OBSERVATIONS ON TH POPULATION FLUCTUATIONS OF THE CITRUS NEMATODE ON CALAMONDIN ORANGE IN EGYPT

Abstract

Citrus nematode population densities in both soil and root samples from ‘Calamondin’ mandarin orange grove were recorded monthly for 1 year. Although soil and root population density of Tylenchulus semipenetrans varied (P = 0.05) in relation to month of sampling transformation of related data to normalize nematode population variances permitted more separation (P = 0.05) among their monthly levels than did non- transformed data. The accuracy and precision of the nematode assays varied greatly from month to month. Many biological, cultural and edaphic factors can influence the variability of nematode infection and reproductivity. Such variability indicated that it is misleading to give only single value derived from the sample mean. Statistical observations on nematode count data were reported and discussed.