BACTERIAL CANKER OF GRAPEVINE IN BRAZIL MIRTES F. LIMA 1 , MARISA A.S.V. FERREIRA 2 , WELLINGTON A. MORElRA 1 & JOSÉ C. DIANESE 2 lEmbrapa Semi Árido, Caixa Postal 23, CEP 56300-970, Petrolina, PE, e-mail: mflima@cpatsa.embrapa.br; 2Departamento de Fitopatologia, Universidade de Brasília, CEP 70910-900, Brasília DF, e-mail: marisavf@unb.br. Corresponding author: Mirtes F. Lima (Accepted for publication on 27/07/99) LIMA, M.F., FERREIRA, M.A.S. V., MOREIRA, W.A. & DIANESE, J.c. Bacterial canker of grapevine in Brazil. Fitopatologia Brasileira 24:440-443. 1999. ABSTRACT In early 1998, symptoms of stem canker and necrotic spots on leaves, leaf veins, petioles, rachis, peduncles, cap stems and berries were observed on plants in vineyards in the "Subrnédio" of the São Francisco Valley. Initially, the symp- toms were observed on 'Red Globe' and seedless grape cul- tivars up to three years old, during the flowering and begin- ning of fruit bearing stages. The incidence of disease symp- toms was 100% and in some cases yield losses were nearly total. Isolations from diseased plants yielded a bacterium RESUMO which was identified asKJIHGFEDCBA Xanthomonas campestris pv. viticola, after biochemical, physiological and pathogenicity tests. The disease has already been detected in vineyards in Petrolina county of Pernambuco State, Piauí State and also in Curaçá, Casa Nova, Sento Sé and Juazeiro counties in Bahia State. Key words: Vitis vinifera, Xanthomonas campestris pv. viticola. Cancro bacteriano da videira no Brasil No início de 1998, observou-se em alguns parreirais do Submédio do Vale do São Francisco plantas com sintomas de manchas necróticas nas folhas, nervuras e pecíolos, na ráquis e pedicelo dos cachos e nos ramos, com posterior formação de cancros. Estes sintomas foram observados, ini- cialmente, em parreirais com menos de três anos de idade, principalmente na fase da floração e início da frutificação em 'Red Globe' e em cultivares de uva sem sementes, com incidência de até 100% e causando perdas totais na produção em algumas áreas. Nos isolamentos a partir de plantas infec- tadas, detectou-se a presença de uma bactéria, identificada como Xanthomonas campestris pv. viticola através de testes bioquímicos, fisiológicos e de patogenicidade. A doença já foi constatada em parreirais do município de Petrolina, no Estado de Pernambuco, no Estado do Piauí e nos municípios de Curaçá, Casa Nova, Sento Sé e Juazeiro, no Estado da Bahia. The "Submédio" of São Francisco Valley, especially the irrigated areas in Petrolina and Juazeiro, are extremely favorable for the growth of grapevines (Viris vinifera L.) due to its climatic conditions which allows 2.5 harvests per year. This region is the largest producer and exporter of grapes in Brazil. In 1996, the area occupied with vines increased over 65%, from 2,902 ha to 4,847 ha (IBGE, 1996), having pro- duced, in that same year, approximately 27 % of the coun- try's total harvest. Viticulture has a major social importance in the region, employing as many as 3-4 people/ha/year. In early 1998, symptoms of stem canker, leaf spots and necrosis were observed on 'Red Globe' vines in the São Francisco Valley. Leaves showed small necrotic lesions that started as interveinal angular spots and sometimes were sur- rounded by a yellow halo (Fig. IA e lB). At later stages, leaves would turn yellow and fali off. Symptoms also devel- oped on leaf veins and petioles, on pedicels and rachis of grape clusters. On the stems, irregular spots coalesced to form long dark streaks that evolved to necrotic lesions and cankers. Longitudinal cracking of the stems was often ob- 440 served on stems exposing the underlying tissues (Fig.l C e lD). Vascular discoloration was also observed. In the begin- ning of fruit set stage, grape clusters showed necrosis of pedicels and rachis (Fig.1E and 1F), followed by fruit wilting and drying Ali symptoms were initially observed on young vines, up to three years of age, during the flowering stage, beginning on fruit bearing at the pea-sized stage or after the first pruning. Cultivars severely affected were 'Red Globe' and the seedless varieties originated from 'Thompson Seedless', on which the incidence was nearly 100%. In some areas, total loss in production was reported. Disease symptoms were detected with variable incidence on 'Italia', 'Festival', 'Pira- tininga', 'Patricia', 'Ribier', 'Catalunha', 'Brasil' and 'Beni- taka'. Cultivar Italia showed tolerance to the disease under field conditions. Similar symptoms were observed in older vines of the same cultivars during the maturation phase. In some areas, disease symptoms became more severe after a heavy rain (100 mm) which occurred in mid-January. More severe and faster developing symptoms were observed on Fitopatol. bras. 24(3), setembro 1999