DISTRIBUTION OF BLACK LEAF STREAK DISEASE ( Mycosphaerella fijiensis Morelet ) IN MATO GROSSO , BRAZIL DISTRIBUIÇÃO DE SIGATOKA NEGRA ( Mycosphaerella fijiensis Morelet ) EM MATO GROSSO , BRASIL

Banana black leaf streak disease caused by the present quarantine pest M. fijiensis occurs in Mato Grosso State since 1999 and requires adoption of sanitation, including detection survey. The aim of this study was to evaluate the distribution of M. fijiensis in Mato Grosso State from 1999 to 2013, as well as how black leaf streak disease periodically was spread in all regions of Mato Grosso State according to the standards of the Ministry of Agriculture, Livestock and Food Supply. Considering the first outbreak year and the previous surveys (Table 1), it can be verified that Mycosphaerella fijiensis Morelet was introduced into Mato Grosso State in accordance with the following periods of times and counties: 2001 to 2003 Nova Bandeirantes and Paranaíta; 2001 to 2004 Barra do Bugres and Gaúcha do Norte; 2001 to 2005 Paranatinga; 2002 to 2004 Porto Estrela, Santo Afonso, and Tangará da Serra; 2002 to 2005 Rosário Oeste; 2004 Acorizal, Guarantã do Norte, and Sinop; 2004 to 2005 Sapezal; 2005 Campos de Júlio, Nova Maringá, Poxoréu, and Sorriso; 2005 to 2006 -Marcelândia and Matupá; 2007 Água Boa, Barra do Garças, Campinápolis, General Carneiro, Novo São Joaquim, and Pedra Preta; 2013 Canabrava do Norte, Confresa, Porto Alegre do Norte, and São José do Xingu. The dispersal of M. fijiensis throughout both time and space showed to be random in Mato Grosso State and its counties, except among some counties adjacent each other, which can be explained by the movement of infected banana seedlings.


INTRODUCTION
Black leaf streak disease is caused by plantpathogenic fungus M. fijiensis.It is extremely severe after bunch production because plants do not produce leaves anymore after flowering, which may cause 100% of yield loss in susceptible cultivars (OROZCO-SANTOS, 1998).M. fijiensis is a regulated pathogen in Brazil as present quarantine pest and requires periodic surveys.This disease is distributed throughout the states of Acre, Amapá, Amazonas, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Pará, Paraná, Rio Grande do Sul, Tocantins, Maranhão, Rio de Janeiro, Rondônia, Roraima, Santa Catarina, and São Paulo (BRASIL, 2013).
Mycosphaerella fijiensis was introduced into Brazil through Amazonas State in 1998 (PEREIRA et al., 2000).In Mato Grosso State since the first detection of black leaf streak in 1999 up to 2004, the banana cultivated area reduced by 63% (IBGE, 1999 and2004).This paper aimed to present the distribution of black leaf streak (M.fijiensis) in Mato Grosso since its first outbreak until 2013.

MATERIAL AND METHODS
The distribution of this disease was monitored from 1999 to 2013 by the Mato Grosso State Institute of Agricultural and Livestock Defense, know as INDEA/MT.INDEA/MT surveyed black leaf streak according to the Ministry of Agriculture, Livestock, and Food Supply (BRASIL, 2002 and2005).The surveys sampling and periodicity were the followings: (i) 1% of rural properties or urban squares at least once each 6 months, in area where the disease has not been detected; (ii) 2% of rural properties or urban squares at least once each 3 months, in area recognized as M. fijiensis free area by the Ministry of Agriculture, Livestock, and Food Supply; (iii) 5% of rural properties or urban squares at least once each 2 months, in adjacent area to probable expansion area and to area recognized as M. fijiensis free area by the Ministry of Agriculture, Livestock, and Food Supply; (iv) 3 adult plants in the pre-flowering stage per hectare at 50% of existing properties along road considered as risk route for the disease; and (v) 3 adult plants in the pre-flowering stage per hectare, in outbreak delimitation survey according to the following proportions: in 50% of all properties located at the radius up to 10 km from the outbreak; in 30% of all properties located at the radius from 10 to 30 km measured from the outbreak; and in 10% of all properties located at the radius from 30 to 70 km measured from the outbreak.In noncommercial urban and rural areas were inspected at least 3 adult plants in the pre-flowering stage per hectare.In commercial production area were inspected at least 5 adult plants in the preflowering stage per hectare.Plants inspected which were suspected to be infected by this fungus were sampled and analyzed in laboratory accredited by Ministry of Agriculture, Livestock, and Food Supply.

Figure 1 .
Figure 1.Dispersal of black leaf streak in Mato Grosso State.

Table 1 .
Demonstrative of black leaf streak surveys per county with disease occurrence, in Mato Grosso.