One of the main methods to control Fire Blight and Apple Scab is based on the crop varieties that are resistant or have low sensitivity to this pest. In Navarre, the Technical Institute for Agricultural Management (ITGA) has a collection of 253 types of apple tree, autochthonous to Spain, providing a valuable source in the quest for solutions. Alejandro Martnez's PhD analysed apple trees that the ITGA has on its experimental farm in Doneztebe/Santesteban and has confirmed that 12 Navarre varieties show resistance to both Fire Blight and Apple Scab. In the case of Apple Scab, the fruit trees have shown that they are totally resistant to this disease, while in the case of Fire Blight, it has been shown that the pathogen attacks them, but does not damage them as much as the rest of the trees.
The Apple Scab may be controlled by treatment with fungicide, but the problem is, if the plant is highly sensitive to the pest, it will need 15 treatments a year. This brings with it great environmental and economic consequences. Moreover, the continued use of insecticides may give rise to the appearance of strains resistant to the fungicides.
Although in a number of European countries and in the USA numerous studies on resistance of apple tree varieties to Fire Blight and Apple Scab have been undertaken, this is the first in Spain. It is true that field evaluations of these pests have been carried, but these were never transferred to the laboratory. The results that appear in the PhD were obtained by means of artificial inoculation.
Perspectives for the future
The ITGA tests were aimed at looking for new alternatives for the future. One line of research is the possibility of planning new varieties of apple trees resistant to Apple Scab and with
Contact: garazi andonegi