Rusts are one of the most complex plant pathogens, with a diverse range of species estimated in size somewhere between 5000-6000, as well as a large range of hosts. Hosts include dicotyledonous families such as Compositaceae, Euphorbiaceae, Leguminaceae and Moncot families such as Orchidaceae and Lilaceae, and ofcourse of most international importance Poaceae (grasses, mayz & Wheat). Rusts could be described as visible black, yellow, orange, red, or brown pustules growing on

Rose black spot is caused by the fungi Diplocarpon rosae, a pathogen that before the 1960's had very little attention because of high pollution levels in cities restricting it. However, due to drops in Sulphur dioxide levels in the atmosphere and a better air quality from then onwards it has had a massive economic impact on the rose industry, estimated in the 10’s of billions and is presently the most damaging widespread disease of cultivated roses. Initially a rose black spo