. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 273 were usually entirely embedded, with the beaks only protruding and were often numerous and crowded. Cultural evidence that Edgerton's specimens were actually genetically connected with the cotton anthracnose are wanting. The fungus has been repeatedly studied in pure culture and numerous inoculations have thoroughly proved its pathogenicity, the disease usually showing within a few days after inoculation, though sometimes incubation is delayed much longer. Infection of stems is often at a wou
. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 273 were usually entirely embedded, with the beaks only protruding and were often numerous and crowded. Cultural evidence that Edgerton's specimens were actually genetically connected with the cotton anthracnose are wanting. The fungus has been repeatedly studied in pure culture and numerous inoculations have thoroughly proved its pathogenicity, the disease usually showing within a few days after inoculation, though sometimes incubation is delayed much longer. Infection of stems is often at a wound such as a leaf scar; or on leaves at some point of weakness. Cotyledons and yoimg plants are especially susceptible. On bolls infection is conmion at the line Fig. 202.—G. gossypU, D, and E, fun- of dehiscence of the carpels. Ac- ^Jlefw! '" °°**°° "°* ^^""' cording to Barre, there is evidence that the fungus may destroy the contents of the boll before it shows upon the outside. Barre showed that 44% of flowers that received spores within ten hours after opening produced dis- eased bolls; but inoculations by spraying produced no results on bolls after they were three-fourths grown. Seed from a field that bore 35% infected bolls gave on germina- tion, 12% of infected seedlings, the disease appearing upon cotyle- dons or hypocotyls even before they unfolded. Atkinson"" found that conidia five months old were alive, but that at seven months they failed to germinate. Barre also found the conidia and the mycelium of the fungus to be comparatively short lived. G. atrocaipi Del. on Atrocarpus leaves has been described as a perfect stage of Glceosporium atrocarpi Del. A fungus on Cattleya "^' "^ described by Maublanc & Lasnier as a Physalospora should perhaps be considered as a Glomerella. Gnomoniella Saccardo (p. 263) Perithecia sunken and usually remaining so, with a long cylin- dric, erumpent ostiole, leathery, black; asci ellipso
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
