The performance of the progeny generated from the nine parents differed sharply. Table 3 summarizes the GCA effects
(combined across location) for the variables analysed. The highest positive GCA effect for fresh-root yield was observed
for clone SM 1665-2 and the most negative for clone SM 805- 15. As is often the case, it is difficult to obtain germplasm that will be outstanding for several variables simultaneously. The progeny of SM 1665-2 had excellent fresh-root yields but also the lowest dry matter content in the roots. However, these GCA values should be treated with caution because of the
significance of their interaction with the environment. When the GCA effects were analysed for each location individually
(data not presented), there were few cases of significant changes in the relative performance of the progeny from each
parental clone.