The Punjab Agricultural University (PAU), Ludhiana, said on Monday that symptoms of late blight have been observed during a survey in potato fields, and warned farmers to take necessary steps to save the crop at the initial stage itself.
A PAU spokesperson said symptoms of the disease have been in fields across Hoshiarpur, Gurdaspur and Ropar and the most probable reason for this is intermittent rain, which has created favourable weather for late blight growth.
The statement from PAU said, “During recent surveys of potato crop conducted in different potato growing areas of the state, initial symptoms of late blight have been observed in some villages of Hoshiarpur (Adamwal, Haryana and Mohaan), Ropar (Jagatpur and Shampura) and Gurdaspur (Chhotepur and Umarpur) districts.”
Dr Narinder Singh, head, department of plant pathology, said, “Due to intermittent rain in December, the prevailing weather conditions are becoming congenial for the outbreak and spread of late blight in major potato growing areas of the state.”
He further said that the temperature range of 11-20 degree C coupled with RH >90 per cent may lead to more disease development as the potato varieties cultivated in Punjab are less tolerant to late blight.
He advised farmers that if they see disease symptoms in their crop, they should spray systemic fungicides such as Ridomil Gold or Curzate M-8 or Sectin 60 WG 700 g per acre or Revus 250 SC 250 ml or Equation Pro 200 ml per acre in 250-350 litres of water.
“These systemic fungicides enter the plant system and are able to eradicate an established infection. If the weather conditions remain favourable for late blight, then the spray of systemic fungicides may be repeated at 10 days interval,” he added.
WHAT IS BLIGHT?
A disease caused by the water mould Phytophthora infestans. It is common in humid regions with temperatures. Hot dry weather checks its spread.
Symptoms: The first symptoms of late blight appear as small, light to dark green, circular to irregular-shaped water-soaked spots. During cool, moist weather, these lesions expand rapidly into large, dark brown or black lesions, often appearing greasy. A pale green to yellow border often surrounds the lesions. Severely infected fields often produce a distinct odour and soon the entire crop can be damaged if not controlled in time.