Interactions among site, plague and a trunk disease in a plantation of Populus deltoides cv Catfish-2 in the Low Delta of Paraná River (Argentina)

Abstract

This work is aimed at studying the interactions among the plantation site quality of poplars with damages caused by «Taladro de los Forestales» (Platypus mutatus Chapuis), and with cankers (one trunk disease). We carried out the study in a 2 ha plantation of Populus deltoides cv Catfish-2, which is the most widespread clone in the delta area. The plantation was 12 years old and it was placed in the Low Delta of Paraná River (Argentina). We detected a direct relation among the forest site quality, the presence of the plague (Platypus mutatus) and a trunk disease (cankers). The poplars of greater diameter and height were the most affected trees by the boring insect's attack and they showed the most quantity of active holes and cracks at galleries height, as a consequence of the plague effect, while the poplars of less growth were those more infected by cankers in their trunks. The percentage of plants affected by the boring insect and infected by cankers was significantly greater at the most productive and the highest forest site («albardón» protected by dams). However, the low sites («bañados» protected by dams) had lower growth values and volumetric yields, fewer active holes, less percentage of plants broken by the wind at the height of galleries produced by boring insects and less number of plants with cankers in the trunks.