Agriculture Reference
In-Depth Information
100
80
60
40
20
0
1970
1973
1976
1979 1982
Year
1985
1988
1991
Fig. 9.9.
Change in litchi production at Beilu, Guangxi from 1971. Improved
management practices were used after 1981, which led to increased production and
reduced, but did not eliminate, year-to-year variation in yield per tree (Mo, 1992).
stimulated to leaf growth after harvest; this is followed by a period of rest, then
fl oral induction and development. These fl ushes are induced by fertilization
and rainfall or irrigation (Yen, 1995). There can be more than one fl ush of
leaves during the 5 months after litchi and longan harvest, with leaves being
forced to mature and growth restricted after this phase. While mature leaves
are essential for fl owering, the presence of young, expanding foliage in the
cool season is inhibitory to infl orescence formation; if removed, fl owering
capacity increases (Lin
et al.
, 1991). In autumn, young, expanding leaves
can be removed mechanically or with a low rate of ethephon (1500 ppm); a
higher rate will abscise more mature leaves. Tree girdling in late summer can
be used to limit new shoot growth. The conditions for fl oral induction, besides
tree condition, are temperature and water stress for litchi and temperature and
possible nitrogen stress for longan. The terminal nature of the infl orescence
inhibits further main axis development, with lateral shoots on branches that
have fruited continuing further shoot growth, with only 22% that produce
fl owers in the following season.
Poor synchronization of fl ushing and fl owering within an orchard
increases management problems. Cultivars vary in their requirements for
induction, leading to early- and late-season bearers.
Pest management
Diseases
A number of disease organisms infecting litchi fruit are listed in the literature,
but none are considered to be serious and all are of a postharvest nature.
Aspergillus
spp.,
Botryodiplodia theobromae
,
C. gloeosporioides
(anthracnose),
