Susceptibility of four grapevine rootstocks to Cylindrocladiella parva

Abstract

The susceptibility of four common grapevine rootstocks (101-14, Schwarzmann, 5C and Riparia Gloire) to Cylindrocladiella parva (black foot disease) infection was assessed in a pot experiment. The roots of 4-month-old callused rooted cuttings were wounded in situ and inoculated with 50 ml C. parva conidial suspension (106/ml) or sterile water (controls). After 6 months of growth, shoot dry weight was significantly higher for control plants (24.2 g) than for those inoculated with C. parva (16.5 g), but did not differ between rootstock varieties. Root dry weight was not significantly affected by C. parva inoculation, but root dry weight of 101-14 was significantly higher than other rootstocks. Incidence and severity of trunk infection were significantly affected by rootstock variety, being lowest in rootstock 101-14 plants than other rootstocks. None of the rootstocks tested was resistant to this pathogen.