Scientists Focus on how Paddy Dwarfing Virus Entered India's Crop Belt

Even though the virus causing the ‘dwarfing’ of paddy in Punjab and Haryana is new in the country, the insect that carries the virus has been here for years, according to a latest research by scientists at Ludhiana’s Punjab Agriculture University (PAU), the Indian Express reported.

The Southern Rice Black-streaked Dwarf Virus (SRBSDV) is carried by the white-backed plant hopper (WBPH) in a persistent, circulative and propagative manner, the Express reported citing scientific research. 

Nonetheless, scientists are still trying to find out how the Dwarf Virus reached the country's paddy belt. They think that WBPH carrying the virus may have migrated on the back of typhoons and strong convection winds.

Dr Mandeep Singh Hunjan, a principal plant pathologist at PAU, told the Express that WBPH’s presence has been detected in India for an extended period. However, the researchers will now focus on finding how the Dwarf Virus, which was first found in China, entered Punjab and Haryana.

Dr Hunjan told the newspaper that it was their priority to discover the name and cause of the disease caused by the virus in order to solve the crop damage issue and help farmers save crops. They are also focusing on the route through which the virus may have entered. It is a double-stranded RNA virus that was reported from Southern China, in Punjab, in 2001.

Dr A S Dhatt, additional director of research at the Punjab Agricultural University (PAU), in August told the Hindustan Times that the PAU started receiving complaints of stunted rice plants in the state in July. However, within a month, such complaints were coming in from almost across Punjab and its neighbouring states.

The experts at PAU said that the infected plants were stunted with narrow, erect leaves; both roots and shoots of the plants were substantially affected. In the badly infected rice fields, the infected plants were withering and the virus affected all rice varieties, the report said. The stunted plants show height reduction by 1/2 to 1/3rd of their original size. They also have shallow roots and can be easily uprooted. 

Scientists also said that nymphs of WBPH can transmit SRBSDV better than adults and they both transmit the SRBSDV to rice plants at various growth stages. In Punjab, young paddy plants of 30 to 35 days were infected, the Express reported.

According to the Express report, some claim that several rice varieties are resistant to the WBPH itself, but there are some varieties that such insects can easily infect.

Scientists have suggested that farmers regularly monitor the rice crop for the presence of WBPH so that preventive measures can be taken on time.