. Taking
into account this aspect, a research was carried out for
13 years in an olive grove (Chemlali cultivar) located in
the area of Sfax (Tunisia). Two different irrigation treatments
were applied: (a) irrigation with good quality water
(GQW) and (b) irrigation with TWW. The main objective
of this 13-year study was to verify the effects of the irrigation
with TWW vs. GQW on some minor parameters of the
virgin olive oil. Many oil parameters significantly increased
in the TWW irrigated plot, in particular lutein, total tocopherols,
squalene, campesterol and stigmasterol whereas
β-carotene, α-tocopherol, δ-tocopherol, β-sitosterol and
total sterols decreased with respect to the GQW treatment.
Irrigation with TWW can be a possible tool to irrigate olive
groves with two positive effects: saving of freshwater and
production of olive oil of good quality
Effects of irrigation with treated wastewater on root and fruit mineral elements of Chemlali olive cultivar
No full textTwenty-year-old “Chemlali” olive trees trained to vase and rainfed were investigated in either “on” (2004) or “off” (2003) year. A randomized block design with three blocks and three treatments was used and each experimental plot consisted of nine olive trees. Three treatments were applied: (1) rainfed conditions (RF, used as control treatment); (2) irrigation with well water (WW); and (3) irrigation with treated wastewater (TWW). Irrigation with TWW led to a significant increase of root N, P, Ca, Zn, Mn, Na, and Cl concentrations, in particular in the on-year. Data showed significant differences, between the two years, for the concentration of the mineral elements in the roots, with general lower values in the on-year, probably as a consequence of nutrients movement upward in the tree. Fruit N, P, K, Zn, Mn, and Cl contents were significantly higher in TWW irrigated trees with respect to both RF andWWtrees, whereas similar values for Ca, Mg, Na, and Cl contents were measured forWWand TWWirrigated trees.The irrigation with TWWallowed to reuse problematic waters and to save nutrients inputs in the olive orchard thus moving towards a more sustainable management of olive orchards in countries where water is the major limiting factor for agriculture
Alternate bearing affects nutritional status and net assimilation rate of an irrigated olive grove under arid conditions
No full textAlternate bearing is a typical behavior of various fruit tree crops and is common among olive cultivars (Olea europæa L. var. sativa Hoffm. e Lk.). Since this phenomenon affects yield and consequently oil production, it is a concern for olive oil industry in order to offer a constant olive oil amount each year. A 4-year field experiment was conducted on cv Chemlali olive trees in ‘on’ and ‘off’ years in order to study, under arid conditions, both annual macro-element balance and net photosynthetic activity. Shoots growth was much higher in the ‘off’ year with respect to the ‘on’ one (+11.70 cm vs. +2.60). Net photosynthesis rate was much higher in the ‘off’ year with respect to the ‘on’ year and the highest values were observed at spring, when there is an intense vegetative growth. Differences for the mineral elements were observed between the ‘on’ and ‘off’ years. Nitrogen accumulated in leaves mainly in spring in the ‘off’ year, whereas high N values were detected also at the end of summer in the ‘on’ year. Consequently, N fertilization can be accomplished in February–March and possibly after harvest (November–December) to be used at budburst in the successive season. A difference was found between leaf P concentrations in ‘on’ or ‘off’ years from flowering to fruit-set, with the lowest values in the ‘on’ year, in particular in June–July. A supply of P at autumn–winter and partially in spring–summer in particular in an ‘on’ year would be appropriate. K accumulated in leaves in ‘on’ year from spring to summer, thus a supply of K in January–February, before new vegetation, for trees either in ‘on’ or ‘off’ year can be necessary for supporting and implementing the root system activity and the successive shoot growth (‘off’ year) and fruit development (‘on’ year). These results should be useful to partially reduce, through an appropriate fertilization schedule, the alternate bearing in olive tree
Long-terms effects of irrigation with treated municipal wastewater on soil, yield and olive oil quality
No full textIn Tunisia, water scarcity is one of the major constraints for agricultural activities. The reuse of treated
wastewater (TWW) in agriculture can be a sustainable solution to face water scarcity. The research was
conducted for a period of ten years in an olive orchard planted on a sandy–silty soil and subjected to two
different irrigation treatments: (a) well water (WW) and (b) treated wastewater (TWW). The main aim
of the present study was to investigate the influence of irrigation with TWW on soil chemical properties,
olive tree yield and on virgin olive oil (VOO) quality during an heavy crop year (“on year”) in “Chemlali”
olive orchard. Soil samples were collected at the beginning of the study (before irrigation), after five and
ten years for each treatment. pH, electrical conductivity (EC), organic matter, major elements, salts and
heavy metals contents in soil were investigated. Standard quality parameters, chlorophyll, -carotene,
total phenols (TP), induction time and total tocopherols such as -,-,-,-tocopherol of VOOs were also
investigated. Results showed that irrigation with TWW increased soil pH, EC, OM, major elements, salts
and heavy metals contents. Data obtained indicated that standard quality indices (free acidity, K232, and
K270) of VOO and oil content were not affected significantly by water quality. Instead, chlorophyll, total
phenols, induction time and -tocopherol values decreased significantly after ten years of irrigation with
TWW. However, both fruit water content, and the concentrations of -carotene and tocopherols (,
and ) in VOO increased
Effects of irrigation with treated wastewater on olive tree growth, yield and leaf mineral elements at short term
No full textIn arid regions, such as Tunisia, the reuse of treated wastewater (TWW) in agriculture can be a sustainable solution for water scarcity. A two-year field experiment was conducted in order to investigate the short term effects of TWW on olive growth, yield and concentration of total nitrogen (Nt), potassium (K), phosphorous (P), and heavy metals (i.e. Zn, Mn, Pb and Cd) in olive leaves. Olive trees were subjected to the following irrigation treatments: (i) trees irrigated with well water (WW) and (ii) trees irrigated with treated wastewater (TWW). For both treatments, the TWW and WW were applied at a rate of 4.5m3 day−1 tree−1 (5000m3 ha−1 year−1). After two years, non-significant injuries caused by salts and/or heavy metals were observed on shoot growth of trees irrigated with TWW. The application of TWW significantly increased concentration of Nt, P and K in the leaves, whereas heavy metals (Zn and Mn) showed a significant increase only after the second year of irrigation
The effect of waste water irrigation on the extra virgin olive oil quality from the Tunisian cultivar Chemlali
No full textEffects of Irrigation with Treated Wastewater on Root and Fruit Mineral Elements of Chemlali Olive Cultivar
No full textTwenty-year-old "Chemlali" olive trees trained to vase and rainfed were investigated in either "on" (2004) or "off " (2003) year. A randomized block design with three blocks and three treatments was used and each experimental plot consisted of nine olive trees. Three treatments were applied: (1) rainfed conditions (RF, used as control treatment); (2) irrigation with well water (WW); and (3) irrigation with treated wastewater (TWW). Irrigation with TWW led to a significant increase of root N, P, Ca, Zn, Mn, Na, and Cl concentrations, in particular in the on-year. Data showed significant differences, between the two years, for the concentration of the mineral elements in the roots, with general lower values in the on-year, probably as a consequence of nutrients movement upward in the tree. Fruit N, P, K, Zn, Mn, and Cl contents were significantly higher in TWW irrigated trees with respect to both RF and WW trees, whereas similar values for Ca, Mg, Na, and Cl contents were measured for WW and TWW irrigated trees. The irrigation with TWW allowed to reuse problematic waters and to save nutrients inputs in the olive orchard thus moving towards a more sustainable management of olive orchards in countries where water is the major limiting factor for agriculture
ALTERNATE BEARING AFFECTS NUTRITIONAL STATUS AND NET ASSIMILATION RATE OF AN IRRIGATED OLIVE GROVE UNDER ARID CONDITIONS
No full textAlternate bearing is a typical behavior of various fruit tree crops and is common among olive cultivars (Olea europæa L. var. sativa Hoffm. e Lk.). Since this phenomenon affects yield and consequently oil production, it is a concern for olive oil industry in order to offer a constant olive oil amount each year. A 4-year field experiment was conducted on cv Chemlali olive trees in ‘on’ and ‘off’ years in order to study, under arid conditions, both annual macro-element balance and net photosynthetic activity. Shoots growth was much higher in the ‘off’ year with respect to the ‘on’ one (+11.70 cm vs. +2.60). Net photosynthesis rate was much higher in the ‘off’ year with respect to the ‘on’ year and the highest values were observed at spring,when there is an intense vegetative growth. Differences for the mineral elements were observed between the ‘on’ and ‘off’ years. Nitrogen accumulated in leaves mainly in spring in the ‘off’ year, whereas high N values were detected also at the end of summer in the ‘on’ year. Consequently, N fertilization can be accomplished in February–March and possibly after harvest (November–December) to be used at budburst in the successive season. A difference was found between leaf P concentrations in ‘on’ or ‘off’ years from flowering to fruit-set,with the lowest values in the ‘on’ year, in particular in June–July. A supply of P at autumn–winter and partially in spring–summer in particular in an ‘on’ year would be appropriate. K accumulated in leaves in ‘on’ year from spring to summer, thus a supply of K in January–February, before new vegetation, for trees either in ‘on’ or ‘off’ year can be necessary for supporting and implementing the root system activity and the successive shoot growth (‘off’ year) and fruit development (‘on’ year). These results should be useful to partially reduce,through an appropriate fertilization schedule, the alternate bearing in olive tree
