In 1977 and 1978 the productive response of hemp pulpe use at various different harvest times was examined at the Ente Nazionale Cellulosa e Carta Campulongu farm (Oristano). In 1977 three different harvest times were compared using the cultivars Superfibra and Carmagnola Selezionata: the first harvesting took piace during female flowering, the second twenty days from the first and the third twenty days from the second. To the three test periods of the previous year a further early harvest was included in 1978, this time during full male flowering. In both years, the best yield tram both cultivars was obtained by harvesting the plant in the time of full female flower, that is in the first ten days of August. There did not appear to be any differences between the two cultivars, while one month's delay in the sowing reduced the 1978 yield as compared to that of 1977.