Pesquisaram-se, por trinta meses, a conservação e a germinação de sementes, a emergência e o desenvolvimento de plântulas da pereira porta-enxerto Taiwan Nashi-C (Pyrus calleryana Decaisne). Sementes com 12% de umidade armazenadas sob ambiente frio (5-10oC), em frascos de vidro com tampa plástica, mostraram alto poder de conservação. Germinações de 100% ocorreram até o 9o mês, diminuindo para 97, 94, 83 e 76% no final do 12o, 18o, 24o e 30o mês de armazenamento, com uma emergência, em condições de ripado, de 88, 89, 81, 76 e 70% respectivamente. Posteriormente ao 12o mês de armazenamento das sementes, a germinação que ocorria próximo aos 35 dias de estratificação, passou a necessitar mais de 50 dias para emissão da radícula. As plântulas, com rápido e vigoroso desenvolvimento vegetativo, atingiram 141,5cm de altura e 11,9mm de diâmetro, em média, após um ano da emergência. O ponto de enxertia foi atingido por 65% dos porta-enxertos aos oito meses de desenvolvimento, com diâmetro médio de 10,4mm. Cerca de 20% dos indivíduos se apresentaram anormais, com segregação genética indesejável para fins de formação de mudas vigorosas de pereira.
Taiwan Nashi-C (Pyrus calleryana Decaisne), an oriental rootstock pear, was investigated for 30 months in respect to seed cold storage, longevity, germination and seedling development. The seeds removed from mature fruits, were washed, dried, treated with Thiran and placed in closed botles under controlled environment (5-10oC) for thirty months. The seeds were stratified trimestrially over moist cotton substrate at 5oC for 40-60 days. One hundred percent germination ocurred until the 9th month, decreasing to 97, 94, 83 and 76% in the 12th, 18th, 24th, and 30th month of seed cold storage, with seedling emergency of 88, 89, 81, 76 and 70% respectivelly. The seedlings presented a rapid and vigorous growth, with average height of 141.5cm and diameter of 11.9mm, after twelve months from emergency. About 20% of the population showed abnormalities, with undesirable segregation

SUMMARYCytoplasmic inclusions, made up of a dense, finely granular matrix up to 3 to 4/zm in diam. were consistently found in ultrathin sections of leaf tissues from Fragaria vesca infected with strawberry vein-banding virus (SVBV). Isometric particles, usually with ring-like profiles, 4o to 45 nm in diam. were seen either embedded in the dense matrix or scattered in some electron-lucent areas of the inclusion. The particle morphology and the type of the inclusion found associated with SVBV places it in the cauliflower mosaic virus group.

O fungicida benomyl, utilizado intensivamente na cultura do morango a partir do final da década de 60, tem sido ineficiente para o controle da flor preta, causada por Colletotrichum acutatum, devido ao aparecimento de formas resistentes ao fungicida, já detectadas desde 1984. Para C. fragariae, no entanto, não há registro de ocorrência de resistência no Estado de São Paulo, embora venha se observando há alguns anos que o produto não tem apresentado resultados satisfatórios para o controle da podridão do rizoma ("chocolate"). Para verificar a ocorrência de resistência em C. fragariae foram testados 22 isolados, coletados em diversas regiões produtoras de morango do Estado de São Paulo, e 22 isolados de C. acutatum, para comparação. Todos os isolados de C. acutatum foram resistentes, mesmo na concentração de 1000 ppm. Dos 22 isolados de C. fragariae, 10 comportaram-se como resistentes, crescendo em todas as concentrações testadas. Os demais só se desenvolveram até 1 ppm, sendo considerados sensíveis. As porcentagens de inibição do crescimento dos isolados de C. fragariae resistentes variaram de 50,0 a 88,8 (1 ppm), 54,5 a 89,8 (10 ppm), 63,6 a 78,7 (50 ppm), 67,3 a 80,3 (100 ppm), 74,4 a 82,0 (500 ppm) e 76,4 a 86,0 (1000 ppm). Inoculando-se isolados resistentes e sensíveis de C. fragariae em plantas da cultivar IAC-Campinas, observou-se que todos foram igualmente patogênicos.
The intensive use of benomyl in strawberry fields since the late 60s. resulted in an ineffective control of the flower blight, caused by Colletotrichum acutatum due to the development of resistance to the fungicide by the patogen, detected in 1984. Until recently, the resistance was not demonstrated in C. fragariae although an increasing failure of benomyl to provide satisfactory control of the crown rot ("chocolate" rot) has been observed, indicating the possible occurrence of resistance. To verify this evidence, 22 isolates of C. fragariae, collected at different localities in São Paulo State, were evaluated and compared with 22 isolates of C. acutatum. All the C. acutatum isolates were benomyl resistant, even at 1000 ppm. Among the 22 C. fragariae isolates, 10 were resitant. The percentages of mycelial growth inhibition of C. fragariae ranged from 50.0 to 88.8 (1 ppm), 54.5 to 89.8 (10 ppm), 63.6 to 78.7 (50 ppm), 67.3 to 80.3 (100 ppm), 74.4 to 82.0 (500 ppm) and 76.4 to 86.0 (1000 ppm). Resistant and sensitive isolates of C. fragariae were inoculated on strawberry plants of IAC-Campinas cultivar, causing similar symptoms

Since 1991, when the whitefly Bemisia argentifolii Bellows & Perring was first described in São Paulo, it dispersed rapidly to all the regions of Brazil. Although the high incidence of geminivirus is correlated with high population of this whitefly, the transmission efficiency of this insect is unknown. To determine whether the B. argentifolii is a vector of BGMV, two experiments were carried out. After an aquisition period of 24 hours on infected beans plants cv. Carioca 80, adults of the whitefly were transferred to seedlings of some cultivars, giving a period of inoculation of 24 hours. In the 1st experiment, the percentage of symptomatic plants were: 25.0% for Carioca 80, 21.0% for Moruna 80, 21.0% for Aeté, 75.0% for Preto and 26.3% for Manteiga. In the 2nd experiment, the percentage of virus transmission were: 63.6% for IAC Carioca and 60.0% for BT-2. The results showed that B. argentifolii is a vector of BGMV and apparently there are no marked differences in efficiency of transmission between this specie and Bemisia tabaci (Genn.).

Serological detection of the Grapevine virus A in vineyards of the State of São Paulo, BrazilThis paper reports the serological detection of Grapevine virus A (GVA) in the vineyards of the State of São Paulo, Brazil. The GVA was detected mainly in grapes (Vitis spp.) infected by Kober stem grooving.

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*Autor correspondente RESUMO: A antracnose do morangueiro, causada por Colletotrichum fragariae Brooks, é uma das mais importantes doenças da cultura. Além dos rizomas, o fungo causa lesões em estolhos, pecíolos, limbos foliares, pedúnculos e frutos. A inoculação de plantas com este patógeno é muitas vezes imprescindível em trabalhos que necessitam uniformidade de inóculo e reprodução de sintomas da doença. Isso ocorre em testes de patogenicidade, em testes de eficácia de métodos de controle, em estudos sobre a variabilidade de diferentes isolados do patógeno e em avaliação de germoplasma quanto à resistência à doença. Objetivouse, neste trabalho, avaliar comparativamente sete métodos de inoculação de morangueiro com C. fragariae, descrevendo os sintomas obtidos em diferentes órgãos da planta. Sintomas foliares (mancha preta da folha) foram observados principalmente quando se utilizou pulverização do inóculo. Os métodos mais eficientes em produzir murcha e lesões nos rizomas foram: ferimento e deposição de 5 mL de inóculo nos rizomas, ferimento e deposição de uma gota de inóculo nos pecíolos e injeção de inóculo nos rizomas. Palavras-chave: Fragaria × ananassa, antracnose, avaliação de doença INOCULATION METHODS OF Colletotrichum fragariae ON STRAWBERRYABSTRACT: The anthracnose crown rot, caused by Colletotrichum fragariae Brooks, is an important disease of strawberries. The fungus also damages stolons, petioles, leaf blades and fruits. The inoculation of C. fragariae is necessary to ensure uniformity and appearance of characteristic symptoms of the disease in pathogenicity tests, variability evaluation of different isolates, efficacy of control measures and germplasm screening for resistance. This study evaluated seven inoculation methods of C. fragariae on strawberry and reports symptoms observed in each case. Symptoms of black leaf spot were mainly observed when the inoculum was sprayed on the plants. The best methods to reproduce wilting and crown rot were: 5 mL of inoculum placed on wounded crowns, a drop of inoculum placed on wounded petioles and crown injection.

Serological identification of the Grapevine fleck virus in BrazilIn the State of São Paulo, four different isolates of the virus that induces chlorotic translucent vein break in the minor veins of grapevines (Vitis spp.) were separated by their differential biological behaviour and tested for their relationship to Grapevine fleck virus (GFkV) by DAS-ELISA and TAS-ELISA with commercial antisera against GFkV. Young leaves from spring shoots and dormant cuttings were used for antigen extraction. All infected plants were previously indexed by graftinoculation to 'Rupestris du Lot'. The four isolates gave positive reactions to the GFkV antiserum. Positive ELISA reactions were observed in 66 samples of 26 varieties, from 11 grape-growing areas from the State of São Paulo as well as 24 samples, of 12 varieties, from five other states of Brazil. Healthy plants consistently gave negative results. Young leaves were better sources of antigen than cortical scrapings of dormant cuttings. The results showed that the four isolates have a serological relationship with the GFkV, suggesting that they belong to the viral complex that induce grapevine fleck disease.