Explainer: Why ‘false smut’ has triggered a false alarm, but dwarf virus is the real killer

Even as farmers in Patiala struggle with crop losses due to floods and dwarf virus, reports of widespread false smut infestation have triggered panic across the district.

However, an official survey has found that the impact of the false smut disease is far less severe than what has been projected on social media, where some people photographed a yellowing powder falling from the crop.

Whereas, dwarf virus has proved to be a silent killer devouring the crops in over 20k acres of land falling in 400 villages of Patiala.

What is false smut

According to a survey conducted by the Punjab Agricultural University (PAU), false smut, or the ustilaginoidea virens fungus, is a fungus that affects rice by producing greenish-yellow and orange spore balls which replaces a few grains in the panicle, thereby giving it a “smutty” appearance.

Dr Mandeep Singh Hunjan, principal plant bacteriologist, Department of Plant Pathology, PAU, explains, “Infection occurs during the booting stage, particularly under warm temperatures, high humidity and rainy conditions. However, not all panicles on an infected plant are affected, and typically only a few grains per panicle are replaced, resulting in very low yield loss,” Dr Hunjan said.

The PAU survey has found that false smut has affected only about 1.5 per cent of the total rice yield.

“This year, the more noticeable appearance of false smut in Punjab was due to favourable weather conditions between August 20 and September 10, coinciding with the flowering period. Our surveys indicate disease incidence remained below 10 per cent, with severity generally under 1-1.5 per cent and only rare cases reaching 5 per cent. Despite its visible symptoms, false smut does not pose a significant threat to overall rice yield,” he added.

Meanwhile, Chief Agriculture Officer (CAO), Patiala, Jaswinder Singh has urged farmers not to panic or fall prey to misinformation being circulated online.

“The recent rainfall may actually help wash away false smut spores. Farmers should not believe rumours that rain will worsen the disease or resort to unnecessary spraying at this late harvesting stage,” he said.

“We expect the weather to stabilise with clear skies from tomorrow. Farmers should allow the crop to dry before harvesting to ensure smooth procurement and lifting at the mandis,” Singh added.

However, some farmers have voiced concern over what they describe as the widespread nature of the outbreak. Progressive farmer Pargat Singh said that false smut has emerged as a major challenge this season across both Punjab and Haryana.

“Prolonged humidity of around 70 per cent, temperatures between 30-35°C, waterlogging, excessive use of nitrogen, delayed or poor quality pesticide application, and the fungus’ ability to survive in weeds have all contributed to the disease’s spread,” he said.

20k acres devastated by dwarf virus in paddy

Southern Rice Black-Streaked Dwarf Virus (SRBSDV) also known as dwarf virus has ruined the crop in 20,000 acres of land in 400 villages of Patiala alone.

It is transmitted by the white-backed planthopper (WBPH), which leads to stunted growth, poor tillering, shallow roots and narrow upright leaves. Infected plants often fail to mature, resulting in significant yield losses.

According to chief agriculture officer, Patiala, Jaswinder Singh, “The impact of virus varies on the field. In some fields, 50 per cent of crop has been damaged while 100 per cent loss has also been reported in some fields.”

A preliminary report of the study conducted by PAU has found that the weather conditions in 2025 — marked by similar rainfall, temperature and daylight hours — mirror those of 2022, when the last major flare-up occurred.