Relation entre le mildiou et la fertilisation azotée de la vigne Dans La région d’Ain Temouchent.

Abstract

Winegrowers have to contend with numerous cryptogamic diseases, in particular downy mildew, caused by a fungal pathogen called Plamopara viticola. This disease affects yields and causes significant economic losses. Many factors, such as crop management and favourable climatic conditions, are responsible for the development of this fungus. Our work focused on another invisible factor responsible for the development of the disease, which is the overdose of nitrogen used by the farmers. In fact, different amount (doses) of nitrogen fertilizers were applied by foliar way of table grapevine aged 3-year-old belonging to "Black October" variety. This application was carried out during the flowering-setting stage. Three applications were applied for each week on the experimental field. Vines that had been overdosed with nitrogen at short intervals were infested by downy mildew.