Under field conditions, distribution (vertical and horizontal) of eleven
nematode genera on three date-palm cvs. Barhi, Samani and Zaghlool. Seasonal
fluctuation of Meloidogyne incognita, and its biological control on date-palm cv.
Zaghlool were investigated during one year of 2012. Results indicated that all
eleven nematode genera recovered were found in high densities at a depth of 30-50
cm for both types of distributions, whereas only three genera viz. Criconemoides ,
Tylenchus and Trichodorus were detected in low densities at depth over 50 up to
100 cm in the case of vertical. However, at depth of 50-100 cm only three genera
e.g. Aphelenchus, Criconemoides and Tylenchus were recovered in low number in
the case of horizontal. Meanwhile, seasonal fluctuation of M. incognita population
(J2) showed generally high peaks on date - palm cvs. Zaghlool, Samani and Barhi
soil in August 2012, where Zaghlool cultivar ranked first in this respect. M. incognita
(J2) population increased gradually during July, August and September on tested
cultivars, then decreased in November and December 2012. Regarding M.
incognita integrated biological control on date-palm cv. Zaghlool, dual treatments
gave better results than single one for both percent reduction of reproduction factor
and percentage increase of crop yield (78.1%), especially, Paecilomyces lilacinus+
Datura stramonium treatment.
Results also indicated amount increase in concentration of total sugar, total
phenol, reducing sugar and free phenols in date-palm cv. Zaghlool of dual treatment
than the single one, where P. lilacinus plus D. stramonium ranked first, however, the
opposite trend was recorded in the case of total amino acids.