Xylella fastidiosa bacteria colonize the host plant xylem vessels and block the water and nutrient flow with consequent yield reduction. Up to now, adequate coffee plantation management procedures have attenuated the disease incidence, such as the use of bacteria-free seedlings and insect vector control. Pruning is an important practice for optimization of coffee orchard production. Coffee growers refer to pruning as training; coffee tree training depends on the coffee plant type and environment, using traditional or drastic trimming. This research aimed at evaluating the efficiency of different prune procedures in the control of X. fastidiosa incidence in coffee commercial cultivars Acaiá IAC 474-19 and Catuaí Vermelho IAC 81. Eight plants of each cultivar were submitted to three pruning types (traditional, "skeleton cut" and trunking); and eight plants were not pruned (controls). Prior to pruning, five plant branches were collected for anatomical studies. Thereafter, five other branches from all treatments were collected in October/2004 (rainy period) and June/2005 (dry period) for the anatomical studies. No significant differences were observed for `Acaiá IAC 474-19' that presented lower proportion of xylem vessel obstruction independent of the prune treatment. Prune treatments in `Catuaí Vermelho IAC 81' were also not significantly different; however, plants submitted to dramatic trimmings such as the "skeleton cut" and trunking showed a trend for lower proportion of xylem vessel obstruction by the bacteria, in both rainy and dry periods. It was suggested that the drastic pruning procedures ("skeleton cut" and trunking) might be advantageous for the Xyllela control in situations of high disease incidence.
Coffea arabica L.; Xylella fastidiosa; xylem obliteration; disease control; pruning techniques
