Pests
Aphids (Myzus persicae )
The nymphs and adults suck the cell sap and devitalize plants. Affected parts become discolored and malformed.
Control: Spraying malathion (0.1%) at 10-15 days interval control pest population.
Mustard sawfly (Athalia proxima)
A serious pest of radish, which feeds on the leaves by making small holes. The pest attack is observed in the vegetative and flowering stage of the crop.
Control: Hand picking of larvae and spraying malathion 50 EC @ 1ml/litre twice at an interval of 10 days is recommended.
Diseases
Alternaria blight (Alternaria raphani)
Small, yellowish, lesions appear on leaves, stems and seed pods. The affected pod becomes black and shriveled, and infected seed fails to germinate.
Control: Regular spraying with dithane M 45 (0.2%) or ridomil (0.1%) controls the disease effectively.
White rust (Albugo candida)
Flowering shoots get deformed and bear only malformed flowers. White powdery substance in patches is observed on the under surface of the leaves.
Control: Clean cultivation and use of resistant varieties help to prevent the disease. Regular spraying with dithane Z 78 (0.2%) effectively controls the disease.
Root rot of radish (Erwinia rhapontici)
Symptoms appear as rotting of pith tissues resulting in cavity formation and wilting of plants. It is a bacterial disease, which spreads through implements and irrigation water.
Control: Dipping of the seeds in a solution of agrimycin-100 (100 ppm) at the time of sowing is effective in checking the disease.
Radish mosaic virus (RMV)
Small, circular to irregular, chlorotic lesion appear on the leaves and the stem. Leaf distortion, stunting or abnormal formation are not observed. The disease is transmitted through aphids.
Radish phyllody
The diseased plant assumes a dull grey to light violet colouration. The symptoms of the disease appear at the time of flowering when all the floral parts become green violet and leafy. The sepals and petals become green thick knob headed leaves. The disease is transmitted by jassids.