Answer: It's hard to pinpoint exactly what that was as there are many leaf diseases that tomatoes can get. The symptoms of blight or leaf spot are very similar, with lower leaves getting brown or black spots, yellowing and then dying. Eventually this fungal disease will spread up the entire plant. It's usually more common during warm, wet weather. To control,
Clean up all diseased foliage and destroy it.
Rotate where you plant crops each season.
Mulch tomato seedlings with plastic, hay or straw after planting and be careful when watering, so as to not splash the fungal spores from the soil onto the plant.
As a last resort and if the condition is severe, you can spray with a preventive fungicide, such as copper, in the early season.
Q&A Library Searching Tips