Plant Diseases and Disorders

Check vegetable crops often for signs of these diseases and disorders.
From: DK - Simple Steps to Success: Vegetable Gardening

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Photo By: DK - Vegetable Gardening ©2007 Dorling Kindersley Limited

Potato/Tomato Blight

Brown patches on leaves, fruits and tubers, caused by a fungus that thrives in warm, wet weather. Grow resistant varieties or spray with copper-based fungicide.

Sclerotinia

Fungus that causes brown, slimy rot with fluffy, white growth, predominantly on stems and fruits of various vegetables. Remove and burn or discard affected plants.

Magnesium Deficiency

Older leaves of various vegetables show yellowing between veins, especially in acidic soil or after heavy rains. Apply Epsom salts to the soil or as a foliar spray.

Clubroot

This soil-borne slime mold infects brassicas, causing swollen roots, wilting foliage, even death. Ensure good drainage, add lime to acidic soil, and choose resistant varieties.

Blossom End Rot

Dry conditions affect calcium uptake, which causes sunken, black patches at the tips of tomatoes and sweet peppers. Correct with adequate, regular watering.

Powdery Mildew

A wide range of crops are affected by these fungi, causing powdery white growth on leaves in dry soil conditions. Water the soil well, but not over the leaves.

Onion White Rot

This fungus persists in the soil for up to seven years and causes fluffy white growth on bulbs and roots and yellowing of leaves. Remove and burn infected plants.

Rust

Orange or brown spots appear on the leaves and stems of various vegetable crops, particularly in damp weather. Remove infected leaves and grow resistant varieties.

Botrytis

A fluffy, gray mold (or whitish spots on tomatoes) that enters plants through wounds or flowers. Remove dead and infected plant material to reduce risk of infection.