# Abstract

Eight varieties were planted in 1977 and studied in 1979-1980. In a partial 4 X 4 diallel, the number of nodes below 150 cm was negatively correlated with cane height. Cane diameter was positively correlated with cane height and negatively correlated with the number of nodes below 150 cm. General combining ability effects accounted for most of the genetic variance in primocane vigour, and in the number of nodes below 150 cm and the number of cropping nodes in fruiting canes. Small but significant specific combining ability effects were also observed for primocane vigour and the number of nodes below 150 cm on fruiting canes. In 21 families from crosses amongst nine varieties, cane height was strongly correlated with cane diameter both between plants and within plants. Principal component analysis identified a vector, denoted "cane vigour", which accounted for 64% of the variance; a second vector, accounting for a further 27% of the variance, showed an association that was independent of cane height between cane diameter and number of nodes. The varieties 741B11 and 7325C4 were identified as the best parents for breeding for many nodes without reducing cane vigour.