LIBRO-CONGRESO-CITRUS

S10
S10P08
Predicting the impact of the climatic variability in the necessities of watering of the grapefruit in
the Island of the Youth in Cuba
Cueto J.C., Pardo A.P., and Durán G.D.
Instituto de Investigaciones en Fruticultura Tropical (IIFT), Grupo Difusión Tecnológica Isla de la Juventud, Cuba. despacho@iift.cu
The expected increase in air temperature and the uncertainty related with the future predicted rainfall imply
that irrigation might become a more important cultural practice for citrus trees located in humid areas. The
objective of this work was to determine the present and future irrigation water needs for grapefruit citrus
trees. The investigation was carried out in the conditions of the Island of the Youth (Cuba). The irrigation
requirements for grapefruit culture during the period 1991- 2009 was calculated, and the predictions for
2050 were also performed. The analysis of the potential evapotranspiration/rainfall (ETo/P) ratio showed that
this value decreases near one from mid-June until the end of August. However, if the current climatic trends
will continue during the decade 2020-2030, the ETo/P ratio might decrease to values well below one. In that
case, irrigation will have to be supplied to the plantations. It is predicted an annual increment of the irrigation
needs of 60 m³/ha.
S10P09
Effect of regulated deficit irrigation on vegetative growth, fruiting, stomatal conductance, leaf
proline content and water use efficiency for Nules clementine grown in the Souss valley of
Morocco
Bagayogo S., El-Otmani M., El-Fadl A, and Benismail M. C.
Institut Agronomique et Vétérinaire Hassan II, Complexe Horticole d’Agadir (IAV-CHA), Horticulture, Morocco.
elotmani.mohamed@gmail.com
Water scarcity is becoming a major problem for agricultural development in the Mediterranean area
including Morocco. This research aims at developing irrigation strategies on citrus with the goal of reducing
water supply without significant negative effects on yield or fruit parameters. The effect of four treatments
on 5-year old Clementine trees (Citrus reticulata) grafted on Citrus macrophylla was assessed using drip
irrigation and supplying different water amounts according to tree phenological stage for a total of 470
mm of water [treatment T0 = crop water needs (ETc)], 580 mm [treatment T1 = 123% T0], 350 mm [T2
= 77% T0] or 304 mm [T3 = 67% T0] applied during the 1 Feb. - 30 Oct. cropping period. Irrigation water
was applied daily using emitters with different water flows and quantities supplied were based on local
evapotranspiration and crop water needs (ETc). The duration of irrigation varied from 1 h in the winter
time (supplying 0.9 mm/day to the least watered trees to 1.8 mm/day to the well irrigated ones) to 2 h 40
min during hot summer days (supplying 1.8 to 3.7 mm/day, respectively). Results show that stressed trees
have reduced vegetative growth but more flower buds and flowers. Stomatal conductance was positively
correlated with water dosage whereas leaf proline content followed the inverse trend. These results and
those on yield, final fruit size and quality (juice content, acidity, sugar content), and on water use efficiency
(as kg fruit produced/m 3 of water used) will be presented and discussed in relation to the water deficit
applied and its stage of application.
S10P10
Response of ‘Star Ruby’ grapefruit trees to deficit irrigation during different stages of fruit
growth: effects on water relations, yield and fruit quality
Pérez-Pérez J.G., Robles J.M., García-Oller M.I., and Botía P.
Instituto Murciano de Investigación y Desarrollo Agrario y Alimentario (IMIDA), Department of Citriculture, Spain.
juang.perez@carm.es
Grapefruit is an emergent crop in the southeast of Spain in recent years. In spite of the fact that grapefruit
is well adapted in semiarid regions, the irrigation necessities for fresh fruit production continue to be very
high. The scarcity of water resources forces citrus growers to optimise water use by using deficit irrigation
164 - VALENCIA CONFERENCE CENTER, 18th-23rd NOVEMBER 2012