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

3. PRODUCTION OF PLANTING MATERIAL
Production of planting material is handled by the Seed and Planting Materials
Division of the Department of Agriculture and registered private nurseries. These nurseries
currently produce grafted plants of Pollock, Purple Hybrid and other locally selected types as
well as recently recommended varieties. The major role of production of grafted plants of
the new varieties is undertaken by the Horticultural Research and Development Institute. The
plant nursery of this institute has so far produced and distributed nearly 8,000 grafted plants
of these new varieties to the Central, Subaragamuwa and Southern provinces, both to small
farmers and large-scale growers. In addition, these grafted plants were distributed to
government and registered private nurseries to establish budwood gardens for future
development programmes on the crop.
3.1 Methods of propagation
Wedge or cleft grafting is the most common method of propagation adapted by
nurserymen, due to its high percentage of success. Stocks are wedge-grafted at the age of 4-6
weeks. Since avocados exhibit the phenomenon of polyembryony, the more vigorous
nucellar seedlings are usually chosen to raise grafted plants. Rootstock seeds are either sown
in seed beds or directly planted in black polythene bags of suitable size. Overgrown
rootstocks can also be used for budding during the active growth period of seedlings, often
indicated by a vigorous growth flush.
3.2 Top-working
In addition to the production of grafted plants, a 'top-working' programme on
seedling trees was successfully carried out by the Horticultural Research and Development
Institute in two districts in order to popularize the new varieties. As there is some limitation
in finding new lands for the expansion of avocado, this method is considered a practical way
of promoting avocado cultivation. This programme is now being handled by the provincial
extension services.
4. ESTABLISHMENT OF ORCHARDS
4.1 Land preparation
As a part of land preparation, growers only weed and remove other surface
vegetation. As most of the land is undulating, small and large scale growers are advised to
follow contour planting and to adopt soil conservation methods. Avocado plantations are
seldom established on flat land as the mid-country is usually hilly and undulating. Since the
crop is gradually spreading to the low-country wet zone as well, many avocado orchards are
being established on somewhat level terrain. In these situations, avocado is inter-cropped
with other perennial crops such as coconut, banana, jackfruit, rambutan, mangosteen, etc.
4.2 Planting season
The planting season is based on the rainfall pattern of the area. There are two
planting seasons in the wet zone, namely Yala (from June to August) and Maha (from
October to December). But the major planting is carried out during Yala, as it follows a
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