Managing sugary ergot in sorghum

By TheHindu on 28 Nov 2016 | read
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Adjusting sowing time may help

Ergot, usually known as sugary disease is widespread in India. Individual grains are infected and in some years grain formation is reduced to a large extent.

In South India the disease is prevalent from October to January in the crop maturing stage during cold weather. Sometimes it is observed in the summer crop also. Ergot infection is conspicuous from blossoming of the cereals to maturity of the plants.

Symptom

Infection is first evident in the conidial honeydew stage of the pathogen when masses of conidia are exuded in sugary suspension on the inflorescence.

The exudation accumulates in droplets or adheres to the surface of the floral structure.

Insects feed on this nectar-like mass and their presence is conspicuous around the infected spikelet. Soon the infected ovaries are transformed into black, horn like structures.

Humid weather or rains at the heading time are favourable for infection. Late sown crops are infected to a large extent.

Commercial grain sorghum hybrids will likely have a negligible incidence of ergot during normal growing seasons, because their high self-fertility results in rapid pollination, greatly reducing the risk of infection.

Management

The seeds can be partially cleaned by immersion in 20 per cent solution of common salt.

The seeds float on the surface and can be manually removed.

Adjustment of sowing time may sometimes helpful in managing the disease.

There is no effective method of controlling sugary disease, though fungicides like ziram, captan or Propiconazole 0.2 per cent foliar spray at the stage of just before earhead emergence and repeated 2-3 times at 5-7 days interval can help.

(Dr. M.Theradimani, Prof, Department of floriculture and medicinal crops, email: mtheradi@gmail.com, mobile: 9443432752 and Dr.T.N.Balamohan, Dean, Horticultural College and Research Institute,TNAU, Periyakulam, email: tnb@tnau.ac.in)

 

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