Bulb and Corm Rots

Common Name


Scientific Name

Fusarium, Sclerotinia, Penicillium fungi

Damage Caused

Rotting of bulb, lack of growth.

Life Cycle

Fungi enters bulb through wounds in soil. Spores spread in storage of bulbs.

Control Method

At planting and lifting time, burn afected bulbs. Soak bulbs in benomyl or thiophanatemethyl fungicide before planting.Treat bulbs with care, to minimise mechanical injury. Avoid exposure to sunlight in storage. Dig up affected areas and replace soil.

Common Name

Scientific Name

Plants Affected


Blue Mould Rot

Penicillium gladiolii

Crocus, Cyclamen, Fressian, Narcisii, Gladioli

Irregular red brown sunken lesions develop on sides of corm and pink bodies appear on skin. Blue green mould seen.

Gladiolus Corm Rot

Sclerotincia draytonii


Yellowing and browning of foliage. Brown rot in corm.

Gladiolus Corm Rot

Fusarium oxysporus


Dark brown corms. Yellow stripping on leaves.

Gladiolus Dry Rot

Stromatinia gladiolii


Established rapid browning and death of leaves. Dark decay of sheaths. Sunken lesions on corms.

Gladiolus hard rot

- -

Leaves purple spots. Red black spots on corms.

Gladiolus scab and neck rot


Leaves are covered in spots leaflets shrivel.

Narcissus Basal Rot


Softening and browning of basal ring followed by rich brown rot through bulb.

Tulip Grey Bulb Rot


Colchium, Crocus, Hyacinth

Bulbs have dry rot, do not emerge.

Carnation Rot

Fusarium poae


Mites transport spores. Buds: brown pink mould seen. Internal rot and decay.

Grey Mould


Chrysanthemum, Cyclamen, Dahlia, Fressia, Impatiens, Rhodedendron, Lavender, Poppy, Roses, Viburnum

Grey mould with black sclerotia. Rotting of bulbs and stalks.

Root and Foot Rots

Phytophora, Pythium.

Asparagus, Carnation, Crysanth, Delphinium, Hyacinth, Hydrenga, Lillies, Lupins, Narcisii, Primula, Viola, bedding plants.

Roots affected. Yellowing and wilting of leaves. Flowers and fruits reduced. Roots febble and black.

Damping Off

Pythium and Rhizoctonia solanii

Antirhinum, Nemesia, Petunia, Salvia, Stock, Tagates.Alyssum, / Carnation, Lobelia.

Death in seedlings, in circular patches. Unthrifty and / shrivelled, wiry.

Information Collated by James M. Burton as part of H.N.D. Course at Pencoed Agricultural College.
Chemical Information Correct as of 06:06:97. Always read and follow the instructions when using fungicides.