MANGO - Tropical Fruits - page 280

years after fi eld planting. The fi rst crop had around 2.3 kg/tree, increasing to
about 12.7 kg/tree/year during the next 5 years. On a per-hectare basis, with
173 trees/ha (57.8 m 2 spacing), the initial yield of 5-year-old trees would be
393 kg/ha, with a yearly increase of 2.2 t/ha (Pennock et al. , 1972). Yields
obtained in Florida, Mexico, and Central and South America have shown
that in the fi fth year after planting, 0.9 t/ha can be expected, increasing to
1.7 t/ha in year 6, 3.5 t/ha in year 7, 5.2 t/ha in year 8 and 8.7 t/ha in year
9. Mature trees can yield 10-30 t/ha, with an average of 22-25 t/ha in the
subtropics. In the tropics, commercial yields of 10 t/ha are expected from
high-quality cultivars.
PEST MANAGEMENT
Diseases
Anthracnose ( C. gloeosporioides ) is perhaps the most important disease
of the mango in almost all production areas (Table 10.5), as it attacks
leaves, fl owering panicles and fruit. Yields are drastically reduced when
the infl orescence is attacked. This disease is especially serious in areas with
high humidity and frequent light showers during the fl owering period. In
Hawaii, where rainfall coincides with the fl owering season, almost the entire
production of infl orescences can be destroyed. In the Ryukyu Islands of Japan
(26°N), a crop of mango can be produced only by constructing polyethylene
shelters over the trees to protect the infl orescence from the frequent light
showers falling during the fl owering season. For this reason, trees are kept
at 1.8-2.4 m in height. In Australia, the cultivars 'Carabao', 'Keitt', 'Tommy
Atkins' and 'Zill' have been identifi ed as possessing tolerance to anthracnose
(Whiley and Saranah, 1981). Control measures include weekly sprayings of
the plants during fl owering, alternating a systemic fungicide with a protectant;
spraying during the coolest hours of the day and applying a protectant as soon
as a noticeable weather change occurs are also recommended. Cleaning the
orchard fl oor by picking old leaves and fallen fruit, as well as weed control, will
also help to reduce the inoculum levels.
Powdery mildew ( Oidium mangiferae ) attacks leaves, stems and
infl orescences and is a common disease of the dry subtropics, and it can also
become serious, especially under drier conditions (Johnson and Coates, 1993).
Normally, the treatments to control anthracnose also control both fungi, and
treatment is necessary until the fruit reaches the size of a cherry.
A disease that has been reported from a number of areas and is very
serious in India, Pakistan and Egypt is mango infl orescence malformation.
Malformation occurs on vegetative shoots and fl owering panicles. Panicles
become short, branchy and compacted and produce solely male fl owers
(Shawky et al. , 1980). Lower temperatures during panicle development are