Paddy dwarfing: scientists in dark on how virus reached crop belt

However, scientists are still clueless as to how the virus reached the paddy belt and believe that WBPH carrying the virus may have migrated with the help of typhoons and strong convection winds.

Talking to The India Express, a principal plant pathologist at PAU, Dr Mandeep Singh Hunjan, said that WBPH’s presence has been observed in India for a long time and will now focus on finding how the virus, first seen in China, entered the state.

Dr Hunjan said: “Our priority was to find out the name and cause of the disease so that some solution could be provided to the farmers as soon as possible to safeguard the crop from further damage. Now we will be focusing on the route of the virus entering the state”.

Scientists are also considering the possibility of a migratory WBPH carrying the virus and transferring it to a native WBPH after coming in contact with it.

They said that after it was seen in China, the virus was observed in several other countries including Korea and Vietnam.

Scientists had also said that nymphs of WBPH can transmit SRBSDV better than adults and that viruliferous WBPH nymphs and adults may transmit SRBSDV to rice plants at different growth stages. In the case of Punjab, the young plants of 30 to 35 days were infected by the insect.

It is also said that several rice varieties are resistant to the WBPH but still there are some varieties which can be easily infected by such insects.

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

Farmers in Punjab and Haryana have been complaining about stunted rice plants for the past 20-25 days. The height of the stunted plants showed a reduction from 1/2 to 1/3rd of the normal plants. These plants had shallow roots and could be easily uprooted. Such plants were observed in almost all the cultivated varieties in the farmers’ fields. Dwarfing of plants was reported at 10 per cent to 25 per cent in most cases while exceeding 40 per cent in a few.