Bioecology and management of root-knot nematode Meloidogyne incognita chitwood in kacholam Kaempferia galanga Linn

Abstract

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.