Cultivating yam
Propagation
The most common method of propagation is by tuber and it is practiced
commercially by cutting the tuber in to several pieces {Top, middle,
bottom) which are called as setts. The cut pieces of tuber must have the
dormant bud or eye in it. To get healthy plant and high yield the use of
tip portion to the tuber would be ideal as compared to middle and
bottom of the same tuber when used as setts. There is a positive association
between size of the setts and emergence early and produce large canopy,
which inturn provides large photosynthetic area with increasing in
photosynthetic efficiency leading to high dry matter production. The
optimum sett size would be 250-300g/ piece/pit. About to 2500-3000
kg/ha is required to cover 1 ha of land. Aerial tubers/bulbils can also be
used as planting material.
Tuber dormancy
The tubers exhibit definite period of dormancy due to the presence of
batatasins (a poly phenolic compounds) which is useful to extend to
storage life of tubers. The period of dormancy varies from 2-3 months
depending on the species.
The cutting of the tuber in to pieces/setts is done 1-2 days before the
scheduled date of the planting. This helps the cut surface heal before
planting. Dusting ashs at cut surface is a common traditional practice.
Treating the cut surface with pesticide also can be done.
The photoperiüdism plays a major not in aerator yam production. The
day length is critical, the day lengths greater than 12 hours favours vine
growth and shorter days favorer tuber formation and tuber yield, ft is
a sun loving crop and lanout to lerate the shade. Hence, the planting
is done March-April which suits this requirement..
The cut tubers are dipped in cowdung stump and 0.2% Dithane M-45
and dried in shade. The /pieces/setts are planted at the centre of the
mounds at a depth of 30-40cm
Regds
