. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 141 It causes a rot of the grape, much dreaded in Europe, attacking leaves, fruit and stem. The fungus can persist long as a sapro- phyte in the conidial condition. Sclerotia are borne within the affected tissues. On germination they may either produce the conidia directly or form apothecia. Both ascospores and conidia are capable of infecting the grape but infection is much more certain from a vigorous mycelium (see S. libertiana, p. 142). Attachment organs, c. f. Fig. 93, which consist of close
. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 141 It causes a rot of the grape, much dreaded in Europe, attacking leaves, fruit and stem. The fungus can persist long as a sapro- phyte in the conidial condition. Sclerotia are borne within the affected tissues. On germination they may either produce the conidia directly or form apothecia. Both ascospores and conidia are capable of infecting the grape but infection is much more certain from a vigorous mycelium (see S. libertiana, p. 142). Attachment organs, c. f. Fig. 93, which consist of close branch- clusters and seem to be induced by contact of a mycelial tip with any hard substance are present in abundance. Both toxins and digestive enzymes are ;^' â¢'^ Botrj^s douglasii on pine is perhaps identical with the conidial form of the last fungus (see p. 140) as may also be the Botrytis of Ward's Lily Disease;'° the Botrytis causing disease of goose- berries '' and many others that have been named as distinct species of Botrytis. S. galanthina Ludwig, close kin to S. fuckeliana, attacks snow- drops. S. rhododendri Fisch. occurs on Rhododendron. The former of these two is supposed to be the ascigerous form of Botrytis galanthina Berk. & Br. but no conclusive proof has been adduced. S. Ubertiana Fcl.^' Sclerotia from a few millimeters up to 3 cm. in length, black; apothecia scattered, pale, 4-8 mm. or more broad, stem slender; asci cylindric, 130-135 x 8-10 /x, apically very slightly bluish; spores ellipsoid, usually minutely guttulate, 9-13 x Ai; paraphyses clavate. This fungus affects numerous hosts. Among the most important on which it causes serious disease are lettuce,^'' '^' ^^' ^ einseng,^' cucumber,'^ carrot, potato, Fig. 96.âs. libertiana. , \ â u iuâ â; ;â Sclerotia and apothecia. parsley, hemp, rape, various bulbs, zmnia, j^^^^ Stevens ajid HaU. petunia, etc. The white mycelium is found superficially and within the host, espec
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
