Introductory Agroforestry

REGENERATION

Natural Regeneration

• Natural regeneration occurred sporadically
• Seed coat is hard
• Germination take place after the seed get soaked for more than 12 hours in water
  
• Long tap root is formed during the first year which is longer than the shoot length

Artificial regeneration
Grewia optiva can be propagated by seeds, transplanting of nursery raised seedings, by cutting or planting stumps.

Seed collection and storage

• The fleshy drupes are edible,
• A substantial quantity of fruit crop is devoured by the birds, if seed collection is delayed.
• The fruits are not borne on the current year's shoot, tree lopped completely do not bear fruits.
• Therefore, trees reserved for seed production should either not be lopped at all or if necessary only partially.
• The fruits are rubbed and washed in water to separate out the seeds.
• Each fruit contains 2-4 seeds;
• There are about 12,000 to 15,000 seeds per Kg.
• The seeds have a hard testa and can be stored well for at least a year without any appreciable drop in vitality.

Nursery Technique:

• Pre-treatment of seed is necessary as seed coat is hard.
• Sowing should not be done on raised beds as sufficient moisture needed for germination.
• The dibbling method of sowing with twice a day irrigation proved to be the best in germination percent.
• The seed is sown in March-April, about 2 cm deep in lines 15 cm apart
• Watering is done regularly till germination is over. Germination starts in about 10 days and takes a month to complete.
• Sowing in March results in prolonged and scattered germination with heterogeneous stock.
• The seedlings are spaced about 10 cm apart in lines.
• The growth of the seedlings is fairly fast and they attain a plantable height of 30 cm or more by July.

Planting Out:

• Planting is done at the onset of monsoon, late planting generally fails.
• Seedlings uprooted from the nursery with balls of earth are wrapped in moist gunny bags and transported safely.
• Planting is done in 30 cm3 pits at a spacing of 4 m x4 m for block planting and 4-5 m for single row planting along the field bunds. For stump planting 15 month aged seedlings are used.

Vegetative Propagation:

• It can be successfully propagated by cuttings, under intermittent mist.
• Soaking the cutting base for 20 hrs in 100 mg/litre IAA gave a maximum rooting of 77.5 % in June.
• It can also be propagated by air layering.

ECONOMIC IMPORTANCE

Small timber:

• The wood is white, heavy, hard, elastic, strong and fine-textured.
• It is used for oar-shafts, axe-handles, shoulder poles, cat frames, bows and several other purposes, where strength and elasticity is required.
• The wood is difficult to saw when green but also difficult to work by hand after seasoning. It is reported to be suitable for paper-making.

Fibres:

• The bark yields a fibre of inferior quality used for cordage.
• The elastic branches are used for making baskets.

Fuel-wood:

• Though used as a fuel wood, not liked very much because of the foul foetid smell it emits on burning.