Tamarind monograph.pdf - Crops for the Future

5.3.2 Transplanting
Transplanting nursery grown plants into the field can have advantages over
direct seeding as the plants are already established. However, most newly
planted trees are subject to ‘transplant shock’, which may result in increased
vulnerability to drought, insects, diseases and other problems. To a greater or
lesser degree, transplant shock lasts until the natural balance between the
root system and the top or crown of the transplanted tree is restored. The
chance of survival can be significantly improved by using practices which
favour the development of the root system. Regular care during the first 2-3
years following transplanting is thus very important.
In order to provide space and an ideal medium for the development of a
vigorous and deep tap root system planting should be done in 1 x 1 x 1m pits
filled with well rotted organic manure at the time of planting.
Nursery grown seedlings or vegetatively propagated plants can be raised in
nursery beds and delivered to the field as bare rooted plants. Alternatively
they can be grown in, or transplanted into, polyethylene bags and taken to
the field as container grown plants. Nursery-grown trees are usually
transplanted during the early rainy season. If kept until the second rainy
season, the plants must be cut back and the tap root trimmed.
A technique for raising large quantities of planting stock for use in roadside
plantings has been described by Swaminath (1988). In this method, nursery
seedlings are pricked out and transplanted into 12 m x 0.6 m x 0.6 m
trenches dug two months beforehand. The trenches are filled with silt to 10-
15 cm from the top. The seedlings are planted 60 cm apart and watered daily
by flooding the trenches. After three months, the watering is reduced to once
every three days, and for the following three months, to only once a week.
The trenches are kept weed free and all side shoots are removed to induce
apical dominance. After about seven months, when the height is about three
metres and girth 6-8 cm, watering is stopped and the seedlings are dug up
with a ball of intact earth. They are then tied with paddy straw and kept in a
nursery and watered until they have recovered from the uprooting shock.
When a new flush of leaves appears, they are ready for transplanting to their
permanent roadside positions.
Nursery produced plants can be transplanted to the field at about 12-14
months, by which time they are about 80 cm tall. Under optimum growing
conditions they may achieve this height in 4-6 months. In India, seedlings
ranging from 0.4-2 m in height are commonly planted (Jambulingam and
Fernandes, 1986). If growth is poor, the seedlings should be retained in the
nursery for another year. However, it is difficult to handle these older
seedlings as their tap roots may have penetrated deep into the soil, in which
case they will require root pruning and care should be exercised in
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