Nematode Infestation in Spice Cultivations

Abstract

About 66 species of plant parasitic nematodes belonging to 27 genera are reported on ten major spices. The most predominant and widely distributed among these are root knot nematodes (Meloidogyne incognita), burrowing nematodes (Radopholus similis) and root lesion nematodes (Pratylenchus spp.). Nematode infestations cause ‘slow decline’ disease in black pepper plantations. Gradual decline and foliar yellowing coupled with severe root damage on account of galls, lesions and rotting are the predominant symptoms of nematode infestation in black pepper. Widespread occurrence of root knot nematodes, M. incognita and M.javanica has been reported in cardamom urseries and plantations in india. Root system of infested plants shows varying degrees of root galling. In ginger and turmeric too. Nematodes such as root knot nematodes are widely distributed in all states where these crops are cultivated. Use of planting materials without symptoms of nematode infestation from known and nematode-free sources is very important aspects of successful management of the nematodes. Exclusion of nematode susceptible intercrops, shade trees, supports or standards can also minimise the nematode infestation. Soil amendments like application of organic cakes, mulching etc. are ideal eco-friendly measures to manage these pests. Efforts to identify nematode resistance have helped to recognise a few resistant lines in some spices. Chemical control of nematodes is a less preferred option now a days and as a result intensive research is on at several laboratories to isolate efficient biocontrol agents against these nematodes. Tropical agro-ecosystems are complex, more resilient and therefore, sustainable ways of nematode management have to be evolved by blending different management options.