ROUSSEAUX Maria Cecilia
congresos y reuniones científicas
Short periods of artificial shading from fruit set to early growth mesocarp and its effect on the determination of oil yield in olive.
CHERBIY-HOFFMANN, S.U.; HALL, A. J; SEARLES, P.S; ROUSSEAUX, M. C.
Simposio; VIIth International Symposium on Olive Growing; 2012
Maximizing productivity in high density olive orchards requires proper management of illumination of the canopy walls and their interior. Currently, this is difficult to achieve due to the limited knowledge about the amounts of incident photosynthetically active radiation (PAR), appropriate to each phenophase involved in yield determination, required to maximize oil yield. In this study, we determined the effect of each of three separate but sequential one month shading periods -imposed from the full bloom to the end of early mesocarp growth - on fruit number, fruit dry weight and oil concentration. Shades covered the north side (S hemisphere) of 3 m high Arbequina trees and the shading levels were 3, 20, 40, and 70% of incident PAR. Fruit density at harvest was reduced when shades imposed during fruit set transmitted less than 40% of incident PAR. Consequently, oil yield decreased due to the reduction in fruit number. No effect of shading on final oil yield was observed when shading treatments were imposed at around the time of pit hardening. Lastly, shading during the first month of oil accumulation was associated with a reduction in oil concentration that affected final oil yield. Oil yield was 45% lower when trees received 3% of incident PAR compared with those under 70% of incident PAR. We conclude that fruit set and early fruit growth are critical periods in which PAR reductions can affect the determination of oil yield.