Complementary irrigation, 80 mm, distributed only during the third stage of fruit development, delayed ripening time and increased fruit size and oil content for fruits of the olive cv. Carolea. Prolonged water deficit reduced fruit growth, oil accumulation rate, K content of the fruit and enhanced ripening and pre-harvest fruit drop. Harvest time affected oil characteristics more than the water availability. Fatty acid composition was not affected by the water regime but polyphenol content increased and alcohol content decreased in the oil produced by irrigated trees.
In 2006 and 2009, trials were carried out in the Apulia region in Southern Italy to evalu-ate the possibility of mechanizing olive harvesting in groves of old and very large trees. The trees belonged to the cultivars ‘Cellina di Nardò’ and ‘Ogliarola Salentina’. They were 60-100 years old and 7-9 m tall with a canopy volume of 140-360 m3. In the first half of November 2006, with a mechanical beater mounted on a tractor plus hand-held pneumatic combs, the harvesting yield was close to 90% of the total olives present in the canopy, and the harvesting working productivity was around 60 kg of harvested olives h-1 worker-1. With a self-propelled shaker attached to the main branches the harvesting yield was about 73% in ‘Cellina di Nardò’, and 40% in ‘Ogliarola Salentina’, while the harvesting working productivities were around 103 and 85 kg of harvested olives h-1 worker-1, respectively. In the second half of No-vember 2009, in ‘Cellina di Nardò’, with a mechanical beater mounted on a tractor plus nets on the ground or a catching frame (reversed umbrella) mounted on another tractor, the harvesting yield was about 97%. The working productivity was about 98 kg of harvested olives h-1 worker-1 with the mechanical beater plus nets and around 133 kg of harvested olives h-1 worker-1 when the mechanical beater was combined with a reversed umbrella. The oil obtained from the mechanically harvested olives was always of high quality. A basic economic evaluation of the harvesting costs is also reported.
2 June 2009 in The Journal of Agricultural Science
SUMMARY: Orange (Citrus sinensisL.) is one of the main fruit crops worldwide and its evergreen orchards may have a great potential for carbon (C) sequestration, but no data are currently available. In order to understand carbon fluxes in orange orchards, an experiment was undertaken on traditional and intensive planting systems.The experiment usedC. sinensisscions grafted ontoCitrus aurantium(bitter orange) rootstock. One orchard contained 14-year-old trees of the cv. Tarocco Scirè (a blood orange) grown in a traditional system with 494 trees/ha. The second orchard contained 12-year-old trees of the cv. Newhall (a seedless navel orange) grown in an intensive system with 1000 trees/ha. Net primary productivity (NPP) was obtained by measuring the annual canopy growth of single orange trees and the above ground dry biomass of the ground cover; soil respiration seasonal pattern was measured with an infrared gas analyser (EGM-4, PP System) from June 2005 to May 2006, every 2 weeks from 12·00 noon to 15·00 h for maximum respiration and from 02·00 to 05·00 h for minimum respiration; a 24 h cycle measurement of soil respiration was made every 3 months.Carbon fixation in the fruits and in the canopy of single trees was almost twice as much (10·7 kg C/tree) in the traditional than in the intensive system (5·5 kg C/tree); however, total NPP of the orchard did not change with planting density, being 5·3 t C/ha/year in the traditional system and 5·5 t C/ha/year in the intensive one. Carbon fixation by the ground cover was higher in the traditional (1·1 t C/ha/year) than in the intensive system (0·5 t C/ha/year). Annual soil respiration was 5·9 t C/ha/year in the traditional system and 4·2 t C/ha/year in the intensive one. The carbon balance was almost four times higher in the intensive system (1·8 t C/ha/year) than in the traditional one (0·5 t C/ha/year), due to large differences in soil respiration.