Incidence of Phomopsis amygdali, Botryosphaeria berengeriana and Valsa cincta diseases in almond under different control strategies 1

The fungi causing cankers and withering of stems and branches of almond under Spanish Mediterranean conditions are: Phomopsis amygdali, Botryosphaeria berengeriana (in the form of its Dothiorella anamorph) and Valsa cincta (anamorph Cytospora cincta). P. amygdali is the most important because of its high specificity. Its development causes serious damage, particularly in orchards near the sea. B. berengeriana is a polyphagous fungus with high virulence but, because its growth depends on high temperature and adequate humidity, it is only present in orchards located in the south of the Iberian peninsula. V. cincta is widespread and causes withering of twigs. Control strategies for these three fungi with systemic fungicides have been investigated in the laboratory and glasshouse by artificial inoculations using both twig segments and seedlings of almond cv. Marcona. Benomyl, thiophanate‐methyl and imazalil applied both as foliar spray and by soil drenching, have shown low fungitoxic activity in the apical part of the stems and twigs of tested plants. P. amygdali and B. berengeriana were the most affected by the three fungicides, while V. cincta was less affected. Benomyl proved to give the best control, followed at a distance by thiophanate‐methyl. No control was obtained with imazalil.