The possibility of doing seedling preselection to obtain dwarfing avocado rootstocks at an early stage was determined in this study. Fifty seedlings, one year oId (1981), of Cv. Colin V-33 were used to evaluate: height; diameter of the stem; principal, secondary and tertiary branches. The trees were grafted in 1984 with different cultivars and selections of normal, intermediate and dwarf size. In 1990 the reduction of height and canopy diameter and the rootstock circumference were evaluated. The correlation analyzes indicate that there is no relationship between the characteristics of the seedlings and the dwarfing effect of the rootstock when analized by cultivar or selection and by the total. When they were analized by tree size, some significant correlations (P = 0.05) were found in the dwarf type between height-height reduction (r 0.64); diameter height reduction (r = 0.76); total branches height reduction (r = 0.65); principal branches/height-height reduction (r = 0.66); and in the group of tall size between total branches-rootstock circunference (r = 0.51). Due to the fact that in the total, tau and in termediate size and in cultivars and selection there was no relationships between one year oid seedlings characteristics and the darfing effect over the scion, we think that is not possible to do preselection at a early stage of the seedling.

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