Genetic parameters estimates and visual selection for leaves production in Ilex paraguariensis

The selection of yerba mate superior genotypes, based on each plant leaf weight, is based on genetic parameters obtained from experimental plantations and it is practically impossible from the fourth year of age. Therefore, we estimate genetic parameters and check the feasibility of selection through notes and weight estimates of each tree at 18.5 years of age. The genetic material consists of a combined trial of provenances and progenies of half-sibs with 140 progenies from 7 provenances, installed in Ivai, Parana, Brazil, in a randomized block design with 10 repetitions. The genetic control of leaf production is of low magnitude (($) over cap (2)(a) = 0.175042 +/- 0.0393) revealing high influence of the environment. The additive genetic correlations between the real weight of leaves x notes and real weight of leaves x visually estimated weight were of high magnitude (higher than 88%). Thus, the selection based on the leaves weight can be carried out without major losses in genetic gains by both methodologies when the purpose is the sexual selection, in which case the sort order has no importance. In the case of vegetative propagation, aiming clonal plantations, in which only the plants with the highest genotypic values should be selected, the selection by means of notes and leaves weight estimates proved to be inefficient.