Silent threat in Punjab’s paddy fields: Rice stunting virus resurfaces causing yield losses

In the heart of Punjab’s paddy belt, a silent adversary has resurfaced — the Southern Rice Black-Streaked Dwarf Virus (SRBSDV). First identified in the region in 2002, has once again struck the kharif crop, stunting rice plants across eight districts.

As farmers grapple with yield losses and uncertainty, scientists and agricultural experts are racing to contain the damage and decode the virus’ resurgence. The virus’ spread has sparked concern among farmers, many of whom are urging the state government to conduct a girdawari (crop loss assessment) and announce compensation.

What is the virus affecting crops

SRBSDV belongs to the Fijivirus genus and was first reported in Southern China in 2001. It made its presence felt in Punjab three years back when farmers began noticing mysterious dwarfing of crops in their fields.

The virus is transmitted by the white-backed planthopper (WBPH), Sogatella furcifera, which spreads the infection persistently. WBPH nymphs are particularly efficient carriers, and their migration — often aided by strong winds — can carry the virus across large distances. WBPH, the primary vector, is a familiar pest in Punjab’s rice-wheat cropping system.

The hallmark of SRBSDV infection is a sharp reduction in plant height, often to half or even one-third of the normal. Infected plants develop narrow, upright leaves with white specks, shallow roots, poor tillering and stunted shoot growth.

In severe cases, plants may wither prematurely, leading to significant yield loss. Field surveys by Punjab Agricultural University (PAU), Ludhiana, show that early-sown crops are especially vulnerable, with incidence rates ranging from 10 to over 40 per cent.

Reasons for virus’ resurgence

Experts attribute the virus’ resurgence to a combination of factors. SRBSDV is believed to have evolved from a related virus through genetic mutation, acquiring WBPH as a new vector. The widespread use of insecticides has altered WBPH populations, making them harder to control.

Changes in transplanting schedules and rice varieties have also created conditions conducive to viral spread. The role of change in climatic conditions leading to occurrence of virus is still under investigation by experts.

PAU has been leading the response. In mid-July, reports of stunted rice plants began surfacing. PAU scientists conducted field visits, collected samples, and confirmed SRBSDV through molecular sequencing. Dr Satbir Singh Gosal, Vice Chancellor, PAU, said the university is monitoring not just rice crops but also weeds and alternate host plants that may harbour the virus.

Dr KS Suri, Principal Entomologist at PAU, has advised farmers to conduct weekly field checks by gently tilting and tapping rice plants to dislodge WBPH nymphs or adults. The transmitting insects can be seen floating on water surfaces or clustering at the plant base. Upon detection, farmers are urged to use insecticides recommended by PAU. These include Pexalon, Ulala, Osheen/Dominant/Token, Imagine, Orchestra and Chess.

Scientists have also laid out the dose or quantity required per acre for different pesticides and the method of their application such as directing the spray specifically at the base of the plants and using proper nozzles like flat-fan or hollow cone for maximum effectiveness. Dr Suri, however, has cautioned against indiscriminate use of pesticides, warning that it can lead to resistance and environmental harm.

How is the menace being tackled

Not all stunted plants are victims of SRBSDV. Dr MS Bhullar, Director of Extension Education at PAU, noted that zinc deficiency can mimic viral symptoms. He has urged farmers to consult extension services for accurate diagnosis and proper nutrient management to avoid misdiagnosis and unnecessary panic.

Since there is no cure for SRBSDV, prevention and early detection are critical. PAU recommends that farmers follow transplanting schedules strictly, as crops transplanted after June 15 show lower incidence.

Monitoring WBPH activity, avoiding seed stock from infected fields, and maintaining weed-free plots are essential. Farmers noticing symptoms should promptly report them to the nearest Krishi Vigyan Kendra or PAU experts.

With rice being a major economic crop in Punjab, the stakes are high. The current outbreak is a reminder of the vulnerabilities in our agricultural systems and the need for integrated pest management, climate-resilient practices, and scientific vigilance.

As Punjab’s farmers stand guard against this invisible enemy, the collective effort of researchers, policymakers, and cultivators will determine whether SRBSDV remains a seasonal menace — or becomes a chronic threat.