The Punjab agriculture department has been put on high alert, as yellow rust disease was detected for the first time on HD 2967 variety of wheat in Bhagtana Tulian village of Dera Baba Nanak block in Gurdaspur district on Monday.
The disease, which is already prevalent in certain pockets of the state, sent an alarming wave among the wheat growers across Punjab when it was detected on the HD 2967 variety.
The atmosphere in Gurdaspur district is conducive for spreading yellow rust - a fungal disease - which manifests as powdery yellow stripes on leaves. These stripes hinder photosynthesis and make grains shrivel besides causing stunt growth of plants.
"It is a serious disease, which has been threatening wheat cultivation in the country for a few years,"says Ravi Kumar Sabharwal, chief agriculture officer, Gurdaspur.
"When low temperature is coupled with rain, fog or dew during the wheat growing season, the disease spreads,"says Sabharwal.
Normally, there is a low temperature in January, but when the temperature remains 3-4 degrees Celsius above the normal and accompanied by rain and fog, the environment becomes conducive for the yellow rust. "The impact of temperature and other factors are visible only in January,"says Sabharwal.
He said Propiconazole fungicide had been provided on subsidised rates throughout the district under the National Food Security Mission.
The disease spreads by wind. It started appearing in the present race taxonomic group, which is a division of a species in 2001, because farmers in wheat-growing states were not replacing their wheat varieties susceptible to the disease, says Sabharwal, adding when wheat varieties are grown in larger areas, they become prone to the disease, that is why, it is recommended that seeds of wheat varieties should be replaced every three years.
Another reason for increasing plant disease is that farmers grow wheat varieties that are not recommended for their regions as a result the plants either become susceptible or act as transporting agents, says Dr Ajaib Singh Randhawa, agricultural officer, Dera Baba Nanak block, Gurdaspur district.
"We have already cautioned farmers that if they find a yellow powdery substance on leaves of wheat crop, they should spray 200 ml of propoconazole fungicide mixed into 200 litre water in one acre of wheat crop,"says Amrik Singh, agricultural officer, Gurdaspur.
Farmers should spray the crop when the weather is clear and there is no rain, fog or dew, he said.
The farmers should consult agriculture experts for confirmation of yellow rust disease symptoms, as yellowing of leaf may also be due to other factors like deficiency of nutrients, Amrik Singh added.