Agriculture Reference
In-Depth Information
at rates depending on their content in the soil; average annual maintenance rates
range from 0.2 kg P
2
O
5
and 0.3 kg K
2
O per adult tree. The use of soluble or liquid
fertilizers is increasing due to increasing trickle irrigation. Foliar applications are
usually made in the spring and summer for correcting Mg, Zn and Mn deficiencies
by using Mg nitrate, Zn sulphate, Mn sulphate at a concentration of 0.5 %, 0.15 %
and 0.22 %, respectively.
In some producing countries, Citriculture is absolutely dependent on irrigation
due to poor or erratic rainfall. In general, flood irrigation is still widespread, but
trickle irrigation is used in the main citrus producing countries and increases every
year. Amounts of water, irrigation dosage and the modules are variable, depending
on the soil and the year, but general figures range from 6,000-7,000 m
3
ha
−1
year
−1
.
Sometimes the structure of ownership, and narrow spacing make mechanization
difficult. Sprays need sophisticated machinery and soil is tilled several times a year
by using small machinery or medium size tractors. Many orchards are treated with
residual, contact, or translocation herbicides, but the semi-non-tillage method quite
widespread, with plant cover in winter, and bare soil in summer.
The use of PGRs contributes to improve production and fruit quality. PGRs im-
prove fruit set of some Clementine varieties, and increase fruit size of Clementine
and Satsuma mandarins and hybrids (see Sections “Fruit set” and “Fruit growth”,
respectively), promote fruit colouring by using ethylene in degreening chambers,
and delay peel senescence of Clementine mandarin. PGRs also control several
physiological fruit disorders (see Section “Physiological fruit disorders”).
Harvesting of citrus fruit is done manually by carefully cutting the peduncle with
special clippers.
References
Agustí M (1999) Preharvest factors affecting postharvest quality of citrus fruit. In: Schirra M
(ed) Advances in postharvest diseases and disorders control of citrus fruit. Research Signpost,
Trivandrum, pp 1-34
Agustí M (2003) Citricultura. Mundi-Prensa, Madrid
Agustí M, Almela V (1991) Aplicación de fitorreguladores en Citricultura. Aedos, Barcelona
Agustí M, Martínez-Fuentes A, Mesejo C (2002) Citrus fruit quality. Physiological basis and tech-
niques of improvement. Agrociencia 2:1-16
Agustí M, Almela V, Juan M (2004) Alteraciones fisiológicas de los frutos cítricos. Ministerio de
Agricultura, Pesca y Alimentación, Madrid
Bain JM (1958) Morphological anatomical and physiological changes in the developing fruit of
the Valencia orange
Citrus sinensis
L. Osbeck Aust J Bot 6:1-24
Calabrese F (2004) La Favolosa Storia degli Agrumi (The fascinating history of citrus fruit).
L'EPOS Società Editrici s.a.s., Palermo
Castle WS (1987) Citrus rootstocks. In: Rum RC, Carlson RF (eds) Rootstocks for fruit crops.
Wiley, New York, pp 361-399
Chica EJ, Albrigo LG (2013) Expression of flower promoting genes in sweet orange during floral
inductive water deficits. J Amer Soc Hort Sci 138:88-94
Davies FS, Albrigo LG (l994) Citrus. CAB Intl, Wallingford
