Amaryllis and Hippeastrum are attacked by several diseases and pests which cause extensive damage to the plants and bulbs during storage.

A. Diseases

The various fungal and viral diseases that attack the Amaryllis and Hippeastrum are mentioned here.

1. Fungal diseases

These flowers are attacked by some fungal diseases. They are discussed here in detail.

a. Red leaf spot disease

Stagnospora curtisi is the causal organism for this disease

Symptoms: The disease appears in the form of spots on the leaves which ultimately turn yellow and fall-off.

Control: The diseases may be controlled by spraying with 0.75% Copper oxychloride or by warm water treatment of bulb at 43.5OC for 2 hours. In Amaryllis. application of Zineb and Ferbam @ 2lb/l00 gal. is more effective in con trolling the fungus than Captan or/ and copper fungicides.

The combination of hot water treatment + 0.5% Benlate dip to control the diseases. In field trials, a dip containing 1 % Aaglitom and 0.2 % Benlate was also effective.

b. Other fungal diseases

Other fungal diseases of Amaryllis are soft rot of bulbs caused by Rhizopus stolonifer, bulb decay caused by sclerotium rolfsii, greymold caused by Botrytis cinerae, root rot caused by Rythium debaryanum, black mildew caused by Asterinella hippeastri, leaf spot caused by Cercospora amaryllidis, brown leaf spot caused by Accidium amaryllidis and anthracnose caused by Septogloeum amaryllidis.


These diseases can also be controlled by treatments suggested to control the red leaf spot of amaryllis. Phoma glomerata, Helminthosporium rostratum and Fusarium spp also adversely affect the growth, bulb formation and flower in hippeastrum.



Next : Viral diseases of Amaryllis and Hippeastrum