. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 194 DISEASES OF CULTIVATED PLANTS Strawberry leaf spot.—Both cultivated and wild straw- berries are often severely damaged by a fungus named Sphaerella fragariae (Tul.), the conidial form of which was at one time the only stage known, and was called Ratnularia Tulasnei (Rab.). Small reddish-brown patches first appear on the leaves, which continue to increase in size for some time and frequently encroach on each other, forming. Fig. 52.—Sphaerella fra^^ar
. Diseases of cultivated plants and trees. Plant diseases; Plants -- Wounds and injuries; Plants, Protection of; Trees -- Diseases and pests. 194 DISEASES OF CULTIVATED PLANTS Strawberry leaf spot.—Both cultivated and wild straw- berries are often severely damaged by a fungus named Sphaerella fragariae (Tul.), the conidial form of which was at one time the only stage known, and was called Ratnularia Tulasnei (Rab.). Small reddish-brown patches first appear on the leaves, which continue to increase in size for some time and frequently encroach on each other, forming. Fig. 52.—Sphaerella fra^^ariae. i, a diseased straw- berry leaf; 2, ascus containing eight spores of the Sphaerella or ascigerous stage; 3, conidia of the Ratnularia or conidial stage. 1-igs. 2 and 3 liighly mag. irregular patches. By degrees the centre of the patch assumes an ashy-grey or almost white colour, and is bounded by a reddish border, which is often ([uitc bright in colour later in the season. The central portion then becoaies studded with very minute white tufts of the conidial form of fruit. Later in the season these minute white tufts are replaced by minute black points—the ascigerous phase of the fungus. Minute sclerotia are also frequently formed in abundance on diseased fading leaves. This pest is everywhere present. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Massee, George, 1850-1917. New York : Macmillan
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Keywords: ., bookpublishernewyorkmacmillan, booksubjectplantdis, bookyear1910
