Abstract
Conidia ofSclerospora sorghi, obtained from either systemically-infected or local-lesion-infected leaves of sorghum (cv. Vidan), were capable of inducing typical downy mildew systemic infection, including oospore formation, in sorghum and corn hybrids. Very young inoculated seedlings displayed chlorotic systemic symptoms already on the first leaf, and often died at fourth-leaf stage. Systemic infection was induced by conidia on sorghum 1–14 days old at inoculation. Incidence of infection was much higher and symptoms less delayed when the shoot rather than coleorhizas of young sorghum and corn seedlings were inoculated; in two-week-old sorghum with three leaves, inoculation of the coleoptile or of the base of the second and third blades resulted in systemic infection; with coleoptile inoculation partial leaf chlorosis was delayed until the fourth-or fifth-leaf stage, showing that penetration without symptoms had occurred as far as the meristematic tissues of young leaves still within the leaf tube.
Conidial inoculation of young sorghum tillers sprouting after cutting down healthy mother shoots resulted in systemic infection.
Conidial inoculum is deemed to be the probable major means for systemic infection of corn and sorghum sown in fields in which oospores are not present; inoculation of new tillers of forage sorghum by conidia from infected plants in a neighboring field can explain the rise in numbers of plants systemically stricken.
Two sweet corn hybrids — one considered resistant in the field, the other very susceptible — proved equally susceptible when inoculated with conidia at 5 days of age.
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Dalmacio, S.C. andExconde, O.R. (1969) Penetration and infection ofSclerospora philippinensis Weston on corn.Philipp. Agric. 53: 35–52.
Kenneth, R. (1966) Studies on downy mildew diseases caused bySclerospora graminicola (Sacc.) Schroet. and S. sorghi Weston and Uppal.Scr. Acad. hierosol. 18: 142–172.
Kenneth, R. (1970) Downy mildews of Gramineae in Israel.Indian Phytopath.23: 371–377.
Kenneth, R. andKlein, Z. (1970) Epidemiological studies of Sorghum Downy Mildew (Sclerospora sorghi) on sorghum and corn in Israel.Israel J. agric. Res. 20: 183 (Abstract).
Kenneth, R. andShahor, G. (1971) [New developments in Sorghum Downy Mildew in sorghum and corn in Israel.]Hassadeh 51: 853–856. (in Hebrew)
Klein, Z. (1969) [Research on the Etiology and Epidemiology of the Downy Mildew Disease of Sorghum and Corn Caused bySclerospora sorghi Weston and Uppal.] M.Sc. thesis, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot, Israel, (in Hebrew)
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Kenneth, R., Shahor, G. Systemic infection of sorghum and corn by conidia ofSclerospora Sorghi . Phytoparasitica 1, 13–21 (1973). https://doi.org/10.1007/BF02980302
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DOI: https://doi.org/10.1007/BF02980302