Observations of the solar wind close to Jupiter by the Voyager 1 and Voyager 2 spacecraft in 1978 and 1979 are compared with the hectometer-wavelength radio emission from the planet. A significant positive correlation is found between variations in the solar wind plasma density at Jupiter and the level of Jovian radio emission output. During the 173-day interval studied for the Voyager 2 data for the radio emission displayed a long-term periodicity of about 13 days, identical to that shown by the solar wind density of Jupiter and consistent with the magnetic sector structure association already proposed for ground-based observations of the decameter-wavelength emission.