Nursery Techniques - Afforestation, Reforestation and Forest Restoration in Arid and Semi-arid Tropics - page 31

2.3 Planning Seasonal Activities

A nursery calendar can be a useful tool for planning nursery operations. Sowing
of seeds, preparing cuttings, transplanting from germination beds to containers,
transplanting from mother beds to containers, and procuring potting mix (medium)
ingredients like clay, sand, and mycorrhizae are some of the activities that are season
dependent. An exact calendar of operations will depend upon the number of plants
and the species to be raised and the method of propagation chosen for each species.
Different species of plants have different fruiting and seeding seasons, and this
fact along with seed viability and desired age of plants at the time of outplanting
should be considered while deciding the sowing time. Species with very short seed
viability must be sown at a fixed time, failing which the nursery will be deprived of
that species. Seeds with long viability can be sown in any of the two main sowing
seasons when temperatures are moderate (e.g. July-October and February-March in
most tropical regions in the northern hemisphere). Whether the required plants are
to be of 6-month, 1-year, or 1.5-year age at the time of outplanting will also affect
the decision on sowing time.
Preparing branch cuttings and root-shoot cuttings is feasible only during seasons
when temperatures are moderate (usually in spring). Most of the shrubs and many
important species of trees are best propagated vegetatively. Full preparedness in
terms of skilled manpower, ready containers (if repotting costs are to be avoided),
and availability of cuttings should be ensured.
A nursery may depend upon certain tanks or ponds for their supply of clay or silt
to be used in potting mix. Such materials will not be available in rainy season when
the tank is full. Therefore, clay should be procured in advance in such cases.
Nurseries that use seeds of known provenance only (as all nurseries in fact should
do) must watch out for the seeds to ripen and collect seeds on time. Precise seeding
time will depend upon the species and its provenance. A guide to most local species'
seeding time should be made available to the person in charge of seed collection for
the nursery.

2.4 Procurement and Storage of Seeds

Seeds can be purchased from market or collected from known stands of trees. Seed
collection is by far the best approach since the quality and provenance of seeds is
known. Seed suppliers may, of course, also offer good quality seeds and sometimes
even better than what one has at hand in the local stands of trees. Moreover, not
all species may be available locally. In any case, it is best to divide seeds into two
categories: those that are used in the main afforestation programme and are locally
available and those which are used in agroforestry or in distribution of plants to the
farmers and other interested citizens and usually not available locally. The former
should be collected from well-formed middle-aged trees of good quality, and the