In 1979, in Apulia (Southern Italy) field experiments have been carried out to test the influence of plant density per hectare, and of two different distances of transplanting on the yield and quality of the cultivars Erzegovina, Perustitza and Xanthi yaka. The theses tried for each cultivar foresaw three densities of transplantation (low, medium, high) obtained with two different distances of transplanting. The following results were obtained : Erzegovina variety recorded an average increase in production of 20.6% with the high density (133,333 plants per hectare) compared with the lowest density (71,428 plants per hectare). The Xanthi yaka variety recorded an average increase of 27.4% with 208,333 plants per hectare (high density) compared with 119,047 plants per hectare (low density). The Perustitza variety recorded an average increase of 53.2% with 208,333 plants per hectare, compared with 89,285 plants per hectare (low density). The surface of the leaves, which is smaller in the highest density and larger in the smallest, is characterized by the following average percentage reductions : Erzegovina, 24.9%; Xanthi yaka, 15.9% and Perustitza, 13.0%, changing from low to high densities. As far as the commercial value is concerned, the best results were obtained for Xanthi yaka, with 208,333 p/ha from cm 30 x cm 16 spaces and with 166,666 p/ha from cm 40 x cm 15; for the Perustitza variety, we have with 125,000 p/ha, with a spacing of cm 40 x cm 20; for the Erzegovina variety, we have, with 133,333 p/ha, with a spacing of cm 40 x cm 18.75 and with 133,333 p/ha, with a spacing of cm 50 x cm 15.