Which of the following is not a symptom of Pythium blight?

The correct response highlights that red streaks on leaves are not a symptom of Pythium blight. Pythium blight is caused by a soil-borne fungus primarily affecting plants during warm, humid conditions. The notable symptoms typically include water-soaked, soft, and slimy leaves, which may appear as a result of the organism's degradation of plant tissues. The presence of cottony mycelium is also characteristic, as it indicates active fungal growth. Additionally, the shape of the diseased areas often conforms to drainage patterns, which can be attributed to the way water accumulates and facilitates the spread of the pathogen. Therefore, the mention of red streaks does not align with these established symptoms, confirming why it is the correct choice for the question.