Alternaria, Gloeosporium, Cerosporium, Ascochyta Gerbera
Leaf spots on gerbera
Necrotic leaf area probably caused by Alternaria
Leaf spots, a fungus, can, in some countries, also cause severe damage to the leaves whereto begin with circular shaped spots with irregular borders appear, subsequently they become bigger and inside they have a series on concentric circles diminishing in size, and with prominent borders.
Generally of a purple-brown colour, leafspots in more serious cases have the tendency to gather together, forming large necrotic areas that subsequently cause the leaves to whither. These pathogens spread by means of the conidia and spores, and flourish in hot and highly humid conditions. Outbreaks of Cercospora can be distinguished from those of Alternaria by the holes found near the centre of the necrotic areas.
The controls of these diseases are primarily of an agronomic nature. These controls seek to avoid high levels of humidity, and to encourage good physiological and sanitary conditions for the plants.
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