Host range, biology and races of Heterdera cajani Koshy, 1967 occurring in Tamil Nadu (India)

Host range of Heterdera cajani was studied using 49 plants belonging to different families. Out of these, 14 plant species were recorded as hosts and 35 as non-hosts. Sesamum malabaricum was recorded as new host for H. cajani. The biology of H. cajani was studied under pot culture condition at a mean atmospheric temperature of 25.5 ± 0.5ºC. The penetration of J₂ started within 12 h and continued upto four days after inoculation. The second and third moults were completed between fifth and seventh day and fourth moult within 9 days. Egg laying started from 16^th to 17^th day. It was observed that for completion of one life cycle of H. cajani, 17 days were required from J₂ to J₂ and it took 28–29 days from J₂ to hard cyst. Twenty five populations of H. cajani collected from different districts of Tamil Nadu were identified as Race A.