Diseases of Periwinkle (Catharanthus roseus) and their managementDr. Vishwanath and Dr. Vineeta College of Agriculture G. B. P. U. A. & T., Pantnagar, Udham Singh Nagar, Uttarakhand
Medicinal uses: it contained a group of alkaloids that, though extremely toxic, had potential uses in cancer treatment. Two of these alkaloids, vincristine and vinblastine, can be used in purified form to treat common types of leukemia and lymphoma. Also work as antispasmodic and antidote.
Diseases and their management
Caused by: Eryisphe spp.
Symptoms: Usually, the white powdery dusting of the fungus developed on the upper leaf surfaces, but it was also seen on the lower leaf surfaces. Symptoms sometimes included yellow and brown lesions (approximately 3-10 mm in diameter) in association with whitish masses.
Control: Spray with Karathane @1 ml/litre of water or sulfex @ 2 g/litre Water
Caused by: Botrytis cinerea
Symptoms: Initiates as small brown to black spots, particulary at the margins of leaves. The spots enlarge and extend inwards, covering entire leaf surface, giving the plant blighte appearance. Under the high humidity, grayish mouldy growth can be observed over the infected areas.
- Proper spacing.
- Spray of captan or zineb (0.2%) or carbendazim (0.05%)
Caused by: Mycoplasma like organisms
Symptoms: Characterized by extreme dwarfing of the plant or plant parts coupled with very short internodes, flattening of stem covered with mass of highly reduced leaves and very often flowers, provided the flowering is terminal.
Control: Spray of Tetramycin @ 0.5 g/litre of water.
Caused by: Phomopsis spp.
Symptoms: Dark spots, which develop on the leaves, may be followed by browning and death of affected leaves. Diseased leaves usually fall off and are not associated with stem infections. The fungus, however, often spreads from stem lesions into the leaf petiole and the base of the leaf. Stem lesions expand rapidly and cause wilting and dieback of the stem. Some lesions may extend the entire length of the stem within a few days after initial appearance.
- In newly planted beds, 2 or 3 soil drenches of the systemic fungicide Benlate 50 WP at monthly intervals, beginning at the time of appearance of the symptoms.
Caused by: Phytophthora spp.
Symptoms: Dark brown lesions on stems and leaves; dieback.
Control: Sanitation. Avoid wet situations.
Caused by: Fusarium spp.
Symptoms: Brown, dry rotting on stem at soil line.
Control: Rotation and solarization.
Submitted by Dr. Vineeta Rathore on Mon, 29/06/2009 - 11:21