Okra variety, Parbhani Kranti, highly prone to leafhopper, Amrasca biguttula biguttula Ishida, creating epidemic conditions in the bills of Uttarkashi in Bhagirathi valley of central Himalaya (India)

In India, a survey conducted in July 1996 in Uttarkashi, a northern border district of Uttar Pradesh in Garhwal Division having boundaries with Tibet and Himachal Pradesh and situated in the Bhagirathi valley of central Himalaya, revealed the occurrence of an epidemic of leafhopper, Amrasca biguttula biguttula Ishida on okra variety Parbhani Kranti. The villages surveyed included Barethi, Nirakot, Jaspur, Tiloth, Silyara, etc. The altitude varies between 3000 and 5500 ft above the mean sea level. The temperature ranged from - 4.2°C to 41.2°C, and the rainfall was about 1/70 mm. The snowfall occurred according to the altitude of hills. Parbhani Kranti variety of okra, known to be resistant to yellow vein mosaic virus transmitted by the white fly, Bemisia tabaci Genn, was mostly grown. In village Barethi situated at an altitude of 3300 ft above m.s.l., okra variety Parbhani Kranti plants suffered severe hopper burn injury with curling and cupping of leaves, thereby reducing the yield to a great extent. About 90–100 per cent plants were damaged by this leafhopper. Farmers sprayed dimethoate and dichlorvos but to no avail. Usually, there were 30 to 50 nymphs per leaf which increased to 120–130 nymphs per leaf in the case of severe infestation. Although damage was evident in all the villages, yet in Barethi, it appeared in an epidemic form and reduced the yield considerably. Another variety, A-4, was relatively less attacked. Both the varieties were free from yellow vein mosaic virus. Parbhani Kranti proved highly susceptible to A. bigudtula biguttula.