Varietal preferendum of date palm scale Parlatoria blanchardi Targ. in palm groves of Metlili-Ghardaïa

Abstract

The date palm scale Parlatoria blanchardi Targ. is one of the most enemy hos threaten the date palm and date production. In this context, our work focused on monitoring this pest in the Metlili-Ghardaïa palm grove for two months: february and march 2020 in order to determine the varietal preferendum of this pest on the most important dominant varieties (Deglet Nour, Ghars, Azerza, Bent khebala). The results showed that this pest not only affects one variety, but it attacks on all varieties grown in the study area, but the highest infestation rate was recorded on the variety Bent khebala and that the variety Azerza is least appreciated by this pest. Also, the degree of date palm scale infestation was observed highest on the north side, indicating that it prefers shady and humid places. The degree of infection remains variable according to the varieties, perhaps due to the physiology of a palm tree (mole, semi-mole) or to the techniques of maintenance of the palm groves: the density of plantation, irrigation ...