Also called false mildew. any fungus of the family Peronosporaceae, causing many plant diseases and producing a white, downy mass of conidiophores, usually on the under surface of the leaves of the host plant.
Plant Pathology. a disease of plants, characterized by mildewed, distorted, and yellowed foliage, caused by any of several fungi of the family Peronosporaceae, as of the genera Peronospora and Phytophthora.
a serious plant disease, characterized by yellowish patches on the undersurface of the leaves, caused by the parasitic fungi of the family Peronosporaceae, such as Peronospora destructor: affects onions, cauliflower, lettuce, etc
any of the fungi causing this disease
A disease of plants caused by oomycete organisms of the order Peronosporales and characterized by gray, velvety patches of spores on the lower surfaces of leaves. Downy mildew of the grapevine nearly destroyed the French wine industry in the 1870s, spurring the development of the first chemical pesticides used on plants.
noun 1. .
noun 1. a movement that may be interpreted as threatening. 2. an act or action that can cause trouble or damage; mistake: If the bus driver had made one false move, we would have skidded off the icy road. noun an unwise or careless action with risky consequences
[fawls-neg-uh-tiv] /ˈfɔlsˈnɛg ə tɪv/ noun, Also, false negative 1. Medicine/Medical. 2. adjective 3. pertaining to or being a false-negative. noun, adjective See false negative
- False-negative reaction
false-negative reaction n. An erroneous or mistakenly negative response.