​BLAST, in agriculture and gardening, is a term synonimous with blight, which see.

That species of blasts called uredines, or fire-blasts, is supposed by Mr. Hales to originate from the solar rays, reflected from, or condensed in the clouds, or collected by the steams in hop-gardens, &c. They wither, scorch, and blacken the leaves, blossoms, and fruits of ​trees, shrubs, grass, corn, &c. and this devastation is at times extended over whole tracts of ground.