Nursery Techniques - Afforestation, Reforestation and Forest Restoration in Arid and Semi-arid Tropics - page 44

atomiser or a knapsack sprayer. Liquid can also be sprayed on the prepared soil and
the soil remixed thoroughly if powder is not available.
Choice of effective pesticides is a widely open issue. However, the common types
of pests that often attack plants in arid and semiarid climate are fortunately not many.
Example of a guide to use of pesticides along with application recommendations will
be found in Table 2.8 . Local agricultural extension centre should be able to provide
more accurate information on this aspect of plant protection.
Bio-pesticides should be given a serious consideration. Pulverising and mixing
with soil the leaves of many local species of plants (e.g. Azadirachta indica or
Calotropis procera ) can help avoid pests. Biopesticides are more ecofriendly, and
the extra effort that goes into their application is easily set off by the reduced cost
and local availability.
Sometimes no effective pesticides are available to manage certain kind of insects.
For example, a mollusc affecting the young seedlings of Azadirachta indica , called
Laevicaulis alte , is not susceptible to most known pesticides; however, it can be
killed by spraying over with a solution of metaldehyde or common salt. An alternative
method in such cases is to hand-pick these slugs at the appropriate time of the day.

2.14 Pot Turning

Plants should be shifted from one bed to another when their roots are likely to have
hit the polypot, a pest has affected the bed, or the plants need to be given a shock-
proofing treatment. Shifting should always be combined with two other operations:
culling-cum-grading and root pruning. Pot turning could involve either changing
polypots within a bed (routine operation to prevent plants from becoming pot-bound)
or relocating them to another section of the nursery (in case of pest attack).
Pot turning for preventing roots from going into ground should be carried out with
a planned schedule. Roots of certain species will grow faster and hit the walls of the
pot sooner, whereas others will be slow. On an average, turning pots after 3 months
of sowing, and thereafter every alternate month, seems to be a sound practice in arid
and semiarid tropical climate. Sharp scissors or secateurs should be used to prune
the roots that may have come out of the pot. This opportunity should also be used for
grading and culling operations. Some plants may die after pot turning, either because
of shock or because of too severe trimming of roots.
Plants should be shifted from one bed to another—or even from one nursery to
another—if a pest attack of epidemic level is encountered. Certain beds in a part
of the nursery may have become infested with a pest and others may still be free
from it. Pests attacking only a particular species may also necessitate such a shifting.
Advantage should be taken of such shifting operations to prune the roots if necessary
and to cull and grade the plants.
Shock-proofing is meant to weed out those poor plant specimens which will later
die during the transportation operation. Pot turning involves handling of plants in
a manner similar to that of transporting, and therefore, even if there seem to be no