downy mildew disease of vine

agent agricultural agriculture algeria algiers alimentation attacked black chlorosis contaminated contamination crop dark dead death disease diseased downy empty environment famine farm feed food fungus glume grain grape horticulture ill infect infected infection inoculated inoculation juice kernel leaf loose mildew natural nature nutrition oomycete pathogen pathology phytopathology plant plasmopara powder protection security seedborne sick sterile symptom threat transmission tree vine viticola yellowing zoospore