blight

blight general term for any sudden and severe plant disease or for the agent that causes it. The term is now applied chiefly to diseases caused by bacteria (e.g., bean blights and fire blight of fruit trees), viruses (e.g., soybean bud blight), fungi (e.g., chestnut blight), and protists (e.g., potato blight). Other plant afflictions (caused by insects or unfavorable climatic conditions) that display similar symptoms are also called blights. See diseases of plants .

blight Yellowing, browning, and withering of plant tissues caused by various diseases; alternatively, the diseases themselves. Blights may be caused by microorganisms, such as bacteria and fungi, or by environmental factors such as drought. Common blights induced by microorganisms include fire, bean, late, and potato blight. They typically affect leaves more severely than other parts.

blight A non-specific term applied to any of a wide range of unrelated plant diseases. The causal agent is usually fungus-like. See (for example) potato blight.