Doenças do álamo

A cultura do alamo no Brasil, assim como no resto do mundo, enfrenta serios desafios em relacao a pragas e doencas. No que se refere a doencas, a ferrugem das folhas, causada por Melampsora medusae, e a mais importante da cultura. A doenca provoca pustulas nas folhas, aonde sao produzidos urediniosporos em grande numero, responsaveis pela disseminacao, podendo ocasionar epidemias no verao. Com o avanco da doenca, a queda das folhas e antecipada, interferindo no crescimento da arvore e armazenamento de energia para o proximo ciclo. Alem da ferrugem, outras manchas foliares como as causadas por Septoria, Alternaria tenuis e Colletotrichum gloeosporioides ja foram detectadas no Brasil. A mancha de Septoria e a mais importante pois o patogeno causa cancros nos galhos e tronco das arvores. Tambem sao relatadas na literatura manchas foliares causadas por Marssonina spp, Taphrina spp e Venturia spp, alem de diversos cancros e algumas podridoes radiculares. Abstract The poplar crop in Brazil, as in the rest of the world, has been attacked by a number of pests and diseases. The leaf rust, caused by Melampsora medusae is the most important disease. It causes pustules in leaves, which produces uredinospores in large quantities which spreads the disease causing epidemics in the summer time. After several cycles of the pathogen, the plant is early defoliated, grows poorly and retains less energy for the next year. Besides this disease, other leaf diseases caused by Septoria, Alternaria tenuis and Colletotrichum gloeosporioides have already been detected in Brazil. Leaf spot caused by S. musiva is the most important because the pathogen causes cankers in stems and branches. Other diseases have already been mentioned in different publications such as leaf spots caused by Marssonina spp, Taphrina spp, and Venturia spp, as well as several cankers and some root rot.