The Tomato Plant is Drying up Like a Prune

Identification

• Tomatoes are prone to late blight caused by Phytophthora infestans. The disease affects all above-ground plant areas. The pathogen is likely to destroy an entire crop within two to three weeks of infection if left uncontrolled.

Damage

• The disease starts with water-soaked, irregular spots on new foliage in the upper areas of the canopy. There is a white, cottony fungal growth on foliage undersides during humid weather. Foliage gradually browns, shrivels and dies. Infected fruit initially displays greasy spots. As infection progresses, fruit assumes a chocolate brown, prune-like color, withers and becomes leathery.

Control

• Use resistant varieties of tomatoes to minimize risk of infection. Fungicidal control options include the use of chlorothalonil, mancozeb and mandipropamid.