Factors influencing attraction of adult Hirschmanniella oryzae towards cabbage seedlings

Abstract

Observations on various factors influencing attraction of Hirschmanniella oryzae towards cabbage roots revealed that al1 factors except coloured lights and darkness affected attraction. Responses of H.oryzae declined as the age of the roots increased and also with an increase in the period of food deprivation of nematodes. Maximum attraction was recorded towards 4-6 day-old cabbage roots with fed nematodes as well as 2, 4 and 6 day unfed ones. Live roots attracted nematodes but roots killed by heating lost attractiveness. Maximum number of nematodes were attracted when roots were incubated for 10-12 h in 3-4 mm thick agar layer of 0.5% concentration at 20-25°. The nematodes showed preference to the region of root tip and aggregated most around it. Attraction decreased with increase in the distance of inoculation of nematodes from the roots.