Nematode Pests of Horticultural Crops and their Management (1+1)

Disease Complexes

Disease Complexes

• Plant parasitic nematodes often interact with fungal, bacterial and viral pathogens to cause disease complexes.
• The nematodes may play the role of an aggravator, incitant, or vector in many such situations.
• Of the many disease complexes, root knot nematode + bacterial wilt are the most lethal.
• There are instances where controlling the primary organism (nematode) has led to management of disease complexes.
• The quantification of the crop losses due to nematodes in such disease complexes is difficult to assess, nevertheless, nematodes do contribute substantially to crop losses in combination with other soil organisms.

Beneficial nematodes:
In addition to the harmful plant parasitic forms, there are groups of nematodes which are beneficial as they parasitize the harmful insects and mollusks and thus can be exploited as biological control agents against these pests. The entomopathogenic nematodes Steinernema and Heterorhabditis spp. and slug parasitic nematode Phasmarhabditis hermaphrodita in a mutual association with bacteria have proved to be successful biocontrol agents and are now being commercially produced in many countries.