Role of Plant Quarantine in Checking Dispersal of Nematodes with True Seed

Abstract

Unknowingly man hashelped, to agreat extent, in the worldwide geographical
distribution ofseveral economically importa.nt plant parasitic nematodes
through the exchange of nematode infested/contaminated plant material.
With the growing awareness of the role of nematodes as a limiting factor in
agricultural production, testing of seed material for nematode infestation is
now being undertaken by many seed health teMing and quarantine laboratories.
Nematodes could be transported with the true seeds, either as internally
seed-borne or as a contaminant with seed in the form of nematode galls,
infested plant debris, soil clods, soil entangled between corrugated seed
surface etc. Important nematode interceptions made while quarantine processing
of true seed material during 1976-1986 period included Aphelenchoids
besseyi, Rhadinaphelenchus cocophilus, Ditylenchus dipsaci, D. angustus,
Anguina tritiei, Heteroderaschachtii, H. humuli. Some of the nematode
species intercepted are still not recorded from India and are known to cause
extensive damage to crops in country of origin.