Phytophthora infestans
Symptoms:
Lesions on stems appear as large watersoaked areas, green to black in color, that eventually turn brown and dry up. Lesions may be surrounded by a white ring of mold if leaf wetness is high.
Lesions on stems appear as large watersoaked areas, green to black in color, that eventually turn brown and dry up. Lesions may be surrounded by a white ring of mold if leaf wetness is high.
Control:
The fungus develops during periods of cool wet weather. Fungicide sprays as a preventative measure during these periods may be needed if the crop is being grown near large areas of tomato relatives (Solanaceous weeds, potatoes).