Control of brown rot of citrus fruits, using the new anti‐oomycete systemic fungicides, has been studied in the field and in packing houses under the climate conditions of Spain. In the field, in rainy weather and at the stage of colour‐break of the fruits, both with artificial inoculation and with natural infection by Phytophthora citrophthora, a single treatment with fosetyl‐A1 at 0.4% a.i. as a foliar spray provided good control of the disease. The highest fungitoxic effects were reached 14–21 days after treatment. Copper oxychloride + mancozeb at 0.3% a.i. showed moderate efficiency. In semi‐commercial experiments in the packing house and in the laboratory, fosetyl‐A1 at 0.3% a.i. strongly controlled infection with zoospores located in different layers of the fruit peel (flavedo or albedo). Fosetyl‐A1 also developed good efficacy in healthy fruits, protecting them from infection by contact. Metalaxyl at.0.2% a.i. also reduced infection by zoospores and contact. Oxadixyl, propamocarb and folpet (reference product) had poor activity against the brown rot fungus. All these data strongly support the value of fosetyl‐A1 for control of brown rot disease of citrus fruit in the field and in the packing house as a post‐harvest treatment. Metalaxyl may also be utilized for this purpose.

The fungi causing cankers and withering of stems and branches of almond under Spanish Mediterranean conditions are: Phompsis amygduli, Bofryosphaeriu berengeriunu (in the form of its Dofhiorella anamorph) and Vnnlsu cincta (anamorph Cyfosporn cincta). P. amygduli 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. cincfu 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. amygdnli and B. berengerim were the most affected by the three fungicides, while V. cinctn was less affected. Benomyl proved to give the best control, followed at a distance by thiophanate-methyl. No control was obtained with imazalil.