Apparent Resistance of Groundnut Cultivar Robut 33-1 to Bud Necrosis Disease. P. W. Amin, Groundnut Entomologist, International Crops Institute for the Semi-Arid Tropics (ICRISAT), Patancheru P.O., Andhra Pradesh, 502 324, India . Plant Dis. 69:718-719. Accepted for publication 2 January 1985. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-718.

Bud necrosis disease (BND), caused by tomato spotted wilt virus (TSWV) and transmitted by thrips Frankliniella schultzei, is the most important virus disease of groundnut in India. A high-yielding cultivar, Robut 33-1, was identified in field tests as having 50–90% lower BND incidence than the commonly grown cultivar TMV 2. The resistance is passive; i.e., when Robut 33-1 plants are infected either by sap inoculation or by infective thrips, they develop normal symptoms of BND. Robut 33-1 plants did not adversely affect the longevity and fecundity of F. schultzei; however, in field tests, thrips infestation was lower on Robut 33-1 than on TMV 2. This indicates a nonpreference of thrips for cultivar Robut 33-1, resulting in low incidence of BND.