Plant protection in ornamental and forest plants.
After persistent low temperatures in the winter, growers are advised to monitor the following shrubs and trees for signs of pests and diseases in spring. The gall-forming aphid Sacchiphantes abietis [Adelges abietis] in spruce [Picea spp.] is treatable with white oil [mineral oil] and pyrethroids. Rhyacionia buoliana in the apical buds of young pines [Pinus spp.] should be removed by hand; in maritime pines [Pinus pinaster] Matsucoccus feytaudi must by law be treated with pyrethroids. Forsythia branches infected with Phomopsis sp., Phyllosticta or Ascochyta should be removed before applying copper as oxychloride or hydroxide. The former may also be used against leaf spot or Fusicoccum amygdali [Phomopsis amygdali] canker in flowering almonds. Mimosa should be given treatment to forestall infection by Verticillium dahliae. Plane tree [Platanus] leaves showing necrotic spots should be removed. Carbendazim at 120 g/hl should be applied at bud burst in nurseries, but care must be taken in towns and housing estates not to use pesticides potentially harmful to humans; thiabendazole in mixtures with acephate, imidacloprid or methomyl can be used against Corythucha ciliata in planes and a watch should be kept for the canker-producing Ceratocystis fimbriata.