Leaf Scald of Sugarcane

Symptômes

Symptoms include two main forms (chronic or acute) and two stages (latent and eclipse). The chronic forms show lines on leaf blades that run parallel to the ribs. They can be as wide as 1 cm. The acute form shows sudden wilting of mature stalks. There are usually no external symptoms. The disease can be latent, it may not be obvious for some time and the plant is seriously affected when the symptoms first appear. The first sign of the disease is the development of white pencil lines with yellow borders following the veins on the leaf that lead to tissue necrosis. The disease can also cause the shoots to be stunted and wilted. Affected leaves usually turn into dull-blue green colour before dense browning. Under stressful conditions, the whole shoot may die. On mature stalks, spindle leaves become necrotic from the tips and moderate to profuse side shoots develop. Side shoots usually show scalding or white pencil lines.