Indian Journal of NematologyYear : 1981, Volume : 11, Issue : 1
First page :
Last page :
ISSN : 0303-6960.
Distribution of phytonematodes associated with citrus
Baghel P. P. S., Bhatti D. S.
Department of Nematology, Haryana Agricultural University, Hissar.
Presented at Nematology Symposium held at Coimbatore, India in February, 1981
Distribution of phytonematodes in soil around the roots of citrus plants at two horizontal spacings (30 and 90 cm from tree trunk) and at two vertical depths (0–15 and 15–30 cm) at monthly intervals for a period of two years was studied. Maximum nematode population/250g soil was recorded in April and October. The plant-parasitic nematodes were observed to increase from March to April and September to October. Relatively, larger number of nematodes were recovered at 30 than 90 cm distance from tree trunk at both the depths. Populations registered at 0–15 cm was slightly higher than 15–30 cm at both the horizontal distances. A similar trend as that of total nematode population was noticed for the population of Tylenchulus semipenetrans in the soil and roots. Numbers of 3rd and 4th stage larvae of this nematode were highest in October and lowest in February. Higher numbers of this nematode in April and October appears to be due to the prevalence of conducive conditions for its multiplication and availability of sufficient fresh roots in these months. Populations of Xiphinema insigni, Helicotylenchus dihystera and Pratylenchus pratensis increased considerably from October to December. Hoplolaimus indicus population showed increase from April to July. This rise in the populations of these nematodes may be ascribed to the favourable temperature and moisture conditions.