LIBRO-CONGRESO-CITRUS

S10P30
Use of plant-soil-atmosphere sensors on a young Clementine mandarin orchard under regulated
deficit irrigation to monitor changes in water relations for better irrigation scheduling
El-Otmani M., El-Fadl A., and Benismail M.C.
Institut Agronomique et Vétérinaire Hassan II, Complexe Horticole d’Agadir, BP: 728 (IAV-CHA), Horticulture, Morocco.
elotmani.mohamed@gmail.com
Water availability for agriculture irrigation is becoming scarce in the Mediterranean Basin. Citrus orchards
use as much as 1 000 m 3 ha -1 , if not more in situations where flood irrigation is still a common practice.
However, producers are looking for ways and strategies to save as much of the resource as possible. For this
reason, young Clementine orchard, planted in 2007 in the area of Agadir, Morocco receiving about 200 mm
of rain per year, was used to test a regulated deficit irrigation strategy (RDI) supplying a combination of 100%,
75% or 50% of crop evapotranspiration ((ETc) at different stages of fruit development on tree vegetative
and reproductive development. Reference ETo was calculated using parameters obtained from a compact
weather station installed near the orchard. To monitor soil water statul, Watermark and FDR probes were
used. Tree Water relations were evaluated using 1) LVDT sensors for measuring tree diameter microvariations,
2) leaf water potential, 3) trunk sap flow and 4) stomatal conductance. Trunk diameter, sap flow and stomatal
conductance were significantly affected by climatic conditions and soil humidity. RDI had an effect on root
and canopy development but effect on fruiting varied among years with the well irrigated trees tending to
have more fruits at harvest. The results are discussed in relation to water economy and water use efficiency
as well as in relation with the accuracy of the sensors and the possibility of their use in irrigation scheduling.
XII INTERNATIONAL CITRUS CONGRESS 2012 - 173
S10