Incidence effect of the bean angular leaf spot in the transmission of Pseudocercospora griseola (Sacc) Crous & U. Braun and in the seed quality

O presente trabalho teve por finalidade propor um estudo sobre o fungo Pseudocercospora griseola (Sacc) Crous & U. Braun, agente causal da mancha angular, atrav??s da avalia????o da incid??ncia e severidade em plantas de feij??o produzidas a partir de sementes provenientes de vagens com diferentes n??veis de severidade da doen??a, assim como verificar o efeito sobre a qualidade fisiol??gica e sanit??ria das sementes produzidas. Para a realiza????o experimental foram coletadas plantas de feij??o com alta incid??ncia de mancha angular, infesta????o natural. A partir do material coletado procedeu-se separa????o das vagens a partir de uma escala diagram??tica variando de 1 a 5, correspondendo cada nota a um n??vel de severidade sobre a superf??cie da vagem. Experimento paralelo foi realizado, avaliando sintomas de mancha angular em diferentes locais da semente: hilo e tegumento. Os testes realizados nas sementes oriundas dos respectivos tratamentos foram: teste padr??o de germina????o (TPG), teste de envelhecimento acelerado (EA), determina????o do teor de ??gua e analise sanit??ria. Os resultados mostraram que a incid??ncia e a severidade da mancha angular nas plantas de feij??o diferiram-se estatisticamente entre si, onde os n??veis da escala 1 e 5 apresentaram-se com menor e maior grau de incid??ncia e severidade de P. griseola, respectivamente. As sementes com sintomas no hilo e sementes com les??es tegumentares apresentaram resultados semelhantes quanto ?? incid??ncia e severidade do agente causal. A correla????o entre a severidade da vagem e a severidade da doen??a nas plantas foi significativa. Quanto ao teste de envelhecimento acelerado, os tratamentos n??o diferiram estatisticamente entre si, resultando numa varia????o de 82 a 88% de pl??ntulas normais. No teste padr??o de germina????o, o tratamento 5 diferiu estatisticamente dos demais tratamentos. Na an??lise sanit??ria, os g??neros f??ngicos relacionados a armazenamento apresentaram maior incid??ncia ?? medida que ocorreu aumento no n??vel de severidade dos tratamentos. Os resultados permitiram concluir que vagens com 60% de sintomas de mancha angular apresentam a capacidade de interferir no potencial germinativo das sementes de feij??o e que maiores n??veis de severidade das vagens ocasionam um maior desenvolvimento da doen??a em campo.The present work purposes to study the fungus Pseudocercospora griseola (Sacc) Crous & U. Braun, causal agent of angular leaf spot on common bean, to evaluate the incidence and severity in produced beans plants from seeds proceeding from pod with different levels of disease, as well as, to verify the effect in the physiological and sanitary quality of the produced seeds. For the development of the experiment, beans plants have been collected with high incidence of angular leaf spot, natural infestation the field. From the collected material it was elaborated a diagrammatic scales varying of 1 the 5, corresponding each note to a severity level on the physical structure of the pod. Parallel experiment was carried out, evaluating symptoms of angular spot in different places of the seed: hilum and coat. The tests carried through in the deriving seeds of the respective treatments had been: tests of germination (TPG), accelerated aging (EA), test of humidity and health. The results had shown that the incidence and the severity of angular leaf spot on common bean had been differed statistical between itself, where the levels of scale 1 and 5 had presented with minor and greater degree of incidence and severity of P. griseola, respectively. Whereas the seeds with symptoms in hilum and in the coat have presented resultes similar to the incidence and severity of the causal agent. The correlation enters the severity of pod and the severity of the disease in the plants was significant. There wasn??t statistical differences between the test of accelerated aging in the tested treatments, resulting a variation of 82-88% of normal seedlings. In the test of germination, treatment 5 differing statistical from the others treatments. In the sanitary analysis the fungus of storage increase incidence to the measure that increased the level of severity of the treatments. It was concluded in this work that pod with 60 % of symptoms of angular leaf spot have the capacity to intervene in the germination of the beans seeds and and that bigger levels of severity of the string beans cause a bigger development of the disease in field