WALNUT TREE MANAGEMENT UNDER VARIETAL HETEROGENEITY CONDITIONS
The principal factors that affect walnut cultivation in Chile are varietal, plantation density, formation system irrigation, pruning, harvesting and sanitary problems. From the varietal point of view, the walnut situation is very interesting. Of the approximately 6,000 ha planted, about 5,000 are planted with non grafted trees. Consequently, there are an endless number of different types, generally within the same orchard. The country, then, has a splendid collection of naturally occurring germplasm. As a positive result of this situation some selections have been made, specially of less vigorous and early producing varieties. Nevertheless, the most negative aspect, is that the large heterogeneity of these seed propagated orchards limits and hinders their commercial exploitation. This can be seen in the phenology and condition of the trees as well as in the characteristics of their production. The trees size and vegetative habit, flowering time, fruit set type, susceptibility to insect pests and to diseases and production characteristics are particularly important. In an effort to take care of this problem, phenological factors, vigorization pruning, regrafting, pruning for illumination and harvesting synchronization were carried out. The results obtained are presented.
Cooper, T. and Lemus, G. (1997). WALNUT TREE MANAGEMENT UNDER VARIETAL HETEROGENEITY CONDITIONS. Acta Hortic. 442, 327-332