D. R. Trindade

Three new pathogens infecting antilles cherry in the State of Pará

Em plantios uniformes, a aceroleira (Malpighia glabra) tem sido afetada por doencas que causam manchas e malformacao nos frutos, tornando estes improprios para consumo in natura. A partir de 1999, tres novas doencas caracterizadas pelo aparecimento de manchas foliares e queda da folhagem vem sendo observadas em plantacoes localizadas nos municipios de Santa Izabel do Para e Igarape Acu. Apos isolamento, exame das estruturas morfologicas e testes de patogenicidade em mudas de acerola, os isolados foram identificados como Calonectria ilicicola (anamorfo: Cylindrocladium parasiticum) que causa manchas foliares relativamente grandes atingindo ate 7 cm de comprimento, de coloracao marrom-escura que coalescem atingindo grande extensao da area foliar e causando a queda de ate 50% das folhas; Corynespora cassiicola que provoca manchas necroticas de formato irregular, com bordas marrom-escuras e centro branco, circundadas por um halo amarelo nitido; Myrothecium roridum que causa manchas concentricas de coloracao cinza. O fungo C. cassiicola tem sido relatado causando doencas em varios hospedeiros na regiao amazonica, enquanto C. ilicicola infeta outros hospedeiros, nos Estados do Maranhao e Para.

White-thread blight: five new hosts in the state of pará, brasil

Since the first description of Pellicularia koleroga Cooke, at present classified as Ceratobasidium stevensii (Burt) Venkat. (sin: Corticium koleroga (Cooke) v. Hohn., Koleroga noxia Donk, Botryobasidium koleroga Cooke) by Deslandes (Bol. Fitossanitario 1:197, 1944), more than 40 important agricultural and forestry species were reported to be damaged by the white-thread blight, making evident the importance of that pathogen to the Amazon region (Albuquerque, Seminario Tecnico, EMBRAPA-IPEAN, 1973; Silva et al., Fitopatol. bras., 8:601, 1983; Lourd & Alves, Fitopatol. bras., 12:88, 1987; Furtado, Manual de Fitopatol., 1997; Benchimol & Muller, Embrapa-CPATU, Comunicado Tecnico 99, 1999; Gasparotto & Silva, Fitopatol. bras., 24:469, 1999). C. stevensii penetrates the plant by natural chaps or twig axils, showing up as whitish mycelial cords (rhizomorphs) that develop upon the host twigs and leaves, causing them to dry. The dead leaves remain hanged on the twigs by the pathogen mycelium as a characteristic sign of the white-thread blight (Figure 1). Morphological and physiological characteristics of the pathogen and disease control were described by Roger, L. (Phytopathologie des Pays Chauds, Lechevalier, 1949). Surveys on Bragantina region plantings, State of Para, Brazil, detected damages caused by C. stevensii on Neem (Azadirachta indica A. Juss.), African mahogany (Khaya ivorensis A. Chev.), coconut (Cocos nucifera L.), banana (Musa L. cv. yangambi) and ornamental Ixora (Ixora coccinea L.). Reproduction of white-thread blight symptoms under greenhouse conditions was obtained about one week after mycelial PDA plug inoculation on the abaxial face of the young leaves of these hosts left in a dew chamber for 48 h. FIG. 1 Signs of Ceratobasidium stevensii (arrows) on (a) K. ivorensis; (b) A. indica; (c) I. coccinea; (d) C. nucifera; (e) Musa sp.

Incidence of Fusarium solani in cassava in the State of Pará, Brazil

This paper describes for the first time the occurrence of Fusarium solani infecting cassava (Manihot esculenta) in the State of Para.

Rot of corn caused by Rhizoctonia zeae in the state of Pará, Brazil

The occurrence of corn rot caused by Rhizoctonia zeae is reported for the first time in the State of Para, Brazil.

Eugenia brachypoda, new host of Cylindrocladium pteridis in the State of Pará, Brazil.

The socoro (Eugenia brachypoda DC) belongs to the Myrtaceae family and voluntarily grows on the margins of rivers and lakes in the micro-region of mid-Amazon. The mature fruits are round and orange to purple in color; the sweet and sour pulp is highly appreciated by the local population, especially of Monte Alegre and Alenquer in the State of Para. In June 1996, seedlings were raised from seeds obtained from the fruits collected from the margin of the LakeArariquara in Alenquer-PA, and planted on uplands in the experimental fields of Embrapa in the eastern Amazon, in Belem, Para. Leaf spots of irregular size and shape (Figure 1), resulting in leaf desiccation and defoliation were observed in May 2002. The fragments from diseased leaf tissues were cut from the margins of the leaf spots, surface disinfected in 1% sodium hypochlorite for 1 min, rinsed in sterile water and plated on 2% water agar. The colonies that developed after three days of incubation at room condition were transferred to PDA, where the fungus showed morphological characteristics typical of Cylindrocladium pteridis Wolf (Figure 1B), teliomorph Calonectria pteridis Crous, Wingfield & Alfenas. The cylindrical, hyaline, uniseptate conidia measuring 65 76 μm x 4.6 5.4 μm (av. 70 x 4.9 μm) were characterized by a clavate vesicle. The fungus has been reported from Brazil as causing lesions on Pinus caribaea Morolet var. hondurensis Barr. & Golfari (Hodges et al. Brasil florestal 6:8-11. 1975), coconut (Cocus nucifera L.) (Silva & Souza, Fitopatol. bras. 6:515-517. 1981; Ponte & Silveira Filho. Fitopatol. bras. 22:567. 1997; Trindade et al. Fitopatol. bras. 23:412. 1998), in buritizeiro (Mauritia flexuosa L.) (Silva Fitopatol. bras. 21:523. 1996) and in Eucalyptus spp. (Ferreira et al., 1992. Fitopatol. bras. 17:226.1992). The pathogenicity test was done by inoculating the host leaves with a PDA culture disc of C. pteridis, and incubating in a

Black sigatoka of banana in the State of Pará

Black sigatoka of banana in the State of Para The most serious disease reported in banana ( Musa sp.) caused by Mycosphaerella fijiensis has

Cylindrocladium pteridis leaf spot of apricot tree in the State of Para, Brazil.

The apricot (Mammea americana L.) is a fruit-bearing tree growm throughtout the entire Amazon region, especially in the state of Para, hence the name abrico-of-Para (Cavalcante. Frutas Comestiveis da Amazonia, 1996). The fruits are used in salads, and in the forms of liquor, jelly and compote, all which keep the taste and flavor for long periods of time. The bark latex and the seed powder of apricot are reported to have an insecticidal effect that efficiently control of ticks, other insects, and animal parasites. Its wood tannins are used in the leather industry (Coral. O Abricoteiro, uma opcao de investimento para o Estado do Para. Boletim Tecnico, SAGRI, 1998). In April 2002, during a routine plant pathological inspection of orchards in Marituba, PA, a generalized attack of a leaf spot disease was observed. Small light brown leaf spots, surrounded by a dark brown halo eventually resulted in the blight of the entire leaf (Figure1 A) and defoliation of the trees. Isolations were made from the lesions by cutting tissues fragments from the lesion margins, which after disinfections in 2% sodium hypochlorite for 1 min and washing in sterile water, were placed on 2% water agar. After a seven-day incubation at 26 + 2 C, the fungal growth showed morphometric characteristics of Cylindrocladium pteridis Wolf (telemorph Calonectrica pteridis Crous et al.). The conidiophores are penicillate, with clavate vesicle and the conidia are cylindrical, hyaline, uniseptate, 65-76 x 4.6-5.5 μm (mean 70 x 4.9 μm) (Figure 1B). For the pathogenicity tests, a 5 mm mycelial disc was placed on healthy apricot seedling leaves, while the PDA discs without the fungus served as control. All seedlings were placed in a moist chamber for 72 h. Symptoms similar to the natural infection appeared on the leaves five days after inoculation while the control seedlings remained healthy. The fungus was reisolated from the lesions. Cylindrocladium pteridis has been reported from Brazil causing lesions on aciculae of Pinus caribea Morelet var. hondurensis ( Senecl.) W.H.G. Barret & Golfari (Hodges et al. Brasil Florestal 6:8. 1975), in Cocus nucifera L. (Silva & Souza. Fitopatologia bras. 6:515. 1981; Ponte & Silveira Filho. Fitopatologia bras. 22:67. 1997; Trindade et al. Fitopatologia bras. 23:412. 1998), in Mauritia flexuosa L. (Silva. Fitopatologia bras. 21:523. 1996) and in Eucaliptus spp. (Ferreira et al. Fitopatologia bras. 17:226.1992). No previous report was found in the literature regarding the occurrence of C. pteridis and symptoms of the foliar lesions on apricot; thus this is the first record of the pathogen on apricot in Brazil.

Coconut stalk rot caused by Cylindrocladium floridanum in the State of Pará, Brazil.

Center of Embrapa, Belem, PA. The fungus was inoculated in healthy fruits causing the same field symptoms and reisolated, fulfilling koch postulates. This is the first report of this pathogen on coconut in the State of Para, Brazil.

Pyricularia grisea causing leaf spots in banana produced by micropropagation

Pyricularia grisea causing leaf spots in banana produced by micropropagation Banana (Musa sp.) seedlings produced by micropropagation in the aclimatation stage have been infected by Pyricularia grisea causing necrotic leaf spot limiting the growth of the explants.

Molecular detection of Xylella fastidiosa in citrus in the state of Para, Brazil

Molecular Detection of Xylella fastidiosa in citrus in the state of Para, Brazil This paper reports the occurrence of chlorosis variegation of citrus (Citrus spp.) in the state of Para, Brazil. The presence of the pathogen was detected by PCR in extracts of total DNA from leaf petioles using specific primes to Xylella