Examination of while tip nematode, Aphelenchoides besseyi population
changes as well as its rate of build-up on four rice cvs. I.e. Giza 171 and 177, Rehoo
and Sakha 101 grown in pots (40-cm-diam.) during the rice growing season 2005
under outdoor conditions indicated that nematode population density was
significantly different dependi:-:g on the rice cultivar and its growth stage. Generally,
population density of A. besseyi remarkably increased during the vegetative stage
(tillering), sharply decline in the flowering stage and then increased once again in the
harvesting period but not exceeded that of the first growth stage. Among tested rice
cultivars, Giza 171 encountered the highest cumulative nematode numbers with
value of 194.3 individuals per g. plant sample and rate of build-up amounted to 4.8,
whereas Sakha 101 gave the least value of nematode numbers (74.8) with rate of
build-up value of 3.93. Regarding nematode population density recovered from
soaking one hundred rice grains in water for 48 or 96 hrs, rice cv. Rehoo
accomplished the highest numbers of A. besseyi (126 or 168), followed by Giza 171
(124.6 or 157) and Giza 177 (99.7 or 130.3), whereas Sakha 101 gave the low
average nematode number with values of 77.6 or 107.0 individuals, respectively. In
the meantime, rice cvs. Rehoo and Giza 171 achieved the highest levels of
nematode infestation with values of 36.25% and 35.2%, respectively, whereas,
Sakha 101 also showed the least level of nematode infestation (23.1 %).