Early tomato blight
Early tomato blight occurs in the spring. The fungus Alternaria solani thrives in damp weather conditions. Early tomato blight kills the fruits and it damages the plant. Yellowing of leaves of tomato plants might indicate that the plant is infected by the early blight fungi. The leaves infected with early tomato blight will wither and fall. The fungal disease easily spreads to the tomato crops in the neighborhood. It might even affect the potato crops in your garden. In the beginning, the early blight fungus infects the lower and older leaves of the plant. Gradually the diseases progresses upwards, infecting the younger leaves of the plant.
Early tomato blight prevention and treatment
Growing the tomato plants in same spot every year might increase the risk of tomato blight. Tomato blight might be prevented by rotating the crop. Each year you can consider different methods for growing the tomato plants. You can grow the tomato plants in containers or grow the tomatoes upside down. Frequent pruning could reduce the risk of this fungal disease. Mulching can protect your tomato plants from fungal attack. Water your plants early in the morning. Remove the diseased foliages from your yard. The harmful fungi could be killed with copper-based fungicides. Potassium bicarbonate, mancozeb, maneb, chlorothalonil, and hydrogen dioxide could kill the early tomato blight fungus.
Late tomato blight
The late tomato blight spreads extremely rapidly. It usually occurs in the cool wet weather conditions in the later phase of the tomato-growing season. Greasy gray spots on the leaves and skin of the fruits and blackening of stems are signs of late tomato blight.
Late tomato blight prevention and treatment
Copper fungicides might slow down the fungal disease. The harmful fungi could be killed with a fungicide made by mixing hydrated lime with copper sulfate. To prevent tomato blight, do not save the seeds of diseased tomato and potato. Watering the plants with drip irrigation could lower the risk of fungal infections.