MSc

The biology of root-knot nematode of kachlolam, its histopathological
effects on roots and the effect of soil type on the pathogenicity of M. incognito
infesting kacholam were studied under pot culture conditions. The effect of
soil moisture and pH on the hatching of eggs and survival of larvae were
studied in vitro in micro pots. Field trials were carried out to assess the crop
loss and to find out a suitable management strategy for the root-knot nematode
infesting kacholam.
The root-knot nematode, Miincognita took 37 days for the completion
of one life cycle in kacholam plants at room temperature of 27 + or - 3 0 C and
the mean number of eggs observed per egg mass was 130.
In kacholam roots, the nematode mainly infests the xylem vessels. The
giant cells were quadrangular in shape and three in number and were observed
adjacent to the head of the nematode.
Field capacity was the most favourable soil moisture level for the
hatching of eggs and survival of larvae of M.incognita. There weas no
statistically significant variation in the hatching of eggs and survival of larvae
under different soil pH levels ranging from 5 to 7.5.
Sandy soil (Entisol) was found to be the best soil type for the



multiplication of M. incognita infesting kacholam roots.


The biometric



characters and yield were reduced with the increase in inoculum levels and a
maximum reduction was noticed at 10,000 12 level in all soil types under pot
culture conditions.

At field conditions, inoculation of 1000 12 per plant resulted in the
reduction of number of leaves, rhizome length, root weight and yield per plant
and per plot yield to the tune of 43.33,23.71,46.26,63.69 and 43.46 per cent
respectively over control plants.
Neem cake 200 g/m2, V AM (Glomus fasciculatumy 300 g/m2 inoculum
per plant and cabofuran 3.33 g/ m2 were found effective for the management of



root-knot nematode, M. incognita infesting kacholam.


But neem cake



treatment was found to be the best in reducing the soil and root population of
nematodes and increasing the plant growth characters (number of leaves,
length of rhizome and weight of roots) and yield (rhizome weight per plant and
per plot) of kacholam.