The impact of the Parlatoria ziziphi infestations on physicochemical quality ofcitrus fruits «case of the clementine variety» in Mitidja (Boufarik, Algeria)

Abstract: In Algeria, citriculture is concentrated in the north part of the country. It ischaracterized by the weakness and low value of produced fruits due to generalizedinfestation of orchards by various pests such as scale insects. Clementine mandarin cvMontrea is dominant in Algeria because of its high productivity in comparison with theClementine fina typr. Our results showed that the infection rates are respectively 13.227% inthe summer, 15.932% in autumn, 16.131% during the winter period and 17.338% in springtime. The importance of the infestation reduces the photosynthesis and the nutritional statusof trees. The North, Center and the East are the favourite spot for this scale. A goodcorrelation was obtained between the rate of infestation and these parameters. We found twotypes of correlations between the development of P. ziziphi and levels of plant organs inchemical and biochemical components. The positive relationship is with phosphorus andpotassium and acidity, and the negative is with magnesium, nitrogen, calcium, sodium,vitamin “C “and dry matter. Therefore, based on these data as well as on others which willbe presented, it appears that P. ziziphi, affects considerably the chemical and biochemicalquality of the Clementine fruits which modify its outside aspect and its characteristic such ascolor, texture, shinning aspects, size weight, and juice quality and content.