Data/hora: 04/06/2024 15:30:52

Biblioteca(s): | Embrapa Trigo.
Data corrente: | 10/01/2010
Data da última atualização: | 30/07/2013
Autoria: | PUGH, G. W.; JOHANN, H.; DICKSON, J. G.
Afiliação: | Grace Wineland Pugh; Helen Johann; James Geere Dickson.
Título: | Factors affecting infection of wheat heads by Gibberella saubinetii.
Ano de publicação: | 1933
Fonte/Imprenta: | Journal of Agricultural Research, Washington, v. 46, n. 9, p. 771-797, 1933.
Idioma: | Inglês
Conteúdo: | Continuing their studies on the wheat ear blight caused by Gibbberella saubinetii [R.A.M., xii, p. 159] the authors give a full report of their field and greenhouse inoculation experiments between 1920 and 1924, the results of which showed that infection was most effective (on pure lines of Marquis and Prelude wheats, which were almost exclusively used) when the ears were sprayed with a conidial suspension of the fungus while blossoming or just after this period, although some infection also resulted from earlier or later applications. The length of the incubation period was shortest at the higher end of the range of controlled temperatures (from 12° to 32° C.) tested, and also decreased as the plants matured. The fact that, in inoculations made before the blossoming period, the great majority of initial infections occurred in the spikelets that were first to open in the ear, and that infection spread further usually in the same order as that in which other spikelets opened up, is interpreted to indicate that the fungus gains entry through the floral parts rather than that it progresses in the ear through the rachis. It is thought that infection most usually occurs through the anthers or other degenerating tissues, on which the fungus first develops as a saprophyte and from which it spreads to the interior of the flower and to the developing grain. This view is supported by the fact that infection was frequently observed to begin in anthers that had failed to emerge from the glumes, and that a high percentage of the spikelets showing initial infection were found to have retained anthers in them. Retention of the latter is not, however, dependent on infection, since in Marquis wheat the percentage of retained anthers was found to be higher in healthy than in infected ears. There was no evidence that initial infection occurs through the outer surface of the glumes.
Thesagro: | Doença; Trigo.
Categoria do assunto: | --
Registro original: | Embrapa Trigo (CNPT)
Exemplares: | CNPT - (23616-1) - ADD - SP - -- - 09697 -  - 09697 - DIS