Avocado Production in Asia and the Pacific - United Nations in ...

attacking young trees in Hainan. It damages mainly the young leaves and breaks out in April
and May. A survey made in May, 1990, indicated that there were 2,853 trees infested with
this insect (53.7% of the 5,316 trees surveyed). Dichlorvos (50%, e.c) is used for spraying or
as a soil drench at the tree base, and good results are obtained.
6. HARVESTING AND YIELD
Avocado tends to set flowers in February and March in Hainan. The maturity period
of avocado varies with varieties. The fruits of local varieties and those of the Pollock variety
mature in July and August. Other introduced varieties, such as Lula, Booth 7, Booth 8, etc.,
mature their fruits at the end of September and mid-October, while Hass matures its fruits in
November and December.
Yellow or purple skin (differing with varieties), dark brown wrinkled dry seed coat,
and certain minimum oil content reached are considered as indexes for fruit maturity. Fruit
maturity may also be estimated by using specific gravity or growth time of the fruit.
Mature fruits are picked manually and carefully to avoid being wounded, and the
stalks, some 0.6 centimetres long, are retained, attached to the fruit. Picking is carried out in
cloudy cool or clear morning.
The average commercial yield in Hainan is 7.5-15 t/ha. Some varieties, such as Lula,
Pollock and the local variety ST 3 , give a yield of 15 t/ha and their quality is good, whereas
some other varieties such as Hass give a rather low yield of 3-4 t/ha (Table 2). This is
probably due to difference in adaptation to climatic conditions. Hass is not suitable for
commercial cultivation in Hainan, where temperature and humidity are high.
7. MARKETING
Avocado is in the stage of trial planting and extension. Most of the fruits are sold at
low prices in the local markets. Very few fruits are seen for sale in towns away from the
orchards. No data on import and export is available.
The fruits for local sale are not treated after harvest. Fruits shipped to the northern
parts of China for marketing are handled in two ways: either they are washed with hot water
(50°C), packed when cool, and shipped and marketed at ambient temperature, or the
harvested fruits are cleaned and stored at low temperature. The recommended temperature
for cold storage is 10 to 13°C for the West Indian race varieties, 7 to 8°C for varieties of the
Guatemalan race, and 4 to 4.5°C for varieties of the Mexican race. The relative humidity is
80 to 90%. The fruits can be stored for one month at low temperature. The recommended
temperature for ripening of the stored fruits is 15 to 21°C.
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