Occurence of banana diseases in the state of Alagoas.
Field studies were conducted in Brazil to survey the diseases of banana occurring in the production areas of Alagoas. This work was conducted during 2006 and 2007, by means of visits to farms and assessment of infected plant materials in 60 banana production areas, distributed in 14 counties of Alagoas. The material collected was analysed in laboratory for identification of pathogens associated with diseases. In this survey, several diseases caused by fungi and nematodes were observed. Yellow sigatoka (Pseudocercospora musae [Mycosphaerella musicola]), Deightoniella spot (Deightoniella torulosa) and Cordana spot (Cordana musae) were the 3 diseases present all areas surveyed, while Chloridium spot (Chloridium musae [Periconiella musae]) occurred only in areas with humidity and associated with other leaf spots and Exosporella spot was found only at Santana do Mundau. Plant nematoses caused by Rhadophulus similis [Radopholus similis], Helicotylenchus multicinctus and Pratylenchus sp. were found only in some counties. Panama disease (Fusarium oxysporum f.sp. cubense) was found only in 4 areas in the south of the state and bacterial wilt (Ralstonia solanacearum race 2) was found only in 3 areas. Even though panama disease and moko disease (Ralstonia solanacearum race 2) were found in low incidence, these diseases still are considered major problems in banana plantations in Alagoas.