The reduction of pesticide use against Pseudomonas syringae pv. actinidea (Psa) in the Bairrada region, Portugal

Abstract

Pseudomonas syringae pv. actinidiae (Psa) is a bacterium that attacks the kiwifruit, being currently its worst disease problem, included in European and Mediterranean Plant Protection Organization (EPPO) A2 List . The Psa can cause yield losses between 10 to 50% and, in extreme cases, the plant death. In Portugal, the disease was detected in 2010 in the northern region and, in 2012, in the Bairrada region. Currently, Psa control strategies are based mainly on chemical control, based on copper fungicides.

In this study, four control methods against Psa were used, combining different copper-based products with a biological control agent - Bacillus subtilis, together with the cutting and burning of infected organs, aiming to develop a control strategy against Psa while reducing chemical control. The study results showed that a strategy combining cultural control, chemical control with copper oxide and biological control with Bacillus subtilis reduces the disease damages in the kiwifruit plant branches, leafs and flowers, while at the same time present better economic results.