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Smut disease of Onion The smut disease of onion is caused by Urocystis cepulae The main symptom is that the Black smut sori are seen at the base of the leaves and leaf surface and when this sori are ruptured then Black powdery mass is seen. The fungus remains viable for 15 years in infected soil by means of spore balls. It persists in soil as a saprophyte. Onion bulbs and onion transplants are important […]

Pythium root rot of Onion Pythium root rot of onion is caused by three species of fungus viz. Pythium aphanidermatum, P. debaryanum and P. ultimum Pythium root rot is characterised by seed rotting and pre-emergence damping off. The disease appears in circular patches in the field here and there. All the affected plants can get killed. if the disease occurs prior to seed germination The disease may occur after establishment of the crop after 15 […]

Downy mildew disease of Onion Downy mildew of onion is caused by fungus called Peronospora sp. Main symptom is that White growth appears on the lower surface of the leaves. The downy mildew fungus produces spores called sporangiophores These sporangiospores are are non septate, long and swollen at the base The main sources of perennial survival of the fungus are the diseased bulbs used for propagating the crop in many areas and oospores present in […]

Basal Rot disease of Onion Basal rot is caused by fungus called Fusarium oxysporum In basal rot, the affected plant shows drying of leaf tip downwards and entire plant shows complete drying of the foliage. The bulb of the affected plant shows soft rotting and the roots get rotted. There will be a whitish mouldy growth on the scale. This disease can begin in the field and continue on in storage. The fungus of Basal […]

  Onion is an important crop. Given below are some interesting facts about onions – Indian onions are famous for their pungency and are available round the year The botanical name of Onion is Allium cepa The family of Onion is Alliaceae The origin of Onion is Central Asia Chromosome number of onion crop os 2n= 16 Red colour in onion is due to a pigment called Anthocynin Prrsence of pyruvic acid caused eye burning […]

To obtain the best yield in potato, disease have to be controlled Following are the diseases of Potato Late Blight of Potato -Instant Info | Agristudent.com Early blight of Potato – Instant Info | Agristudent.com Tuber Rot of Potato – Instant Info | Agristudent.com Black scurf disease of Potato – Instant info | Agristudent.com Common Scab of Potato: Instant Info I Agristudent.com Soft Rot of Potato – Instant info | Agristudent.com

Soft rot of Potato Causal organism Bacteria named Erwinia carotovora Symptoms Black lesion appear on the base of the plant Browning of infected tubers. Yellow appearance of the plant. Finally the plants wilt and die Soft, reddish or black ring appear on the infected tuber Pathogen characteristics It is a gram negative rod shaped bacterium with 1 to 6 peritrichous flagella. Mode of spread and survival Infected tubers attract the flies (Hymelia and Phorlin sp) […]