Dear Friends,

Recently I visited some wheat fields in Aligarh and Bulandshar and was surprised to see exceptionally high incidence of both Black and Yellow rust of wheat. The disease is more common in the late sown (December sowing) crop and generally the Black rust is noticed first.

Cause:

The disease is caused by a fungus Puccinia grmnis pv. tritici . The black stem rust disease of wheat in India perpetuates on wild grasses from where the rust spores are by wind currents every year. Spores may be carried from low to very high altitudes of 12,000 to 14,000 feet and from short distances to very long distances of several hundred kilometers.

Symptoms:

The disease is charaterised by irregular black pustules on the stem usually 3-10 mm in length. These uredial pustules occur on stem, leaf sheath, leaves and earhead but the stem is often most severely affected. The pustules of black rust are reddish-brown in colour and elongated in shape. This rust spreads fast under relatively warmer and humid environmental conditions. By the time the crop matures, dark, black, enlongated telial pustules are formed. The name black rust was given to this rust due to the prominence of its dark black telia.
Black rust, though prevalent all over the country, appears in epidemic forms in the southern, central and eastern India, which are characterised by high temperatures in the wheat growing season. Black rust is a killer of wheat plants and in severe infection there is heavy crop failure

1.     Use genuine and certified seeds.

2.     Grow resistant varieties.

3.     Avoid late sowing.

4.     Avoid excess use of nitrogen. Use of Potash is known to reduce rust infection.

5.     Give at least 2 sprays of TKS-Manco Meta to avoid onset of the disease in January and February.