Lightning damage
Areas of necrosis (burns, dehydration) in the foliage of all, or part, of the plant (photos 1 and 2) appear in a usually circular area after it has been struck by lightning. This could be confused with late blight symptoms (close observation of the foliage and an absence of mycelium will provide an accurate diagnosis). The presence of a metallic element may sometimes be observed on the soil in the centre of the area.